井渠结合灌区地下水开采方案设计研究——以泾慧渠灌区试验区为例

Design of Groundwater Exploitation Scheme in Well-canal Combined Irrigated Area——A Case Study of Test Area in Jinghui Irrigation District

首先根据泾惠渠灌区试验区近60a的气象、土壤资料,利用CROPWAT模型计算区域冬小麦、玉米、棉花的灌溉需水量。根据研究区需水、供水之间的关系以及渠井适宜比理论提出3种地下水开采方案。在试验区水文地质条件的基础上,运用Visual Modflow软件建立了地下水流数值模型,并从地下水合理埋深、丰枯季地下水量构成等角度,对不同开采方案下的地下水动态变化进行了分析和验证。结果表明:通过对未来年地下水位的预测可知,3种开采方案下的地下水埋深都在合理的埋深范围内;对比分析发现第2种方案的地下水开采所引起的降深适中,开采量有可靠的补给保证,并在丰枯两季形成动态调整,为最优方案。该研究为今后试验区地下水的合理开采提供了科学依据。

Based on the data of the meteorological and soil in Jinghui irrigation test area,irrigation water demand of winter wheat,corn,cotton is calculated by the CROPWAT model.According to the relation between water requirement and water supply,three types of groundwater exploitation schemes is proposed based on the theory of ratio of drainage water and well water,agroundwater flow numerical simulation model is built by Visual Modflow with the hydrogeological conditions in the test area,and the groundwater dynamic changes are analyzed and verified from the perspective of reasonable groundwater depth and volume of groundwater.The results show that：according to the forecast of groundwater level in the future,the groundwater depth under the three kinds of schemes all are within a reasonable range;the drawdown of groundwater under the second scheme is the most modest,and the groundwater has a reliable supply and dynamic adjustment in the plentiful water season and withered water season,so the second scheme is the best.The research provides a scientific basis for the reasonable exploit of groundwater in the test area.