GEOLOGICAL SURVEY CIRCULAR 826 

A Review and Evaluation of Alternatives 

for Updating U.S. Geological Survey 

Land Use and Land Cover Maps 

By Valerie A. Milazzo 

GEOLOGICAL SURVEY CIRCULAR 826 

1980 
United States Department of the Interior 

CECIL D. ANDRUS, Secretary 

Geological Survey 

H. William Menard, Director 

Library of Congress Cataloging in Publication Data 

Milazzo, Valerie A. 

A review and evaluation of alternatives for updating U.S. Geological Survey land use and land cover maps. 

U.S. Geological Survey 

(U.S. Geological Survey circular 826) 

Bibliography: p. 

Supt. of Docs. no.: I 19.4/2:826 

1. Land use-United States-Maps. I. Title. II. Series: United States. Geological Surve3·. 

Circular 826. 

QE75.C5 no. 826 [HD205] 557.3s [333.73'13'09731 80-607113 

Free on application to Branch of Distribution, U.S. Geological Survey 

604 South Pickett Street, Alexandria, VA 22304 
PREFACE 

Land use and land cover maps and data must be kept current for effective planning and management of the Nation's land resources. In order to 

meet the increasing demands for up-to-date land use and land cover information, a primary goal of the U.S. Geological Survey's national land use 

and land cover mapping program is to. update existing maps and data 

in a timely and uniform manner. Plans are now underway to begin the 

selective updating of this land use and land cover information as part of 

an ongoing program of nationwide land use and land cover mapping. 

Requisite to establishing an update-mapping program, however, is a careful evaluation of the various alternatives for updating land use and land 

cover maps. 

This circular has been written to satisfy three purposes. The first is 

to present a review of the considerations that are important in planning 

a program to update nationwide land use and land cover maps. The second is to evaluate the options within each of the considerations for their 

applicability to the requirements of the U.S. Geological Survey's land use 

and land cover mapping program and to offer recommendations concerning those options thought to best satisfy these requirements. The third 

purpose is to stimulate thinking about additional approaches to updating 

land use and land cover maps. We hope that users of land use and land 

cover maps and data will consider their require-ments and de.sires for 

updated land use and land cover data, and we invite their input. An 

addressed, postpaid response card which can be detached for use in replying is included in the back of this circular. 

III 
COVER: Two aerial photographs of a southern part of Tempe, Ariz., in 1970 (top) and 1979 (boHom). 

The photographs shown are portions of two 9-by ,_inch black-and-white aerial photographs taken for 

the Agricultural Stabilization and Conservation Service of the U.S. Department of Agriculture. They 

are shown here at a scale of about 1 :20,000. Each photograph is overlaid with a polygon map delineating Level II land use and land cover categories as interpreted from the photograph. 
CONTENTS 

Page 

Preface ------------------------------------------------------------------ III 

~bstract ----------------------------------------------------------------- 1 

Introduction ------------------------------------------------------------- 1 

How often should maps be updated? ---------------------------------------- 2 

The nature of land use and land cover changes -------------------------- 2 

Procedures for determining update frequency --------------------------- 3 

Recommendations ---------------------------------------------------- 4 

What remotely sensed source materials should be used 'for detecting and 

compiling changes in land use and land cover? ------------------------ 5 

Large-scale, low-altitude aerial photographs ---------------------------- 5 

Small-scale, high-altitude aerial photographs ---------------------------- 6 

Landsat multispectral scanner (MSS) imagery -------------------------- 6 

Landsat MSS digital data --------------------------------------------- 7 

Landsat return beam vidicon (RBV) imagery --------------------------- 8 

Recommendations ----------------------------------------------------- 8 

What base maps should be used for presenting data on land use and land 

cover changes? ----------------------------------------------------- 8 

1 :250,000-scale topographic maps -------------------------------------- 8 

1:100,000 intermediate-scale quadrangle maps --------------------------- 9 

1:100,000 and 1:50,000 intermediate-scale county maps ----------------- 9 

Recommendations ---------------------------------------------------- 9 

What maps or portions of a map should be updated? ------------------------ 10 

Full map-sheet update ------------------------------------------------ 10 

Partial map-sheet update ---------------------------------------------- 10 

Recommendations ---------------------------------------------------- 11 

What methods should be used for identifying and mapping changes? ---------- 11 

Original source material-to-new source material ------------------------ 11 

Original map-to-new source material ----------------------------------- 12 

Original map and source material-to-new source material ---------------- 15 

Original map-to-new map --------------------------------------------- 15 

Recommendations ---------------------------------------------------- 15 

What procedures and what formats should be used for updating maps? -------- 15 

Map recompilation --------------------------------------------------- 15 

lJpdated original map ------------------------------------------------ 16 

Map overlay showing changes ----------------------------------------- 16 

Generation of statistical products ------------------------------------- 16 

Recommendations ----------------------------------------------------- 16 

Summary ---------------------------------------------------------------- 18 

References --------------------------------------------------------------- 18 

ILLUSTRATIONS 

Page 

FIGURE 1. Example of a land use and land cover change map -------------------------------------- 13 

2. Possible land use and land cover change mapping errors resulting from an original map-to-new 

source material change detection approach ------------------------------------------- 14 

3. Land use and land cover changes from 1970 to 1972 for a selected area within Fairfax County, 

Va. ------------------------------------------------------------------------------- 17 

v 
TABLES 

Page 

TABLE 1. USGS land use and la.nd cover classification system for use with remotely sensed data -------- 1 

2. Suggested update cycles for land use and land cover data based on stratification of Level II 

categories -------------------------------------------------------------------------- 5 

VI 
A Review and Evaluation of Alternatives for Updating 

U.S. Geological Survey Land Use and Land Cover Maps 

By Valerie A. Milazzo 

ABSTRACT 

Since 1974, the U.S. Geological Survey has been 

engaged in a nationwide program of baseline mapping 

of land use and land eover and associated data at a 

scale of 1:250,000. As 1 :100,000-scale bases have become available, they have been used for mapping certain areas and for special applications. These two 

scales are approP'riate for mapping land use and land 

cover data on a nationwide basis within a praetical time 

frame, and with an acceptable degree of standardization, accuracy, and level of detail. An essential requisite 

to better use of the land is current information on land 

use and land covell' conditions and on the rates and 

trends of changes with time. Thus, plans are underway 

to update these maps and data. The major considerations in planning a nationwide program for updating 

U.S. Geological Survey land use and land cover maps 

are as follows: (1) How often should maps be updated? 

(2) What remotely sensed source materials should be 

used for detecting and compiling changes in land use 

and land cover? (3) What base maps should be used 

for presenting data on land use and land cover changes? 

(4) What maps or portions of a map should be updated? (5) What methods should be used for identifying and mapping changes? ( 6) What procedures should 

be followed for updating maps and what formats should 

be used? These factors must be considered in developing a map update program that portrays an appropriate level of information, relates to and builds upon 

the existing U.S. Geological Survey land use and land 

cover digital and statistical data base, is timely, costeffective and standardized, and meets the varying needs 

of land use and land cover data users. 

