Agricultural water-saving regionalization in Guanzhong area

Agricultural water-saving regionalization is one of the most effective methods of promoting regional water resources utilization and alleviation of agricultural water shortage. In view of the present water resources shortage and high agricultural water consumption in Guanzhong area, studies were carried out on agricultural water-saving regionalization. Data on topography, climatic, water utilization and cropping characteristics of Guanzhong area were collected and analyzed using combined principal component analysis and the fuzzy cluster analysis methods. Based on integrated analyses of topography, climate, water utilization, social economy and cropping structure in Guanzhong area, 13 indexes (aridity, elevation, irrigation water use, farmland irrigation rate, farmer net income, total agro-output value, multi-cropping, grain-crop seeding ratio, oil-crop seeding ratio, vegetable seeding ratio, melon/fruit seeding ratio, other crops seeding ratio) were used to build a regional index system. The 13 primary indexes were selected after variation and correlation analysis of regionalization principles. Another 6 principal component indexes (with no correlation with each other) were calculated via principal component analysis to replace the primary indexes. This improved computational efficiency and research quality. The 42 counties of the Guanzhong area were divided into 6 agricultural water-saving regions using hierarchical clustering. The agricultural water-saving regions included mainstream region of Weihe River and Luohe River, mountain region at the upper reaches of Jinghe River and Weihe River, mountain region at the upper reaches of tributaries of Weihe River, plain region at river confluence reaches, plain region at the lower reaches of Luohe River, and Xi'an and its surrounding areas. This study finally mapped out primary agricultural water-saving patterns based on the characteristics of each water-saving region. The patterns included planting structure adjustment, drought-resistant crop promotion, agronomic water-saving measure development and efficient water-saving irrigation adoption. It was concluded that future studies focused on the development of detailed partitioning water-saving measures based on real field surveys and in-depth data collection.