河南省南水北调受水区浅层地下水埋深变化分析

Analysis of Shallow Groundwater Depth Change in the Receiving Area of South-to-North Water Diversion Project in Henan Province

南水北调中线工程运行后地下水大量压采,需定量评估河南省受水区地下水埋深的变化特征。利用河南省2000—2020年受水区342口浅层地下水监测井的平均埋深、枯水期最大埋深和丰水期最小埋深年数据,通过空间插值法、水位动态法分析11个地市地下水埋深的变化特征,采用径向基函数神经网络模型计算地下水埋深关键驱动因素的贡献度。同时,统计用水结构中地下水的占比进行分析论证。结果表明:空间上,调水压采的成效主要为埋深4~<8 m向0~<4 m转换,集中在淮河流域中南部和长江流域埋深较小的区域。时间上,调水后受水区地下水埋深恢复情况丰水期最小埋深>平均埋深>枯水期最大埋深,同时郑州等7个地市的三个地下水埋深指标均得到恢复。影响因素上,相较降水量,地下水开采量对地下水埋深的影响更大。用水结构上,用水总量及四个分类中地下水占比在调水后显著下降。

After the operation of the middle route of the South-to-North Water Diversion project,a large amount of groundwater extraction is pressured,so it is necessary to quantitatively evaluate the variation characteristics of groundwater depth in the receiv‐ing area of Henan Province.Based on the annual data of average groundwater depth,maximum groundwater depth in dry season and minimum groundwater depth in wet season of 342 shallow groundwater monitoring wells in Henan Province from 2000 to 2020,the variation characteristics of groundwater depth in 11 cities were analyzed by special interpolation method and water level dynamic method,and the radial basis function neural network model was used to calculate the contribution rate of key driving fac‐tors of groundwater depth.At the same time,the proportion of groundwater in the water consumption structure is analyzed and demonstrated.The results show that:in-terms of space,the effect of pressure extraction of the South-to-North Water Diversion Project is mainly the conversion of groundwater depth from 4~<8 m to 0~<4 m,concentrated in the central and southern parts of the Huaihe River Basin and the Yangtze River Basin where groundwater depth is relatively small.In terms of time,the recovery of groundwater depth in the receiving area was minimum groundwater depth during wet season>average groundwater depth>maxi‐mum groundwater depth in dry season.At the same time,three groundwater level indicators in seven cities including Zhengzhou City have been restored.In terms of influencing factors,compared with precipitation,groundwater extraction has a greater influ‐ence on groundwater depth.In terms of water use structure,the proportion of groundwater in total water use decreased signifi‐cantly after water diversion project.