INTRODUCTION 

Since 1974, the U.S. Geological Survey 

(USGS) has been engaged in nationwide baseline mapping of land use and land cover and 

associated data at a scale of 1 :250,000. As 

1 :100,000-scale base maps have become available, they have been used for special applications and for mapping certain areas. These 

1 

scales are appropriate for mapping land use 

and land cover data on a nationwide basis 

within a practical time frame, and with an 

acceptable degree of standardization, accuracy, 

and level of detail. Land use and land cover 

has been mapped using remotely sensei data 

at Level II of the classification systen presented by Anderson and others (1976) (see 

table 1 of this report) and using the compilation specifications documented by Loelkes 

(1977). As part of this program, the land use 

TABLE 1.-USGS land use and land cover classification 

system for use with remotely sensed date, 

fFrom Anderson and others, 1976] 

Level 1 Level 11 

1 Urban or Built-up Land ___ 11 Residential 12 Commercial and Services 13 Industrial 14 Transportation, Communications 

and Utilities 15 Industrial and Commercal 

Complexes 16 Mixed Urban or Built-up Land 

17 Other Urban or Built-up Land 2 Agricultural Land _________ 21 Cropland and Pasture 22 Orchards, Groves, Vineyards, 

Nurseries, and Orname"l'tal 

Horticultural Areas 23 Confined Feeding Operations 24 Other Agricultural Land 3 Rangeland ________________ 31 Herbaceous Rangeland 

32 Shrub and Brush Rangeland 33 Mixed Rangeland 4 Forest Land ______________ 41 Deciduous Forest Land 

42 Evergreen Forest Land 43 Mixed Forest Land 5 Water _____________ -------51 Streams and Canals 52 Lakes 

53 Reservoirs 54 Bays and Estuaries 6 Wetland __________________ 61 Forested Wetland 

62 Nonforested Wetland 7 Barren Land -------------71 Dry Salt Flats 

72 Beaches 73 Sandy Areas Other than E'eaches 74 Bare Exposed Rock 

75 Strip Mines, Quarries, ahc:l Gravel 

Pits 

76 Transitional Areas 77 Mixed Barren Land S Tundra ___________________ 81 Shrub and Brush Tundra 

82 Herbaceous Tundra 

83 Bare Ground Tundra 

84 Wet Tundra 

85 Mixed Tundra 

9 Perennial Snow or Ice ____ 91 Perennial Snowfields 

92 Glaciers 
and land cover maps and as~sociated data are 

digitized and the information is s~tored in digital format in a computerized geographic information system, as described by Mitchell and 

others (1977). The system has the capability 

to input, store, manipulate, and retrieve the 

data and makes possible the generation of digital data base tapes and a wide array of graphic 

and statistical output products. 

An essential requisite to better use of the 

Nation's land is current information on land 

use and land cover and on the rates and trends 

of changes-hence, the need for a program of 

map update. Before e~mbarking on such a program, howeve·r, a systematic appvoach to monitoring and mapping changes in land use and 

land cover must be developed. A program to 

update the USGS land use and land cover maps 

must portray an appropriate level of information, relate to and build upon the existing 

USGS land use and land cover digital and statistical data base, incorporate the elements of 

timeliness, cost-effectiveness, and standardization, and meet the varying needs of da.ta users 

at regional, Sta.te, and other agency levels. An 

evaluation of the various considerations in the 

updating of land use and land cover maps is 

requisite to the establishment of a nationwide 

p~ogram of map update that will best achieve 

these objectives. 

The major considerations in planning a nationwide program for updating USGS land use 

and land cover maps are the following: 

• How often should maps be updated? 

• What remotely sensed source rna te,rials should 

be used for detecting and compiling 

changes in land use and land cover? 

• What base ma.ps should be used for presenting data on land use and land cove·r 

changes? 

• What maps or portions of a map should be 

updated? 

• What methods should be used for identifying 

and mapping changes? 

• What procedures and what formats should 

be used for updating maps? 

Options within each of these categories must 

be evaluated in terms of advantages and limitations in the task of map update in order to 

recommend the optimal alternatives for imple2 

mentation in an ope·rational natic nwide program of land use and land cover map update. 

HOW OFTEN SHOULD MAPS BE 

UPDATED? 

Since land use and land cover changes occur 

at highly variable rate's fro.m place to place, 

there is a need to establish diffe·ring intervals 

for monitoring and mapping changes. Frequency of update, in the ideal sense, is not only 

a factor of the dynamics of land use and land 

cover change but also is related to the type of 

change, the relative importance of the change, 

and to the loca,tion, concentration, and amount 

of change. In reality, howeve·r, such factors as 

priorities, schedule capacities, cooperative 

agreements, map scales and data level may 

make a difference in the decisionmaking process involving frequency of update determinations. In addition, one must rememb~r that the 

ability to update is also dependert upon the 

availability of suitable remotely sensed source 

materials. 

THE NATURE OF LAND USE AN"l LAND 

COVER CHANGES 

Before attempting to establish a frequency 

for ma.p update, an understanding of the nature of land use and land cover cl' ange is required. Changes take place at variable rates 

in different loc~tions and at different times 

within the same area. Anderson (1977) cites 

some examples of the dynamics of land use 

and land cover change. The revers,ion of Cropland and Pasture to Fore~st Land in New England is occurring slowly while in parts of the 

South Cropland and Pas,ture a~e converting to 

planted pine (Forest Land) at a Inuch faster 

rate. In central Florida during the 1950's, citrus acreage expanded rapidly and changes in 

land fro·m other uses to the Orchards, Groves, 

and Vineyards category were numerous and 

frequent. By the 1960's, the citrus grove expansion had 'S·tabilized and land use and land 

cover changes involving this category had decreased significantly. 

Residential subdivision development, highway construction, and land use ~and land cover 

changes involving mostothe1r Urban or Built-Up 

Land uses take place in very shor4:. periods of 

time. Although the land area involved may be 
considerably less than for nonurban categories, 

the number and frequency of the changes and 

their far-re,aching impact on the landscape 

make changes in these "dynamic" urban categorie·s importanrt t9 identify as frequently as 

possible. Other categories of land use and land 

cover may undergo little or no change over 

long periods of time. In some areas, there is 

a pronounced absence of economic or environmental conditions for change. For example, in 

many parts of the arid Southwest having extensive areas of Barren Land and desert vegetation, very little change occurs. Areas characterized by tundra or perennial snow and ice 

cover are relatively unchanging. These areas 

are characterized by certain types of land use 

and land cove·r categories and can be termed 

as "stable" land environments because of their 

resistance to change. 

Finally, regional variations based on historical patterns are likely to affect land use and 

land cover change. The kind and the magnitude 

of the changes experienced in an area in the 

past may not be the same as those likely to 

occur in the future. For example, urbanization 

is slowing down in the Northeast and Midwest 

parts of the Nation, while the Southeast and 

Southwest are experiencing considerable growth 

in urban land use and land cover categories. 

Thus, even though the land use and land cover 

categories involved in change have the same 

dynamics, the rate of change varies with region 

and time. 

There are other considerations affecting the 

frequency of map update in addition to and 

apart from those already discussed. These considerations include obsolete specifications and 

classification system compilations, errors, map 

scale, classification level, or cooperative arrangements with certain users. These considerations are, however, incidental determinants 

of update frequency since they would most 

likely affect update only on a one-time basis. 

PROCEDURES FOR DETERMINING UPDATE 

FREQUENCY 

Determining the frequency for updating land 

use and land cover maps can be ap,proached 

from two distinct viewpoints, each yielding a 

different approach for frequency dete·rmination and a different inte·rval of update. In the 

3 

first, update frequency is determined according 

to elapsed time. In this approach, a n1ap is 

updated at a predetermined time inte·rval regardless of the a,mount and type of cl' anges 

that have actually taken p·lace. 

The second approach is based on crite:~·ia of 

change, where the amounts and the types of 

change dictate the frequency of update. Each 

land use and land cover map is updated according to certain predetermined land use and land 

cover change criteria concerning amourt and 

type of change, regardless of ·the time elapsed. 

This approach could result in the update of 

maps with the same or similar general land 

use and land cover features at different frequencies and al8o in subsequent updates for 

the same m•ap at varying intervals. 

The approach chosen for frequency determination at this stage-either based on elapsed 

time or on change criteria-will dictate the 

procedures to be followed. If map update frequency is based on elapsed time, specific time 

intervals need to be established for mz.p update. This could be accomplished by stratifying the land use and land cover maps according to a ranking of Level II land use and land 

cover ca,tegories (see table 1), into are·as of 

high and low national priorities, areas of high 

and low change potential (dynamic versus 

stable land environments), by regions, by age 

of compilation source material, and by other 

considerations concerning the nature of land 

use and land cover change mentioned previously. Each of these groups of maps wo 1lld be 

as'Signed a preferred update interval. Three 

other time factors can also be considered in 

establishing update intervals for selected maps 

under the elapsed time approach. One is to 

tie-in update frequency with the census for 

urban areas. This census, once taken decennially, is planned to be updated every 5 years 

beginning in 1985. A second consideration is 

to plan updates that coincide with the acquisition and availability of aerial photographs. A 

third factor, budget and manpower constraints, 

would establish a minimum practical thne interval for map update. Within the USGS 

nationwide mapping program, 5 years from 

the date of the compilation source ma.terial has 

been established as the minimum time for the 

scheduling of land use and land cover map up-
date. Given the scale and the level of land use 

and land cover detail mapped under this p·rogram, a minimum 5-year update cycle is compatible with :the expres~sed goal to maintain 

current land use and land cover information. 

