Laserfiche WebLink
For each upstream sub-basin, the user will specify the sub-basin ID and its corresponding <br />? <br />irrigated acreage. Additionally, for each upstream sub-basin, the user will specify an <br />adjustment factor (0.50, 1.00, etc.) that could be used to increase or decrease unit consumptive <br />use. The default adjustment factor will be one . <br />By selecting one of four options, the user will specify monthly depletion distribution coefficients that <br />will be used to relate annual irrigation consumptive use to monthly streamflow depletion. Table 1 shows <br />the default depletion coefficients for option Nos. 1, 2, and 3. <br />TABLE 1. DEFAULT DEPLETION COEFFICIENTS <br />MONTHLY DEPLETION DISTRIBUTION COEFFICIENTS <br />(values in percent) <br />MONTHOPTION 1OPTION 2OPTION 3 <br />JAN0.0-3.5-11.5 <br />FEB0.0-3.3-10.8 <br />MAR0.0-3.1-10.2 <br />APR0.0-2.9-9.6 <br />MAY20.324.337.5 <br />JUN35.145.472.6 <br />JUL27.836.455.7 <br />AUG18.222.831.4 <br />SEP-1.1-4.1-14.9 <br />OCT-0.3-4.4-14.6 <br />NOV0.0-4.0-13.4 <br />DEC0.0-3.8-12.5 <br />TOTAL100.0100.0100.0 <br />Option No. 4 will allow the user to specify depletion distribution coefficients that are different from the <br />default values. Option No. 1 represents field conditions in which the irrigated lands are relatively close <br />to the stream and/or the hydraulic conductivity of the alluvial material is relatively high. Option No. 3 <br />represents field conditions in which the irrigated lands are relatively far from the stream and/or the <br />hydraulic conductivity of the alluvial material is relatively low. Option No. 2 represents field conditions <br />between Option Nos. 1 and 3. <br />The monthly depletion distribution coefficients were derived using a number of hypothetical irrigation <br />depletion analyses in which ranges of hydrogeologic properties and farm head gate efficiencies were <br />selected that are believed to be representative of field conditions within the CRDSS river ba sins. The <br />depletion analysis uses the Glover procedure for estimating the timing of irrigation return flows. Table 2 <br />summarizes the range of values used for the depletion analysis. <br />3 <br />A275 01.09.95 1.15-15 Hyre, Fosha <br />