Guidelines for Writing Hydrologic Reports u

G

S

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U.S. Department of the Interior U.S. Geological Survey

INTRODUCTION

The written report is the principal 

product of the Water Resources Division 

(WRD) of the U.S. Geological Survey 

(USGS). Whatever the medium for disseminating and archiving the report 

paper copy, diskette, CD-ROM, or online much of the speed and economy of 

technological advances will be wasted 

unless the author's initial efforts result in a 

technically accurate, clear, and timely 

document.

The following guidelines are 

intended to assist WRD authors in the 

writing phase of reports that document the 

results of their data collection, hydrologic 

study, and research activities. They 

should be considered guidelines only, 

and, with the exception of a few "rules" 

regarding report policy, not as rigid doctrine. When given a choice of various 

ways to approach the preparation of some 

aspect of a report, strong preference 

should be given to doing it in a way that 

conforms to established USGS standards 

for text and illustrations. The many desktop publishing and illustrations software 

packages now available allow authors to 

produce a high-quality manuscript at their 

own desk, but in some cases the illustrations produced do not strictly conform to 

established standards. In such cases, 

authors, illustrators, editors, reviewers, 

and approving officials need to weigh the 

effort (in terms of time and cost) that 

would be required to bring the illustrations into conformance with the USGS 

standards against the benefits of expedited 

publication, which would be achieved by 

allowing minor departures from the standards, that would best serve the USGS 

and its customers.

Guidelines for the preparation of 

text, tables, and illustrations in USGS 

reports are not presented here; those 

guidelines are contained in four basic 

source books, listed at the end of this document, that should be available to every 

employee who is or aspires to be an 

author. Every author also should have at

hand a general style manual for guidance 

on issues of proper English usage grammar, syntax, spelling, punctuation, capitalization, and vocabulary.

The approach taken here is to 

describe the characteristics of the various 

parts of a scientific report and their functions within the overall document. This 

approach is similar to that used by Olcott 

(1987) in a more detailed paper.

WRITING STYLE

Scientific writing must be accurate, 

coherent, and concise. The meaning of 

each word must be clear and unambiguous to the reader. Excessive use of technical jargon detracts from readability. 

Even complex, highly technical reports 

should have clearly stated and easily 

understood objectives, discussions and 

applications of results, and conclusions. 

"Write not merely to be understood, but 

rather so that you cannot possibly be misunderstood." (D.E. Hillier, U.S. Geological Survey, oral commun., 1970).

POLICY

The USGS is obligated to make the 

results of its scientific and engineering 

investigations available in a manner that 

will best serve the whole public. In the 

preparation of reports, that obligation is 

met by adhering to the following rules:

 Maintain impartiality, objectivity, 

and integrity. Do not show bias in 

data or interpretations. Do not criticize others: agencies, firms, scientists, or members of the public. Do 

not make statements of what must or 

should be done. A report may suggest additional data collection, further investigation, or possible study 

approaches that would help define or 

assess a hydrologic concern, issue, or 

problem. A report may state the relevance of the information presented to 

water management or public policy 

decisions, but should not state what

the proper water-management action 

or public policy should be.

 Do not compete with the private sector. Avoid site-specific, "consulting-type" reports. Stress the 

scientific aspects and transfer value 

of USGS studies.

 Acknowledge cooperators, all significant assistance, and nonoriginal 

material. Obtain written permission to use copyrighted material and 

acknowledge its use. Avoid use of 

company or brand names, if possible, 

or include a disclaimer statement if 

names are used.

 Ensure equal release of information. Do not discuss unannounced 

or pending USGS plans and policies 

or describe results of studies or data 

that have not been approved and 

released.

 Emphasize the USGS, not its subdivisions. Do not refer to Divisions, 

Branches, Districts, or other organizational units except where necessary 

for identification.