A procedural advantage to the time interval 

approach to map update frequency is that no 

routine review or inspection of candidate land 

use and land coveT maps is required prior to 

updating. Since the need for map update is 

based solely on the age of the land use and 

land cover data, a map need not be reviewed 

to satisfy any other criteria or conditions of 

land use and land cover change for update 

selection. 

The second approach to the determination 

of map update frequency, in which frequency 

is dict,ated by specified change criteria, requires 

a diffe,rent procedure. Since the amount and 

type of land use change determines the need 

for update, each land use and land cover map 

must be reviewed periodically with more current remotely sensed source materials to identify the changes. Thus an additional stepphotoinspection-is required to determine update frequency. 

The photoinspection process establishes a 

cycle for the periodic review of maps to determine the need for update. This cycle designates a minimum or maximum time inte,rval 

for the photoinspection of land use and land 

cover maps. A cycle could range anywhere 

from 1 year to 5 years or more. The same 

strategy developed for selecting maps for update based on elapsed time eriteria can be used 

to target maps for photoinspection and to determine likely routine time frequencies for 

photoinspection with available remotely sensed 

source materials. On this basis, photoinspection is done at constant predetermined time 

intervals. 

The frequency of photoinspection would not 

automatically correspond to the frequency of 

actual map update. Due to the nature of land 

use and land coveT change, not all the maps 

would meet the change crite,ria for update 

selection at the given photoinspection time. 

Thus, although photoinspection is conducted 

routinely on a prescheduled frequency, map 

update is performed only as often as necessary. 

4 

RECOMMENDATIONS 

If a map update program is to be effective, 

it must incorporate the element of time together with an understanding of land use and 

land cover dyna.mics in the deternination of 

update frequency. It is recommended, therefore, that updarte frequency be st-uctured on 

the basis of need as dete,rmined by criteria of 

land use and land cover chang~ and that 

elapsed time be considered an imp'lrtant, supportive input to update planning. The overall 

approach to establishing a frequer~y for land 

use and land cover map update sh0uld encompass two s~tages : 

1. A photoinspection procedure should be established to periodically revi o.w land use 

and land cover maps in orde,r to identify 

the changes that justify updating the 

maps. Routine photoinspection for seleeted areas should be conducted on predetermined cycles based on elapsed time. 

2. A map update procedure should be established in which maps are selected for 

update p~rimarily on the oo sis of land 

use and land cover change, where the 

amounts and types of chang?.'S identified 

in ~the photoinspection phas~~ determine 

the need for map update. The frequency 

of actual map update canne~ be predetermined since it is dependent on the 

outcome of photoinspecHon. 

In establishing a routine cycle of photoinspection for the purpose of de~termining the 

need for map update, two considemtions should 

be taken into account : ( 1) The dynamics of 

the land use and land cover cakrrories with 

respect to change over time and (2) the relative importance of the land use and land cover 

changes with respect to their cultural, economic, and environment:al impacts .. With these 

two facto.rs in mind, a hierarchi<>al arrangement of Level II land use and lane cover categories can be made on the basif' of change 

potential, in rte~rms of the relative r~.te at which 

changes might occur in the respective land 

use and land cover categories and in terms of 

the potential impact of the changes. In a second stratifica,tion, these Level II land use and 

land cover categories can be grouped into the 

general land use and land cover e"'lvironments 
for which they are likely to represent the 

dominant land use and land cover condition 

(see table 2). These general environments can, 

in turn, be ranked according to probable rates 

of land use and land cover change and the 

relative importance and impact of the change 

taking place on the landscape. To each of these 

groups, a target time frame can be assigned 

which represents an optimum photoinspection 

or update cycle based on the likely rate and 

impact of the changes to be encountered. A 

suggested frequency of update resulting from 

such a stratified matrix approach is shown in 

table 2. 

TABLE 2.-Suggested update cycles for land use and 

land cover data based on stratification of Level II 

categories 

Update Land 11se and land cover Level II cycle environment category (years) 

SMSA's, urban and built-up __________ 11-17, 76 _____________ 5-7 

areas, and other dynamic 

change at·eas. Critical environment areas _______ 51-54, 61, 62, 72 ________ 7-10 Energy resource areas ________________ 75, 76 _____________ 7-1 0 

Agricultural, Rangeland, and ___ 21-24, 31-33, 41-43 ______ 10-15 

Forest Land areas. Stable land areas ______________ 71, 73, 74, 77,.81-85 ______ 15-20 

91, 92 

WHAT REl\IOTELY SENSED SOURCE 

l\IATERIALS SHOULD BE USED FOR 

DETECTING AND COMPILING CHANGES 

IN LAND USE AND LAND COVER? 

A land use and land cover map update program should be designed to make maximum 

use of remotely sensed data. Present remotesensing technology offers a wide selection of 

sensors and capabilities. From past experience 

in land use and land cover mapping, some 

general guidelines have been established by 

Loelkes (1977) for the selection of remotely 

sensed source materials. These guidelines are 

the following: 

1. The format of the remotely sensed data 

must be such that it is or can be rectified, 

if necessary, to a tilt-corrected format. 

2. The scale should be no larger than 1 :60,000. 

3. Source photographs for the winter season 

(leaf-off condition) should be used, if 

available. 

4. There must be no snow cover. 

5. The photographs should contain no more 

than 10-percent cloud cover. 

5 

In addition to these guidelines, two additional 

criteria should be considered. The resolution 

of the remotely sensed source should be sufficient for interpretation of Level II land use 

and land cover categories accurately and consistently. Comparability with the past or future land use and land cover data sho1

1ld be 

provided in that the level and class of information extracted from the update source is 

the same as that contained in the earlier map 

data base. 

There are several kinds of remotely sensed 

data that can be used to update land use and 

land cover maps. They are large-scale, lowaltitude aerial photographs; small-scale, highaltitude aerial photographs; Landsat multispectral scanner ( MSS) imagery ; L!lndsat 

MSS digital data; and Landsat return beam 

vidicon (RBV) imagery. Given the IJre,sent 

technology, each has certain advantages and 

limitations for land use and land cover change 

detection and map update. Some of the more 

pertinent characteristics of each are described 

below. 

LARGE-SCALE, LOW-ALTITUDE AERIAl. 

PHOTOGRAPHS 

These photographs range in scale from 

1:20,000 to 1:40,000 and a.re taken from aircraft at altitudes of 10,000 to 40,000 fL They 

have the following advantages for lari use 

and land cover map update: They can be rectified to a tilt-corrected forma.t for mapping; 

the resolution is sufficient for interpreting 

Level II categories; and they often provide 

more frequent covera,ge for some areas than 

is provided by higher altitude sources. Largescale, low-~altitude aerial photographs p·1S·sess, 

however, several limitations for map update. 

Since land use and land cover map update is 

of a nationwide scope, the land area involved 

preeludes extensive use of large-scale remotely 

sensed da.ta due to the lack of complete coverage needed over some large areas. In addition, 

the cost,s associated with low-altitude aerial 

photograph acquisition and data utilization 

and integration over large areas are exc~ssive. 

Finally, the scale and resolution of larg·~-scale 

photographs far exceed that required for efficient Level II land use and land cover mapping 

on a nationwide basis, the-reby lessening the 
comparability of updated data with the existing land use and land cover data base developed from high-altitude source materials. There 

is a tendency when using larger scale photographs to see and therefore extract more detailed l~and use and land cove'r information. 

Generally, the structure of the mapped Level 

II categories de,rived from large-scale sources 

is somewhat different f~om the same Level II 

categories derived from small-scale sources. 

With the low-altitude, large-scale photographs, 

the .classification is derived f~om an aggregation or building up of more detailed information; with high-altitude, small-scale photographs, more general information is broken 

down into its component parts in case's where 

this information conforms to the classification 

system and mapping specifications in USGS 

Open-File Report 77-555 (Loelkes, 1977). 

