WSP11570

• File Number: 8111.807
• Description: Arkansas River Compact Administration - Stream Gage Evaluation
• Basin: Arkansas
• Date: 1/1/1980
• Author: USGS
• Title: Cost-Effective Stream Gaging Strategies for the Lower Colorado River
• Water Supply Pro - Doc Type: Publication

I
I

I

I

I

I

I

I

I

I

I

I

I

I

I
I

I

I

I

approach was devised that arrives at an efficient set of decisions, !'

if not at the true optimum. The approach begins with an initial feasible

set for N, which may be supplied externally by the analyst or is developed

by the approach itself. If internal specification of the initial set of N

is desired, the requirements for minimum visits to each of the stations

are satisfied in a least cost manner. Any money remaining after these

constraints are satisfied is allocated to trips on routes that reduce the

total uncertainty in an economically efficient manner. Because these two

steps guarantee only a feasible set of decisions, the initial set of

decisions is manipulated iteratively, one value of N. at a time, until no
"
further reduction in uncertainty can be obtained without violating one of

the constraints. The locally optimum set of values for! obtained in this

manner specify an efficient strategy for operating the stream gaging network,

which may even be the truly optimum strategy. The true optimum cannot be

guaranteed without testing all undominated, feasible strategies, which is a

mounumental computational chore for the number of stream gaging stations

operated in the Lower Colorado River Basin.

Accuracy of annual mean discharge

In spite of the massive amounts of streamflow data that are collected

throughout the world, relatively little has been done to evaluate the

accuracy of the resulting numbers. A split-sample approach that is

applicable at a gaging station, where sufficient historical discharge

measurements exist, was developed by Burkham and Dawdy (1968). In this

technique the existing discharge measurements are randomly divided into

an analysis group and a control group. Initially the analysis group is

small relative to the size of the control group. The analysis group

14