北京地下水系统演化与地面沉降过程

采用地下水动态监测网、GPS监测网数据、气象监测数据与SAR数据、GIS等技术相结合,建立地下水系统演化与地面沉降过程模型,系统分析了北京地区地下水降落漏斗区地面沉降的形成过程。研究表明:降雨量呈逐年下降趋势,地下水开采量随之增大;平原区地下水位呈下降趋势,间接导致了地下水降落漏斗和地面沉降的形成演化。地面沉降对地下水降落漏斗的响应模式存在着季节与年际差异性,时空分布上存在不均匀性,最大地面沉降速率约为41.43 mm/a;揭示了地下水降落漏斗与地面沉降漏斗空间展布特性存在一致性,但并非完全吻合。     

Investigation of land subsidence due to groundwater withdraw in Rafsanjan plain using GIS software

Nowadays, the purpose of predicting land subsidence is to manage the optimum usage of groundwater, which is considered according to irregular use of groundwater. Digging deep and semi-deep wells and continuous drought, mainly in wasteland and semi-wasteland zone in recent years causes the land subsidence in Rafsanjan plain. The Rafsanjan basin is located in the nearly central part of Iran in the Kerman province, with a general elevation between 1,400–1,500 m above sea level. In this research, first, the deep and semi-deep wells were investigated and groundwater table data were colleted. Second, these informations were analyzed and corrected. These data were used to create great bank of information data, to manage and program the geographic information system (GIS) software. Then by investigation of an existing land subsidence data, which were collected by GPS in August 1998 and April 1999, by the GIS software, the results show that discharging of groundwater is the main factor of the land subsidence in Rafsanjan zone. Therefore, the critical land subsidence zone of the Rafsanjan plain was determined, and precaution and recommendations are presented.     

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。     

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.     

A new GIS-based data mining technique using an adaptive neuro-fuzzy inference system (ANFIS) and k-fold cross-validation approach for land subsidence susceptibility mapping

In this paper, we evaluate the predictive performance of an adaptive neuro-fuzzy inference system (ANFIS) using six different membership functions (MF). In combination with a geographic information system (GIS), ANFIS was used for land subsidence susceptibility mapping (LSSM) in the Marand plain, northwest Iran. This area is prone to droughts and low groundwater levels and subsequent land subsidence damages. Therefore, a land subsidence inventory database was created from an extensive field survey. Areas of land subsidence or areas showing initial signs of subsidence were used for training, while one-third of inventory database were reserved for testing and validation. The inventory database randomly divided into three different folds of the same size. One of the folds was chosen for testing and validation. Other two folds was used for training. This process repeated for every fold in the inventory dataset. Thereafter, land subsidence related factors, such as hydrological and topographical factors, were prepared as GIS layers. Areas susceptible to land subsidence were then analyzed using the ANFIS approach, and land subsidence susceptibility maps were created, whereby six different MFs were applied. Lastly, the results derived from each MF were validated with those areas of the land subsidence database that were not used for training. Receiver operating characteristics (ROC) curves were drawn for all LSSMs, and the areas under the curves were calculated. The ROC analyses for the six LSSMs yielded very high prediction values for two out of the six methods, namely the difference of DsigMF (0.958) and GaussMF (0.951). The integration of ANFIS and GIS generally led to high LSSM prediction accuracies. This study demonstrated that the choice of training dataset and the MF significantly affects the results.     

Simulation of groundwater flow and environmental effects resulting from pumping

In coastal lowland plains, increased water demand on a limited water resource has resulted in declining groundwater levels, land subsidence and saltwater encroachment. In southwestern Kyushu, Japan, a sinking of the land surface due to over pumping of groundwater has long been recognized as a problem in the Shiroishi lowland plain. In this paper, an integrated model was established for the Shiroishi site using the modular finite difference groundwater flow model, MODFLOW, by McDonald and Harbaugh (1988) and the modular three-dimensional finite difference groundwater solute transport model, MT3D, by Zheng (1990) to simulate groundwater flow hydraulics, land subsidence, and solute transport in the alluvial lowland plain. Firstly, problems associated with these groundwater resources were discussed and then the established model was applied. The simulated results show that subsidence rapidly occurs throughout the area with the central prone in the center part of the plain. Moreover, seawater intrusion would be expected along the coast if the current rates of groundwater exploitation continue. Sensitivity analysis indicates that certain hydrogeologic parameters such as an inelastic storage coefficient of soil layers significantly contribute effects to both the rate and magnitude of consolidation. Monitoring the present salinization process is useful in determining possible threats to fresh groundwater supplies in the near future. In addition, the integrated numerical model is capable of simulating the regional trend of potentiometric levels, land subsidence and salt concentration. The study also suggests that during years of reduced surface-water availability, reduction of demand, increase in irrigation efficiency and the utilization of water exported from nearby basins are thought to be necessary for future development of the region to alleviate the effects due to pumping.     