SMALL-SCALE, HIGH-ALTITUDE AERIAL 

PHOTOGRAPHS 

Small-scale, high-altitude photographs have 

nominal scales between 1:80,000 and 1:120,000 

and are obtained from aircraft flying at altitudes of 40,000 to 60,000 ft. They are principally NASA high-altitude RB-57 and U-2 photographs and photographs acquired for USGS 

topographic mapping. Such photographs are 

usually black-and-white panchromatic or colorinfrared. They have been used successfully in 

compiling nearly all past land use and land 

cover data. 

Small-scale, high-altitude photographs have 

the following advantages for map upda,te: They 

can be rectified to a tnt-corrected format for 

mapping; the re,solution and scale are sufficient for interpreting and mapping Level II 

ca,tegories accurately and efficiently for large 

areas at 1 :250,000- and 1 :100,000-scales; and 

they P'rovide data comparability with the existing land use and land cover data base. The 

limitations are that the available or existing 

source may not be the optimal source for land 

use and land cover mapping based on the guidelines mentioned previously and the coverage 

is often nonrepetitive or infrequent thereby 

limiting the selection of areas that can be 

updated. 

6 

LANDSAT MULTISPECTRAL SCANl'TER (MSS) 

IMAGERY 

Much research has been conducted on the 

use of Landsat imagery for land use and land 

cover mapping and change detection. However, to date, the potential value of Landsat 

MSS imagery for consis~tent meF.suring and 

mapping of spatial and temporal changes in 

land use and land cover has not been fully 

demonstrated. Clearly, Landsat MSS imagery 

presents several advantages over conventional 

aerial photographs. It affords syn0ptic coverage of land use and land cover as frequently 

as every 18 days. In addition, c1verage for 

nearly all parts of the country is readily available at relatively low cost and fills in the gaps 

left by conventional aerial photographs in providing the necessary source for lr.nd use and 

land cover update maps where and when 

needed. Its repetitive capability makes possible 

the routine monitoring of areas for changes in 

land use and land cover. Landsat MSS imagery 

can also be used to "target" specific areas, 

having extensive Level I-type land use and land 

cover change, which may then be updated using 

higher resolution sources. 

The outstanding advantages of frequency of 

coverage, repetition, availability, and low cost 

make Landsat MSS imagery a uniquely appealing source for land use and land cover map 

update. However, it does possess certain formidable limitations for opera,tional use. Studies 

undertaken in southern Arizona (Place, 1974) 

and elsewhere (Fitzpatrick-Lins, 1978) using 

Landsat MSS imagery have showr that Landsat imagery is not wholly approprir.te for Level 

II land use and land cover mapping. Several 

USGS Level II land use and land cover categories cannot be identified and mapped from 

the Landsat imagery alone. Particularly, the 

resolution of the MSS imagery does not permit accurate and consistent separation of those 

land use and land cove~r categories most likely 

to undergo temporal changes. As a result, Landsat imagery would be least suitable as a source 

of land use and land cover change information 

in those very areas where most of the changes 

are occurring. The inability of Lardsat to replicate the same Level II categories contained in 

the baseline land use and land cover maps, as 

well as from one Landsat scene to the next, 
limits its use as source material for detailed 

map update since comparability with the existing baseline data cannot be realistically 

achieved. 

LANDSAT MSS DIGITAL DATA 

A somewhat more promising application of 

Landsat data for land use and land cover mapping and change detection is offered by computer-aided analysis of Landsat MSS digital 

data. Ongoing research and development activities conducted by the USGS (Milazzo and 

others, 1977) suggest the potential for using 

Landsat digital data for land use and land cover 

change detection in an operational map update 

program. Lands~at digital data afford the same 

currency of information as the MSS imagery. 

In addition, computer processing makes possible 

the examination and classification of large 

amounts of data quickly. Since the data are already in a digital format, they form the basis 

of a geographic information system capable of 

providing simultaneous area measurement tabulations. Thus, the need to convert a graphic 

land use and land cover map into digital format 

to derive area statistics is eliminated. 

In computer processing of Landsat digital 

data for land use and land cover change detection, changes are derived by comparing the relative spectral responses occurring over time. 

Georectified and reformatted tapes from two 

time periods are overlaid in the computer and 

the spectral differences between the two scenes 

print out as possible areas of change. These 

areas are then grouped in a specialized classification and related to corresponding USGS 

Level I and (or) Level II categories. In this 

technique, the mapping of change is accomplished by comparing two data sets, not two 

separate maps or interpretations. In theory, 

this technique seems quite workable for change 

detection. However, in practice there are several significant problems which, given the present technology, may or may not be resolved. 

One problem lies in converting spectral differences into valid land use and land cover category changes. It is unrealistic to expect a 

specialized land use and land cover classification 

7 

developed from computer-classified Landsat 

data to match category for category or to merge 

with the USGS Level II classification system 

which is designed for human compilerr using 

other remotely sensed sources. Due to the incompatibility of these two systems, the detection of either "from" or "to" changes in each 

of the USGS Level II categories cannot be accomplished. Hence, a direct update of l2nd use 

and land cover maps derived from other remotely sensed sources with Landsat digital data 

is not feasible. 

Another formidable problem in using Landsat digital data for change detection and map 

update is that such a map of "changes" is 

likely· to contain conside~rable noise, or false 

changes-areas tha,t appear different spectrally, but their use or cover category has not 

changed. The identification of false changes is 

due to a number of factors including misregistration of pixels in the Landsat scenes being 

compared; comparison of da,ta from different 

seasons, particularly involving crop rotation 

cycles, where the rotation causes the same agricultural activity to be erroneously identified 

as a land use and land cover category change; 

identification of differences in soil moisture 

content or other environmenta,l anomalies that 

result in different spectral signatures for the 

same land use or land cover category ; and 

misclassification of land use and lanc1

. cover 

due to poorly grouped spectral classes. One way 

to reduce the occurrences of false change identification is to raise the threshold level. Differences as small as one picture element (pixel), 

1.1 acres, can be identified from the Landsat 

digital data. By raising the threshold, one can 

sample la,rger groupings of pixels, for example 

8-pixel by 8-pixel windows, in which only 

changes of approximately 64 acres or greater 

are mapped. Although this approach significantly reduces the amount of "salt and pepper" 

type false changes, it also results in a loss of 

sensitivity to many valid land use ard land 

cover changes, which often occur ir small 

areas. There is also a loss of comparability 

with the Level II classification system in which 

land use and land cover is mapped at 10- and 

40-acre minimums. Therefore only a few gross 

Level I category changes such as Forest to 

Agriculture are identified. 
LANDSAT RETURN BEAM VIDICON (RBV) 

IMAGERY 

The newly acquired NASA Landsat RBV 

imagery appears to be a promising source for 

land use and land cover mapping and update 

roughly equivalent to the small-scale, high-altitude aerial photographs used in past mapping. 

Although no thorough evaluation has been conducted, the imagery viewed thus far suggests 

promise for use as either a photographic source 

for direct updating of maps in cases where the 

resolution permits reliable discrimination of 

discrete Level II land use and land cover categories or for targeting those areas where 

enough Level I changes have occurred to justify 

update using higher resolution materials. 

RECOMMENDATIONS 

The level, amount, and accuracy of land use 

and land cover data that may be obtained from 

remotely sensed data depend on the altitude and 

resolution of the sensor and, to some extent, 

on the scale of the derived product. Anderson 

and others (1976) recommend the use of highaltitude source data from altitudes of 40,000 ft 

or more, with scales of 1:80,000 or smaller for 

the extraction of Level II land use and land 

cover information. In keeping with this recommendation, the principal remotely sensed 

sources used for the mapping of Level II land 

use and land cover data have been NASA highaltitude U-2 and RB-57 photographs and photographs acquired for USGS topographic base 

mapping. Small-scale, high-altitude photographs 

have been used successfully for compiling 

nearly all past land use and land cover information and are capable of meeting the seven 

recommended guidelines for remotely sensed 

da.ta selection previously enumerwted. It is 

expected that small-scale, high-altitude photographs will continue to be the mainstay of future land use and land cover map compilations, 

and it is recommended that they continue to be 

one of the primary photographic sources for 

updating land use and land cover maps. 