An additional issue that falls within 

the scope of USGS report policy is that of 

authorship. Reports can have multiple 

authors with the authors' names listed 

typically in the order of their level of 

effort in the preparation of the report. To 

be listed as an author, one should have 

been substantially involved in that preparation. Participation in a project through 

data collection, laboratory analysis, data 

management, or general supervision or 

advice provided are not, in and of themselves, sufficient basis for inclusion in the 

list of authors. Listing of more than four 

authors in a USGS report should be done 

only rarely and with strong justification. 

Many people contribute ideas and effort 

to a study and ultimately to the report. 

Acknowledgments, and in some cases, 

reference to written or oral communications, are appropriate forms of recognition for these many contributors.
ORGANIZATION

Most scientific reports contain a 

table of contents that summarizes the 

report content in the form of an outline of 

section and subsection titles. This outline 

indicates the organization of the report 

and thus the logical argument or series of 

steps used to present the data and observations, to analyze and interpret that 

information, and to reach a conclusion. 

The first-order headings in the table of 

contents should reflect the major concepts 

or key words in the report title. Secondand third-order headings further subdivide the material under the major headings; words in these subheadings must fit 

logically under the first-order headings. 

Headings limit the content of the text that 

follows, and in USGS reports should 

describe those contents. Use wording 

such as "Aquifer Tests," "Hydraulic Properties of Aquifers," and "Potential Yields 

of Aquifers" rather than the nondescriptive headings such as "Methods," 

"Results," and "Discussion," which are 

used in many journal papers.

COMPONENTS OF A 

REPORT

Title

The title is the ultimate abstract of a 

report. A good title attracts the attention 

of a potential reader and helps the reader 

to decide if the report should be obtained. 

The title uniquely establishes the content 

of a scientific report and, if pertinent, the 

geographic location of the study and the 

dates when data used in the analyses were 

collected. The title should contain key 

words that reflect the contents of the 

report. Avoid abbreviations, acronyms, 

literature citations, and company or brand 

names.

Abstract

An abstract is a condensation of 

the essential information contained in the 

report. A good abstract helps a potential 

reader decide if all or part of a report 

should be read. It is neither a sentence 

outline of the report nor a summary, but a 

tersely worded, factual account of the reason for and objective of the work being

reported, the methods used (if new or 

unusual), the results obtained, and the 

conclusions reached. The abstract 

should be informative rather than indicative; it should state what the report "tells," 

not what it is about. The abstract should 

be suitable for publication separate from 

the entire report. The summary and (or) 

conclusions section of a report provides 

the source material for the abstract, which 

should be written last.

Introduction

As the name implies, this section of 

the report introduces the reader to the discussion. First and foremost, it presents 

and explains the problem, issue, or subject that is addressed in the report. 

Reports that are products of studies made 

in cooperation with and funding from 

other agencies must include a statement to 

that effect. The involvement of the USGS 

in such studies should be stated in terms 

of data or analyses provided to understand, explain, or resolve the hydrologic, 

concern, issue, or problem being 

addressed. The purpose and scope of the 

report should be stated. The purpose is 

that of the report, not of the overall study, 

and should reflect the title and main section headings. The scope sets limits on 

what is contained in the report. The introduction also may include background 

information pertinent to the study, such as 

climate and physiographic setting of the 

study area, previous investigations, methods of study, and acknowledgments. 

Acknowledgments are a courtesy to individuals who have contributed substantially and directly either to the conduct of 

the study or to the review and preparation 

of the report.

Body of Report

The body of the report contains 

the data that were collected to address the 

problem and the purpose of the study 

described in the Introduction, and the 

analyses and interpretation of those data. 

This section presents, in a logical order, 

the results of a study in discussions supported as necessary with tables and illustrations.

Summary and (or) 

Conclusions

The summary and (or) conclusions section(s) draws together and briefly 

reiterates the main results and conclusions 

of the study described in the report. At a 

minimum, this section should address the 

problem stated in the "Introduction" and 

ideally provide solutions to the problem. 

Material not included in the body of the 

report should not be introduced here. 

Summaries of long or complex reports 

should begin with a brief reiteration of the 

problem and, if important or innovative, 

the methods of study. Short, simple 

reports can be adequately summarized by 

drawing together the conclusions. In 

either case, conclusions should be as specific, and, if appropriate, as quantitative 

as possible by using numbers mentioned 

in the body of the report.

