受地形特征以及人类活动的影响,华北平原地下水浅埋区水循环主要以垂直方向上的入渗和蒸发为主,其中,非饱和带对降水和地下水之间的转化具有重要作用。本文选择衡水作为华北平原地下水浅埋区的典型代表点,利用HYDRUS-1D建立了一维数值模型,以平水年2005年夏季作为模拟期,通过计算降水入渗量、蒸散发量、土壤水储存量的变化及地下水补给量等,揭示了该实验点的土壤水分运动特征以及土壤水在降水和地下水转化之间的作用。结果表明降水后土壤水和地下水都得到补给,土壤水储量增加,但由于强烈的蒸发和蒸腾作用(分别占降水补给量的63%和12%),水分消耗较快,因此总的入渗补给量为25%,土壤总储量增加不大;此外,土壤水和地下水联系密切,土壤深层水分在饱和和非饱和状态之间频繁转换,其间没有明确的界面分割,由此说明土壤水在"三水转化"过程中的重要性。
Owing to topography and the human activities,the recharge and discharge such as precipitation infiltration and evapotranspiration in vertical direction are the major processes of water cycle in the shallow groundwater areas of NCP.During these processes,soil water movement in the unsaturated zone plays an important role in the transformation between precipitation and groundwater.The soil water movement models were constructed by the HYDRUS-1D at the typical experimental sites of Hengshui.And the precipitation infiltration,evaporation,soil water storage and groundwater recharge in the summer of 2005.The results show that after the precipitation infiltration,it recharges the soil water and groundwater quickly.Though the soil water storage increase after precipitation,the water is easily lost by evaporation and transpiration because of strong evaporation effect which accounts for 63% and 12%,respectively.So the total infiltration accounts for 25%,and the storage of soil water increase a little.The interconnection between soil water and groundwater is intimate and there is no clear interface between them.