Ranking irrigation schemes based on principle component analysis in the arid regions of turkey.

Water is a scarce resource and thus irrigation schemes in arid regions have become more important. The irrigation sector which uses most of the water resources has to cope with global warming, disasters and water scarcity around the world, particularly in the Mediterranean countries, including Turkey. Irrigation schemes, which were built by DSI (State Hydraulic Works) and whose operation and maintenance management was transferred to water user associations, play a crucial role in irrigated agriculture in Turkey. In order to improve the performance, weakness and strengths of irrigation schemes are determined by performance indicators (system operation, financial and production efficiency) which show the overall information about them. In the present study, seven irrigation schemes located in an arid region of central Anatolia were chosen to assess the irrigation performance using principal component, correlation and cluster analysis while quality index showed the rank of the irrigation schemes. We found that the average total annual volume of irrigation supply was 7,648.58 m3 ha−1 and the average relative water supply was 1.91 during the 11 years between 2006 and 2016. In this region, higher inverse correlations were due to using surface irrigation methods (51.3%). As of 2017, the irrigation schemes have weak water distribution systems, on an average, consisting of 55.5% open canals, 22.5% canalette and only 10% pipes. According to the quality index, financial and system operation indicators are more effective than that of production efficiency indicators. In conclusion, average irrigation ratio (55.68%) can be increased by improving the water distribution system, and the technology used on both management and farm levels.