IDENTIFYING OPPORTUNITIES FOR DISTRICT-WIDE WATER SAVINGSUSING REMOTE SENSING TECHNOLOGY

摘要

Irrigated agriculture is the largest water user in New Mexico; in southern New Mexico’sLower Rio Grande region, agriculture uses about one million acre-feet of water eachyear. Previous research has estimated that the average irrigation efficiency in the area is44%. This relatively low aggregate efficiency indicates a large potential for watersavings from agriculture. In order to determine the potential water savings, the amount ofwater depleted by crop evapotranspiration (ET) in the Mesilla Valley section of the EBIDwas estimated using satellite information and ground-level measurements to calculateplant consumptive water use on scales ranging from individual farms to the largerwatershed.Two areas of potential water savings were evaluated using the satellite-generatedconsumptive use information: 1) potential water saving at the farm level and 2) potentialwater saving at the district level.This study found that the majority of farms in the study region were growing crops underdeficit irrigation conditions. Therefore, irrigation improvements at the farm-level arelikely to increase both yields and water depletion.Potential water savings at the district level were evaluated by comparing the total volumeof water diverted for irrigation versus aggregate ET. From the satellite-generated ETdata, district-level efficiency was determined to be 55% in 2002 (a full allocation year).Thus, there appears to be a potential for improving district-level efficiency. This can beaccomplished by using regional ET depletion values to plan water releases from thereservoir and improve the diversion and distribution within the canal networks.