References

In nearly all reports, reference is 

made to the work of others on the same or 

related subjects. A reference list at the 

end of a report enables the reader to locate 

the literature cited in the text. All cited 

references must be included in the list, but 

additional pertinent literature can be 

included (then termed "Selected References"). References to reports as being 

"in press" are permissible, but references 

to manuscripts as "in preparation," "in 

review," or "submitted (to a journal)" are 

not permitted in USGS reports. References to oral or written communication, 

which appear in text only, should include 

an individual's name, affiliation, and the 

date the communication was received or 

written.

Other Report Components

 Foreword. An introductory statement, written by someone other than 

the author(s), that describes the circumstances and significance of the 

report.

 Preface. A statement written by the 

author(s) that presents the main goals 

of a comprehensive study of regional 

or national scope and the relation of 

the following report to that study and 

(or) to other reports.
 Appendixes. Supplemental information, such as data tables, descriptions of methods of analysis, 

mathematical derivations, or documentation of computer programs, 

that would be useful to the reader, but 

which is not essential to arriving at 

the conclusions stated in the report.

 Glossary. Definitions of selected 

technical terms used in the report.

TABLES

Tables are essential to many scientific reports because some information is 

presented most effectively in tabular format. However, a table should supplement, not duplicate, information given in 

the text. The essence of a table is the logical arrangement of information. Because 

a table must be able to stand alone, it 

should have a brief, descriptive title that 

contains no acronyms or abbreviations. 

Each column has a descriptive heading 

and units (if applicable). No vertical rules 

(lines) are used between columns. A 

bracketed headnote below the title provides information that applies to the entire 

table; all abbreviations, acronyms, and 

symbols used in the table are spelled out 

or defined in the headnote. Footnotes are 

used to provide additional information 

about column headings and individual 

entries.

ILLUSTRATIONS

All illustrations in a scientific report 

must be accurate, must clearly convey the 

author's meaning, and must be consistent 

within the report. Illustrations that portray 

similar information, such as discharge 

hydrographs for several streams in the 

study area, should be in the same format. 

Each illustration in a report should have a 

purpose either to give the reader a 

visual impression of the data or the relation between different types or sets of 

data or to clarify or emphasize something 

said in the text. In addition to meeting 

these general criteria, illustrations in 

USGS reports should include, at a minimum, the elements and (or) characteristics indicated in the subsections below.

Maps

A base map is the background on 

which all other information, such as data 

points, contours, and patterns, is superimposed. It should be selected early in a 

project on the basis of anticipated density 

of data and the degree of background 

detail needed. All similar maps in a 

report, such as a series of maps that show 

ground-water levels at various times, 

should be compiled on the same base.

GENERIC MAP

\

X KILOMETERS

'V

EXPLANATION 

Pattern

 Line symbol

 Line symbol 

£ Point symbol

 Point symbol

(7)

Figure 1.1

The basic elements of a map include 

the following (keyed to the sketch above):

1. Latitude and longitude. Show location of study area.

2. Bar or rake scale. In inch-pound and 

metric units; units used in the report 

on top.

3. Base credit. Provides the source for a 

non-original map.

4. Mapping credit. Provides sources for 

the geology and hydrology 

depicted if not original by the 

author.

5. Topographic data. Indicates contour 

interval(s) and datum if contours are 

shown.

6. Explanation. Defines or explains all 

patterns, line symbols, and point

symbols that are not part of the base 

map.

7. Caption. Describes briefly what the 

map shows. Avoid paragraph-long 

captions in USGS reports.

Graphs

Graphs are an effective means to 

illustrate the relation between two (or 

more) factors or sets of data (such as 

stream stage and water level in a nearby 

well) or how a factor or condition (such as 

ground-water levels or concentrations of 

dissolved oxygen in a stream) varies with 

time.

