基于GMS的渠井结合灌区适宜渠井用水比例研究

Rational Ratio of Canal-well Water in Canal-well Combined Irrigation District Based on GMS

为实现泾惠渠灌区地下水多年动态平衡,确定适宜的灌溉渠井用水比例,运用GMS中MODFLOW模块建立了月尺度的地下水数值模型;结合灌区地下水位年内变化特征、各灌季农灌用水情况和"丰蓄枯补,渠井结合"的原则,对3种代表年分别设置3种灌季渠井用水方案,并进行模拟比较。结果表明,平水年冬、春、夏灌季和全年渠井用水比例分别为2.1、1.8、0.7、1.36时,能使地下水位大致稳定且实际中较为可行;丰水年冬、春、夏灌季和全年渠井用水比例分别为2.3、2.0、1.1、1.64时,地下水能得到补充;枯水年冬、春、夏灌季和全年渠井用水比例分别为1.8、1.9、0.6、1.14时,地下水位下降较少。灌区的夏灌渠井用水比例对全年渠井用水比例影响最大,应尽可能提高夏灌渠井用水比例,实现地下水位的稳定或小幅上升。研究结果为灌区水资源的高效利用及水位恢复提供了参考依据。

In order to realize groundwater perennial dynamic balance and determine the rational ratio of canal-well water,this study took the Jinghuiqu Irrigation District,a typical canal-well combined irrigation district for an example.The article analyzed the groundwater level variation characteristics within a year,based on years of rainfall,seasonal irrigation,and groundwater level etc.,and a monthly groundwater flow model was developed using the MODFLOW module of GMS.Besides with the incorporation of the rainfall and irrigation water of every seasonal irrigation in different years,it set several groups of ratios of canal-well water for comparison,and then decided the rational ratios of canal-well water for seasonal and the whole year irrigation.The results show that in normal year,the groundwater level can keep stable with the ratio of canal-well water of 2.1,1.8,0.7and 1.36 for winter,spring and summer and the whole year irrigation;in wet year,the groundwater can be replenished with the ratio of 2.3,2.0,1.1and 1.64;in dry year,the groundwater level could have a small drop with the ratio of 1.8,1.9,0.6and 1.14;the summer irrigation ratio affects the whole year irrigation ratio greatly,so it should be as larger as possible to stabilize groundwater level.The research can provide basis for utilization of water resources and recovery of water level in irrigation district.