西辽河平原区地下水埋深变化趋势与超采分析

Analysis of the Groundwater Depth Variation and Over-Exploitation in the West Liaohe Plain

内蒙古西辽河流域是我国重要的粮食生产基地,近年来种植面积无序扩张使地下水超采问题日益突出。为合理管控地下水资源,通过收集1990~2019年西辽河平原区的地下水埋深监测站信息,利用水位动态法划分地下水超采区、疏干体积法推算地下水超采量。结果表明:(1)区域地下水位呈不同程度的下降趋势,且均通过显著性检验;(2)一般超采区占西辽河平原区面积的53.69%,严重超采区占平原区面积的0.68%;(3)2019年通辽市境内地下水超采量6.25×10^(8)m^(3)。通过地下水位年变差特征值法对西辽河平原典型区的地下水超采成因与治理难度进行预判分析,研究结果为西辽河流域“量水而行”综合治理提供科学依据。

The West Liaohe River basin located in Inner Mongolia is an important food production area in China.In recent years,the problem of groundwater over-exploitation has become increasingly prominent in the basin due to the massive expansion of agriculture.In order to manage groundwater resources in the basin more rationally in the future,this paper collected monitoring data of groundwater depth during 1990-2019,delineated the groundwater over-exploitation areas by the water level dynamic method,and calculated the quantity of excess pumping amount by the drainage volume method.The results show that:(1)The regional groundwater level show a downward trend in varying degrees,and all have passed the significance test;(2)In the West Liaohe plain,the moderate over-exploitation area accounts for 53.69%of the plain area,and the severe over-exploitation area accounts for 0.68%of the plain area;(3)In 2019,the groundwater over-exploitation volume in Tongliao City was 625 million m^(3).In addition,based on the eigenvalue analysis of groundwater level's annual variation,this paper predicates the cause of groundwater over-exploitation and the difficulty of groundwater management in a few typical locations,which could provide scientific basis for the economic development according to water availability initiative in the West Liaohe River basin.