Effect of Reforestation 

on Streamflow in 

Central New York

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1602

Prepared in cooperation with the New 

York State Department of Conservation 

Division of Lands and Forests
Effect of Reforestation 

on Streamflow in 

Central New York

By WILLIAM J. SCHNEIDER and GORDON R. AYER

GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1602

Prepared in cooperation with the New 

York State Department of Conservation 

Division of Lands and Forests

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1961
UNITED STATES DEPARTMENT OF THE INTERIOR 

STEWART L. UDALL, Secretary

GEOLOGICAL SURVEY 

Thomas 8. Nolan, Director

For sale by the Superintendent of Documents, U.S. Government Pi in ting Office 

Washington 25, D.G.
CONTENTS

Page

Abstract__ __--___--_--__-_-___---_-_--------_____---____.._--_-_ 1

Introduction._____________________________________________________ 1

History of project--_____-_-_---_------------------------------ 2

Purpose and scope of present analysis-------__-_--___--__--_-____ 2

Acknowledgments -____--_-______--------------_----------_---- 3

Description of areas_______________-----_--_--_-_____-_____-_____ 3

Location_____-_---_____-_-_--_-----_-__-_____________________ 3

Climate._____________________________________________________ 3

Physiography _________________________________________________ 4

Geology and soils__---_-------------------------------_-------- 5

Streamflow.--________-__--_-__----------------------------_-_ 6

Characteristics of the specific basins..- ------------------------------ 7

Sage Brook area___-_________----_-_---.-_---_----------_-_---_ 7

Cold Spring Brook area___._._____-_-_____---___--__-_-___-____ 7

Shackham Brook area________________________________________ 11

Albright Creek area_________-_______---_-___-__-____-_____-__ 13

Reforestation of the study areas.._____---____-___-_______-___----___ 16

Records available_______________-__--_-__--_--___--_----_-__-. 30

Streamflow-___________-_____-_____---------_-__------_---_-__ 30

Precipitation.---_______________ _______________________________ 31

Hydrologic analyses________________--_-______-_-____-_-_--_-_____ 31

Reliability of data.______________--_-_--__--_-___--______-___-- 32

Streamflow data__________________-___---_-___-_-___--____. 32

Precipitation data___--____-_------------------------_-_-_- 32

Determination of precipitation indexes__--____----_--_____-__--._ 35

Relation between runoff and precipitation________________________ 36

Correlation analysis______________________________________ 37

Covariance analysis _______-_-------__-___-__________--__ 41

Relation between runoff from reforested area and from control area__ 42

Seasonal and annual runoff----------_-_---_---------_______ 42

Peak discharges--_-------__------------------_----------_- 45

Low flows.__-_-_._______________-_-_-_---____--_-_--__-._ 51

Other analyses___________________-_--__-___---_-_______--_--_- 52

Base-flow recession_______________--__-__-___--_-_-_-______ 52

Relation between volumes of direct runoff and precipitation from

individual storms.--------------------------------------- 53

Methods rejected._________________________________________ 54

Summary__ _____________________________________________________ 56

Evaluation of the study.___________________________________________ 56

References cited_-_-_-________---_--__---------------------------__ 60

ILLUSTRATIONS

FIGURE 1. Location of streamflow areas_____-_-_________---_-------- 4

2. Monthly distribution of precipitation for Shackham Brook

area, 1935-57----_--------------------------_-------- 5

3. Monthly distribution of runoff from Shackham Brook area,

1934-57_-__-._______-.._-_-_-.____ .__._ 6

in
IV CONTENTS

Page 

FIGURE 4. Hydrograph for Shackham Brook near Truxton, 1948_____ 7

5. Topography and location of instruments in Sage Brook area__ 8

6. Soils in Sage Brook area______________________________ 9

7. Topography and location of instruments in Cold Spring Brook

area._______________________________________________ 10

8. Soils in Cold Spring Brookarea___________________________ 11

9. Topography and location of instruments in Shackham Brook

area._______________________________________________ 12

10. Soils in Shackham Brook area ________________________ 13

11. Topography and location of instruments in Albright Creek

area._______________________________________________ 14

12. Soils in Albright Creek area _________________________ 15

13. Reforestation in Sage Brook area_________________________ 20

14. Reforestation in Cold Spring Brook area __________________ 21

15. Reforestation in Shackham Brook area.___________________ 22

16. Types of plant cover in Sage Brook area._________________ 23

17. Types of plant cover in Cold Spring Brook area____________ 24

18. Types of plant cover in Shackham Brook area-____________ 25

19. Types of plant cover in Albright Creek area, 1948._________ 26

20. Percentage of crown cover in Sage Brook area, 1948-_______ 27

21. Percentage of crown cover in Cold Spring Brook area_______ 28

22. Percentage of crown cover in Shackham Brook area_______ 29

23. Relation between precipitation gages 1 and 2 for Shackham

Brook area______________------------------_--------- 30

24. Relation between cumulative precipitation for gages in study

areas and cumulative areal index of precipitation_________ 34

25. Annual precipitation recorded by gage 1 in the Shackham

Brook area, 1934-57-__________________ _ 35

26. Relation between runoff and precipitation in the Cold Spring 

Brook area for the 6-month period ending April 30, showing 

the change with time_________________________________ 40

27. Relation between runoff from Shackham Brook area and Albright Creek area for the 6-month period ending April 30, 

showing the change with time__________________________ 43

28. Relation between runoff from Shackham Brook area and Albright Creek area for the 6-month period ending October 31, 

showing the change with time________________________ 44

29. Relation between runoff from Shackham Brook area and Albright Creek area for the 12-month period ending April 30, 

showing the change with time__________________________ 45

30. Relation between peak flows of Shackham Brook and Albright

Creek for the 6-month period ending April 30____________ 48

31. Effect of date of occurrence on relation between peak discharges of Shackham Brook and Albright Creek__________ 49

32. Effect of date of occurrence on relation between peak discharges of Shackham Brook and Albright Creek__________ 50

33. Base-flow recession rates for Cold Spring Brook at China____ 52

34. Relation between storm precipitation and volumes of direct

runoff for Sage Brook area___________________________ 55
CONTENTS

TABLES

Page 

TABLE 1. Types of cover in study areas___________________________ 16

2. Crown cover in reforested areas___________________________ 17

3. List of species planted in reforestation program_____________ 18

4. Reforestation in Sage Brook area________________________ 18

5. Reforestation in Cold Spring Brook area_____ ____________ 18

6. Reforestation in Shackham Brook area______________ __ 19

7. Precipitation and runoff totals for selected hydrologic periods. _ 37

8. Relation of runoff to precipitation_________________________ 40

9. Related peak discharges on Shackham Brook and on Albright

Creek________________________________ 46

10. Annual low flows for Shackham Brook and Albright Creek

areas_______________________________ ___ _____ 51

11. Coefficients of base-flow recession._____________________ . 53
EFFECT OF REFORESTATION ON STREAMFLOW 

IN CENTRAL NEW YORK

By WILLIAM J. SCHNEIDER and GORDON K. AYER

ABSTRACT

Hydrologic data have been collected since 1932 in central New York State to 

determine the effect of reforestation on streamflow. Data are available for three 

small partly reforested areas and for one nonreforested control area. From 35 to 

58 percent of the 3 areas were reforested, mostly with species of pine and spruce. 

The trees were allowed to grow without thinning or cutting, and by 1958 these 

reforested areas had developed into dense coniferous woodlots.

Intensive statistical analyses of the data from the four study areas were made 

in 1958. Analyses were made for three hydrologic periods: the dormant season 

represented by the 6-month period ending April 30, the growing season represented 

by the 6-month period ending October 31, and the year represented by the 12- 

month period ending April 30. Analyses of the hydrologic data using multiplecorrelation with time as a variable and analyses of covariance between early and 

late periods of record indicated that several significant changes had occurred in the 

streamflow from the partly reforested study areas. Based on correlation with 

precipitation, total runoff for the dormant season from the 3 study areas was 

reduced by annual rates of 0.17 to 0.29 inches per year. Based on correlations 

with streamflow from a control area, total runoff from the partly reforested 

Shackham Brook area was reduced by average rates of 0.14 inches per growing 

season, 0.23 inches per dormant season, and 0.36 inches per hydrologic year. Peak 

discharges on Shackham Brook during the dormant season were reduced by 1958 

by an average of 41 percent for the season, with reductions ranging from an 

average of 66 percent for November to an average of 16 percent for April. No 

significant changes were found in the peak discharges for the growing season, rates 

of base-flow recession, volumes of direct runoff, or annual low flows of streams in 

the three partly reforested areas.

The significant reductions in total runoff are attributed to increases in interception and transpiration in the reforested areas. The reductions in peak discharges 

during the dormant period are attributed largely to increased interception and 

sublimation of snowfall, and a gradual desynchronization of snowmelt runoff from 

the wooded and open areas of partly reforested watersheds. The changes in 

streamflow occurred gradually over the years; it could not be determined from the 

data whether changes in streamflow were still occurring in 1958, or whether they 

had reached a maximum.

INTRODUCTION

During the latter part of the 19th century, many farmers migrated 

westward from central New York. This migration, coupled with 

low crop yields from depleted soils and a general abandonment of 

marginal farmlands, resulted in a decrease in farmland in the State 

of about 5 million acres between 1880 and 1930. The abandoned 

farmland soon acquired a heavy cover of weeds and brush.

Chapter 195 of the Laws of 1929 enacted by the New York State 

Legislature authorized the State Conservation Department to acquire

1
2 EFFECT OF REFORESTATION ON STREAMFLOW

parcels of this abandoned or marginal farmland for the perpetual 

planting, growing, and harvesting of trees. Within 5 years, the State 

Conservation Department had acquired and reforested more than 

340,000 acres in 33 counties of the State. In 1932, the U.S. Geological 

Survey, in cooperation with the New York State Conservation 

Department, initiated a project to determine the effect of this reforestation on streamflow.

HISTORY OP THE PROJECT

Collection of hydrologic data was begun in 1932 with the establish" 

ment of facilities to measure streamflow and precipitation in the 

Shackham Brook watershed and in the Sage Brook watershed. Parts 

of these watersheds were reforested in 1931 and 1932. In 1935 the 

data-collecting program was expanded to include the Cold Spring 

Brook watershed which had been reforested the previous year. In 

1938 the data collecting program was again expanded to include 

installations in the Albright Creek watershed, an area in which 

land-use practices were undergoing little if any changes. Information 

collected on Albright Creek would be used to measure the rate and 

extent of any changes defined by the data for the Shackham Brook 

area.

The project was designed to detect possible changes in streamflow 

regimen that might occur over a period of years as a result of the growth 

of the trees by (a) determining changes in the relation of the streamflow 

to precipitation and other causative factors, and (b) determining 

changes in the relation between streamflow from a reforested area 

and streamflow from a nonreforested area.

Several previous reports have been prepared on various phases of 

the project. Cross l listed and evaluated many hydrologic factors 

affecting streamflow and outlined a comprehensive program for the 

measurement of these factors. A progress report was prepared by 

Ayer (1949) which analyzed the relations between rainfall and runoff 

for the study areas. Outlaw (1953) investigated the geology and 

hydrology of the Shackham Brook watershed, and Barkow 2 analyzed 

the streamflow data of the Sage Brook area.

PURPOSE AND SCOPE OP PRESENT ANALYSIS

An intensive analysis of the hydrologic data collected thus far was 

begun in 1958. For almost a quarter of a century, data on streamflow 

and precipitation were collected in four study areas while the trees in 

the reforested portions of these areas were permitted to grow without

i Cross, W. P., 1935, A program for the investigation of the influence of forests on streamflow in the State 

of New York: Columbus, Ohio, Ohio State Univ., unpublished thesis.

