Analisis Kerentanan Sistem Irigasi Akibat Perubahan Iklim dengan Tolok Ukur Indeks Kelentingan di Empat Daerah Irigasi Wilayah Daerah Aliran Sungai Brantas

Climate change which mainly affected by the increase of climate variability from time to time is highly impacted to the vulnerability of irrigation system, in a way that by the increase of water demand can not be fulfilled by water availability (the decrease of capacity). While, basic measure of conducting irrigation system management currently is solely based on comparison value between demand and irrigation water availability (K-factor) without considering the increase of climate variability. Resilience Index (Ik)  as one of basic measures in water resource management can be used as a limitation in irrigation system operational management.  The results of the study show that  Molek, Jatikulon, Menturus  and Konto irrigation areas (DI) are impacted by climate change with different scales of resilience. The resilience index of 100% for Molek Irrigation area, 80% for Jatikulon irrigation area, 50% for Menturus irrigation area, and 33% for Konto irrigation area. Climate change is predicted causing the decrease of harvested area, in such a way that in the condition of El Niño around 48% in Konto Irrigation Area, 34% in the Menturus Irrigation Area, 28% at the Jatikulon Irrigation Area, and 15% in the Molek Irrigation areas.  Nevertheless, in the La-Nina condition, there was no the increase of harvested area in the entire of irrigation area studied, even, there was a decreased of harvested area of 28% in Konto irrigation area, and 6% in Menturus irrigation area.  The most powerful threat toward irrigation system sustainability is the environment, followed by physical, social, and economic aspects respectively. The results of this study implicate to the imprevement of irrigation management policy, namely to the operational pattern of irrigation system, which use resilience index (Ik) as basic measure of irrigation system management out of the K-factor.