淮北平原降雨入渗补给系数随地下水埋深变化特征

水文地质参数对地下水资源评价起着至关重要的作用。其中,降雨入渗补给系数是影响浅层地下水水量、水质的重要参数。它对研究区域水量转化和水量平衡也十分重要。但是由于受降雨量、土壤类型、植被、地下水埋深等诸多因素的影响,准确判断降雨入渗补给系数存在很大困难。如果没有考虑这些因素的影响,尤其是降雨量和地下水埋深的影响,所推求的降雨入渗补给系数就会存在较大误差。结合安徽省淮北平原区五道沟水文实验站观测的降雨量、地下水补给量、地下水水位资料,利用两种不同的方法推求了不同降雨量等级的次降雨入渗补给系数。根据统计学理论研究了不同降雨量条件下,次降雨入渗补给系数随地下水埋深变化的分布规律,建立了次降雨入渗补给系数与地下水埋深的回归模型,并进行了相应的检验。研究表明,在控制地下水埋深的条件下,次降雨入渗补给系数随地下水埋深的变化符合指数分布;在地下水位自由变动的条件下符合伽玛分布。

Characteristics of Rainfall Infiltration Coefficient of Supply with Groundwater Depth Change in the Huaibei Plain

Rainfall infiltration coefficient of supply is the main parameter which influences amount and quality of the shallow groundwater.It is also very important for water volume changeable and balance.Due to influence of the rainfall,soil type,vegetation,groundwater depth and many other factors,it is very difficult to determine the rainfall recharge coefficient accurately.Without considering these factors,especially the impact of rainfall and groundwater,it exists a big error to estimate rainfall recharge coefficient.Combination of hydrological observations of rainfall of the Anhui Huaibei Plain and Wudaogou Experiment Stations,groundwater recharge,groundwater level data,it takes two different methods to calculate the different rainfall levels.According to the statistical theory,under the condition of the different rainfall,the distribution of the rainfall recharge coefficient changes with the groundwater table,establishes the regression mode between the rainfall and groundwater recharge coefficient and the corresponding test.The study has shown that the coefficient of rainfall recharge groundwater level changes in line with the exponential distribution in the control of groundwater conditions and in line with the gamma distribution under the free water table conditions.