»Barkow, David, 1957, A study of the effects of reforestation on streamflow in the Sage Brook watershed 

near South New Berlin, New York: Ithaca, N.Y., Cornell Univ., unpublished thesis.
DESCRIPTION OF AREAS 3

cutting or thinning. The analysis was undertaken as a logical and 

perhaps final step in the investigation. Because sufficient years of 

record were available for reliable hydrologic analyses, and because 

some form of management of the state-owned acreage in the watersheds is likely in the near future, the present analysis was deemed 

advisable. This report describes the results and conclusions of the

analysis.

ACKNOWLEDGMENTS

This report was prepared on basis of data collected over a period 

of years in cooperation with the New York State Department of 

Conservation, Division of Lands and Forests.

Data on reforestation were furnished by the State Division of Lands 

and Forests, C. D. Kingsbury, superintendent. The cover surveys 

of the reforested areas were made by personnel of the Division under 

the supervision of Charles F. Baker, R. Milton Hick, and James D. 

Kennedy, district foresters.

H. C. Riggs, hydraulic engineer, U.S. Geological Survey, provided 

valuable assistance in the statistical analysis of the data and in reviewing the manuscript. Dr. Harold G. Wilm, associate dean, 

College of Forestry, University of the State of New York, at Syracuse, 

reviewed an early draft of the manuscript and offered many helpful 

comments and suggestions.

DESCRIPTION OF AREAS 

LOCATION

The geographic location of the four streamflow areas is shown in 

figure 1. The Sage Brook area is located east of Norwich in Chenango 

County. The Cold Spring Brook area is located in Delaware County, 

south of the Sage Brook area, and just east of the line between Broome 

County and Delaware County. The Shackham Brook area and 

Albright Creek area lie to the northwest of the areas previously 

described. The Albright Creek area lies entirely within Cortland 

County, while the Shackham Brook area lies in both Cortland County

and Onondaga County.

CLIMATE

The four areas of this study all lie within a climatic region characterized by a continental type of climate. The mean temperature for 

July is about 66° F, with maximum temperatures during the summer 

months often exceeding 90° F. Winters are severe; the mean temperature for January is about 22° F, and minimum temperatures below 

 30° F have been recorded. The average growing season is about 

150 days, extending from early May until late September. The 

seasonal transitions in temperature usually occur during late April 

and October.
EFFECT OF REFORESTATION ON STREAMFLOW

/ ^nvm NEW YORK - j 

QUADRANGLE LOCATION

i 1 --%

\

CA YUGA

TOMPKINS

Ithaca r t.

f-L.-

 -| '__' T

i o

f

L_, ~\ Utica0/

! --1, HE'RKIMER 

1 i ONE I DA o 

ONONDAGA MADISON 1 Herkimer

J Morrisvillej /-. ~

SHACKHAM BROOK \ \ ^~^ 

NEAR TRUXTON^ \ 1 

, __ . .-- T- . /

^ALBRIGHT CREE'lT" / Cooperstown 

 AT EAST HOMER (

1 0Cortland / OTSEGO

CORTLAND Norwich ./ 

XSAGE BROOK NEAR .' '~ 

,'SOUTH NEW BERLIN ^-^

' C HEN AN GO \ /-' 

-' \ BROOME . r"~ DELAWARE

r f\ r* A ^-t \ ' O i U Lr A I 1 i Delhi

25 MILES ! - - !

! AT CHINA

FIGTJBE 1. Location of streamflow areas.

Precipitation over the region is from windborne moisture transported from the Gulf of Mexico and the Atlantic Ocean by the action 

of cyclonic storms. Winter precipitation usually results from general 

storms associated with frontal activities and occurs chiefly as snow. 

Mean annual snowfall for the general vicinity of the four streamflow 

areas is about 60 to 70 inches; however, local topographic features 

produce significant variations from this average. Summer precipitation generally occurs during thunderstorms; it is frequently very 

intense, of short duration, and very localized. The precipitation is 

distributed fairly uniformly throughout the year, as shown in figure 2.

PHYSIOGRAPHY

Physiographically the four areas are in the Appalachian Plateaus 

province, which lies along the western base of the mountains. The 

plateau is here bounded on the east by the Catskill Mountains and on 

the north by the Helderburg escarpment. Although well dissected 

by streams, the area is not mountainous. Elevations range from 500 

to 600 feet on the northern side of the province to more than 2,000 feet 

on the eastern and western sides. The four streamflow areas considered in this report all show relief typical of the plateau.
DESCRIPTION OF AREAS

, -Maximtt'm

-Average

rnfrnum

FIGUEB 2. Monthly distribution of precipitation for Shackham Brook area, 1935-37.

GEOLOGY AND SOILS

The geology of the four areas studied in this report is generally 

similar. All are underlain by rocks of unaltered sediments of Devonian age, consisting principally of shales and sandstones. The bedrock is overlain by Pleistocene deposits of glacial tills ranging in depth 

from less than 2 feet to several hundred feet. However, depths in 

the four areas considered in this report range generally from 2 to 10 

feet, with occasional depths of as much as 30 feet in the valleys.

The soils of the four areas consist mainly of glacial tills which have 

been weathered at the surface. They are typical gray-brown podsolic 

soils and may be described as follows (Marbut, 1935):

The upper horizon, usually 1 to 4 inches thick, is composed of forest 

litter and mulch. This is underlain by the A horizon of about 5 to 

10 inches of grayish-brown, silty or sandy loam, commonly friable 

because of the infiltration of humus. Under this is the B horizon of 

generally less than 15 inches of illuviated soil containing much more 

clay and having much sparser root penetration than the A horizon. 

Unweathered glacial till, usually called the C horizon, occurs between 

the bottom of the B horizon and the surface of the bedrock.

Ground-water movement occurs and storage exists in both the 

glacial till and the bedrock. Although the nature of the bedrock 

permits little penetration of ground water, some movement and 

storage does occur in the joints, cracks, and bedding planes. These 

quantities are very small. The friable upper layers of soil have high 

infiltration capacities, but the relative impermeability of the lower 

layers of compacted clay causes perched water tables in many places 

and produces a complicated ground-water pattern. This general
6 EFFECT OF REFORESTATION ON STREAMFLOW

description of ground-water conditions is based on unpublished data 

by M. L. Brashears, Jr., U.S. Geological Survey.

STREAMFLOW

The pattern of streamflow in central New York represents the 

integrated effect of the climatological and physical characteristics of 

the area. Streams in the area show the typical annual cycle of high 

runoff in the spring and seasonal low flows in the fall. The magnitude 

of the annual cycle is indicated in figure 3. Most streams in the area 

also reflect a rapid response to rainfall, particularly the smaller ones 

which show sharp rises in flow during periods of heavy rainfall. A 

typical hydrograph reflecting this response to rainfall is shown in 

figure 4.

FIGURE 3. Monthly distribution of runoff from Shackham Brook area, 1934-57.
CHARACTERISTICS OF THE SPECIFIC BASINS

90-

'70-

en 60-

uj40- 

u

cc

530-

c/> 

Q 

>20-

10-

JAN. I FEB. I MAR. I APR. I MAY ' JUNE I JULY I AUG. I SEPT. I. OCT. I NOV. I DEC. 

FIGURE 4. Hydrograph for Shackham Brook near Trurton, 1948.

CHARACTERISTICS OP THE SPECIFIC BASINS 

SAGE BROOK AREA

Sage Brook at South New Berlin, N.Y., drains 0.70 square mile. 

It flows in a southeasterly direction. The main stream is 0.57 mile 

long. Including the major tributary, the basin has a stream density 

of 1.00 mile per square mile. Average channel slope of the main 

stream and tributary is 258 feet per mile.

The basin is somewhat rectangular in shape with well-defined relief. 

Elevations range from 1,430 feet at the stream-gaging station to 1,940 

feet in the northeastern corner of the area. The topography is shown 

in figure 5. Outcrops of sandstone occur in the northern part of the 

basin and shale in the southern part. The soil over most of the area 

is composed of Oquaga silt loam. This loam is generally shallow and 

well drained. Complete descriptions of the soils are given in Soil 

Survey of Tioga County (U.S. Dept. Agriculture, 1920). The distribution of the soil types in the basin is shown in figure 6.

COLD SPRING BROOK AREA

Cold Spring Brook at China, N.Y., drains 1.51 square miles. It 

flows in a southerly direction. The main stream is 1.75 miles long. 

Including the major tributaries, the basin has a stream density of 2.09 

miles per square mile. The average channel slope of the main stream 

and tributaries is 269 feet per mile.
8 EFFECT OF REFORESTATION ON STREAMFLOW

Recording rain gage

Stream flow 

gage

500 

I

1000 

I

CONTOUR INTERVAL 50 FEET

1500 FEET 

_I

FIGURE 5. Topography and locations of instruments In Sage Brook area.
CHARACTERISTICS OF THE SPECIFIC BASINS 9

EXPLANATION

Oquaga silt loam 

Morris silt loam

Other 

mm

silt loams

1500 FEET

ffiouBE 6. Soils in Sage Brook area.
10 EFFECT OF EEFOEESTATION ON STBEAMFLOW

The basin is approximately circular in shape, with well-defined 

relief. Elevations range from about 1,480 feet at the stream-gaging 

station to about 2,180 feet at the northern edge of the basin. The 

steepest slopes occur in the southern or downstream part of the basin. 

The topography is shown in figure 7. Outcrops of sandstone occur 

mainly along the ridges and upper slopes. The soils consist of 

Lordstown and Canfield silt loams and are described in Soil Survey of 

Delaware County (U.S. Dept. Agriculture, 1930). In some local 

areas, surface drainage is impeded by small sags and depressions. 

The distribution of the soil types in the basin is shown in figure 8.

0 400

CONTOUR INTERVAL 100 FEET

800 FEET 

_i

7")

Streamflow gage 

FIGTJBE 7. Topography and location of instruments in Cold Spring Brook area.
CHARACTERISTICS OF THE SPECIFIC BASINS 11

EXPLANATION

800 FEET

FIGURE 8. Soils In Cold Spring Brook area.

SHACKHAM BROOK AREA

Shackham Brook near Truxton, N.Y., drains 3.12 square miles. 

The main stream is 2.50 miles long. Including the principal tributaries, the basin has a stream density of 1.47 miles per square mile. 

Average channel slope of the main stream and tributaries is 156 feet 

per mile.

The basin is somewhat irregular in shape, with well-defined relief. 

Elevations range from about 1,290 feet at the stream-gaging station 

to slightly more than 2,000 feet on the eastern ridges. Land slopes 

are steepest in the southern parts of the basin, and some of the 

tributaries in this area flow on bedrock channels from an elevation 

of about 1,600 feet down to their confluences with the brook. The 

topography is shown in figure 9. The soils are mainly Lords town,

682754 61 2
12 EFFECT OF REFORESTATION ON STREAMFLOW

4000 FEET

CONTOUR INTERVAL 100 FEET

Streamflow gageFIGURE 9. Topography and location of instruments in Shackham Brook area.

Volusia, and Manlius silt loams. Drainage in the Volusia and 

Manlius loams is impeded by compacted clay layers, causing perched 

water tables and hillside seeps. Several minor swampy areas exist 

in the extreme headwaters of the brook. The soils are described in 

Soil Survey of Tioga County (U.S. Dept. Agriculture, 1939-53). 

