Laserfiche WebLink
<br />N <br />..... <br />t:,O <br />l-"- <br /> <br />ABSTRACT <br /> <br />The cost-effectiveness relationships for various <br />agricultural and desalination alternatives for controlling <br />salinity in irrigation return flows are developed. Selection <br />of optimal salinity management strategies on a river basin scale <br />is described using a four level decomposition analysis. The <br />first level describes the cost-effectiveness of individual <br />alternatives applicable in subbasin or irrigated valley situ- <br />ations. Included at this level are desalination of drainage <br />return flows with multi-stage flash distillation (MSF), vertical <br />tube evaporation - MSF (VTE-MSF), vapor compression - VTE-MSF <br />(VC-VTE-MSF), electrodialysis (ED), reverse osmosis (RO), <br />vacuum freezing - VC (VF-VC), and ion exchange (IX). Feedwater <br />is assumed to be supplied by groundwater wells or surface <br />diversions, whereas brine disposal may be accomplished with <br />either injection wells or evaporation ponds. Agricultural <br />salinity control alternatives at the first level include canal, <br />ditch, and lateral lining, and on-farm improvements (irrigation <br />scheduling, automated surface irrigation, sprinkler irrigation, <br />and trickle irrigation). The second level representing the best <br />management practices for the subbasin is defined by selecting <br />the minimum cost policy of level 1 alternatives which reduce <br />subbasin salinity by preselected amounts. The establishment <br />of second level cost-effectiveness functions allow evaluation <br />of salinity management at the river subsystem cost-effectiveness <br />functions provide the optimal basin-wide strategies and their <br />respective structures. A case study of the Grand Valley in <br />western Colorado is presented to demonstrate the model. <br /> <br />This report was submitted in fulfillment of Grant No. <br />R-803869 Colorado State University, under the sponsorship of <br />the U. S. Environmental Protection Agency. This report covers <br />the period July 15, 1975 to July 14, 1977, and was completed <br />as of October 1, 1977. <br /> <br />iv <br />