淮北平原浅层地下水多年动态变化及监测统测评估

【研究目的】变化环境下地下水时空规律的研究有助于水资源精细化管理和区域水资源安全保障。【研究方法】本文基于淮北平原区典型气象站1953—2019年月降雨数据，采用小波分析及M-K检验法，研究多年尺度降雨周期性变化及趋势规律；结合395个国家级监测井及地下水统测数据，采用主成分分析法进行监测井优化评价。【研究结果】淮北平原多年降雨量呈现多时空尺度变化特征，南部地区主周期较北部地区偏小，但周期尺度较多，变化更为复杂；西北部的浅层地下水位持续下降，其余区域水位处于有升有降的波动状态；南部区域浅层地下水水位在1970年、2003年及2019年3个时段呈现出先降低再恢复，北部部分区域地下水水位则呈现先升高再降低的特征，研究区水位总体存在下降趋势，但2000年以来水位总体有所回升；经主成分分析优化后的277个监测井（221个水利井和56个自然资源井）能代表395个原国家监测井的总体水位变化情况。【结论】国家地下水监测工程长序列监测数据能够很好地服务于流域尺度水资源评价及管理，但省市级尺度或重点区域还需要进行优化和加密，地下水位统测可有效填补，该工作应在重要河湖两侧、淮河北岸一带、东北部山前平原等高水力梯度区域进行加密。

Analysis of multi-year rainfall variation and shallow groundwater flow field monitoring in Huaibei Plain

This paper is the result of groundwater survey engineering. Objective] The study on the temporal and spatial law of groundwater under changing environment is helpful to the fine management of water resources and the guarantee for regional water resources security. Methods] Based on the rainfall data of typical weather stations in the Huaibei Plain from 1953 to 2019, the wavelet analysis and M-K test method was used to study the periodic changes and trend of rainfall on a multi-year scale. Combined with 395 national monitoring wells and groundwater monitoring data, the principal components analytical method was used to optimize the evaluation of monitoring wells. Results]The results show that the rainfall in Huaibei Plain appears multiple temporal and spatial scales variation characteristics: The shallow groundwater level has declined continuously in the northwest, while fluctuated greatly in the other regions; In 1970, 2003 and 2019, the shallow groundwater level in the southern region decreased firstly and then recovered, and on the contrast, the shallow groundwater level in the northern region increased firstly and then decreased; The groundwater level in the study area has generally declined; And since 2000, the water level has somewhat risen; The 277 monitoring wells (221 water wells and 56 natural resource wells) optimized by principal component analysis can represent the overall water level changes of 395 original national monitoring wells. Conclusions] The long-term monitoring data of the national groundwater monitoring project can well serve the evaluation and management of water resources at the basin scale, but still need to be optimized and densified at the provincial, municipal scales or key areas. The artificial observation in unified time period can also make up for this deficiency which should be densified in the high hydraulic gradient areas such as both sides of important rivers and lakes, the north bank of Huaihe River, and the piedmont plain in the northeast.