开采条件下山东德州深层水资源组成及其与地面沉降的关系

针对德州长期过量开采深层水导致地下水位不断下降、地面沉降等环境地质问题,以深层地下水动态、地面沉降监测及其对应的粘性地层为主要研究对象,应用水文地球化学、地下水动力学和同位素技术方法,初步查明深层水主要形成于末次冰期盛期的大气降水补给;考虑地面沉降条件下,开采资源中20.6%的侧向径流补给和越流补给来自区域径流系统,反映深层地下水具有一定的更新能力;含水层弹性释水占17.5%,其中61.9%来自粘性土的压密释水,这是产生地面沉降的直接原因。     

开采浅层地下水对地面沉降影响的探讨

苏锡常地区由于长期过量开采深层地下水，已诱发了严重的地面沉降灾害。为此，江苏省政府下达了在2005年全面禁采深层地下水的文件。为解决用水问题，许多专家、学者建议开采利用浅层地下水。在苏锡常地区开采浅层地下水是否会同样诱发严重的地面沉降问题，是目前争议的焦点。文章详述了苏锡常地区水文地质条件及地面沉降现状，确定了地面沉降的各种影响因素，分析对比了浅层地下水与深层地下水在开采条件下所能引起的地面沉降量，说明采用合理的开采工艺开发利用浅层地下水不会诱发严重的地面沉降。     

河北省邯郸、邢台东部四县地下水越流问题的同位素分析

深层地下水的属性、深浅层地下水的水力联系(越流)是水文地质工作者一直研究和争论的问题。在对邯郸、邢台东部四县深、浅层地下水的氢、氧同位素样品的采集与测试中,发现该区地下水中氚同位素含量较高(15～30 TU,最高达51.1 TU)。本文利用区域大气降水中氚同位素衰减规律与特征,结合研究区地下水的水位和水质动态特征、含水层及隔水层的岩性特征,对特定水文地质条件下浅层地下水向深层地下水越流的可能性进行了分析研究,认为:本区存在浅层地下水越流至深层地下水的可能,在深层地下水中出现的高氚含量是其重要的证据。     

从地面沉降论河北平原深层地下水资源属性及合…

以河北平原中、东部及滨海地区为例，根据地面沉降量反求深层地下水开采量的构成，确定了由含水层及粘性土压密所释放的水量分别多年累积开采量的２４．３６％和３６．４５％，并根据水文地质、地下水动态资料的深入分析，推测在未来的地下水开采，深层地下水可获得来自系统外部的补给量将不大于总开采量的４％，，由此获得了深层地下水资源属性及合理评价的新认识。     

衡水市区深层地下水资源构成分析

衡水市区深层地下水严重超采,引起一系列环境地质问题。基于地下水均衡理论,建立地下水均衡模型,确定浅层地下水对深层地下水越流补给量,提出深层地下水开采资源的资源构成,为合理开采深层地下水资源,保护地质生态环境,完善地下水压采方案提供了科学依据。     

深层水漏斗区开采量组成变化特征与机制

为阐明强烈开采条件下华北平原深层水的开采水量来源及组成问题,以德州地区深层水漏斗分布区为重点研究区,通过基于大量钻孔资料对含水层组及其粘性土夹层或透镜体的分析和野外地下水采样、动态监测及地面沉降测量资料等分析,采用分层、分区计算方法对漏斗中心至外围的各分区弹性释水量、粘性土压密释水量、侧向流入和越流补给量进行均衡计算。结果表明:在强烈开采条件下,深层水开采量中弹性释水量和压密释水量所占比率不是常量,随着深层水位下降的幅度和深度增大、超采释压持续时间愈长、开采层中粘性土夹层或透镜体愈多,则区内弹性释水和压密释水的强度及累积地面沉降量愈大;愈靠近漏斗中心,弹性和压密释水强度愈大,相同降深下平均单位降深的地面沉降量愈小。在深层水开采量中粘性土压密释水占35.5%~61.9%,与地面沉降密切相关。     

关于河北平原区深层地下水资源属性的探讨

以河北平原为例,采用同位素、地下水资源评价和地下水水位动态3种思路分析了深层地下水资源属性。根据实测地面沉降量反求深层地下水储存资源量的构成,确定了在以往的深层地下水资源计算时储存资源量少计算了32.77%,弹性释放系数比以往的数据大;根据深层地下水动态特征,分析认为深层地下水资源在同一水文年内可以得到部分恢复,在深层地下水降落漏斗区地下水循环速率将加大,并根据沉积学的观点,认为河北平原含水层在各期古河道带交叉重叠部位或在重叠部位附近可能是连通的,浅层地下水可以沿着各期古河道带沉积的砂性土构成的含水层向下补给深层地下水,其补给量远大于通过巨厚的黏性土层向深层地下水的越流补给。     

