Kinerja Sistem Daerah Irigasi Dengan Tolok Ukur Berkelanjutan (Kasus Daerah Irigasi Nepen, Boyolali, Jawa Tengah)

Oleh :
Rahayu Mahanani Wijiastuti - S94090801 - Sekolah Pascasarjana

Irrigation infrastructure is often damaged because of the unstable flow. Damage will be impacts to increase maintenance cost of infrastructure and production. Therefore, the flow must be maintained to ensure the infrastructure functioning in order to meet the sustainability principles. This research was conducted in the Nepen Irrigation Area, Boyolali, Central Java Province. The study compare water management based on k-factor with risk factors namely reliability index (Ia) and resilience index (Ik). Irrigation water requirements were analyzed based on climatological data from Adi Soemarmo station for the period 2003 to 2004. Irrigation water demand was calculated using the Penman Monteith method. The data used is based on the water level data in the Nepen weir. The flow data was reducted by irrigation water requirement to obtain residual value. Residual values was used as the basis of factor analysis to obtain k-factor, Ia and Ik. In the present study has defined a good k factor should be
0.8, Ia
0.8 and Ik
0.5. The study was conducted with the scenario of planting pattern to get the best value of k-factor, Ia and Ik. The results showed that the growing season (MT) evaluation and a period of 15 per day at the Regional Irrigation Nepen demonstrate the value of k factor > 80%, but the value specified benchmarks are not achieved. To get the best value Ia and Ik was used of scenario of cropping pattern of the land area planted with a planting area of 272.5 ha in MT-1, MT-2 of 410 ha, and MT-3 of 410 ha, get the value of factor k at each time of planting nearly reaches 100%, while the value of the reliability index (Ia) and the resilience index (Ik) almost reaches the value 1. This explains the k factor can not guarantee the sustainability of irrigation systems in the form of guarantee water supply.