In addition to the use of small-scale photographs for updating maps, it is also reasonable 

to consider using large-scale photographs in a 

limited and complementary way when more 

suitable smaller scale sources do not exist or 

when a more detailed land use and land cover 

classification is required for special applications. 

The use of Landsat digital data in updating 

land use and land cover maps relies on the development of new and improved d~,gital data 

analysis techniques and on continuei improvements in computer technology. At present, 

Landsat digital data are most appr')priate for 

monitoring gross land use and land cover 

changes and for assisting in the urdate selection process for manually compiled land use and 

land cover maps. The data do not c':mstitute a 

primary source for such an updatE., but may 

rather function in a complementary role. 

WHAT BASE MAPS SHOULD BE USED FOR 

PRESENTING DATA ON LAND USE AND 

LAND COVER CHANGES~ 

There are three primary USGS n1ap bases 

that can be used in the mapping of land use 

and land cover data. These are the 1 :250,000-

scale topographic maps, the 1:100,000 interInediate-scale quadrangle maps, and the internlediate-scale county maps at 1:100,000 and 

1:50,000. Each of the map bases is considered 

in terms of at least five factors: (1) costs to 

produce, (2) impact on existing statistics, (3) 

amount of information portrayed, ( 4) usefulness to users, and (5) versatility, or number 

and types of products that can be derived. 

8 

1 :250,000-SCALE TOPOGRAPHIC I 1APS 

The 1: 250,000-scale topographic map possesses the following general advantager as a base 

in updating land use and land cover maps: It 

has proven to be a satisfactory base and scale 

for the presentation of Level II lard use and 

land cover data in a standardized, nationwide 

program of land use and land cover nTapping; it 

is available nationwide-maps are ccmplete for 

all 50 States; the scale is adequate for mapping 

Level II land use polygons at 10- and 40-acre 

minimum sizes; most baseline land urP. and land 

cover and associated data mapping has been 

keyed to the 1: 250,000-scale base map; and 

most baseline land use and land cover· maps and 

associated data have been digitized using the 

1: 250,000-scale map base control. 

The 1: 250,000-scale topographic map has 

certain limitations in its use as a base for up-
dating maps. The positional accuracy does not 

meet National Map Accuracy Standards 

(NMAS) in most cases, even though maps are 

revised periodically; bases for some areas, and 

hence planimetric data, are often out-of-date; 

and the scale does not satisfy the needs of 

many land use and land cover data users. 

1:100,000 INTERMEDIATE-SCALE QUADRANGLE 

MAPS 

The use of the 1: 100,000 intermediate-scale 

topographic quadrangle map as a base for updating land use and land cover has the following 

advantages: It has good positional accuracyit meets NMAS; it provides relatively up-todate planimetric base data; the scale is wellsuited to Level II land use and land cover mapping and data presentation at 10- and 40-acre 

minimum mapping units; it permits easy readability of Level II polygons and identifiers, particularly in congested areas; and it allows the 

flexibility of mapping polygons at lower minimum 111apping sizes since 10- and 40-acre mapping units are well above the threshold of 

clarity and readability at this scale. 

There are disadvantages to the use of the 

1: 100,000-scale 111aps: Almost 2,000 maps are 

required to cover the conterminous United 

States at 1: 100,000-scale, as compared to 473 

for the 1: 250,000-scale series; there is incomplete coverage nationwide-bases are generally 

not available for those areas where updates 

may be needed most ; land use and land cover 

compilations on the 1: 100,000-scale base offer 

the same information to the user as does the 

1 : 250,000-scale map when the same classification level and the same minimum mapping 

units are used; and, it is more costly to compile 

and produce the 1: 100,000-scale map than the 

1: 250,000-scale map. In addition, a mixture of 

baseline land use and land cover maps at 

1: 250,000-scale and updated land use and land 

cover maps at 1: 100,000-scale creates confusion 

for users and makes cross-sheet boundary land 

use and land cover data utilization difficult, 

which diminishes the range of usefulness of the 

map product for many State and regional applica,tions. In the geographic information system, comparability between the merged graphic 

and statistical data generated from land use 

and land cover polygons digitized using 

1: 250,000-scale base control and those :rl)lygons 

digitized using 1: 100,000-.scale base control 

may not be achieved due to positional accuracy 

differences between the two base-s. 

1:100,000 AND 1 :50,000 INTERMEDIA TE-~0ALE 

COUNTY MAPS 

The advantages and limitations de-scr~bed for 

the 1: 100,000-scale quadrangle series F.pply to 

the 1: 100,000-scale and 1: 50,000-scale county 

map series as well. In addition, use of this base 

for land use and land cover map upcate deviates even further from the goal of standardized map products in the national mapping program. This map series can function more 

appropriately as a supplement to the standard 

land use and land cover map series and is quite 

appropriate for special applications. 

9 

RECOMMENDATIONS 

Most land use and land cover maps tllat have 

been digitized thus far have been concentrated 

in those areas mapped on the 1: 250,000-scale 

base. These are usually the older maps and are 

therefore the ones more likely to be among the 

first selected for upda,te. For these maps, revised 1: 250,000-scale topographic bas~ maps 

have become available, or new 1:100,001 intermediate-scale topographic quadrangle maps 

have been or will soon be completed. In both 

cases, the use of a map base in the updat-e phase 

that is different from that used in the initial 

mapping of land use and land cove1r will impact 

the statistical data base already developed from 

the digitized map. Misregistration of land use 

and land cover polygons ~ould occur due. to differences in positional accuracy. Hence, the integrity of the statis,tical data being built upon 

and added to the data base may be affected adversely. This is especially so in the case of the 

1: 100,000-scale serie~s map versus the 1:250,-

000-scale map. 

An additional input to the selection of a map 

base for land use and land cover update involves 

regional considerations. In some parts of the 

Nation, the land use and land cove'r patterns 

are less complex than in other parts. For example, many areas in the Central United 

States, as well as many parts of the West and 

Southwest, have extensive acreage in a few 
stable land use and land cover ca.te·gories such 

as Rangeland and Barren Land. In such areas 

where rapid or numerous land conversions are 

unlikely, or overall map content and de·tail are 

minimal, the 1: 250,000-scale base remains 

adequate for the presentation of land use and 

land cover information. In other parts of the 

Nation, where land use and land cover patterns 

are more dense and complex and where changes 

in land use and land cover occur with greater 

number and frequency, it is desirable to map 

land use and land cover on the 1: 100,000-scale 

bases. Given these considerations, it seems reasonable to continue the use of two bases for nationwide land use and land cover mapping. 

The following app·roach to the selection of a 

map base for first-round land use and land 

cover map update is suggested: 

• The 1: 250,000-.scale bases should be used for 

land use and land cover map update in 

those areas where 1: 100,000-scale bases 

are not available and should continue to be 

used for map update in those a.reas where, 

given the nature of the re·gional land use 

and land cover patterns, it is desirable to 

continue the pre,sentation of updated map 

data at that scale, even if 1: 100,000-scale 

bases are available. 

• Update of existing 1: 250,000-scale land use 

and land cover maps should be on the 

1: 100,000-scale base's if such bases are 

available at the time of update and if the 

regional location and nature of the land 

use and land cover patterns and expected 

changes make it advantageous to convert 

to the larger scale base. 

• For those land use and land cover maps already compiled at 1: 100,000-scale, update 

should be continued on the 1: 100,000-scale 

bases. 

The approach to map update outlined here 

t1ries to balance the blend of old and new. It attempts to maintain the much needed and used 

digital and statistical data base already developed for the 1: 250,000-scale map while allowing the gradual incorporation of and eventual conversion to the 1: 100,000-scale base on 

a regional basis for land use and land cover 

mapping. 

WHAT MAPS OR PORTIONS OF A MAP 

SHOULD BE UPDATEr? 

Once a map has been selected for updating, 

a determination of the exact are~.l extent of 

the required update must be made. The maps, 

or parts of maps, should be chosen where, upon 

inspection, the amount, concentration, and type 

of changes are sufficient to justif~r an update. 

The map may be updated by either the full map 

sheet or by partial m·ap sheet. 

