利用EARTH模型计算河北栾城地下水垂向补给量

准确计算地下水的垂向入渗补给量是合理评价和利用地下水资源的基础.EARTH模型是一种集中参数的水文模型,可刻画水流在包气带中的运移过程,弥补黑箱模型的不足.以中国科学院栾城农业生态试验站的地下水位观测资料以及气象资料为基础,综合运用降水、蒸发、土壤水、地下水动态观测资料,利用EARTH模型计算了河北平原地下水垂向入渗补给量.计算结果表明,2003年1月1日至2005年8月31日期间,栾城农业生态试验站在降水量1404.1 mm、灌溉量1050.0 mm的条件下地下水入渗补给量为487.2 mm,平均年入渗补给量为182.6 mm, 占降水和灌溉总量(2454.1 mm)的19.9%.在模拟结果的基础上,对不同年份的降水量(含灌溉)和入渗补给量分布的对比分析表明,河北栾城地下水补给滞后现象明显,在研究时间段内峰值滞后18～35 d.

Estimation of Vertical Groundwater Recharge by EARTH Model in Luancheng,Hebei Province

Precise estimation of vertical groundwater recharge is important for reasonable estimation and utilization of groundwater resource.EARTH is a lumped parameter hydrological model that can describe the flow process in the unsaturated zone.It overcomes the deficiency of the black model and is applicable under the case of deep depth,scarcity of soil parameters or observed data.Observed data of rainfall,evaporation,soil moisture and groundwater are applied synthetically in the transient lumped parameter model(EARTH) to calculate vertical recharge of groundwater in Luancheng,Hebei Plain.During January 1,2003 to August 31,2005,the vertical groundwater recharge in the area was 487.2 mm,accounting for 19.9% of the total of precipitation and irrigation with respect to the annual vertical groundwater recharge of 182.6 mm/a in a condition that the precipitation and irrigation are 1 404.1 mm and 1 050.0 mm respectively.Based on the simulation results of rainfall comparison(including irrigation) in different years with the infiltration recharge,hysteresis phenomenon can be found for the deep unsaturated zone in Luancheng,and the recharge peaks delay 18 to 35 days with the rainfall peaks.