大型灌区节水水平评价指标体系构建与实证

灌区是中国农业节水的主战场，对灌区节水水平进行评价可为灌区现代化改造提供借鉴与指导，合理适用的评价指标体系是进行灌区节水水平评价的核心内容。针对当前灌区评价指标选取存在的冗余、不完备的问题，为构建满足简洁性与完备性的反映灌区节水水平的评价指标体系，该研究从工程节水、田间节水、用水管理、水资源保护及用水效益5个方面初步建立了大型灌区节水水平评价指标体系，利用筛选模型从70个指标中优选出了23个灌区节水评价指标，表达了86.42%的信息，使最终的指标体系兼具简洁性与完备性，并对河南省沿黄渠村灌区、彭楼灌区、广利灌区、大功灌区4处大型灌区进行了节水水平实证研究。结果表明，4处灌区相应的节水评价指数分别为0.666、0.730、0.657、0.616，其中彭楼灌区由于具有较高的骨干渠系配套程度和明显的工程节水优势使其整体节水水平较高，渠村灌区和广利灌区的节水水平次之，大功灌区的节水水平相对较低；受益于大型灌区续建配套与节水改造项目4处灌区在工程节水方面表现相对较好，评价结果与实际情况相符，表明该研究构建的节水水平评价指标体系科学合理；为进一步提升灌区的节水水平，4处灌区需加强用水管理水平、增加用水效益以及注重水资源保护建设。研究成果为科学评估大型灌区节水建设提供了一种有效的方法，并对推进农业节水化进程具有积极的指导作用。

Construction and empirical analysis of the evaluation index system for the water-saving level of large-sized irrigation districts

Abstract: About 215 billion cubic metres of water has been consumed by large and medium-sized irrigation districts in recent years, particularly over 35% quantity of the total water consumption in China. The irrigation district has been the main field of agricultural water-saving construction. Therefore, it is necessary to accurately assess the water-saving level in modern irrigation districts. In this study, an index system was established to evaluate the water-saving level in large-scale irrigation districts. Five aspects were considered, including engineering water-saving, farmland water-saving, water use management, water resources protection, and water use benefit. Eight standards were selected, such as measurability, vulnerability, predictability, typicality, controllability, integrity, responsiveness, and stability. A screening model was constructed to identify the indexes to be shortlisted or not. Subsequently, 23 indexes from the 70 primary indexes, 86.42% of the information was expressed by 32.86% of the elementary indexes, indicating the concise and adequate index system. The final indexes were formed, including the backbone canal lining ratio, the completion rate of engineering projects, backbone canal intact rate, backbone hydraulic structures intact percentage, water utilization coefficient of canal system, high-efficient water-saving irrigation coverage percentage, field water utilization coefficient, multi-cropping index, gross irrigation water consumption per mu, real collection rate of water charges, water user association coverage rate, allocation rate of water measuring equipment on lateral gate, 2 fees implementation rate, number of management personnel per 10 000 mu, proportion of management personnel with junior college degree or above, informationization coverage rate, proportion of irrigation water in total water consumption, drainage ditch intact rate, water ecological monitoring system coverage rate, proportion of ecological water in the total water consumption, grain yield produced by 1m3 irrigation water, proportion of primary industry production in irrigation district, and water consumption per-10 000-yuan-GDP. Four large-scale irrigation districts (Qucun, Penglou, Guangli, and Dagong) are all located along the Yellow River in Henan Province. The indexe system was then investigated empirically to determine the water-saving level. The water-saving level indexes for the four objective Irrigation Districts were 0.666 (Qucun), 0.730 (Penglou), 0.657 (Guangli), and 0.616 (Dagong), respectively. On the whole, the score of the water-saving level index was ranked in the descending order of Penglou, Qucun, Guangli, and Dagong. The scores of the 5 secondary indexes showed that Penglou achieved the best effect of engineering water-saving, whereas, Dagong was a negative example. This was due to the well-matched infrastructure engineering, where the backbone canal system was of systematic construction and renovation in the past 10 years. Guangli performed relatively lower than the rest because the high-efficient coverage percentage of water-saving irrigation was rather weak and the gross consumption of irrigation water per mu was pretty high, particularly for the long-term goals of farmland water-saving. There was no significant difference in the score of water use management level among the four irrigation districts, but their agriculture water rate, water user association promotion, and water measuring facilities setting, all needed to be rather improved. Water resources protection was the common weakness of the four irrigation districts, indicating the concept of project construction without considering ecological protection over the past years. Consequently, five recommendations can be addressed to further improve the water-saving level in the irrigation districts. 1) To coordinate the backbone and field construction, 2) To establish the new water-saving system under the agricultural water price reform, 3) To strengthen the dredging and transformation of drainage ditches, 4) To improve the water resources and environment monitoring network, 5) To promote the efficient saving on water irrigation, particularly for the planting area of cash crops. The findings can provide an effective way to scientifically evaluate the water-saving construction in large-scale irrigation districts, thereby promoting the process of agricultural water-saving in China.