25

20

^O 15 2 LJJ -W

10 GENERIC GRAPH

23456 

TOTAL RAINFALL, IN INCHES

EXPLANATION 

^J Pattern

 Line symbol

 Line symbol

 Point symbol

 Point symbol

(4)

Figure 1.

The basic elements of a graph 

include the following (keyed to the sketch 

above):

1. Format. Boxed in with tick marks on 

all four sides.

2. Axis labels and values. Shown on 

left and bottom, although right vertical axis may be divided and 

labeled for multivariable, multiscale 

graphs.

3. Explanation. Defines or explains all 

patterns, line symbols, and point 

symbols that are not defined or 

labeled on the graph.

4. Caption. Describes briefly what the 

graph shows. Include geographic 

location if not obvious from entries 

or labels on graph.
Sections

A hydrogeologic (or geologic) section is a representation of the hydrologic 

(or geologic) features or conditions at and 

beneath the land surface along a vertical 

plane. Sections portrayed as representing 

actual or "to scale" conditions must 

include adequate control points (wells) to 

establish their accuracy. Distances 

between control points in sections and 

along the section trace shown on a map 

must coincide. The same principles apply 

to cross sections, which show conditions 

or features within water bodies, such as 

streams, lakes, or estuaries.

The basic elements of a hydrogeologic or geologic section include the following (keyed to the sketch below):

A d\) A '

UNITS ^-S 

500-|

(l

400 H

300-

200-

100-

GENERIC SECTION

0 X KILOMETERS

Vertical exaggeration x 00 

Datum is ^mt^^^^^^^^^^^^s^^^^,

(£) EXPLANATION

 Line symbol

 Line symbol

0 Point symbol

 Point svmbol

(I)

Figure 1.

1. Units of vertical axis. Numerical values for tick marks are shown on left 

axis, optional on ticks on right axis.

2. Scale. In inch-pound and metric

units; units used in the report on top.

3. Vertical exaggeration. If more than 

10, use VERTICAL SCALE 

GREATLY EXAGGERATED.

4. Datum note. Needed if datum (usually sea level) is not labeled on vertical axis.

5. Designation of line or trace of section. For "to scale" sections, letter designations are used (A-A 

shown here) and shown on a map. 

For diagrammatic or generalized 

sections, compass directions are 

sufficient, for example EAST and 

WEST.

6. Explanation. Defines or explains all 

patterns, lines, and symbols not 

defined or labeled on the section.

7. Caption. Describes what section

shows. Include the geographic location, if not obvious from labels or 

names at land surface of section, 

and indicate on which illustration 

(map) in report the trace is shown.

Photographs

Photographs that are sharply focused 

and have good contrast are most effective. 

Photographs that show unique conditions 

of stream channels or banks, flood extent, 

or stratigraphy are appropriate, but photographs of standard laboratory or field 

equipment or field installations (observation wells or stream-gaging stations) are 

not recommended. Because the printing 

of color photographs can greatly increase 

the cost of a report, black-and-white photographs should be used wherever possible.

REFERENCE AND 

SOURCE BOOKS

Alt, D.F., and Iseri, K.T., 1986, Publications 

policy and text preparation guide; v. 1 

of WRD publications guide, U.S. Geological Survey, Water Resources Division, 429 p.

Hansen, W.R. ed., 1991, Suggestions to 

authors of the reports of the United 

States Geological Survey (7th ed.): U.S. 

Government Printing Office, 289 p.

Miller, R.A. and Balthrop, B.H., compilers, 

1995, Standards for illustrations in 

reports of the U.S. Geological Survey, 

Water Resources Division: U.S. Geological Survey Open-File Report 95- 

415, 239 p.

Olcott, P.G., 1987, Reflections on writing 

hydrologic reports: U.S. Geological 

Survey Open-File Report 87-398, 8 p.

U. S. Government Printing Office, Style 

manual 1984: Washington, D.C., 479 p.

For more information, contact:

Assistant Chief Hydrologist for

Water Information 

U.S. Geological Survey 

Mail Stop 440, National Center 

Reston, Virginia 22092

September 14,1995 Fact Sheet FS-0217 -95