太行山山前平原地下水补给规律分析:以河北栾城为例

采用水均衡法与通量法对太行山山前平原(河北栾城)进行了地下水补给评价,结果表明:近20 a地下水入渗补给量为8～172mm/a(水均衡法),平均值49.3 mm/a,变化幅度大.其中2004年入渗补给量(63mm/a)比采用通量法计算结果(28.2mm/a)大一倍,表明土壤优先流对入渗补给作用显著.年入渗补给量总体上随有效降雨量增加、地下水位下降速率减少、作物实际蒸发蒸腾量减少而增加,但与有效灌溉量和灌溉量之和的相关性不显著.通过长序列地下水位与灌溉量等数据估算得到研究区侧向净补给量为125.2 mm/a,约占地下水总补给量的71.7％(175.4 mm/a),说明地下水主要以侧向补给为主.同时计算了入渗补给与侧向补给地下水的延迟时间,分别为60 a和1个月.

Estimating Groundwater Recharge of Taihang Mountain Piedmont in Luancheng County,Hebei Province, China

Groundwater recharge was evaluated by water mass balance method and flux method,in Luancheng County,North China Plain.The result showed that the recharge of groundwater of 20 years was different from 8 to 172 mm/a,and the average was 49.3 mm/a,using the method of water mass balance.The recharge of 2004 evaluated by water mass balance(63 mm/a) was larger than the result of flux method(34.8 mm/a),which showed that the preferential flow played vital role in the soil water flow.Higher effective rainfall,smaller decline rate of groundwater level and smaller evapotranspiration,the recharge almost increased.However,the correlation between recharge and the sum of irrigation and precipitation was not notabily relevant.The net lateral recharge was 125.2 mm using the data of groundwater and irrigation from 1990 to 2010,about 71.7% of the total recharge(175.4 mm/a),which explained that the net lateral recharge of groundwater was larger than the vertical recharge.The time of influence on groundwater table of vertical and lateral recharge were 60 years and 30 days respectively.