从地面沉降论河北平原深层地下水资源属性及合理评价

以河北平原中、东部及滨海地区为例，根据地面沉降量反求深层地下水开采量的构成，确定了由含水层及粘性土压密所释放的水量分别为多年累积开采量的２４．３６％和３６．４５％，并根据水文地质、地下水动态资料的深入分析，推测在未来的地下水开采中，深层地下水可获得来自系统外部的补给量将不大于总开采量的４％，由此获得了深层地下水资源属性及合理评价的新认识。中国法分类号Ｐ６４１．７，Ｐ６４１．８     

山东省滨州市咸水入侵防治对策研究

滨州市深层地下水开采量主要由弹性储存量、越流补给量、径流量、压密释水量组成,地下水滞留时间长,更替时间缓慢.通过40年来深层地下水水动力场、水化学场和开发利用状况分析,认为过量开采是深层地下水位持续下降和降落漏斗形成的主因,地下水降落漏斗的快速扩展是咸水入侵的根本原因.采用解析法计算两个约束条件下深层地下水的允许开采量2001.9 m3/a.为合理开发利用地下水和防止成水入侵,提出了限量开采、回灌补源等措施.     

天津市地下水流-地面沉降耦合模型

天津市平原区地面沉降主要由地下水大量开采引起,影响范围广、危害大,已成为天津市主要的环境地质问题。分析了研究区的水文地质条件,结合地下水开发利用状况,将研究区概化为6个含水层组,地下水流考虑三维非稳定流,地面沉降选用一维固结压缩模型,运用地下水流模型Modflow 2005和地面沉降模拟模块 Sub,建立了天津市平原区地下水流-地面沉降数值耦合模型,模型面积为1.1×10⁴ km²,利用1998-2008年地下水位等值线、过程线、地面沉降过程线等资料对模型进行了识别。模拟期的地下水均衡分析表明,在多年开采条件下,越流补给、压缩释水、侧向边界流入分别占深层含水层补给量的41.84％、32.15％和24.17％。将调试后的模型应用于南水北调实施后地下水控采条件下的地面沉降趋势预测,显示出停采或减少地下水的开采,有利于减缓地面沉降下降速度,且表现出开采层位越往下,地面沉降恢复难度越大的变化趋势。     

浅层地下水人工回灌应用于上海市工程性地面沉降防治的试验研究

上海地面沉降主要由过量开采地下水资源和大规模工程建设等因素共同影响,工程性地面沉降引起的地面沉降漏斗严重影响了周边地区生命线工程的建设及运营安全。通过开展试验研究,将深部承压含水层中应用成熟的地下水人工回灌技术引入浅部含水层中,但由于浅部含水层砂层结构及水动力条件与深部含水层差异较大,回灌工艺及方法也存在差异。本次试验工作中,改进了地下水人工回灌工艺流程,并通过同步地面形变监测分析了浅层地下水人工回灌对控制地面沉降的作用效果。结合上海地区实际地层特征以及各种回灌工艺的实际效果,评价了浅层地下水人工回灌技术在防治工程型地面沉降中推广应用的可行性及适用性。     

Groundwater resources protection and aquifer recovery in China

The groundwater resources in China and especially the northern part represent a vital water resource. Both the shallow and deep aquifers are highly overexploited in a large area of north China. The heavy overexploitation of groundwater resources is causing major environmental damage. To protect groundwater resources, several technical feasibility studies were performed. Artificial recharge using floodwater and wastewater was tried. Surface spreading systems are applicable in many areas of the Yellow River basin and Hai River basin. Deep aquifer injections were undertaken in the urban area. A far better strategy is to reduce the extraction of groundwater, especially to stop or slow down land subsidence and seawater intrusion. To address the problem of falling groundwater levels and aquifer recovery, there is a need reduce groundwater extraction and artificial recharge.     

海河流域地下水资源保护

地下水资源在海河流域至关重要的资源。海河平原的浅层和深层含水层大面积处于严重超采状态。地下水资源的的过量开采造成了严重环境问题。为了保护地下水资源，评价了可行的技术。利用洪水和废水进行人工回灌已进行了试验。在很多地区可以应用地表回灌系统，城市地区实施深层含水层的回灌。更好地策略是减少地下水的抽取量，特别是为了减缓地面沉降和海水入侵。应该联合运用减少地下水抽水量和人工回灌，以解决地下水位持续下降和含水层恢复的问题。     

雄安新区白洋淀湿地地表水和地下水转化关系及其对芦苇分布的影响

查明地表水和地下水作用关系对湿地生态保护与修复具有重要意义。采用地表水和地下水位监测、氢氧稳定同位素分析、湖床沉积物温度示踪等方法,研究了白洋淀渗漏对周边浅层地下水的影响范围和深度,评价了地表水垂向渗漏速率,并探讨了芦苇分布面积和地表水位以及地下水位埋深的关系。结果表明：白洋淀渗漏受地质结构和水力梯度等因素影响,对浅层地下水垂向上影响深度为20 m,水平向上影响范围存在较大空间变异。周边浅层地下水的补给来源为大气降雨和地表水,其中地表水渗漏的补给比例为0~90.5%。淀区渗漏速率0.01~0.59 mm/d,和含水层埋深关系密切,埋深越小,越有利于地表水渗漏。1976-2020年,白洋淀芦苇分布面积和地表水位关系密切。当地表水位为6.3~6.8 m时,芦苇分布面积最大,在水位小于6.3 m条件下芦苇面积随着水位增高而增加,大于6.8 m条件下随着水位增高而减少。芦苇台地下水位埋深和地表水位显著相关,在2020年4-9月芦苇生长期,除雨季前期外多数时段台地地下水埋深均适宜芦苇发育,建议在雨季前期实施生态补水,通过降低台地地下水位埋深促进芦苇生长发育。研究结果可为白洋淀生态补水、渗漏防治和生态保护提供参考。     

