Institutional Performance of Irrigation System in Spatial Dimensions in Semi-Arid Region Timor Island East Nusa Tenggara

Thirty-four percent (34.40%) of irrigation areas in Indonesia are under the authority of the central government, 17.89% under the authority of the provincial government and 47.71% are under the authority of the District/Municipality government. Various efforts have been made by the government to improve the performance of surface water irrigation systems that cover 78% of the total irrigation area, however, the performance did not improve significantly. One of the cause is due to the damage of national surface water canals that affect the performance of the irrigation system. The purpose of this study was to analyze the factors that influence the institutional performance of the irrigation system in the spatial dimension in the semi-arid region of Timor Island, East Nusa Tenggara. The spatial approach of the Geographically Weighted Regression (GWR) method was chosen as an alternative approach in the analysis of irrigation system performance because it considers the variability of hydrogeological characteristics and the performance of different irrigation systems in each irrigation area based on their authority. The results of this study indicated that the total cropping intensity had a significant effectand decreased the performance of the irrigation system. The higher rice productivity and the maintenance frequency of the main system (headworks and canals) would improve the performance of the irrigation system. Meanwhile, the lower damage rate of the main system would improve the performance of the irrigation system. Irrigation area under the authority of district/municipality had a lower/worse irrigation system performance than those under the authority of provincial and central governments.