FULL MAP-SHEET UPDATE 

Full map-shee·t update involves updating an 

entire map (at any scale) at one time. This 

approach has the advantage of providing continuity with the forme·r baseline map, in that a 

completely updated version of the old map is 

released in the same form. This ler.ves the user 

with no question as to what partF of the map 

have been updated. Also, all of the land use and 

land cover data contained on the map are from 

the same source and time. The disadvantages, 

however, in the full map update 2.pproach are 

significant for small-scale maps such as the 

1: 250,000-scale map. Suitable photographic 

coverage for the entire map is usually difficult 

and costly to procure. Even so, updating the 

full map sheet is appropriate in cases where 

changes in specifications or classification system necessitate complete recompilation and 

revision of the map or where the changes are 

in fact extensive enough to cover most of the 

map area. 

PARTIAL MAP-SHEET UPDATE 

In this approach, only those parts of a map 

are updated where a ·Significant amount of 

change has occurred, is likely to be found, or 

where user interest or needs are greates·t. These 

map pa.rts may be defined by geographic coordinates, quarter-map sections, SMEA's, political 

boundaries such as those for counties or States, 

designated regional, environmental, or administrative areas, seleeted land use and land cover 

categories, or other criteria. This approach has 

the advantage of providing the user with an 

updated map product quickly, ef!ciently, and 

inexpensively. However, a limitation exists in 

that the release of a full map for which only 

specific parts have been updated creates the 

10 
need for additional map legend explanations, 

such as a coverage diagram, to tell the user 

what parts of the map have been updated and 

to what date. Another disadvantage is that the 

user must obtain supplemental material for 

identifying the exact boundaries of the updated 

areas on the map. The need for supplemental 

data could be increased by successive rounds 

of map update when update is undertaken for 

different parts of the map at different times. 

This would ultimate,ly decrease the comparability and usability of the data. 

Another disadvantage of partial map update 

is that it creates innumerable internal edgejoining difficulties be1tween the polygons at the 

boundaries of the updated area and those 

(either extensions of the same polygon or different land use and land cove~r polygons) outside the updated area. To effec,t a proper internal joining, the limits of the update area must 

become the arbitrary or artificial boundaries 

between the new and the old adjoining land use 

and land cover polygons. If this joining procedure is followed through successive rounds of 

partial map sheet update, a se,ries of artificial 

boundaries may be set up on the map. These 

boundaries could crea~te a visible pattern of 

land use and land cover polygons that follow 

the outline of each updated area rthereby segmenting the map on this basis. This adversely 

affects the attempt to portray land use and land 

cover polygons by natural boundary delineation. 

RECOMMENDATIONS 

One of the more difficult decisions concerning 

the update of land use and land cover maps 

deals with recommending the areal extent of 

map update. Because both 1:250,000- and 

1: 100,000-scale maps have been used as bases 

for initial data compilation in the USGS land 

use and land cover mapping program, a different decision concerning what maps or portions 

of a map should be updated is required in each 

case. The following recommendations for the 

areal extent of map update are proposed: 

• For existing 1: 250,000-scale land use and 

land cover maps that are to be updated at 

the same scale, update should be done for 

the complete map sheet. 

• For existing 1: 250,000-scale land use and 

land cover maps that are to be c1nverted 

to the 1: 100,000-scale bases for map update, update should be done on 1: 100,000-

scale bases covering either the complete 

1 :250,000-scale map sheet or selected 

quadrants. 

• For 1: 100,000-scale land use and land cover 

maps and aH other maps to be upiated on 

1: 100,000-sC'ale bases, update sl,ould be 

done for the complete map sheet. 

Thus, whatever the map scale for the presentation of updated land use and land <'OVer information, it is generally recommended that the 

complete map be updated at one tim~. Since 

land us~ and land cover data are compHed and 

formatted by full map sheet, it should likewise 

be updated on that same basis. This ~uproach 

maintains continuity in mapping design and 

eliminates the hazards associated with overcustomizing the map product to the point where 

it serves a decreasing number of users. 

WHAT METHODS SHOULD BE USED FOR 

IDENTIFYING AND MAPPING CHANGES? 

Change detection is a separate and distinct 

step in the land use and land cover map update 

proces,s. It deals with the detection and identification of temporal changes in land use and 

land cover from a comparison of remotely 

sensed and (or) map source materials from two 

or more time periods and the mapping of those 

changes in accordance with established land use 

classification standards and map compHation 

specifications. There are four basic me,thods for 

detecting land use and land cover changes : 

original source material-to-new source material, original map-to-new source mate,rial, original map and source material-to-new 'Source 

material, and original map-to-new map comparisons. 

11 

ORIGINAL SOURCE MATERIAL-TO-NEW SOURCE 

MATERIAL 

In the original source material-to-new source 

material change detection technique, changes 

are de,rived from a comparison of the original 

compilation photograph'S with the new photograph'S. In thi8 approach, one compiler determines the land U8e and land cover c~ tegorie:s 
from the old photographs and makes the change 

asses,sments from the new photographs at the 

same time. This technique has certain advantages in that the compile1

r can see the actual 

land use and l~and cover fe,atures as they appeared at both times, and e·rrors in the original 

compilation, eithe·r of commission or omission, 

can be identified if they are involved in change. 

This technique thus allows for a limited correction of the data base. 

There are at least five limitations of the original source-to-new source p~rocedure for detecting changes in land use and land cover. Firs,t, 

the costs of storing or reacquiring all of the 

original compilation mate~rials are high. Second, 

in an original source-to-new source comparison, 

the compiler is looking at only the areas involved in change on the two sets of photographs. Since no reference is made to the land 

use and land cover information on the original 

map, the compiler is likely to miss original 

compilation mapping errors that are not involved in change. The third limitation of of 

an original source-to-new source change detection procedure is that it tends rbo add more land 

use and land cover detail in an update because 

the compiler intentionaHy focuses on small, 

discrete land use and land cove1r categories in 

order to search out every possible change that 

might meet minimum mapping unit size1s. Thi8 

results in a tendency to rearrange the more 

gene~ralized existing boundaries of the land use 

and land cover polygons in order ·to accommodate many small polygons of change. 

A fourth limi~tation of the original source 

material-to-new source ma.te·rial method i8 that 

it generates an undue numbe·r of inte·rpretation 

and delineation "disagreements" between the 

original data and the data interp.reted during 

update. The disagreements usually involve indefinite categorie'S and boundaries which must 

be subjectively interpreted and delineated. The 

individual conducting the update, who has 

access to both sets of sources, may not make 

the same decisions as were made by the original compiler. The· end result may be an update 

fraught with unneceiSsary data base correetions. Finally, the detection of valid land use 

and land ·cover changes by direct visual comparisons between two or more remotely sensed 

sources acquired in diffe,rent years is cumbersome, time consuming, and difficult because the 

sources are frequenMy of different film types, 

film quality, seasons of year, and scales. The 

first three variables may be selectively controlled. Scale differences can be minimized, but 

this usually requires costly rescaling of the 

photographs by either optical-mechanical methods or by labora,tory processing. 

ORIGINAL MAP-TO-NEW SOURCE MATERIAL 

In the original map-to-ne·w sour~e material 

procedure, land use and land cover changes are 

identified by comparing the original compilation with the new photographic sc~1rce materials. In this technique, a transparency is made 

of the old land use and land cover oompilation. 

The transparency could be a matte-p•)sitive base 

with land use and land cover polygons and identifie·riS shown in blue-line or a negative scribecoat guide of the old land use and land cove~r 

data. This transparency, which serves a1s the 

compilation base for the mapping of land use 

and land cover changes, is then overlain on the 

new photographic base film which has been 

rectified and (or) scaled, either photomechanieally or photo-optically, to the ~scale of the 

compilation base. Using either the scaled base 

film or the new source in i,ts original form as 

viewing film, each delineated polygon on the 

base map is compared with the coJ·responding 

land use and land cover feature, appea,ring on 

the new source photographs. Any changes in 

land use and land cover between the photograph 

and the map are recorded on the compilation 

base ; only the actual areas of change are 

mapped. The ba,se photographs are used to help 

locate and position the new land use and land 

cover polygons on t:he compilation base. Each 

polygon of land use and land cover change can 

be labeled by a four-digit "from-to" code (fig. 