The distribution of the soil types in the basin is shown in figure 10.
CHARACTERISTICS OF THE SPECIFIC BASINS 13

Lordstown silt loam Canfield silt loam

Manlius silt loam Volusia silt loam

FIGURE 10. Soils in Shackham Brook area.

ALBRIGHT GREEK AREA

Albright Creek at East Homer, N.Y., drains 7.08 square miles. 

It flows in a southerly direction. The main stream is 5.45 miles 

long. Including the principal tributaries, the basin has a stream 

density of 1.56 miles per square mile. Average channel slope of 

the main stream and tributaries is 108 feet per mile.
14 EFFECT OF REFORESTATION ON STREAMFLOW

The basin is long and relatively marrow with,well-defined relief. 

Elevations range from about 1,155 feet at the stream-gaging station 

to about 2,020 feet in the upper end of the basin. The topography 

is shown in figure 11. Soils in the basin consist of Lordstown and

3000 

I

\

CONTOUR INTERVAL 200 FEET

V

Streamflow 

gage.

SOOqFEET

FIGURE 11. Topography and location of instruments in Albright Creek area.
CHARACTERISTICS OF THE SPECIFIC BASINS 15

Volusia silt loams, similar in characteristics to those in the Shackham 

Brook area. The distribution of the soil types in the basin is shown 

in figure 12.

EXPLANATION

Lordstown silt loam)

FIGURE 12. Soils In Albright Creek area.
16 EFFECT OF REFORESTATION ON STREAMFLOW

REFORESTATION OF THE STUDY AREAS

Much of the land in the four watersheds had been cleared for 

farming by the early settlers. In general, about one-fifth of the 

land remained in second-growth mixed-deciduous woodlots. By 

1930, large portions of the farmlands, particularly marginal lands 

at the higher elevations and with the steeper slopes, had been abandoned and allowed to develop a heavy cover of weeds and brush. 

Prior to the extensive reforestation that began in 1931, there were 

only 2 coniferous plantations totaling 46 acres in the 4 areas.

The reforestation consisted mostly of plantings of coniferous trees. 

Species of pine and spruce were predominant, with a few larches and 

firs interspersed in a few areas. A few small plantings of black 

locust and black cherry trees were made in some areas. The seedlings 

were planted by placing the young tree in a slit made with a grubhoe 

and then back-filling the trench. Choice of the areas to be planted 

was governed by the boundaries of the state-owned land rather than 

by natural features such as ridges or slopes. Because of this manner 

of planting, none of the basins considered in this report was completely 

reforested.

Plant cover in the partly reforested watersheds was determined 

from two field surveys of each area. The surveys to determine plant 

cover prior to reforestation were made in 1933 on the Sage Brook area 

and the Shackham Brook area, and in 1935 on the Cold Spring Brook 

area. Although seedlings had been planted in the areas when these 

surveys were made, the surveys represent the plant cover prior to the 

reforestation. Surveys to determine plant cover after reforestation 

were made in 1948 for all three areas. A summary of these two 

surveys is given in table 1, which also includes information on the 

Albright Creek area. Comparison of the 2 surveys indicate that 

47 percent of the Sage Brook area, 35 percent of the Cold Spring

TABLE 1. Types of cover in study areas

Area

Cold Spring Brook .......

Shackham Brook. ........

Albright Creek ...........

Year

U933 

1948, 1958 

11933 

1948, 1958 

U933 

1948, 1958 

1948, 1958

Type of cover

Deciduous

Acres

97 

132

500 

500 

504 

546 

904

Percent

22 

30 

51 

51 

25 

27 

20

Coniferous

Acres

27 

188 

0 

250 

19 

1,125 

0

Percent

6 

43 

0 

26 

1 

57 

0

Mixed woodlot

Acres

53 

64 

0 

90 

0 

0 

0

Percent

12 

14 

0 

9 

0 

0 

0

Pasture and 

crops

Acres

265 

58 

475 

135 

1,474 

326 

3,627

Percent

60 

13 

49 

14

74 

16 

80

i Prior to reforestation.
REFORESTATION OF THE STUDY AREAS 17

Brook area, and 58 percent of the Shackham Brook area were 

reforested.

The 1948 surveys also included estimates of the crown cover of the 

trees as a percentage of total ground area for both the Cold Spring 

Brook area and the Shackham Brook area. For example, an estimate 

of 60 percent crown cover indicates that the canopy of the trees 

in the area cover 60 percent of the ground surface, and that the 

openings between the trees represent the remaining 40 percent of 

surface area. The surveys were made during the growing season, 

when the deciduous trees were in full foliage. The cover for the three 

areas also was determined in 1958 A summary of the data on crown 

cover is given in table 2.

The field surveys made in 1958 also measured the average size and 

density of the trees in the reforested area. The surveys indicated 

that generally the tree heights averaged from about 25 feet for the 

spruces to more than 40 feet for the larches.

Plant cover for the Albright Creek area was determined from aerial 

photographs taken in 1948, and checked by field reconnaissance in 

1958. The field check indicated that no changes in land use took 

place between 1948 and 1958. Engineers of the Geological Survey 

who visited the area between 1941 and 1948 reported little or no 

change in land use during this period. Therefore, the estimate of 20 

percent deciduous woodlots and 80 percent pasture and croplands 

represents the land use in the Albright Creek basin for the entire 

period of record used in this study.

Table 3 is a list of types of trees planted in the reforestation program. 

Information contained in tables 4 through 6 indicates in a general 

way the planting pattern used by the foresters. Maps of the areas 

delineating the reforested sections, the types of plant cover, and the 

percents of crown cover were prepared from data obtained from the 

field surveys previously described, and are shown in figures 13 through 

22.

TABLE 2. Crown cover in reforested areas

Area

Gold Spring Brook- ____

Shackham Brook _ .... .....

Year

1948 

1958 

1948 

1958 

1958

Estimated crown cover in percent of ground area

100-90

Acres

1480 

85 

1,278 

1,805 

300

Percent

49 

9 

64 

90 

67

90-60

Acres

375 

760 

499 

180 

40

Percent

38 

78 

25 

9 

9

60-30

Acres

75 

100 

40 

12

48

Percent

8 

10 

2 

1 

11

30-0

Acres

45 

30 

ISO 

0 

60

Percent

5 

3

9 

0 

13

i395 acres estimated at 90 percent in 1948 and at 85 percent in 1958.
18 EFFECT OF REFORESTATION ON STREAMFLOW

TABLE 3. List of species planted in reforestation program

Common name Speciet

Balsam fir_ ____________________ Abies balsamea (Linneaus) Miller

Black cherry__________________ Prunus serotina Ehrhart

Black locust ____________________ Robinia pseudoacacia Linneaus

European larch____ ___________ Larix decidua Miller

Norway spruce __________________ Picea abies (Linneaus) Karsten

Red pine_______________________ Pinus resinosa Alton

Scotch pine_____________________ Pinus sylvestris Linneaus

White Pinus strobus Linneaus

White spruce__________________ Picea glauca (Moench) Voss

TABLE 4. Reforestation in Sage Brook area 

[Block numbers refer to figure 13]

Block

1

2 

3 

4

5 

6

Acreage 

of block

21

39 

29 

30

32

88

Date planted

May 1932 ......

..... do... .......

 . -do... ...

. .do... .......

.... .do...... .

 -do... 

Number and kind of trees

28,350 Black locust ____ 

Average size and density in 1958

Height 

(feet)

42

24 

22 

31

34 

32

Diameter 

(DBH) 

(inches)

4.9

4.4 

3.6 

5.8

3.8 

4.1

Trees 

per 

acre

520

720 

485 

313

395 

820

TABLE 5. Reforestation in Cold Spring Brook area 

[Block numbers refer to figure 14]

Block

1 

2

3

4 

5 

6 

7 

8 

9

10 

11 

12 

13

14

15 

16

Acreage 

of block

42 

19

20

18 

15 

11 

7 

10 

24

6 

8 

33 

16

8

10 

17

Date planted

May 1934 _ ...

May 1940 _ ... 

May 1934 

May 1940 ......

May 1934. __ 

 do... -_ 

- .do........

... ..do... ...

..... do... ...

... ..do... ...

May 1940. __ . 

May 1934 ......

. .do.........

 -do 

 do 

May 1940 

May 1934 ......

May 1940 ......

May 1934 ...... 

May 1940 ......

Number and kind of trees

10,100 Red pine.. __ . 

12,253 Red pine ___ ... ........

12,520 Red pine _____ . ........

5,000 Red pine ..... .......

5,000 European larch ...........

Average size and density in 1958

Height 

(feet)

25

35

35 

35 

35 

25 

25 

35

30 

25

35 

25 

25

35

35

Diameter 

(DBH) 

(inches)

5

7

7 

7 

7 

3 

3 

6

3 

3 

6 

3

4

3

3

Trees 

per 

acre

900

650

650 

650 

650 

500 

500 

700

1,000 

700 

700 

700 

650

700

700
REFORESTATION OF THE STUDY AREAS 19

TABLE 6. Reforestation in Shackham Brook area 

[Block numbers refer to figure 15. Block acreage includes acreage outside watershed]

Block

1 

2

3 

4

5

6

7

8

9 

10 

11

12 

13

14 

15

16 

17

18 

19 

20

21

22

23 

24

Acreage 

of block

57 

178

36

25

158

147

75 

53

16 

12 

105

40 

109

204 

50

82 

28

80 

11

18

46 

44

36

89

Date planted

Feb. 1931 

.... .do 

Feb. 1931. __ .. Apr. 1933 . ..

May 1939 (replant)... 

Apr. 1933. - ..

May 1939 (replant)... 

Feb. 1931 __ - 

May 1934 (replant)... 

Apr. 1933.. 

May 1939 (replant)... 

Apr. 1933 . 

May 1939 (replant) _ 

Feb. 1931. . __

.....do. ..

 .do.. ...

May 1934 (replant) ... 

Feb. 1931 _______

.....do. _ 

TWa\7 1QS9

.. do... .

 ..do.... 

. .do..... 

 ..do..... ...... ..

.... .do... 

.....do...... .......... 

.....do.. ...........

I 

1 Number and kind of trees

4 750 Bl&ck cliGrrv

177, 075 White pine.. 

127, 860 Red pine. - 

1O SJO1 T?£ifl nina

12, 801 White pine.. . .........

Average size in 1958

Height 

(feet)

25 

21

24 

12

21

26

25

28

20

18

25

30

18

26

20

22

27 

26 

29

30

22

24 

21

Diameter 

(DBH) 

(inches)

5 

6

5 

2

4.5

5.5

5.5

5

4.5

3.5

6

6.5

6

5

6

7

4.5 

4.5 

6

6

4

4 

4
20 EFFECT OF REFORESTATION ON STREAMFLOW

N

A

Reforested blocks

500 

I

1000I

1500 FEET 

__I

FIGTJEE 13. Reforestation in Sage Brook area. Block numbers refer to table 4.
REFORESTATION OF THE STUDY AREAS 21

EXPLANATION

800 FEET

FIGURE 14. Reforestation in Cold Spring Brook area. Block numbers refer to table 5.
22 EFFECT OF REFORESTATION ON STREAMFLOW

EXPLANATION

FIQUBE 15. Reforestation In Shackbam Brook area. Block numbers refer to table 6.
REFORESTATION OF THE STUDY AREAS 23
EXPLANATION

Deciduous woodland

Coniferous woodland

Pasture and cropland

Mixed woodland

BEFORE REFORESTATION 

FIGUBE 17. Types of plant cover in Cold Spring 
REFORESTATION OF THE STUDY AREAS 25
26 EFFECT OF REFORESTATION ON STREAMFLOW

EXPLANATION

Deciduous woodland

Pasture and cropland

6000 FEET

FIGUBE 19. Types of plant cover in Albright Creek area.
REFORESTATION OF THE STUDY AREAS 27

EXPLANATION

0 500 

I i i i i I

1000 

I

1500 FEE! 

__I

FIOUBE 20. Percentage of crown cover in Sage Brook area, 1948.

