MEASUREMENT AND COMPUTATION OF STREAMFLOW
VOLUME 1. MEASUREMENT OF STAGE AND DISCHARGE
VOLUME 2. COMPUTATION OF DISCHARGE

U.S. Geological Survey, Water Supply Paper 2175

By S. E. Rantz and others

Links to table of contents and pdf below:

PURPOSE OF THE MANUAL

The purpose of this manual is to provide a comprehensive description of state-of-the-art standardized stream-gaging procedures, within the scope described below. The manual is intended for use as a training guide and reference text, primarily for hydraulic engineers and technicians in the U.S. Geological Survey, but the manual is also appropriate for use by other stream-gaging practitioners, both in the United States and elsewhere.

SCOPE OF THE MANUAL

The technical work involved in obtaining systematic records of streamflow is discussed, in two volumes, in accordance with the following six major topics:

Volume 1. Measurement of stage and discharge

Selection of gaging-station sites
Measurement of stage
Measurement of discharge

Volume 2. Computation of discharge

Computation of the stage-discharge relation
Computation of daily-discharge records
Presentation and publication of stream-gaging data

In order to make the text as broadly usable as possible, discussions of instrumentation and measurement are aimed at the technician, and discussions of computational procedure are aimed at the junior engineer who has a background in basic hydraulics. Many of the procedures for determining discharge that are discussed in volume 2 require specialized instrumentation to obtain field data that supplement the observation of stage. The descriptions of such specialized equipment and associated observational techniques are given in appropriate chapters in volume 2 so that the reader may have unified discussions of the methodologies applicable to each type of problem in determining discharge.

In general the authors have attempted to prepare a manual that will stand independently-references are given to supplementary published material, but the reader should find relatively few occasions when there is pressing need to consult those references. There are three notable exceptions to that statement.

The subject of indirect determination of peak discharge (v. 1, chap. 9) is treated here only in brief because of space limitations; the subject is treated fully in five reports in the Geological Survey report series, “Techniques of Water-Resources Investigations.” The five reports are named in the reference section of chapter 9.
Among the methods discussed in this manual for computing the discharge of tidal streams are four mathematical techniques for evaluating the differential equations of unsteady flow (v. 2, chap. 13). The four techniques are given only cursory treatment because a detailed description of the complex mathematical techniques is considered to be beyond the scope of the manual.
The processing of streamflow records by digital computer (v. 2, chap. 15) is a subject that is given only generalized treatment here. It was not practicable to include a detailed description of each step in the sequence of operation of an automated computing system because of space limitations, and also because the particulars of each step are somewhat in a state of flux in response to continual improvement in storage and access procedures.