1) which identifies the former (fro'll) Level II 

land use and land cove~r category (as mapped 

in the old compilation) and the new (to) Level 

II land use and land cover category (appearing 

on the new remotely sensed source) . This is the 

least co8tly, the easiest, and the mo<;'t expedient 

method of detecting land use and land cover 

change and maintains an overall ac~uracy level 

oommensurate with the es,tablishei standards 

for USGS land use and land cove-r mapping. 

12 
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FIGURE 1.-Example of a land use and land cover change map showing only the 

polygons of land use and land cover change occurring between 1972 and 1978 for 

a portion of the Ocala, Fla., 1 :100,000-scale topographic map. Changes were derived from a comparison of the 1972 land use and land cover map with 1978 aerial 

photographs. Polygons are identified by two Level II land use and land cover 

codes indic·ating the former and the new categories, respectively (See table 1 for 

identification of Level II category codes). 

13 
0 G 

21 + 

G 

8 ~2 (} 

21 

ORIGINAL REMOTELY SENSED 

SOURCE MATERIAL 

21 EJ B 

CJ?a 

B 

21 ~ 

11-12 

21-11 

B 'D A~ 

v:-21~13 

0,.~1-17 21-11 ~ .... I I 

:...~ 

ORIGINAL LAND USE AND 

LAND COVER MAP 

NEW REMOTELY SENSED 

SOURCE MATERIAL 

LAND USE AND LAND COVER 

CHANGE MAP 

EXPLANATION FOR FIGURE 

A - False change polygon mapped due to boundary delineation error in original map compilation 

B - False change polygon mapped due to interpretation error in original map compilation 

C - False change polygon mapped due to polygon omission in original map compilation 

D - True change polygon mapped falsely due to polygon omission in original map compilation 

E - True change polygon not mapped due to error in original map compilation (dashed lines 

indicate valid change polygon not delineated on change map) 

FIGURE 2.-Possible land use and land cover change mapping errors resulting from an original map-to-new source 

material change detection approach. 

However, in the original map-to-new source 

material approach to change detection, there is 

an inherent danger that errors in the original 

compilation may go undetected. Figure 2 shows 

examples of five types of errors that can occur. 

These errors are more · easily identified and 

corrected if the old compilation source material 

14 

and the original map are compared with the 

new remotely sensed source. The differences in 

the final maps of iand use and land cover 

change that result from the original map-tonew source and the original m31p a11 d source-tonew source change detection methods are also 

illustrated in figure 2. 
ORIGINAL MAP AND SOURCE 

MATERIAL-TO-NEW SOURCE MATERIAL 

Perhaps the mos.t thorough and comprehensive technique for detecting land use and land 

cover change is provided by the original map 

and source material-to-new source materia,} 

method. It combines the elements of ,the two 

change detection techniques described previously. In this procedure, the land use and land 

cover map is scaled to the new remotely sensed 

source material which is then compared simultaneously with both the original map and the 

original source materials. This p·rocedure has 

the following advantages: The oompile·r is able 

to see the actual land use and land cover features as they appeared at both times as well as 

to see how they were originally mapped ; the 

original land use and land cover map can serve 

as a base control for measuring and mapping 

all land use and land cove:r changes ; the same 

general level of detail in land use and land 

cover mapping used in the original compilation 

is retained in the update; and all errors in the 

original compilation can be identified thus permitting complete correction of the data base. 

There are also two limitations as,sociated 

with the original map and source material-tonew source matedal change detection procedure. The eosts to store or reacquire the original compilation sources are high, and the 

detection and assessment of land use and land 

cover change by direct compa.rison between two 

or more photographs can be a difficult and timeconsuming procedure owing to differences in 

film type and quality, season of the year, or 

scale. 

ORIGINAL MAP-TO-NEW MAP 

A final change detection method is the original map-to-new map procedure. In this technique, a new map is compHed using new source 

material. Polygons of land use and land oove~ 

change can be derived from a comparison of 

the original map with the new map. This procedure possesses one advantage in that the original compilation source material is not needed. 

The,re are also sevocal disadvantages to using 

this method for land use and land cover change 

detection. First, after the new land use and 

land cover map is produced, an extra step is 

required to isolate the polygons of land use and 

land cover change. Second, some of the land use 

and land cover changes identified may be a result of purely subjeetive differences in cate·gory 

interpretations and boundary delineations between the two compilations and do not necessarily reflect valid sequentia,l changes. Third, 

the time and cost to manuaHy compile a new 

land use and land cove~r map are excessive and 

seldom warranted. A final disadvantag1~ to this 

method is that the remote'ly sensed source materials used to compile the new map may not 

be as good as the source materials usei in the 

original compilation (In this case, the original 

map is replaced by one that is indeed m0·re current but does not achieve the same quality or 

accuracy level.) . 

RECOMMENDATIONS 

Of the four change detection methois, it is 

recommended tha.t maps be updated whenever 

possible by using the original mar-to-new 

source material method. However, since the 

change's mapped by the original ma.p and source 

material-to-new source material approach a.re 

likely to be more correct, it is strongly recommended that the old compilation photcgraphic 

source material if still readily available be used 

to supplement the basic original mar-to-new 

source material method for detecting cl·anges. 

WHAT PROCEDURES AND WHAT FORMATS 

SHOULD BE USED FOR UPDATING MAPS? 

The final considerations in a land use and 

land cover map update program deal with map 

update procedures and product formats. Procedures for updating land use and land cover data 

include complete or partial map recompilation, 

the incorporation of detected changes in an 

updated original map, the mapping of detected 

changes on a separate map overlay, or the separate generation of statistical data. 

MAP RECOMPILATION 

If ~the map recompilation procedur1~ is selected, all or parts of a map are rec'1mpiled 

from new remotely sensed source materials. In 

a complete reoompilation approach, r. whole 

new land use and land cover map is produced 

15 
from new remotely sensed source materials. 

This is the most drasUc of the alte·rnative~s-a 

"start from scratch" approach. The new map 

has the same product format as the original. In 

this approach, all data are changed or corrected 

as necessary, and no attempt is made to keep 

previously mapped land use and land cover 

bounda.ries or categorie·s. 

A partial recompilation is a less drasrtic approach to map update than the complete recompilation alternative. In this approach, only 

s·pecified portions of the original map, or selected map content, are corrected or updated 

by recompilation. The result is a complete land 

use and land cover map in the same format as 

the original compilation that combines parts of 

the original with the revised or new compilation. Again, the partial recompilation approach 

could be used most practically when parts of 

the original compilation need extensive reworking, for example, where Forest Land or Forest/ 

Wetland delineations are significantly inaccurate due to poor quality sources or where 

inappropriate seasonal coverage was used in 

the original mapping phase. Any parts of the 

old map, however, known to be of acceptable 

quality and accuracy and mee~ting >Specifications 

are retained. 

UPDATED ORIGINAL MAP 

In an update of the original compilation, only 

the changes that have occurred over a specified 

time period are delineated and these changes 

(new polygons) are incorporated with the original compilation. In this approach, the original 

compilation is pre,served as the base. The previous land use and land cover boundaries and 

categories are held as mapped, and only appropriate corrections, additions, and deletions are 

made. In this procedure, a separate ove1rl~y 

regis.tered to the original map is used to recotd 

only the polygons of change. The land use and 

land cover polygons on the old map that correspond to these areas of change are deleted on 

the original base. The ove·rlay is then composited with the original compilation, either 

photographically or digitally by compute·r. The 

result is an updated map in the same format 

a.s the old compilation. 

MAP OVERLAY SHOWING CHANGES 

In this approaeh, the changes in land use and 

land cover over a specific time period are isolated and mapped on a sepa.rate overlay keyed 

to the original compHation. A sin ,gle map or 

ove,rlay is produced, ei,ther by photographic 

laboratory process.ing or by computer, showing 

only the polygons of change. Eacr polygon is 

labeled by a four-digit change code which identifie~s both the prior Level II land use and land 

cover category (from the original map) and 

the new land use and land cover carte·gory (from 

the new photographic source) . An example of 

a prototype map showing land use and land 

cover changes for a part of the Washington, 

D.C., metropolitan area is shown in figure 3. 

