An analysis on influencing factors of irrigation water effective utilization coefficient - a case study of Jiangsu province, China

The irrigation water effective utilization coefficient (IWEUC) is a critical indication of agricultural water use efficiency. To improve water-saving potential, the inter-annual variation of IWEUC from 2014 to 2021 in Jiangsu Province was analyzed. Taking consideration of natural factors, planting structure, management levels, and water-saving engineering, the primary influencing factors of IWEUC were investigated through principal component analysis. The results revealed that IWEUC in Jiangsu Province was higher than annual national level and showed an insignificant increasing trend. IWEUC and its trend were negatively correlated with irrigation district size. Water-saving irrigation areas had an extremely significant impact on IWEUC (P < 0.01). The positive load of water-saving engineering investment was rated first. Furthermore, economic and water-saving benefits for different irrigation district scales based on the TOPSIS model were evaluated. Despite restricted government support, the economic gains for large irrigation districts were superior to those for small irrigation districts. In the past decade, agricultural water declined while agricultural water conservation rose. The completion of integrated agricultural water pricing reform, as well as the improvement of water-saving engineering and optimization of management level, had a significant beneficial influence on IWEUC. Jiangsu's IWEUC has been efficiently implemented, and provides guidelines in other regions.