关中地区农业节水分区研究

农业节水分区是促进区域水资源高效利用,缓解农业用水短缺的有效方法之一。针对关中地区水资源短缺、农业用水量大的现状,进行了该地区农业节水分区。收集分析了关中地区的地形地貌、气候特征、水资源利用状况以及农业结构方面的资料,采取系统聚类法结合主成分分析的方法展开关中地区农业节水分区的研究。结合关中地区农业相关的自然社会特点,构建了由气候指标、地形地貌指标、水资源及缺水程度指标、耕地灌溉程度指标、社会经济情况指标和农业结构指标等组成的农业节水分区指标体系;对指标进行变异分析和相关分析,筛选出13个原始指标;借助主成分分析法将原始指标表示成6个主成分以提高计算效率;运用系统聚类法把研究区内的42个县级区域划分成6个农业节水区,并结合自然、社会和经济情况对各区进行了水资源利用情况分析,对各区农业节水措施给出相应的对策建议。

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.