582764 61-
28 EFFECT OF REFORESTATION ON STREAMFLOW
REFORESTATION OF THE STUDY AREAS 29

582754 61-
30 EFFECT OF REFORESTATION ON STREAMFLOW

RECORDS AVAILABLE

STREAMFLOW

Stream-gaging stations were established on Shackham Brook near 

Truxton on November 26, 1932; on Sage Brook near South New 

Berlin on November 29, 1932; on Cold Spring Brook at China on 

November 22, 1935; and on Albright Creek at East Homer on October

21. 1938. Data-collecting facilities on Shackham Brook, Sage Brook, 

and Cold Spring Brook consist of continuous water-stage recorders 

and concrete controls with V-notch weirs; on Albright Creek, a continuous water-stage recorder and concrete control. Records of 

discharge and runoff have been published annually in Geological 

Survey Water-Supply Papers entitled "Records of Surface Water of 

the United States, Part IB."

PRECIPITATION

Both recording and iionrecording gages were used to measure 

precipitation in the four areas. The recording gages are of the 8-inch 

weighing type; the nonrecording gages are of the 4-inch tube type 

from which the total catch is determined volumetrically. The gages 

were not shielded.

Precipitation for the Shackham Brook area was measured by 

recording gage 1, near the center of the basin, and recording gage 2, 

located about 500 feet higher in elevation and 1,000 feet west of 

gage 1. Records from gage 1 consist of weekly recorder charts from 

January 1, 1933, to June 25, 1937, and daily recorder charts thereafter. Weekly recorder charts from gage 2 are available from October

22. 1935.

Precipitation for the Sage Brook area was measured at a site about 

800 feet upstream the stream-gaging station. Records from a nonrecording gage are available from December 1932. From June 1, 

1935 both a recording and a nonrecording gage were in operation, the 

former providing a record on a weekly chart. Precipitation totals 

from the nonrecording gage were measured daily prior to June, 1935, 

and weekly thereafter.

Precipitation for the Cold Spring Brook area was measured by a 

recording gage located several hundred feet east of the streamflow 

station. Weekly recorder charts are available from October 24, 1934. 

A nonrecording gage also measured precipitation at the same location 

since January 26, 1940.

Precipitation for the Albright Creek area was measured by recording 

gage 1, located near the center of the area, and by nonrecording gage 2, 

located about 4,000 feet upstream from the recording gage. Weekly
HYDROLOGIC ANALYSES 31

recorder charts from recording gage 1 are available from October 22, 

1938; daily totals of nonrecording gage 2 have been measured since 

April 4, 1940.

Data obtained from all recording gages, and from the nonrecording 

gage in the Sage Brook area, are published in U.S. Weather Bureau 

Hydrologic Bulletins, North Atlantic District. Locations of the 

precipitation gages are shown in figures 5 to 8.

HYDROLOGIC ANALYSES

In the selection of a method of hydrologic analysis, certain basic 

assumptions must be made. These assumptions are (a) that the data 

adequately describe the variables under consideration, and (b) that 

the relation between the variables is properly described. The reliability of the interpretations or conclusions of an analysis is directly 

related to the validity of these assumptions.

The reliability and completeness of the data collected in the four 

study areas formed the basis for selection of the methods of analysis. 

Methods of analysis therefore were limited to those for which complete 

and reliable indexes of the variables could be determined. The 

indexes used in the analyses were evaluated and tested for both 

consistency and reliability. The type of data available for analysis, 

as well as its consistency, governed the selection of the analytical 

techniques described in this report.

In relating the various indexes, or variables, time was used as a 

factor in determining whether a change in the relationship between 

the variables had occurred. Because changes in cover of the reforested areas progressed gradually from brush and weeds to coniferous 

woodland, it was assumed that any changes in streamflow resulting 

from the reforestation also would be gradual. Therefore changes 

which occurred in the streamflow from the reforested areas were 

determined from hydrologic analyses that were designed to detect 

trendlike changes occurring gradually from the time the trees were 

planted until 1958.

RELIABILITY OF DATA

STREAMFLOW DATA

Streamflow data were computed on a daily basis for the four study 

areas from stage-discharge relations established for each of the 

stream-gaging stations. Because of the stability of the stage-discharge 

relation, the records for all four stations are considered accurate 

measurements of the streamflow except for very brief periods when 

the relation cannot be applied. Estimates of flow made for these 

brief periods total generally less than 1 or 2 percent of the annual 

streamflow and therefore represent a negligible amount of error. The
32 EFFECT OF REFORESTATION ON STREAMFLOW

O

or 

o

o

z

z 

o 400

CL

O 

UJ 

IT 

0.

u 200

>

13 

O

I955j

0 200 400 600 800 

CUMULATIVE PRECIPITATION, IN INCHES, FOR GAGE 2

FIGURE 23. Relation between precipitation gages 1 and 2 for Shackham Brook area.

use of the artificial controls anchored to bedrock insures that all 

streamflow leaving the basin passes the control section, and that subsurface flow passing the gaging station is negligible.

PRECIPITATION DATA

The precipitation data collected in the four study areas were 

thoroughly analyzed to determine the consistency as an index of the 

actual basin precipitation. Several tests were made to determine 

this reliability. Each record was analyzed for any trend or abrupt 

change in the measured precipitation, and the effects of location of 

the gages also were studied. The two methods used to detect changes 

were the double-mass curve technique and the time-trend analysis. 

The double-mass curve technique was used to determine any abrupt 

change in each of the precipitation records. The double-mass curve 

was constructed by plotting the cumulative precipitation for one gage
HYDROLOGIC ANALYSES 33

against that of another gage or average for a group of gages for a 

concurrent period of record. An abrupt change in the slope of the 

resultant relation usually indicates some inconsistency in the record 

of one of the gages. The time-trend analysis was used to detect any 

gradual trend rather than abrupt change in the precipitation record. 

The analysis was made by correlating the precipitation with the year 

in which it occurred.

For the Shackham Brook and Albright Creek areas, the precipitation record of gage 1 was compared with the record of gage 2 for each 

respective area. The relation between cumulative precipitation for 

gages 1 and 2 in the Shackham Brook area is shown in figure 23. In 

both basins, the relation was fairly consistent throughout the period 

of concurrent record. However, the total precipitation measured by 

gage 2 exceeded that measured by gage 1 by 5 percent for the Albright 

Creek area and 2 percent for the Shackham Brook area. These differences are probably due to orographic effects caused by differences 

in elevation and exposure.

An areal index of precipitation was determined from 7 first-order 

Weather Bureau gages that form a network around the study areas. 

The records for Ithaca, Cortland, Morrisville, Norwich, Utica, 

Cooperstown, and Delhi were used. These records were analyzed for 

consistency among themselves by comparing the records of each 

against the combined records of the remaining 6 gages using the 

double-mass curve technique. The location of these gages with 

respect to the study areas is shown in figure 1. Comparisons of 

cumulative precipitation for these stations indicated that the records 

were consistent and reliable. The precipitation records for Binghamton were not used because of an abrupt change in the record due to 

change in location and exposure of the gage. The areal index of 

precipitation for comparison with the records of precipitation in the 

study areas was obtained by averaging arithmetically the annual 

precipitation for the 7 stations.

Comparisons were made between precipitation records for the study 

areas and the areal index. The relations are shown graphically in 

figure 24. All precipitation records in the study areas showed good 

agreement with the index except for the record of Sage Brook. A 

change in the relation was noted for the years 1948-50 inclusive. 

An investigation of the record indicated that from August 1948 to 

1950, a mechanical malfunction of recording gage 1 caused an underregistering of precipitation. Corrections based on both the areal 

index and nonrecording gage 2 were therefore applied to the monthly 

precipitation totals for this period.

The precipitation record for each gage in the study areas also was 

tested for a trend toward increasing or decreasing precipitation over
34 EFFECT OF REFORESTATION ON STREAMFLOW

1000

800

600

400

200

SHACKHAM BROOK (GAGE 1)

BROOK

SAGE BROOK (ADJUSTED) V'

200 400 600 800 1000

CUMULATIVE PRECIPITATION, IN INCHES, FROM AVERAGE 

OF SEVEN INDEX STATIONS, 1933-57

FIGURE 24. Belatlon between cumulative precipitation for gages in study areas and cumulative areal

index of precipitation.

the period of record. Tests for trends were made using the model 

equation

P=a+b1 T (1)

in which P is the annual precipitation and T is the year of record 

of P in numerical sequence beginning with T=l for the first year of 

record. The test was made for each gage for both the 6-month 

seasonal periods ending April 30 and October 31, for the 12-month 

period ending April 30, and for the calendar year. The coefficient 

6t was tested for significant difference from zero as described by 

Snedecor (1946, p. 118-121). None of the precipitation records 

showed a statistically significant trend at the 95-percent level during 

the period of observation. Annual precipitation for 1934-57 recorded 

by gage 1 in the Shackham Brook area is shown in figure 25.
HYDROLOGIC ANALYSES 35

en 50

- 40

Average

10

FIGUBE 25. Annual precipitation recorded by gage 1 in the Shackham Brook area.

On the basis of the tests previously described, all precipitation 

records for the study areas except for Sage Brook from August 1948 

to July 1950 were considered reliable measures of the precipitation 

at the site. The record for the Sage Brook area from August 1948 to 

July I960, with appropriate adjustments, also is considered consistent with the rest of the record.

DETERMINATION OP PRECIPITATION INDEXES

Recorded precipitation may not represent the average basin precipitation because of storm patterns or orographic effects. Therefore, 

in basins where more than one precipitation gage was operated, the 

precipitation data obtained from the gages in each basin were 

combined, and the average was considered to be a precipitation index 

for the basin. The data of the recording gage 1 in the Sage Brook, 

adjusted during the period August 1948 to July 1950, were used as the 

basin index from June 1935. Prior to this date, the record of nonrecording gage 2 was used. The data of the recording gage in the 

Cold Spring Brook area were used as an index of precipitation for 

that basin from October 1934. Since gage 2 was not operated in the 

Shackham Brook area until June 1936, the record of gage 1 adjusted 

to the relation between gages 1 and 2 was used as an index prior to 

June 1936, and the average of gages 1 and 2 used as an index of precipitation from May 1940.
36 EFFECT OF REFORESTATION ON STREAMFLOW

RELATION BETWEEN RUNOFF AND PRECIPITATION

Total runoff was correlated with associated precipitation for the 

four study areas to determine if changes in runoff occurred in any 

of the four areas. A correlation of monthly totals of runoff and precipitation was considered, but pilot correlations indicated poor results 

because of carryover effects from month to month. These carryover 

effects were of two general types: (a) the lag between rainfall and the 

resultant runoff occasionally resulted in a carryover of this runoff 

into the following month, and (b) the quantities of precipitation stored 

in the form of snow during the winter period varied from month to 

month. Neither of these carryover effects could be determined 

satisfactorily from the available data, particularly the precipitation 

stored as snow in the basins.

Because of these carryover effects, the precipitation-runoff relation was studied on seasonal and yearly bases. Although the 

growing season extends from about mid-May to about mid-October 

in the study areas, the period of May through October inclusive was 

used for the study. Consequently, the dormant season as considered 

in this study extended from November through April inclusive. 

