以焉耆县为例,采用趋势法、指标法、规划定额法、万元产值预测与回归分析等方法,从生活需水、生产需水、生态需水3个方面预测需水量。利用焉耆县近10 a的流量频率分析曲线,选取典型年,采用同倍比放大法,推求设计代表年内流量分配,并预测地表供水量。在供、需水计算基础上,采用定性用水定额法对研究区水资源供需平衡进行分析,计算出焉耆县各水平年全年缺水量及最大缺水月份;根据地下水水量平衡原理,得出焉耆县地下水补给与排泄处于均衡状态。研究表明,考虑研究区的地下水生态水位,确定利于灌区水资源合理配置的地下水开采量为2.47亿m3。
Taking Yanqi County as an example, this paper used a series methods of trend method, index method, quota method, ten thou- sand dollars of production value forecast and regression analysis method to forecast water-demand. The surface water-supply was forecasted by analyzing the frequency curve of the water in the past 10 years and by selecting the typical year and getting the flow distribution of representa- tive years. The water supply and demand balance in the study area were analyzed by the method of qualitative water quota, and the annual and the maximum monthly water shortage were calculated. Using the water balance principle, it calculated the amount of groundwater recharge and discharge. According to the actual situation, it brought out the exploitation plan of the groundwater and the rational allocation of water re- sources in the irrigation area.