不同降水及灌溉条件下的地下水入渗补给规律  

Effects of precipitation and irrigation on vertical groundwater recharge

作　　者：霍思远[1,2] 靳孟贵[1,2] 

机构地区：[1]中国地质大学(武汉)生物地质与环境地质国家重点实验室,湖北武汉430074 [2]中国地质大学(武汉)环境学院,湖北武汉430074

出　　处：《水文地质工程地质》2015年第5期6-13,21,共9页Hydrogeology & Engineering Geology

基　　金：国家"973"计划项目(2010CB428802);国家自然科学基金项目(U1403282;41272258)

摘　　要：天然降水和人工灌溉是华北平原浅层地下水的主要补给来源。长期过量开采地下水导致华北平原地下水位持续下降,详细分析降水变化规律及灌溉制度的影响有利于深入认识补给及正确评价入渗补给量,对合理开发利用地下水资源具有重要意义。基于实测资料,用HYDRUS软件建立一维变饱和流数值模拟模型,模拟分析了衡水地区近60年在天然降水条件下的垂向入渗补给规律,以及在年周期内灌溉活动对于入渗补给规律的影响。结果表明：研究区多年平均降水入渗补给量为66.6 mm/a;枯水年份降水入渗补给量为30 mm/a,丰水年入渗补给量为120-150 mm/a;年补给量与年降水量具有显著的正相关性;入渗补给系数与降水强度呈负相关关系;入渗补给量随灌溉量的增加而增加,实验条件下小麦底墒水与玉米灌溉对应入渗补给系数较大,实际灌溉中应基于当年降水情况及土壤墒情确定合理的灌水定额。Rainfall recharge and irrigation return flow are principal sources of shallow groundwater in North China Plain. Long-term groundwater over-exploitation has resulted in the decline of water table since the past decades in the North China Plain. It is conducive for recharge estimation and groundwater resource management by analyzing precipitation variation and irrigation scheduling. One-dimensional variably saturated flow models were established by using HYDRUS software. Simulations were run to evaluate the rainfall recharge in Hengshui area during the past sixty years, and to analyze the effects of irrigation on recharge. The simulation results showed that average annual recharge quantity was 66.6 mm/a in Hengshui area, the annual recharge quantity was about 30 mIn/a or 120 - 150 mm/a separately in dry year or wet year. The annual recharge quantity has significant positive correlation with annual precipitation, while negative correlation was found between recharge coefficient and rainfall intensity. Recharge quantity increases with irrigation volume; the recharge coefficient of single irrigation separately in October and July is relatively large in the experiment, reasonable irrigation quota should be made based on the rainfall condition and soil moisture.

关 键 词：降水入渗补给 灌溉回归水 垂向入渗补给 数值模拟 HYDRUS 衡水地区 

分 类 号：P641.76[天文地球—地质矿产勘探]