GENERATION OF STATISTICAL P""ODUCTS 

In this approach, a new map product is not 

provided. The land use and land cover change·s 

between the original map and the new remotely 

sensed sources are recorded on an ove·rlay in 

manusc.ript forma,t only, solely for the purpose 

of digitizing. Once the new data are digitized, 

updated statistics are released in computer 

printout format, which provide information 

concerning the prior and new lane, use or land 

cover and the areas of change. The original 

land use and land cover map remains unchanged; only the statistics reflect the changes. 

RECOMMENDATIONS 

The products of an update program should be 

(1) maps showing complete land use and land 

cover information to the date of the most recent 

source materials, (2) updated •statistics, and 

( 3) overlays showing only the changes that 

have o~curred until the time of update. 

It is recommended that the upda·ted original 

procedure be used whenever pos.rible to generate a map product showing comt:·1ete land use 

and land cover information. In the updated 

original approach, changes are incorporated 

into the original compilation ·to create a new 

map showing the current land use and land 

cover information at the time of update. Except for a written explanation in the legend of 

the map identifying the upda1ted area (s) (if it 

is less than the full map sheet), nc provision is 

16 
0 

I 

0 2 

I 

3 

2 

I 

4 

3 MILES 

KILOMETERS 

EXPLANATION FOR FIGURE 

Land use change, 1970-72 

Commercial and services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... o-o 

Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1·1 

~~~~£!;.~~::~~~~~: : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : ~:~ Strip and cluster development .................................. 5-5 

Agriculture, with residence .................................... 6-6 

b~f~;r~~~~~~~a~:: :::::::: :~ :::::::::::::::::::::::::: :~:~ Water ..................................................... 9-9 

Change polygons are identified by numbers separated by a hyphen; the 

first digit indicates the land use in 1970, and the second digit indicates the 

land use in 197 2. For example, a change polygon coded 6-4 means that the 

land use changed from Agriculture (6) in 1970 to Single·family residence (4) 

in 1972. Land use in transition is shown by an asterisk(*) following the use code. 

FIGURE 3.-Selected area within Fairfax County, Va., modified from 

the map of Washington urban a1·ea, District of Columbia, Maryland, 

and Virginia (I-858-D), showing land use and land cover changes 

between 1970 and 1972 (Wray 1975). 

made to distinguish between the old land use 

and land cover polygons and the new ones. 

Another product, updated s,tatistics, should 

accompany the complete land use and land 

cover map. The statistics reflect the amount 

and type of change and its location in terms of 

selected data associated by drainage basin, 

17 

county, census tract, or othe·r associated map 

data. 

A separate overlay showing the "from-to" 

polygons of land use and land cover change for 

a given period also should be provided. either 

in the form of a manually-compiled cr computer-derived map, for those users whose ap-
plications require the specific polygon data on 

change. It is recommended that the change 

overlay be made a part of the standard set of 

associated maps and data which supplement the 

land use and land cover maps. Since a change 

overlay can be produced quickly and with ve,ry 

little additional preparation and expense, it 

probably will be the first product of the map 

update program. 

It is recommended that map recompilation 

be unde1rtaken only in cases where there were 

significant changes in the classification system 

and (or) mapping specifica,tions, or othe-r situations where it is infeasible or imp,ractical to 

build upon the established land use and land 

cover map base. 

SUMMARY 

In the review and evaluation of various considerations in accomplishing map update within 

the framework of the present USGS land use 

and land cover mapping program, recommendations for updating land use and land cover maps 

in accordance with the goals of the USGS land 

use and land cover mapping program have been 

offered. In summary, the recommendations are 

as follows: 

• Initiate periodic inspection of land use and 

land cover maps using available remotely 

sensed source materials to identify 

changes, with inspection scheduled at a 

5-year minimum interval and actual frequency of map update dependent on the 

amount and type of land use and land 

cove~r change. 

• Continue to use small-scale, high-altitude 

photographs as the principal remotely 

sensed source material for updating land 

use and land cover maps. 

• Use the 1:250,000-scale base maps for updating land use and land cover maps of 

those areas where either 1: 100,000-scale 

bases are not available or for those regions 

where it is desirable to continue the presenta,tion of map data at 1: 250,000-scale. 

Use the 1: 100,000-seale base maps for updating those maps already compiled at 

that scale or for updating existing 

1 :250,000-scale land use and land cover 

maps for which 1: 100,000-scale bases are 

available and the regional location or the 

nature of the land use and land cover data 

make conversion to the large,r scale base 

desirable. 

• For existing 1:250,000- and 1 : ] 00,000-scale 

land use and land cove1r maps which are to 

be updated at their respective scales, update the complete map sheet. For exis,Ung 

1: 250,000-scale land use and land cover 

maps that are to be converted to the 

1: 100,000-scale bases, update should be by 

whole 1: 100,000-scale map she.Bts covering 

either the full 1: 250,000-scale map area or 

selected quadrants. 

• Use the original map-to-new source material 

method as the principal land use and land 

cover change detection techniClue. Supplement this method by using the original 

compilation remotely sensed Pource material where needed and when available. 

• Update maps using the updated original approach in which only the outd~.ted portions 

of the original map are replaced with new 

data. Present data in a complete land use 

and land cover map format. Provide updated statistics on land use and land cover. 

Provide a separate overlay showing only 

the polygons of land use and land cover 

change as an optional associated map supplement. Conduct recompilations only 

when necessary. 

18 

These recommendations do not necessarily 

represent the only approaches to updating land 

use and land cover map's. They are suggested 

as a foundation for the development of a 

strategy for updating maps in the nationwide 

land use and land cover mapping program. We 

hope that the recommendations will stimulate 

users to consider and exp,ress tl'eir requirements for updated land use anc land cover 

information. 

REFERENCES 

Anderson, J. R., 1977, Land use and land cover changes 

-A framework for monitoring: U.S. Geological Survey Journal of Research, v. 5, no. 2, p. 143-153. 

Anderson, J. R., Hardy, E. E., Roach, J. T., 1972, A 

land use classification system for use with remote 

sensor data: U.S. Geological Survey Circular 671, 

16 p. 
Anderson, J. R., Hardy, E. E., Roach, J. T., and Witmer, R. E., 1976, A land use and land cover classification system for use with remote sensor data: U.S. 

Geological Survey Professional Paper 964, 28 p. 

Fitzpatrick-Lins, Katherine, 1978, Accuracy and consistency comparisons of land use and land cover 

maps made from high-altitude photographs and Landsat multispectral imagery: U.S. Geological Survey 

Journal of Research, v. 6, no. 1, p. 23-40. 

Fitzpatrick-Lins, Katherine, 1978a, Accuracy of selected 

land use and land cover maps in the greater Atlanta 

region, Georgia: U.S. Geological Survey Journal of 

Research, v. 6, no. 2, p. 169-173. 

Loelkes, G. L., Jr., 1977, Specifications for land use 

and land cover and associated maps: U.S. Geological 

Survey Open-File Report 77-555, 82 p. 

Milazzo, V. A., Ellefsen, R. A., and Schwarz, D. W., 

19 

1977, Updating land use and land cover maps: Remote Sensing of the Electromagnetic Spectr.lm, v. 4, 

no. 4, p. 103-116. 

Mitchell, W. B., Guptill, S. C., Anderson, K. E., Fegeas, 

R. G., and Hallam, C. A., 1977, GIRAS: A geographic 

information retrieval and analysis system for handling land use and land cover data: U.S. Geological 

Survey Profes,sional Paper 1059, 16 p. 

Place, J. L., 1974, Change in land use in the Phoenix 

(1 :250,000) quadrangle, Arizona, between 1970 and 

1973-ERTS as an aid in a nationwide program for 

mapping gene·ral land use: Earth Resources Technology SateUite-1 Symposium, 3d, Washington, D.C., 

1973, Proce,edings, v. 1, sec. A, p. 393-423, 25 figs. 

Wray, J. R., 1975, Land use change map, 1970-1972, 

Washington urban area, D.C., Md., and Va.: U.S. 

Geological Survey Map I-858-D, scale 1 :100,COO. 

-ti U.S. GOVERNMENT PRINTING OFFICE: 1980 0- 311-344/155 REGION 3-1 



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Publicatiort-A Review and Eval'uaUon of Alternatives for Updating U.S. Geological Survey Land 

Use and Land Cover Maps, 1980, Geological Survey Circular 826 

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