In studying the relation between runoff and precipitation on a yearly 

basis, the hydrologic years ending March 31, April 30, June 30, 

September 30, October 31, and December 31 were considered. The 

data indicated that the best yearly relation between precipitation 

and runoff existed for the hydrologic year ending April 30. Therefore 

the 3 hydrologic periods used for this study were the 6-month periods 

ending April 30 and October 31 and the 12-month period ending 

April 30. These three periods are identical with those used by Johnson 

and Kovner (1956).

The effect of antecedent precipitation upon the relation between 

seasonal runoff and seasonal precipitation also was studied. The 

seasonal precipitation and the precipitation for the antecedent 

6-month period were combined in various proportions to obtain 

seasonal indexes of precipitation. The seasonal indexes were then 

correlated with the seasonal runoff. It was determined from the 

correlations that no significant carryover effect from antecedent 

precipitation existed for either the growing or dormant seasons, or 

for the hydrologic year. Therefore, the precipitation index, unadjusted for carryover effects, was used for correlation with runoff.

Runoff and precipitation totals for the three hydrologic periods 

at each of the study areas are listed in table 7.
HYDROLOGIC ANALYSES 37 

CORRELATION ANALYSIS

Total runoff was correlated with precipitation for each of the three 

hydrologic periods. Changes in the relation were determined by 

the establishment of a time-trend in the relation through the use of 

time as a third variable.

Several model equations were considered for a multiple correlation 

between precipitation, runoff, and time. The model equations 

considered were

E=a+blP+b2 T (2) 

* (3) 

P (4) 

(5)

in which E is the runoff in inches for the hydrologic period, P is the 

precipitation index for the period, and T is the position of the period 

in numerical sequence, beginning with T I for the first year of 

record. Correlations using the above models indicated that the 

equation

E=a+blP+b2 TP (6)

best described the relations. The selection of equation 6 was based 

on a comparison of the standard errors of estimate for equations 2 to 5 

using the data for the Shackham Brook area. The form of this 

equation indicates that the magnitude of a change in runoff is dependent upon the magnitude of the associated precipitation as well as the 

time sequence. Correlations therefore were made using this model 

equation for the three hydrologic periods at each of the four study 

areas. The significance of a time-trend change in runoff was determined from the probability of the 62 coefficient differing from zero, as 

described by Ezekiel (1950, p. 321-325).

The time-trend change in runoff was significant at the 1-percent 

level for the 6-month hydrologic period ending April 30 for all 3 

reforested areas. It was not significant at the 5-percent level for the 

correlations for the control area on Albright Creek, nor for the correlations for the other periods for the reforested areas. Therefore,
38 EFFECT OF REFORESTATION ON STREAMFLOW

for this latter group, linear correlations were recomputed using the 

equation

R=a+blP. (7)

The regression equations for all three hydrologic periods for each 

of the four study areas are shown in table 8. The relation for the 

Cold Spring Brook area for the 6-month period ending April 30 is 

shown graphically in figure 26.

TABLE 7. Precipitation and runoff totals, in inches, for selected hydrologic periods

Year

6-month period ending 

April 30

Precipitation Kunoff

6-month period ending 

October 31

Precipitation Runoff

12-month period ending 

April 30

Precipitation Kunoff

Albright Creek area

1839 

1940 

1941

1942 

1943 

1944 

1945 

1947

1948. 

1949 

1950 __

1951 

IQCO

1953 

1954

1955 

1956

1957 - _ -

16.78

16.71

14.27

23.59

14.48

19.14

15.53

16.45

17.47

20.88

20.20

20.78

17.93

22.07

1O OR

23.96

1Q Q7

16.13

16.41

16.90

1*7 QQ

14.76

23.70

16.31

18.22

15.13

19.26

15.50

15.89

19.63

21.75

16.30

15.53

13.60

19 98

22.65

15.65

21.11

20 19

25.47

26.67

21.02

28.40

25.55

22.27

23.75

21.15

15.46

23.27

17.76

23.92

25.27

24 14

26.68

1.07

6.77

1.59

6.15

9.62

5.45

11.54

11.01

11.62

6.08

4.45

4.84

2 11

4.16

2.93

4. 79

3.30

4 Qfi

5.70

37.82

34.46

49.06

41.15

40.16

43.93

45.65

43.02

43.15

43.95

41.93

33.39

45.34

37.74

47.88

45.24

40.27

17.97

24.65

16.35

29.85

25.93

23.67

26.67

30.27

27.12

21.97

24.08

26.59

18.41

19.69

16.53

24.77

25.95

20.61

Cold Spring Brook area

1935 

1936 

1937 

1938 _ 

1939

1940 _ 

1941

1942 _ 

1943

1944 

1945- __ 

1946

1947 _ 

1QAQ

1949 ___ 

1950 ____

1951 _ ..... ___ 

1952 __

1953 

1954 ___ ...

1955

1967 

15.78

20.32

16.83

14.01

18.25

15.33

15.06

12.61

1Q 47

13.59

19.10

14.30

16.42

21.07

17.93

19.81

22.47

22.39

23.18

20.04

24.64

21.86

18.14

17 94

26.57

16.75

13.70

20.40

18.63

15.90

11 94 10 159

13.26

20.69

15.43

17.13

17 91

15.76

22.02

22.54

19.11

16.45

16.44

20.06

23.15

14 94

21.87

18.80

24.62

31.38

19.13

18.96

17.52

25.66

24.75

17.87

26.46

26.45

19.37

21.56

14.22

19.50

22.10

20.97

19.15

19.56

32.74

22.83

21.52

7.88

3.10

5.65

10.47

2.25

3.54

1.96

a 74

8.57

2.64

11.38

9.24

9.70

6.89

4.21

6.50

4.98

4.10

4.47

4.45

9.82

6.34

3.52

42.19

35.63

38.63

49.63

34.46

34.02

30.13

45.13

38.34

36.97

40.76

42.87

40.44

39.49

34.03

41.97

44.49

44.15

39.19

44.20

5159

40.97

34.45

19.85

19.35

30.87

20.88

19.44

13.90

26.27

21.83

23.33

26.81

26.37

27.61

22.65

26.23

29.04

24.09

20.65

20.91

24.51

32.97

21.28
HYDROLOGIC ANALYSES 39

TABLE 7. Precipitation and runoff totals, in inches, for selected hydrologic

periods Continued

Year

6-month period ending 

April 30

Precipitation Runoff

6-month period ending 

October 31

Precipitation Runoff

12-month period ending 

April 30

Precipitation Runoff

Sage Brook area

1933 

1934 ...... __

1935. _

1936 

1937 

1938 

1939 

1940 

1941 

1942.. ..

1943 

1944 . . ...

1945-. . ..

1946 .

1947 . ..

1948 

1949 ..

1950 

1951 

1952 

1953 

1964 ..

1955 .

1956 . .-

1957 _ . _

20.07

18.03

13.91

15.11

17.43

14.69

14.93

22.63

14.49

17.63

12.52

14.23

17.91

20.03

18.08

22.46

21.93

19.13

17.23

22.01

14.24

n

nc

16.01

22.84

15.53

13.34

18.15

17.57

14.74

11.72

22.65

12.36

16.54

19 9Q

14.22

12.64

12.98

18.41

19.78

18.65

16.13

13.65

16.97

19.50

19 AO

22.78

28 77

16.91

21.33

21.81

14.70

17.81

17.68

26.76

24.79

19.27

27.33

22.84

21.50

17.87

18.05

23.47

21.55

17.28

16.28

17.64

22.74

19.90

22.67

3.71

10.85

1.57

4.25

3.60

.67

3.17

1.19

6.90

8.06

4.57

13.70

7.35

10.32

4.15

3.66

5.82

4.77

2.79

2.89

3.89

3.64

4.62

2.57

34.07

39.94

48.84

34.94

35.24

36.92

32.13

32.50

32.51

49.39

39.28

36.90

39.85

37.07

39.41

37.90

36.13

45.03

44.01

39.21

35.41

34.87

44.75

34.14

19.72

33.69

17.10

17.59

21.75

18.24

17.91

12.91

29.55

20.42

21.11

25.99

21.57

22.96

17.13

21.97

25.60

23.42

17.92

16.64

20.86

23.14

17.24

Shackham Brook area

1933 

1934 

1935... _ .

1936 

1937 

1938 

1939 _ 

1940 _ - __

1941 _ -

1942 . _ ...

1943 

1944. 

1945 . 

1946 

1047

1948 _ 

1949 ...

1950 

1951 

1952 

1953 _ 

1964 _ ......

1955 

1956 . __ 

1957

15.07

19.57

22.16

21.68

17.24

16.87

19.05

18.93

16.32

24.28

16.14

20.82

15.09

17.69

18.06

19.44

22.52

25.53

20.60

22.51

19.25

22.63

20.36

14.45

16.21

17.98

22.97

25.01

21.11

20.67

20.91

19.30

16.48

27.41

18.53

19.72

16.95

21.17

15.78

17.65

23.02

17.69

16.54

13.37

17.69

19.97

14.47

19.42

16.06

25.58

18.83

27.91

20.58

16.88

21.92

21.24

24.68

29.24

21.64

26.84

27.38

19.86

18.08

22.38

18.70

16.79

21.63

15.71

13.79

27.05

15.17

16.60

1.58

6.30

2.73

8.97

5.67

1.09

7.82

1.81

5.63

11.66

5.25

12.07

10.67

10.62

5.08

4.89

3.74

2.50

5.55

3.07

3.02

3.07

4.39

4.05

34.49

35.63

47.74

40.51

45.15

37.45

35.93

40.85

37.56

48.96

45.38

42.36

41.93

45.07

37.92

37.52

44.90

44.23

37.39

44.14

34.96

36.42

47.41

29.62

»18.56

19.56

29.27

27.74

30.08

26.34

22.00

27.12

18.29

33.04

30.09

24.97

29.02

31.84

26.40

22.73

27.66

26.76

20.19

22.09

16.44

20.71

23.04

18.86

1 Partly estimated.
40 EFFECT OF REFORESTATION ON STREAMFLOW

30

o

2 20

10

10 20 

PRECIPITATION, IN INCHES (P )

30

FIGURE 26. Relation between runoff and precipitation in the Cold Spring Brook area for the 6-month 

period ending April 30, showing the change with time.

TABLE 8. Relation of runoff to precipitation

Station

Sage Brook near South New Berlin __

Period

Months

6 

6 

12

6 

6 

12

6 

6 

12

6 

6 

12

EndingApr. 30 

Oct. 31 

Apr. 30

Apr. 30 

Oct. 31 

Apr. 30

Apr. 30 

Oct. 31 

Apr. 30

Apr. 30 

Oct. 31 

Apr. 30

Years of 

record

1934-57 

1934-57 

1935-57

1935-57 

1935-57 

1935-57

1934-57 

1934-57 

1934-57

1940-57 

1940-57 

1941-57

Regression equation

#=-t-1.21+0.97P-0.010rP 

#=-9.34+-0.68P 

#=-9.50+0.79P

R = -1 .04+1 .25P-0.016 TP 

#=-4.52+0.48P 

#=-1.39+0.63P

p_ i A 7«j_n cop _ ft fill TP

#=-4.84+0.49P 

#=-4.96-H>.73P

#=+7.97+0.52P 

#=-8.98+0.64P 

#=-4.90+-0.68P

The magnitudes of the indicated changes in the relation between 

precipitation and runoff were determined from the multiple-regression
HYDROLOGIC ANALYSES 41

equations. The reductions in runoff between the initial year and 

the final year for the 6-month period ending April 30 are:

Reduction of runoff

Area 

Sage Brook, __ _____ ____

Cold Spring Brook __ ___ __

Shackham Brook ________ _ _

Albright Creek__ ________ _

j

Period of record used 

_____ 1934-57

_____ 1935-57

_____ 1934-57

_____ 1940-57

Total reduction Annual rate of 

in runoff reduction 

(inches) (inches per year)

4. 18 0. 17 

6. 76 . 29 

5. 13 . 21 

0 0

These indicated reductions are based on the mean precipitation for 

the period of record at each station.

