重庆市不同规模灌区农灌水有效利用系数测算与对比研究

通过对重庆市不同规模灌区农田灌溉用水有效利用系数计算结果的比较研究,对出现的中型灌区农田灌溉用水有效利用系数大于小型灌区的结果进行合理性分析,并为重庆市农田灌溉用水有效利用系数的进一步提高,提出相关建议,为政府相关部门的科学决策提供参考.综合考虑重庆的地形、气候、土壤等因素.根据选定灌区的实测数据,采用首尾测算法计算2017年重庆市不同规模灌溉农田灌溉水的有效利用系数,采用单因素和主成分分析法,分析影响农田灌溉水有效灌溉系数的主要因素. 1)通过测算, 2017年重庆市中型灌区农田灌溉水有效利用系数为0.499,小型灌区为0.487,推算全市为0.495; 2)在影响农田灌溉水有效利用系数的主要因素中,当地的节水工程和管理状况所占的比例大于自然因素; 3)中型灌区在节水工程的投资、管理和维护等方面均优于小型灌区; 4)自然因素中,降水量对农田灌溉水有效利用系数具有一定的负面影响.

A Comparative Study of the Effective Utilization Coefficients of Irrigation Water in Irrigation Areas of Different Scales in Chongqing

In order to improve effective utilization coefficient of farmland irrigation water in Chongqing and help the relevant administrations to make scientific decisions, the effective utilization coefficient of farmland irrigation water of irrigation areas of different scales in Chongqing in 2017 was calculated with the method of head-and-tail algorithm and its major influencing factors were analyzed by means of single factor and principal component analyses, with comprehensive consideration of Chongqing''s topography, climate, soil and others. Through calculation, the effective utilization coefficient of farmland irrigation water was found to be 0.499 and 0.487 in Chongqing''s medium-sized irrigation areas and small-scale irrigation areas in 2017, respectively. It was inferred that the average for the whole city was 0.495. Of the major influencing factors, the proportion of local water-saving engineering projects and their management was larger than that of the natural factors. The medium-sized irrigated areas were superior to the small ones in terms of investment, management and maintenance of the water-saving projects. Of the natural factors, precipitation had a certain negative effect on the effective utilization coefficient of farmland irrigation water. In conclusion, using the head-and-tail algorithm to calculate the effective utilization coefficient of farmland irrigation water in irrigation areas of different scales is feasible. Moreover, it is reasonable and credible that the effective utilization coefficient of irrigation water in medium-irrigated areas is greater than that in small irrigated areas. The methods to improve the effective utilization coefficient of irrigation water in Chongqing are summarized in terms of nature, management and water-saving engineering.