سمیه نقوی

Given rapid socio-economic development, increasing food demand and decreasing available resources, the challenge of seasonal fluctuations of surface water has become a major problem in the agricultural sector, causing a change in consumption from surface water to groundwater resources and reduction of farmers’ income. Therefore, optimal programming of the cropping pattern is necessary to handle such challenges. To accomplish this aim, a model of irrigation water allocation was developed based on cropping pattern using multistage stochastic programming in accordance with surface water supply fluctuations. In this model, different stochastic states were considered for all irrigation seasons in the irrigation network of the Jiroft plain in Kerman Province, Iran, which faces a severe shortage of surface water resources and the tendency of farmers to overuse groundwater resources. By solving a multistage stochastic model, it can be observed that, by utilizing an appropriate programming of the cropping pattern, more benefits for the farmers could be realized in the conditions of available surface water fluctuations. The results also indicated that if the surface water released into the canals increased in the spring, the share of profitable high water consumption crops in the pattern will increase, which will strengthen farmers’ profits and put pressure on groundwater resources. However, this could not be expected to lead to a significant reduction of groundwater resource consumption and a significant increase of cropping intensity. According to the results obtained, surface water resources cannot meet the water needs of the region, even by using optimal cropping patterns, and this has led to overuse of groundwater resources in this area. Finally, such planning can help adoption of desired policies for irrigation water management through the proper release of these resources.