Optimization of irrigation water allocation by using linear programming: case study on Belitang irrigation system

The irrigation water requirement in the Belitang Irrigation System cannot be fulfilled during dry season due to the limited water availability. Therefore, some agricultural land in the Belitang Irrigation System receive inadequate irrigation water. To solve this problem, it is necessary to optimize the allocation of irrigation water, thus, the existing potential area could be optimized This study aimed to obtain optimum cropping area and maximum benefits by optimizing the allocation of irrigation water based on the dependable discharge and existing area. The optimum cropping area was obtained by making several alternative cropping patterns. The linear programming was used to analyze the optimization of irrigation water allocation. The results showed that the irrigation water allocation with a dependable discharge of 80% exhibited an optimum cropping area of 58,609 ha, cropping intensity of 271.36% and maximum benefits of IDR 1,041,186,630,000.00. From the results of these studies, the cropping pattern that can be applied by considering the water availability and the existing area to obtain the optimum cropping area and maximum benefit per year is paddy-paddy-paddy/second crop.