南水北调中线河南省受水区浅层地下水水位演化规律

南水北调中线工程供水后对河南省受水区浅层地下水位、用水结构等产生了重要影响。首先回顾了河南省平原区以往地下水位埋深变化，并通过收集、统计2008—2018年河南省受水区浅层地下水位的监测成果，基于ArcGIS软件，针对南水北调中线供水前后河南省受水区浅层地下水位变化进行量化分区；结合降水量、地下水资源量、供水量等资料对供水前后河南省受水区用水结构变化等进行分析。结果表明:自20世纪60年代至2008年，河南省平原区浅层地下水位平均埋深整体逐渐增加；河南省受水区地下水资源量随降水量增加呈线性增加趋势；南水北调中线一期供水后，2015—2018年平均地下水供水量在地下水资源量中的占比较2008—2014年减少9.55%；受水区浅层地下水位有所回升，且主要体现在埋深 > 8~12 m范围向埋深 > 4~8 m及≤4 m范围的转变，埋深 > 12~16 m及 > 16~20 m范围在受水前后基本保持不变，埋深 > 20 m的区域范围有所减少；2008—2014年各监测点分布县区的浅层地下水位呈下降趋势，2015—2018年供水期间有2/3以上县区浅层地下水位逐渐恢复；农林渔业用水和工业用水占比在供水后均有所减小，城乡生活、环境综合用水占比增加明显。研究结果表明南水北调中线工程对河南省受水区浅层地下水位恢复及缓解供水矛盾问题等产生积极有效的影响。 

Evolution law of the phreatic aquifer water table in the water intake area of South-to-North Water Diversion Central Line in Henan Province

The water supply of the South-to-North Water Diversion has presented a significant impact on the phreatic aquifer water table and the water consumption structure in the intake area of Henan Province. This paper firstly reviews the previous changes of groundwater level burial depth in the plain area of Henan Province, and by collecting and counting the monitoring results of shallow groundwater level in the receiving area of Henan Province from 2008 to 2018, we quantified and partitioned the changes of shallow groundwater level in the receiving area of Henan Province before and after the water supply of the South-to-North Water Transfer Central Line based on ArcGIS software. Then we analyzed the changes of water use structure in the receiving area of Henan Province before and after water supply by combining the information of rainfall, underground water resources and water supply. The results show that from the 1960s to 2008, the average buried depth of shallow groundwater in plain area of Henan Province has gradually increased; the groundwater resources increased linearly with the increase of precipitation. The average groundwater output from 2015-2018 is reduced by 9.55% compared with that of 2008-2014 due to South-to-North Water Diversion Project on Henan section. The phreatic aquifer water table presents recovery, with the area of phreatic line depth of > 8-12m changing into > 4-8 m and ≤4 m. The area of phreatic line depth of > 2-20 m remains at stable, and the area of phreatic line depth larger than 20 m reduces gradually. The phreatic aquifer water tables in the monitoring points area showed a downward trend before the water supply, which presented a gradually recovery after the water supply in more than 2/3 of the counties. The proportion of water used for agriculture, forestry and fishery and industrial use decreased after the water supply, while the proportion of water used for urban and rural living and environmental integration increased significantly. The research results indicate that the South-to-North Water Diversion Project has a positive and effective impact on the restoration of shallow groundwater level in the receiving area of Henan Province and the alleviation of water supply contradiction problems.