Proposed model for efficient water management at Razmgan irrigation project, a semi-arid region in Khorasan, Iran

Abstract

Yield decrease caused by crop water deficit, especially in low scale farms and established orchards at semi
arid regions, results in a significant decrease in agricultural productivity. In this study an optimal water release 
of the reservoir based on prioritization in water allocation to the crop sensitive growth periods was linked to a 
non-linear optimization model in order to enhance the net income in a given cropping pattern. The proposed 
model by optimal water allocation for each growth stage of the crop reduced the impact of the imposed water 
stress in the dry season and increased the net income. The LINGO software has been used to evolve the 
optimal amounts of both water and land for the existing crops. The proposed model was applied for Razmgan 
area a semi-arid region which is located 10 km south of the Shirvan city, northern Khorasan province, Iran. 
Various scenarios of the water release from the existing auxiliary reservoir, to remove/reduce the imposed 
water-stress during the crop growth stages have been explored. Results show in the optimal case, whole of the 
existing water deficit is removed in months of July, August, September, October and November, only 13% of 
the deficit remains in month of May and in month of June the amount of deficit decreases to 42.16%. Also the 
proposed model is efficient and annual net income will increase to 26.21%, moreover, the total water 
consumption will decrease to 10.71% than the current status.