Investigating the Water Withdrawal from Surface Resources and the Beneficial Water Consumption in the Agricultural Sector of Khuzestan Province

This study was conducted to evaluate the real cropping pattern of Khuzestan province in a normal water year (2018-2019) in terms of water withdrawal management from surface resources. For this purpose, the actual evapotranspiration of the products was calculated from the ratio of the available yield of different products (according to the agricultural statistics of 2018-2019) to the potential yield (the highest yield according to the agricultural statistics) by applying the country's water demand line system based on 10-year meteorological data. The results showed that the total water withdrawal from surface resources for the cultivated area of the crop year 2018-2019 (except greenhouses, livestock, poultry, and some products with a small area) was 18856 MCM, so the actual consumption (net irrigation requirement) was estimated 4310 MCM. Considering the Khuzestan Water Scarcity Adaptation Program, the total demand for agriculture and the environment with a confidence level of 80% in the Karun and Karkheh basins was 36 and 23.8% lower than the river flow, respectively, while it decreased to -72% in the Jarrahi basin, which indicated the failure to achieve the minimum environmental requirement. Since the Karkheh River flow has a more severe fluctuating behavior than that of Karun, this behavior cannot be predicted in the linear analysis of average values, and in droughts, it is less than the mentioned number. Therefore, dynamic planning in the field of cropping pattern change, providing various types of drought insurance, implementing infrastructure for the temporary purchase of water rights by the government, and other support policies are suggested in basins such as Karkheh, which has a highly fluctuating behavior in water supply.