COVAKIANCE ANALYSIS

The relation between runoff and precipitation also was studied by 

analysis of covariance between early and late periods of each station 

record. The analyses were made for the 6-month periods ending 

April 30 and October 31 and for the hydrologic year ending April 30. 

The analysis of covariance was used to determine if the relation 

between precipitation and runoff for the latter part of each station 

record differed from the relation for the earlier period.

The limitations imposed by grouping the data into early and late 

periods were recognized. The covariance analysis is best suited to 

the testing of groups of data, each of which is homogeneous. An 

abrupt change in the relation of the variables provides the ideal 

point for separating the data into groups. However, the data from 

the reforested areas cannot be grouped on the basis of abrupt change; 

gradual rather than abrupt changes in streamflow of the reforested 

areas were to be expected if these changes were related to the tree 

growth.

The chronological tabulation of precipitation and runoff data for 

each study area was divided into halves to obtain the early and late 

period of each record. Covariance between precipitation and runoff 

for the late period was compared with the covariance for the early 

period to determine changes in (a) the relation between means for 

the early and late periods, and (b) the relation between the regression 

slopes for early and late periods. Significance of indicated changes 

was determined by using the Fisher F-test in the manner described 

by Wilm (1944).

The analyses of covariance indicated significant changes in both 

means and regression slopes between early and late periods of record 

for the 6-month period ending April 30 for all 3 reforested areas. 

A significant change in regression slopes between early and late 

periods of the station record was also determined for the 6-month 

period ending October 31 for the Shackham Brook area.
42 EFFECT OF REFORESTATION ON STREAMFLOW

RELATION BETWEEN RUNOFF FROM REFORESTED AREA AND 

FROM CONTROL AREA

SEASONAL AND ANNUAL RUNOFF

Total runoff from the partly reforested watershed of Shackham 

Brook near Truxton was correlated with the total runoff from the 

specific control area of Albright Creek at East Homer and the year 

of occurrence, to determine changes in the runoff relation for the period 

of record 1941-57. The relation was studied for the same 3 hydrologic periods as the precipitation-runoff study; these are the seasonal 

6-month periods ending April 30 and October 31, and the 12-month 

period ending April 30.

The model equations used in the precipitation-runoff study (equations 2-5 previously listed) were considered by substituting the 

Albright Creek runoff for precipitation in the equations. The model

Rs^a+h RA +b2 TRA (8)

in which Es is the runoff in inches of Shackham Brook for a given 

hydrologic period, EA is the runoff in inches of Albright Creek for the 

same period, and T is the position of the period in chronological sequence beginning with T l for the first year of record, gave best 

correlation of the data as determined from a comparison of the 

standard errors of estimate for each model considered. Regressions 

based on equation 8 were computed as follows :

Computed regressions 

__ ________ Years of

Months Ending record Regression equation

6-_-_-...__. Apr. 30 1941-57 Ra= +0.72 + 1.17 RA -0.015 TRA

6__-__-____ Oct. 31 1940-57 Rs= +0.43+1.11 RA -0.024 TRA

12_.____.-_._ Apr. 30 1941-57 Rs= +3.33+1.03 RA -0.015 TRA

The three relations are shown graphically in figures 27 to 29.

Significance of a time trend in the relation between runoffs was 

determined in the manner previously described. Reductions in runoff of Shackham Brook were found significant at the 5-percent level 

for all 3 hydrologic periods. For the value of the mean runoff from 

Albright Creek for each hydrologic period, the reductions in total 

runoff from 1941 to 1957 from Shackham Brook as determined by 

the regression equations are as follows:

Computed reduction of runoff from Shackham Brook, 1941-57

Period Annual rate of 

Total reduction reditction in runoff

Months Ending in runoff (inches) (inches per year)

6.____._ Apr. 30 4.78 0.23

6____-____. Oct. 31 2.57 .14

12___._______ Apr. 30 6.05 .36
HYDROLOGIC ANALYSES 43

Kunoffs from Albright Creek and Shackham Brook also were 

studied by analyses of covariance in the same manner as used in the 

precipitation-runoff study. The analyses of covariance indicated 

significant reductions at the 5-percent level in the mean flow of 

Shackham Brook during the latter half of the record for both the 6- 

and 12-month periods ending April 30. Kesults of the analysis of 

covariance for the 6-month period ending October 31 were 

inconclusive.

30

. - 20

1940

- -f 0.72 +1. \7ffA - 0.015 TRA

10

10 20 

RUNOFF, IN INCHES, ALBRIGHT CREEK

30

FIGURE 27. Kelation between runoff from Sbackham Brook area and Albrigbt Creek area for the 6-montb 

period ending April 30, showing the change with time.
44 EFFECT OF REFORESTATION ON STREAMFLOW

.-5

10

RUNOFF IN INCHES, ALBRIGHT CREEK

FIGURE 28. Relation between runoff from Shackham Brook area and Albright Creek area for the 6-month 

period ending October 31, showing the change with time.
HYDROLOGIC ANALYSES 45

fts -- 3.33+ 1.03 RA -0.015 TRA

20 30 

RUNOFF, IN INCHES, ALBRIGHT CREEK (f?A)

FIGURE 29. Relation between runoff from Shackham Brook area and Albright Creek area for the 12-montb 

period ending April 30, showing the change with time.

PEAK DISCHARGES

Peak discharges of the reforested area of Shackham Brook were 

correlated with the concurrent peak discharges of the control area, 

Albright Creek. The relation was studied for the 6-month periods 

ending April 30 and October 31. These periods were selected because 

(a) they approximate closely the dormant and growing seasons in 

central New York, and (b) the 6-month period ending April 30 represents the period in which snow accumulation and snowmelt have 

pronounced effects on peak discharges. All peak discharges above 

10 cfs per square mile on Albright Creek during November through

582754 61 5
46 EFFECT OF REFORESTATION ON STREAMFLOW

April and 2 cfs per square mile on Albright Creek during May through 

October were used in the study. The concurrent peak on Shackham 

Brook was identified as that peak resulting from the same meteorologic 

event which caused the peak on Albright Creek. The peak discharges 

selected for this study are listed in table 9.

TABLE 9. Related peak discharges on Shackham Brook and on Albright Creek

Year

1938 

1940.. -

1941 - 

1Q19

1913 .....

1944. 

1945. ....

1946.. --..

1947 - ..

icua

Date

Dec. 10 

Feb. 20 

Mar. 6 

27 

30 

Mar. 31 

Apr. 4 

8 

18 

Dec. 13 

16 

28 

Apr. 6 

Dec. 24 

Mar. 9 

17 

Nov. 18 

21 

Dec. 2 

Feb. 24 

Mar. 12 

Nov. 9 

Mar. 16 

17 

23 

25 

Apr. 10 

12 

24 

Jan. l 

Feb. 27 

Mar. 3 

6 

14 

15 

16 

17 

22 

Nov. 2 

22 

Feb. 14 

Mar. 4 

6 

9 

Jan. 20 

30 

Mar. 15 

25 

Apr. 3 

5 

6 

Mar. 16 

18 

19 

21 

22 

Apr. 1 

14 

Nov. 20 

Dec. 30

Peak discharge (cfs)

Shackham 

Brook

92 

155 

56 

94 

53 

108 

114 

251 

58 

72 

45 

234 

190 

278 

193 

171 

56 

72 

59 

132 

84 

130 

32 

110 

36 

112 

182 

53 

42 

50 

28 

42 

24 

30 

76 

228 

179 

193 

55 

50 

56 

24 

148 

155 

67 

132 

124 

195 

51 

172 

155 

118 

40 

236 

236 

148 

40 

44 

193 

66

Albright 

Creek

121 

325 

80 

144 

90 

237 

314 

462 

135 

124 

90 

363 

351 

374 

294 

357 

74 

110 

110 

190 

100 

213 

115 

280 

85 

263 

252 

100 

90 

93 

72 

117 

74 

80 

140 

563 

286 

236 

147 

80 

133 

71 

269 

317 

135 

188 

122 

395 

95 

401 

288 

348 

108 

469 

300 

262 

SO 

76 

484 

116

Year

1949............

1950... _ ......

1951 

1952... 

1953 

1954...... ......

1956....... .....

1957 

Date

Jan. 5 

6 

Feb. 15 

Dec. 12 

13 

26 

Jan. 6 

10 

24 

Mar. 28 

Apr. 4 

Nov. 25 

Dec. 4 

8 

Jan. 4 

21 

24 

Feb. 1 

21 

Mar. 24 

30 

Apr. 2 

12 

Jan. 15 

18 

26 

Feb. 2 

Mar. 11 

21 

Apr. 5 

Dec. 11 

Jan. 24 

Feb. 21 

Mar. 24 

Jan. 23 

Feb. 17 

21 

Mar. 1 

25 

Apr. 17 

Dec. 14 

28 

Mar. 1 

22 

Nov. 16 

Dec. 4 

Mar. 7 

Apr. 16 

29 

Dec. 22 

Feb. 27 

Mar. 5 

15 

Apr. 5

Peak discharge (cfs)

Shackham 

Brook

66 

66 

66 

48 

62 

32 

36 

60 

24 

135 

274 

100 

205 

68 

52 

54 

52 

54 

84 

28 

278 

107 

93 

33 

48 

34 

18 

46 

31 

44 

107 

73 

97 

161 

66 

161 

124 

33 

29 

41 

42 

52 

60 

64 

29 

26 

56 

129 

88 

53 

52 

22 

53 

57

Albright 

Creek

121 

118 

116 

113 

103 

73 

80 

116 

75 

377 

507 

177 

407 

131 

156 

86 

112 

86 

182 

82 

531 

124 

95 

107 

121 

138 

74 

208 

82 

131 

253 

144 

238 

311 

421 

370 

199 

160 

95 

92 

149 

160 

257 

191 

98 

64 

251 

228 

79 

131 

142 

127 

127 

131
HYDROLOGIC ANALYSES 47

Multiple correction was made using the model equation

log S=a-\-bi log A+b2 T (9)

in which S is the peak discharge of Shackham Brook, A is the concurrent peak discharge of Albright Creek and T is the period in a 

numerical sequence during which the peak occurred, beginning with 

T=l. The multiple regression for the 6-month period ending April 

30 was based on 118 peaks between 1939 and 1957, and was computed 

as

log £=-0.133+0.977 log .4-0.012 T (10)

This relation is shown graphically in figure 30.

The 62 coefficient of 0.012 was tested for statistical significance in 

the manner previously described and was determined significant above 

the 1 -percent level. A reduction in peak discharge of 41 percent is 

indicated for Shackham Brook; that is, for a peak discharge of a given 

magnitude on Albright Creek, the comparable peak discharge on 

Shackham Brook was 41 percent lower in 1957 than the comparable 

peak in 1939.

A multiple correlation using equation 9 also was made for the 

6-month period ending October 31. The regression based on 25 pairs 

of concurrent peak discharges was computed as

log £=-0.877+ 1.358 log 4-0.010 T (11)

The coefficient of T was determined not significant at the 5-percent 

level, indicating that a change could not be statistically determined 

in the relation between peak discharges of Shackham Brook and 

Albright Creek for the period May 1 to October 31.

