Evaluation of irrigation hydro-module of major plants of cropping pattern to reduce water stress and optimize agricultural water consumption in Honam sub-catchment

For sustainable water resources utilization, knowledge of the existing conditions as well as a proper method to allocate and exploit water is inevitable. To this end, water resources and cropping pattern of Honam sub-catchment in Karkheh River Basin, Iran, were geographically identified and then digitized over 913.8 ha of irrigated lands, during 2017-2018 growing season using field survey and satellite imagery. Also, irrigation homogenous units were separated and hydro-module of cropping pattern was determined per unit according to surface irrigation application efficiency of the study area. The results of the cropping pattern showed that the areas under the major crops including wheat and barley, alfalfa and clover, and sugar beet were 444, 153, and 40 ha, respectively. Alfalfa and barely had the highest and lowest irrigation requirement among the major crops with 11910 and 3000 m3.ha-1, respectively. Nineteen irrigation homogenous units were delineated, and their mean annual hydro-module was determined as 1.26 L.s-1.ha-1. Meanwhile, mean hydro-module of nineteen homogenous units was obtained as 0.86 L.s-1.ha-1 according toestimated volume of water and average of application efficiency (30%) in the study area. The results also indicated that the allocated water for 12 out of 19 homogenous units was more than the determined hydro-module, and for the remaining 7 units it was less. It can be concluded that it is feasible to reduce drought stress and improve yield and water productivity based on determined hydro module and water consumption volume of subcatchment cropping pattern.