GIS for the assessment of the groundwater recharge potential zone

Water resources in Taiwan are unevenly distributed in spatial and temporal domains. Effectively utilizing the water resources is an imperative task due to climate change. At present, groundwater contributes 34% of the total annual water supply and is an important fresh water resource. However, over-exploitation has decreased groundwater availability and has led to land subsidence. Assessing the potential zone of groundwater recharge is extremely important for the protection of water quality and the management of groundwater systems. The Chih-Pen Creek basin in eastern Taiwan is examined in this study to assess its groundwater resources potential. Remote sensing and the geographical information system (GIS) are used to integrate five contributing factors: lithology, land cover/land use, lineaments, drainage, and slope. The weights of factors contributing to the groundwater recharge are derived using aerial photos, geology maps, a land use database, and field verification. The resultant map of the groundwater potential zone demonstrates that the highest recharge potential area is located towards the downstream regions in the basin because of the high infiltration rates caused by gravelly sand and agricultural land use in these regions. In contrast, the least effective recharge potential area is in upstream regions due to the low infiltration of limestone.     

Assessment of water level threshold for groundwater restoration and over-exploitation remediation the Beijing-Tianjin-Hebei Plain

The Beijing-Tianjin-Hebei Plain (BTHP) is the political, economic and cultural center of China, where groundwater is the main source of water supply to support social and economic development. Continuous overdraft of the resources has caused a persistent decline of groundwater level and formed a huge cone of depression at a regional scale. This paper addresses current groundwater situation over the BTHP area. The paper also delineates the groundwater flow field, using groundwater level data, in order to provide an effective method for the restoration of groundwater level and associated water resources management. Based on the analysis of multiple factors, such as groundwater level, soil salinization, ground subsidence, groundwater recharge and storage, urban underground space security, formation of fractures, and seawater intrusion, the threshold for groundwater level restoration is defined, and some measures for groundwater over-exploitation management are accordingly proposed. The study shows that: (i) Since the 1980s to 2020, shallow groundwater level in the western part of the BTHP area has dropped by 25 m to 60 m, while the cumulative decline of deep groundwater in the central and eastern regions is in the range of 40–80 m; (ii) The water table of the shallow groundwater within the depression zone over the Western Piedmont Plain should be controlled in the range of 15–30 m below ground level (mbgl), while the depth of groundwater level in large and medium-sized urban areas should be controlled within 20–30 mbgl. The groundwater level in the resource preservation area should be controlled within 10–15 mbgl, and the groundwater level in the area with identified soil salinization in the central and eastern plain should be controlled within 3–10 mbgl. However, for the deep groundwater in the central and eastern plainwater, the main focus of the resources management is to control the land subsidence. The water level in the severe land subsidence area should be controlled within 45–60 mbgl, and in the general subsidence area should be controlled within 30–45 mbgl; (iii) Based on the water level recovery threshold and proposed groundwater overdraft management program, if the balance of abstraction and recharge is reached in 2025, the shallow groundwater abstraction needs to be gradually reduced by about 2×10⁸ m³. Meanwhile, the ecological water replenishment of rivers through the South-to-North Water Transfer Project should be increased to 28.58×10⁸ m³/a, and the deep groundwater abstraction needs to be gradually reduced by 2.24×10⁸ m³. To reach the target of shallow groundwater level in 2040, surface water replacement is recommended with a rate of 25.77×10⁸ m³/a and the ecological water replenishment of rivers in the South-to-North Water Diversion Project should reach 33.51×10⁸ m³/a. For deep groundwater recovery, it is recommended to replace the deep freshwater extraction with the utilization of shallow salt water by 2.82×10⁸ m³ , in addition to the amount of 7.86×10⁸ m³ by water diversion. The results are of great significance to the remediation of groundwater over-exploitation, the regulation of water resources development and utilization, and ecological protection in Beijing-Tianjin-Hebei plain.     

水位与沉降双控模式下浅层地下水压力回灌试验研究

通过浅层地下水压力回灌对比试验研究,掌握上海地区特殊地质条件下浅层地下水回灌技术工艺,并对浅层地下水压力回灌技术控制地面沉降的效果进行了分析。研究表明,采用变压力、变流量地下水人工回灌可有效实现地下水位和地面沉降的双重控制,效果显著,可有效应用于上海地区地下空间开发引发的工程性地面沉降防治实践。