The peak discharges occurring during the dormant season were 

further investigated to determine the existence of any internal seasonal trend during the period of record. To accomplish this, variables 

representing the seasonal trend were added to equation 9 to obtain

log S=a+b2 log A+hT+btP+bs TD (12)

in which D is the position in a numerical sequence of the calendar 

date of the peak, ranging from 1 for November 1 to 183 for April 30. 

The regression, based on the 118 pairs of concurrent peak discharges, 

was computed as

log £=+0.012+0.986 log 4-0.028 T 0.00151 D

+ 0.000143 TD (13)

in which all coefficients were determined significant above the 1 -percent level. The relation is shown graphically in figures 31 and 32.
PEAK DISCHARGE, IN CUBIC FEET PER SECOND, SHA

yi O 

o o ___
HYDROLOGIC ANALYSES 49

1945

/ NOV. 

.APR.

,APR.

^DEC.

1957

50 100 500 50 100 500 

PEAK DISCHARGE, IN CUBIC FEET PER SECOND, ALBRIGHT CREEK AT EAST HOMER, N. Y.

FIGUKB 31. Effect of data of occurrence on relation between peak discharges of Shackham Brook and

Albright Creek.
50 EFFECT OF REFORESTATION ON STREAMFLOW

.500

!lOO

50

y

NOVEMBER

,,1951 

X1957

1939 

v!945 

/1951 

/1957

JANUARY

£500

cc 

<100

2

Q

.50

FEBRUARY

x!939 

//\ 945

1951

1957

A

APRIL

939

957

50 100 5W 50 100 500 

PEAK DISCHARGE, IN CUBIC FEET PER SECOND, ALBRIGHT CREEK AT EAST HOMER. N. Y.

FIGURE 32. Effect of data of occurrence on relation between peak discharges of Shackham Brook and

Albright Creek.

Analysis of the results shows that the reduction of peak discharges 

of Shackham Brook from 1934 to 1957 during the period November 

through April varies within the period as shown below:

Reduction of peak discharges from Shackham Brook, 1984-57

Average reduction for 

Month month (percent)

November________________ 65.6

December________________ 59.0

January__________________ 50. 7

February_________________ 40. 6

March_______________ 29.9

April________________ 15.6
HYDROLOGIC ANALYSES 

LOW FLOWS

51

The minimum daily flow of Shackham Brook in each hydrologic 

year ending April 30 was compared with that of Albright Creek for 

the same year. The minimum daily flows are shown in table 10. 

Correlation was made using the model equation

Qs^a+hQ.A+bs T (14)

in which Qs is the annual minimum daily flow of Shackham Brook 

near Truxton, QA is the annual minimum daily flow of Albright Creek 

at East Homer, and T is the position of the hydrologic year in a 

numerical sequence beginning with T= 1. 

The regression equation was computed as

Qs= + 0.066+0.164 #4+0.0003 T (15)

in which the b2 coefficient of +0.0003 was determined to be not significantly different from zero at the 5-percent level, indicating that 

no significant change had occurred in the low flows of Shackham 

Brook.

TABLE 10. Annual low flows for Shackham Brook and Albright Creek areas

Year ending April 30 

1939------.------__

1940---_--.-_----_-

1941____ __________

1942_-__--__-_____

1943___------_-__.

1944--_____---____

1945--_- ._ _ __

1946- 

1947__-_-_________

1948- _ _ ...

1949 

1950. 

1951- 

1952-_______-_____

1953_-_________-__

1954___--_-___-___

1955 

1956-. ____________

1957- 

Minimum daily flow (cfs)

Shackham Brook

0.075 

.096 

.098 

. 104 

. 144 

.088 

.212 

. 131 

. 138 

.092 

.074 

. 121 

. 110 

. 120 

.042 

.006 

.071 

. 107 

.224

Albright Creek

0.085 

. 186 

.09 

. 19 

.37 

.215 

.41 

.50 

.86 

.45 

. 168 

.26 

.180 

. 170 

0 

. 110 

.030 

.27 

.32
52 EFFECT OF REFORESTATION ON STREAMFLOW

OTHEB ANALYSES 

BASE-FLOW RECESSION

Base-flow recession may be represented by the equation

Q t=Q0e-" 1 , (16)

where Qo represents the initial discharge, Q t represents the discharge 

at t days later, and k is a physical constant. If t is equal to 1 day, 

the equation becomes

Q t=KQ» (17) 

where

K=e~\ (18)

with K representing the coefficient of recession, or the recession rate.

Base-flow recession rates, as defined by equation 17, were determined 

for the three reforested areas and for the control area. For each 

station, data for the relations were obtained for the first 5-year period 

of record and for 1952-57 by determining the rates of discharge at the 

beginning and end of a calendar day.

Two distinct recession rates occurred during each year at all four 

stations. One rate occurred during the growing season; the other 

during the dormant season. A transition between the recession rates 

occurred in late April or early May and again in October or early 

November. Base-flow recession rates, therefore, were computed for 

growing and dormant seasons. A study of the dates of the transitional periods did not indicate any apparent trend or change in dates 

between the early and later years of record for any of the stations.

Base-flow recession relations were computed for the four stations 

using equation 17. These relations for Cold Spring Brook at China 

are shown graphically in figure 33 and the recession coefficients, K, for

0.3

0.2

0.1

Growing season 

Dormant season

0.1 0.2 0.3 

DISCHARGE, IN CUBIC FEET PER SECOND

0.1 0.2 0.3 

DISCHARGE. IN CUBIC FEET PER SECOND

FIGTJKE 33. Base-flow recession rates foi Cold Spring Brook at China.
HYDROLOGIC ANALYSES 53

all computed relations are listed in table 11. Small changes in the 

recession rates between 5-year periods for both growing and dormant 

seasons were tested for significance by analyses of covariance between 

the comparable groups of data. No significant changes between early 

and late periods were found at the 5-percent level for either season for 

any of the four areas.

TABLE 11. Coefficients of base-flow recession

Stream

Sage Brook near South New

Berlin.

Shackham Brook near Truxton___

Albright Creek at East Homer____

Seasonal period

Dormant- __

Growing. ___ _ .

Dormant- _ _ _

Years

1936-40

1953-57 

1936-40

1953-57 

1935-39

1953-57 

1935-39

1953-57 

1936-40

1953-57 

1936-40

1953-57 

1940-44

1953-57 

1940-44

1953-57

Keeession 

coefficient

K

0 903

903 

825

817

872

892 

779

795 

919

924 

871

880 

910

911

875

878

RELATION BETWEEN VOLUMES OF DIRECT RUNOFF AND 

PRECIPITATION FROM INDIVIDUAL STORMS

Direct runoff is a residual of precipitation after the demands of 

interception and infiltration are met. Changes in these demands 

would affect the amount of direct runoff and the relation between 

precipitation and direct runoff. To test for a change, direct runoff 

was correlated with the storm precipitation which caused the direct 

runoff.

Direct runoff from each storm was determined from the hydrograph by subtracting the base flow from the total flow. The base 

flow was delineated by extending the hydrograph prior to the beginning of the direct runoff to the time of the peak discharge, and by 

extending backward the hydrograph subsequent to direct runoff to a 

point about 6 to 12 hours past the peak. The two recessions then 

were connected by a smooth transition.

Volumes of direct runoff were computed for the first 5-year period 

and for the water years 1952-57 for each study area. For each period, 

direct runoff was computed for all storms of more than one-half inch 

of precipitation and for a representative number of storms below onehalf inch of precipitation. However, no runoff periods were used in
54 EFFECT OF REFORESTATION ON STREAMFLOW

which either snowfall or snowmelt was a factor. An index based on 

the antecedent 30-day rainfall total was used to delineate the runoff 

potential of the storm as either high, average, or low. Other measures 

of antecedent rainfall were also considered, but graphical correlations 

indicated that the index based on the 30-day antecedent rainfall best 

described the runoff potential.

The data on runoff and storm precipitation were transformed 

logarithmically to approximate a linear relation within the range of 

data, and early and late periods were then tested for differences by 

analyses of covariance. No significant differences at the 5-percent 

level were detected between early and late periods in either means or 

slopes of the relations for any of the four stations. Results of this 

study are inconclusive because of the large scatter in the data.

The relation between storm precipitation and direct runoff is shown 

graphically in figure 34.

METHODS REJECTED

Several other methods of hydrologic analysis were considered and 

rejected. The unit-hydrograph approach was rejected early in the 

study because the precipitation and runoff data, which were collected 

independently of each other, were not adequately synchronized for 

such a study. Flood frequency, low-flow frequency, and flow-duration techniques of analyses were also rejected because no rigorous 

statistical comparisons could be made of data arrayed in this manner. 

Comparisons by these techniques would be by visual means only, and 

therefore not conclusive. An attempt was made to improve the relation between peak flows for a 5-year period on Shackham Brook near 

Truxton with associated storm precipitation by including storm intensity. Graphical correlations showed no improvement. Grouping 

of the data into groups of high, average, and low potential, as in the 

study of volumes of direct runoff, also gave no appreciable improvement in the relation. The study therefore was not continued beyond 

this step.
HYDROLOGIC ANALYSES 55

0.5

0.1

</>

LU

o 0.05 zz

tC 

u_ 

O

Z

ID

cc

fcLU

a:

0

LL. 

O

LU

Z)

>

0.005

0.001

" 

~~

_

RUNOFF POTENTIAL

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STORM PRECIPITATION, IN INCHES

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FIGURE 34. Relation between storm precipitation and volumes of direct runoff for the Sage Brook area.
56 EFFECT OF REFORESTATION ON STREAMFLOW

SUMMARY

The statistical analyses indicate that certain definite changes have 

occurred in the streamflow of the three partly reforested areas between 

the time of reforestation and 1957. Based on correlations with precipitation, the following changes in runoff for the 6-month period 

ending April 30 are indicated:

Changes in runoff in partly reforested areas, 1984-57

Area 

Sage Brook. ____ ____ _ ____

Cold Spring Brook_ __ _ __.

Shackham Brook _ __ _.

Total reduction Annual rate of 

in runoff reduction 

(inches') (inches per year)

_______ 4. 18 0. 17

_______ 6.76 .29

. __ . 5. 13 .21

Percent reduction for period 

of record

23

31

23

These changes are based upon the mean precipitation for the period 

of record of each area.

Correlation between the flows of Shackham Brook and its control, 

Albright Creek, indicate that the following reductions have occurred 

in the flows of Shackham Brook:

Reductions in flow, Shackham Brook, 1939 57

Total runoff

NovemberApril May-October Annual

Total____-_-______________percent 22 37 22

Annual rate_______-_--_______inches .23 .14 .36

Peak discharges

Nov. Dec. Jan. Feb. Mar. Apr. 

Average reduction for month-.percent 66 59 51 41 30 16

No significant changes with time were found in (a) the peak discharges of Shackham Brook for the period May 1 to October 31, 

based on correlation with peak discharges of Albright Creek; (b) 

base-flow recession rates for any of the four streams; (c) volumes of 

direct runoff, from correlation with storm precipitation; and (d) annual minimum daily flows of Shackham Brook near Truxton, based 

on correlation with annual minimum daily flows of Albright Creek at 

East Homer.

