Optimization of water distribution for channel irrigation networks Krueng Baro Kiri scheme (Aceh-Indonesia)

The standard area of Krueng Baro irrigation scheme is 11.950 Ha, divided into Baro Kanan irrigation (8,920 Ha) and Baro Kiri irrigation (3.030 Ha). This irrigation focuses on increasing the productivity of food crops in Pidie District. Previous research reported that the distribution efficiency of the Baro Kiri primarychannel (74,1%) was smaller than the Baro Kanan (86,8%). The decreasing efficiency level of the channel results in a large number of unirrigated paddy fields that which in turn decrease the rice productivity. This study aimed to determine the optimum area of the rice fields that can be irrigated and examine the amount of discharge distributed to each channel by minimizing water loss. The method used was the optimization linear program. The optimization had the objective function of minimizing water loss. The land area was a decision variable, while the water loss in each channel and the water availability in each weir were the constraint function. The optimization results created an area of 2.810 Ha out of 3.030 Ha total area of rice fields in Krueng Baro Kiri by minimizing water loss in each channel based on the efficiency value of each channel. The rice field terrace that had highly reduced from the standard area in the Krueng Baro Kiri were the ones in the channel section of R4 and R5, 10 Ha of the standard rice field area. This occurred because these two channel sections (R4 and R5) had the smallest efficiency value of 47,26%, and 58,03%, respectively.