WSP09382

• File Number: 8271.300
• Description: Colorado River Basin Salinity Control Program - General Information and Publications-Reports
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 8/1/1970
• Author: Wynn Walker
• Title: THESIS -- Hydro-Salinity Model of the Grand Valley
• Water Supply Pro - Doc Type: Report/Study

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Lateral seepage is the'$.?llveyance efficiencYi multiplied

by the total lateral diversions. This is also a direct

addition to the ground water.

(2) Field tailwater. These flows are computed on the basis

of farm efficiency. Farm efficiency is defined as the

ratio of the water eUectively utilized by crops to the

quantity delivered to the field. However, the farm

efficiency used in the model is defined by

E= 1.0 - (D-DB)/LD................(l)

where E ill the farm efficiency, D is the total drainage

outflows, DB is the total drainage base flows, and LD is

the lateral diversions correGted for seepage losses. The

difference between D and DB is the quantity of field tail-

water in the drainage flows and is obtained from farm

efficiency studies made in Area 1.

(3) Diverted water to the root zone. This is the remaining

water in the lateral diversion supply diverted to the

acreage of cropland.

Root zone

The water reaching the root zone is computed from the lateral

diversions subbudget, and transferred to the subroutine ACUS where

the root zone subbudgets are computed. A description of these calcu-

lations can be found in the section describing subroutine ACUS.

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