作物生长季节降水量和农业地下水开采量对地下水变化影响研究——以河北晋州地区为例

晋州地区是典型的农业井灌区,通过对该地区农作物生长季节降水量-农业地下水开采量-地下水埋深之间互动变化特征及其机制研究发现,枯水年份,农业地下水开采量的大小与小麦、玉米生长季节的降水量变化密切相关;平水年份,小麦生长季节的降水量变化对农业地下水开采量影响占主导,其次为玉米生长季节的降水量变化;丰水年,农业地下水开采量仅与小麦生长季节的降水量变化之间具有明显相关性,与玉米生长季节的降水量变化相关性明显弱化。不同水文年降水量变化,在影响农业地下水开采量增减的同时,对地下水的入渗补给量呈现与开采量逆向变化,二者叠加影响地下水位动态变化。平水年份或丰水年份,小麦生长季节地下水埋深增大,玉米生长季节降水量一般能满足玉米需水量,地下水埋深减小。因此,充分利用作物生长季节降水量,对减少地下水开采和高产农业的稳定发展有重要意义。

Influence of Precipitation during Crops Growing and Groundwater Yield for Agriculture on Groundwater Dynamic: A Study Case in Jinzhou Area of Hebei Province

The crops are irrigated with groundwater entirely in Jinzhou area.We studied the interactive characteristics and mechanisms between precipitation during crops growing,groundwater pumping for agriculture and groundwater depth.The results indicate that there exists a close correlation between groundwater pumping for agriculture and the change of precipitation during wheat growing and corn growing in dry years.The groundwater pumping is mainly influenced by rainfall during wheat growing,and is influenced by rainfall during corn growing in normal years.In wet years,there is an obvious relation between the groundwater yield and precipitation during wheat growing,and the relation become weak during corn growing.The precipitation impacts on groundwater yield for agriculture and precipitation recharge for groundwater changes adversely with groundwater yield,and the both influence on the groundwater depth change.The groundwater depth increases during wheat growing and decreases during corn growing in normal years or wet years.