EVALUATION OF THE STUDY

The study of the effect of forests on streamflow in central New 

York is unique in that no abrupt treatment such as denudation was 

applied. The ecological conditions existing at the time of reforestation were virtually undisturbed except for the planting of coniferous 

trees. By planting the seedlings in grub-hoe slits, no grasses were 

removed and no areas of bare soil were exposed. In fact, care was 

taken to disturb the ground cover as little as possible in order that 

the newly planted seedlings might benefit from the shade afforded
EVALUATION OF THE STUDY 57

by the weeds and grasses during the process of becoming established.

Thus the major change since reforestation has been a gradual 

succession of the vegetation from brush and weeds to coniferous 

woodlands in parts of each of the reforested areas. The trees were 

permitted to grow undisturbed. As they grew, the usual changes in 

ground cover occurred. By 1957, the plant growth beneath the tree 

canopies had disappeared, and a litter of conifer needles had accumulated. Because no thinning or cutting of the conifers was done, the 

branches of the trees in many of the plantations intermingled as they 

grew and formed a tight crown cover. These changes were gradual. 

Therefore it is logical to expect that changes in streamflow resulting 

from the changes in plant cover also would be gradual. This premise 

that changes in the streamflow would be gradual formed a basic 

consideration in the selection of techniques of analysis used in this 

study.

It is recognized that a lack of shielding of the gages probably has 

caused an underregistering of the actual precipitation. The tendency 

of the gages to underregister may also be inferred from the fact that in 

many years, the runoff for the period November through April exceeded the measured precipitation for the same period. However, 

the measured precipitation does represent an index of the basin precipitation, and tests have shown these indexes to be consistent with 

the areal pattern of precipitation for central New York.

The consistency of the precipitation indexes for the study areas 

also indicates no appreciable effect of a rain shadow or change in 

exposure. Field observations of the gage locations in 1957 revealed 

no serious encroachment of the surrounding trees upon the cone of 

influence of any of the gages. The minor changes in location of 

Shackham Brook 2 and Albright Creek 1 gages made for the convenience of the observers did not change the general exposure of either 

gage. Furthermore, both gages agree well with the areal pattern of 

precipitation.

In studying the relation between precipitation and runoff, no 

effect of antecedent precipitation was found for any of the three 

hydrologic periods. An apparent explanation for this is found in the 

physical interpretation of the ground-water elevations. On April 30 

each year, the ground-water elevation is at or near the ground surface 

throughout most of the four areas, and therefore on this date the 

ground-water reservoir has a relatively constant volume of storage 

at the beginning of each hydrologic year. This relatively stable 

volume of storage on April 30 of each year also accounts for the lack 

of effect of antecedent precipitation on the May through November 

hydrologic period. In a similar manner, the relatively depleted 

ground-water reservoir on October 31 of each year provides no appre-
58 EFFECT OF REFORESTATION ON STREAMFLOW

ciable carryover effect of antecedent precipitation on the 6-month 

period beginning November 1.

The model equation used in the study of the relation between 

runoff and precipitation indicates that changes in this relation are 

related not only to time, but to the magnitude of the precipitation as 

well. This is understandable from consideration of such factors in 

the hydrologic cycle as evapotranspiration, interception, infiltration, 

and soil moisture. The total quantity of each of these factors in 

any year is dependent upon the total amount of water available for 

the process and thus ultimately upon the precipitation. Thus 

greater precipitation in any year would result in proportionally 

greater amounts of water for the hydrologic processes.

The reductions in runoff as determined from the statistical studies 

are remarkably consistent. For Shackham Brook near Truxton, 

the average reduction in runoff during the period of record for November through April was 0.21 inch per season based on the relation with 

precipitation and 0.23 inch per season based on the relation with 

runoff from the Albright Creek control area. Also for Shackham 

Brook near Truxton, average reductions of 0.23 and 0.14 inch per 

season were determined for the growing and dormant seasons respectively. For the hydrologic year, an average reduction of 0.36 

inch per year was determined, as compared with 0.37 inch per 

year as determined from the two 6-month periods.

Reductions in runoff for the period November through April were 

found at all three reforested areas. The magnitude of reduction 

varied for each area, but this variation could not be related to any 

measure of the reforestation nor to the size of the basin. An apparent 

relation was found between the magnitude of the reduction and the 

stream density of the basin, but this relation had no physical meaning 

and therefore was rejected.

The decreases in total flows and in winter peak flows in the three 

experimental areas are attributed to the partial reforestation of 

the areas. Trees affect streamflow by intercepting rain and snow, 

changing infiltration capacity of the soil, retarding snowmelt in the 

wooded areas, and increasing transpiration.

Coniferous trees intercept an appreciable portion of precipitation. 

Horton (1919) has indicated that as much as 0.18 inches of a 1-inch 

rainfall may be intercepted by pine trees. This figure agrees with 

data reported by Johnson (1942) although Johnson reported about 

30-percent interception during the winter season when precipitation 

fell mostly as snow. Also, Mayr (1925) has stated that as little as 

1 percent of a light snow might reach the ground in a dense plantation 

of young spruce.
EVALUATION OF THE STUDY 59

Interception of precipitation in the reforested areas undoubtedly 

increased as the trees grew. The increased interception probably 

accounts for the major part of the reduction in streamflow for the 

winter period, and for at least part of the reduction in runoff for the 

growing period. The changes in runoff in the growing season may 

also reflect changes in the infiltration capacities of the soils in the 

forest areas. Increased infiltration capacities of the forest soils would 

reduce direct runoff from a storm and thus provide more soil moisture 

for evapotranspiration.

Forest cover also has an effect on snowmelt. Wilm (1948) concluded from a review of past literature that forests tend to retard the 

melting rates of snow. More recently, Garstka and others (1958, 

p. 39-47) observed that the snow had disappeared from 97 percent of 

the area of a 42-acre clearing while still covering 43 percent of the 

area of the surrounding forest. The retarding of snowmelt in the 

reforested parts of the Shackham Brook area, with its resulting desynchronization of snowmelt runoff, and increased interception of the 

precipitation undoubtedly account for the reduction of peak discharges on Shackham Brook. Similar reductions in peak discharges 

for Cold Spring Brook at China and Sage Brook near South New 

Berlin could not be shown because of a lack of specific control areas 

for correlation. However, it is reasonable to assume that a reduction 

in peak discharges also has taken place in these two areas.

The indicated reductions of peak discharges on Shackham Brook 

represent average figures. They do not indicate that all peaks in the 

latter years have been reduced. In fact, several peaks occurring during March and April in the latter years were relatively higher than 

comparable peaks during the earlier years. These peaks were of 

various magnitudes. The relative increase in a few peaks also can be 

attributed to the desynchronization of snowmelt runoff from the open 

and reforested areas, as the snowmelt that is retarded in the reforested 

areas on one peak may be available to supplement the direct runoff 

on a subsequent peak.

Although there have been many studies of the effect of forests on 

streamflow, three investigations stand out for their scientific approach 

and firm results. In one of the first comprehensive studies in the 

United States, Bates and Henry (1928) showed that removal of the 

forest cover of an area in the Rio Grande National Forest near Wagon 

Wheel Gap, Colorado, increased annual water yields by about 0.96 

inches per year, or about 15 percent. Peak discharges also were 

increased by as much as 35 percent.

Hoyt and Troxell (1934) reported that complete destruction by fire 

of the forest cover in the Fish Creek basin in California resulted in an
60 EFFECT OF REFORESTATION ON STREAMFLOW

average annual increase of 1.55 inches, or 29 percent, and an increase 

of 0.19 inches, or 475 percent, for the summer months. The high 

percentage increase for the summer months results from the extremely 

small runoff from the area under the forested conditions. Hoyt and 

Troxell also indicated that peak discharges were increased, as well as 

the minimum daily flows in the summer periods.

The denudation of an experimental area in the Coweeta Experimental Forest, N.C., was reported by Hoover (1944) to have increased 

annual runoff by 17.29 inches in the first year following cutting of all 

brush and trees, and by 13.26 inches in the second year after some 

regrowth had occurred. Hoover also reported that no significant 

changes occurred in peak discharges; no direct runoff occurred either 

before or after treatment, and all runoff was controlled by groundwater conditions.

The results of the present study in central New York agree in 

general with those of the three studies discussed above: reforestation 

produced the opposite effect of deforestation or denudation. The 

transition from grasses to coniferous woodland has caused progressively larger changes in certain phases of streamflow as the size of the 

trees increased. It is logical to assume, however, that these changes 

will not increase indefinitely. At some phase in their development 

the trees in the reforested parcels in the three areas will exert maximum and perhaps relatively stable influence on the streamflow. 

There is no evidence from the studies that the change had approached 

or was approaching this maximum point by 1957, nor can the available 

data be extrapolated to determine when this will occur. Perhaps 

some indication that the optimum point is approaching is found in 

the fact that the conifers now have almost complete crown closure.

REFERENCES CITED

Ayer, G. R., 1949, A progress report on an investigation on the influence on

reforestation on streamflow in State forests in central New York: U.S.

Geol. Survey open-file report, 185 p. 

Bates, C. G., and Henry, A. J., 1928, Forest and streamflow experiment at Wagon

Wheel Gap, Colorado: U.S. Weather Bur. Monthly Weather Rev., Supp.

30, 79 p. 

Ezekiel, Mordecai, 1941, Methods of correlation analysis: New York, John Wiley

and Sons, 531 p. 

Garstka, W. U., Love, L. D., Goodell, B. C., and Bertie, F. A., 1958, Factors

affecting snowmelt and streamflow: U.S. Bur. Reclamation and U.S. Forest

Service, 189 p. 

Hoover, M. D., 1944, Effect of removal of forest vegetation on water yields: Am.

Geophys. Union Trans., v. 25, p. 969-977. 

Horton, R. E., 1919, Rainfall interception: U.S. Weather Bur. Monthly Weather

Rev., v. 47, p. 603-623. 

Hoyt, W. G., and Troxell, H. C., 1934, Forests and streamflow: Am. Soc. Civil

Engineers Trans., v. 99, p. 1-30.
REFERENCES CITED 61

Johnson, E. A., and Kovner, J. L., 1956, Effect on streamflow of cutting a forest

understory: Forest Science, v. 2, p. 82-91. 

Johnson, W. M., 1942, The interception of rain and snow by a forest of young

ponderosa-pine: Am. Geophys. Union Trans., 23d Ann. Mtg., pt. 2, p,

566-570. 

Marbut, C. F., 1935, Soils of the United States, Part 3 in Baker, O. E., editor,

Atlas of American agriculture: Washington, D.C., U.S. Dept. Agriculture,

98 p. 

Mayr, Heinrich, 1925, Waldbau auf naturgesetzlicher Grundlage: 2d. ed., Berlin,

Verlag von Paul Parey, 568 p. 

Outlaw, D. E., 1953, A geologic and hydrologic study of Shackham watershed,

New York State: U.S. Geol. Survey open-file report. 

Snedecor, G. W., 1946, Statistical methods: 4th ed., Ames, Iowa, Iowa State

Coll. Press, 485 p. 

U.S. Soil Conservation Service, 1920, Soil Survey of Chenango County, New

York: Washington, B.C., U.S. Soil Conserv. Service, ser. 1918, 37 p. 

 1930, Soil Survey of Delaware County, New York: Washington, D.C.,

U.S. Soil Conserv. Service, ser. 1930, 31 p.

1953, Soil Survey of Tioga County, New York: Washington, D.C., U.S.

Soil Conserv. Service, ser. 1939, no. 20, 133 p. 

Wilm, H. G., 1943, Statistical control of hydrologic data from experimental

watersheds: Am. Geophys. Union Trans., v. 24, p. 618-624. 

 1948, The influence of forest cover on snowmelt: Am. Geophys. Union

Trans., v. 29, p. 547-557.

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