Groundwater resources management under environmental constraints in Shiroishi of Saga plain, Japan

A sinking of the land surface due to the pumping of groundwater has long been recognized as an environmental issue in the Shiroishi plain of Saga, Japan. Land subsidence can have several negative economic and social implications such as changes in groundwater and surface water flow patterns, restrictions on pumping in land subsidence prone areas, localized flooding, failure of well casings as well as shearing of structures. To minimize such an environmental effect, groundwater management should be considered in this area. In this study, a new integrated numerical model that integrates a three-dimensional numerical groundwater flow model coupled with a one-dimensional soil consolidation model and a groundwater optimization model was developed to simulate groundwater movement, to predict ground settlement and to search for optimal safe yield of groundwater without violating physical, environmental and socio-economic constraints. It is found that groundwater levels in the aquifers greatly vary from season to season in response to the varying climatic and pumping conditions. Consequently, land subsidence has occurred rapidly throughout the area with the Shiroishi plain being the most prone. The predicted optimal safe yield of the pumping amount is about 5 million m³. The study also suggests that pumping with this optimal amount will minimize the rate of land subsidence over the entire area. An erratum to this article can be found at     

华北平原典型地段地面沉降演化特征与机理研究

华北平原是世界上最大的地下水系统之一,地面沉降问题突出。由于沉积环境变化多样、地质条件差异性显著和人类开采活动强烈,使得该地区地面沉降成因机理复杂。本文采用卫星对地观测技术与传统手段相结合,监测地面沉降灾变过程,分析华北平原地面沉降发展历史和现状。结合应力-应变图解法及土工实验研究地面沉降差异性特征及滞后变形成因机理。取得了以下关键认识:(1)华北平原地面沉降空间分布差异性明显,沉降主要分布在平原区第四纪沉积凹陷,呈现东西分带、南北分段特点。地面沉降空间发展部分受到北东向和北西向构造控制。在沧县隆起区,地面沉降也比较发育,主要原因是沧县隆起在第四纪时期构造运动相对不活跃,沉积了较厚的第四系;存在与构造走向一致的3期古河道,该地区赋存丰富的地下水资源并被大量开采。(2)地面沉降发生发展与地下水开采历史密切相关,沉降主要压缩贡献层随地下水开采层位变化而变化。北京平原100 m以深地层对地面沉降贡献呈增加趋势。天津平原目前地面沉降的主要贡献层来自300 m以下地层。(3)气候干旱导致地下水补给量减少,同时增加了地下水的开采,因而是引起地面沉降的重要间接驱动因素。高层建筑荷载、基坑降排水、地热开采对地面沉降的影响应引起足够重视。(4)地面沉降具有很强的滞后性,最大滞后时间可达25年。除了渗透固结成因以外,土体蠕变是另外一个重要原因。更新世地层在不同荷载下,蠕变特征明显。沧县隆起晚更新世地层次固结可达到总变形28.3%。(5)土的物理性质、地下水位变化模式对土层变形特征具有重要影响。不同埋深地层在地下水位变化条件下的变形特征存在较大的差异(弹性、黏弹性、黏弹塑性)。浅部含水组呈现以弹性为主的变形特征。     

黄河三角洲地下水动态变化及其与地面沉降的关系

为了分析黄河三角洲地下水动态及其与地面沉降的关系, 利用多年地下水和地面沉降监测数据, 发现黄河三角洲广饶县和东营区的地下水动态变化剧烈且地面沉降严重, 含水层多处于超采状态, 浅、深层地下水降落漏斗先后出现.深层地下水降落漏斗中心水位下降速度达2~3m/a.近年来, 东营和广饶地面沉降漏斗中心沉降量和速率分别为155.1mm、28.2mm/a和356.0mm、64.7mm/a.借助GIS技术及数理统计法, 发现深层地下水降落漏斗与沉降漏斗空间耦合良好, 深层地下水位与地面高程呈线性正相关, 相关系数为0.92, 深层地下水过度开采已成为影响沉降的最根本因素.井灌区第三粘性压缩层成为地面沉降主要贡献层, 且深层地下水降落漏斗中心的地下水位已低于第三承压含水层临界水位, 沉降趋于严重.      

Simulation of spatial and temporal trends in nitrate concentrations at the regional scale in the Upper Dyle basin,Belgium

Models are the only tools capable of predicting the evolution of groundwater systems at a regional scale, by taking into account a large amount of information. This study presents the association of a water balance model (WetSpass) with a groundwater flow and solute transport model (SUFT3D, saturated and unsaturated flow and transport in 3D) in order to simulate the present and future groundwater quality in terms of nitrate in the Upper Dyle basin (439 km²) Belgium. The HFEMC (hybrid finite element mixing cell) method implemented in the SUFT3D code is used to model groundwater flow and nitrate transport. Spatially distributed recharge, modelled with WetSpass, is considered for prescribing the recharge to the groundwater flow model. The feasibility of linking the WetSpass model with the finite-elements SUFT3D code is demonstrated. Time evolution and distribution of nitrate concentration are then simulated using the calibrated model. Nitrate inputs are spatially distributed according to land use. The spatial simulations and temporal trends are compared with previously published data on this aquifer and show good results.     

湛江市区滨海平原地面沉降现状与防治对策

湛江市区地面沉降自20世纪80年代发生以来,随着地下水开采深度的增加,地面已出现了不同程度的沉降,影响了社会的稳定和经济的可持续发展。文章根据多年来的地面沉降与地下水动态监测、调查成果,对湛江市区滨海平原地面沉降历史与现状、地面沉降基本规律进行总结,提出了地面沉降防治措施建议,为地方制定水资源规划和地下水资源的管理决策提供科学依据。     

地面沉降对高速铁路的影响分析

北京平原区快速发展的地面沉降对高速铁路的发展构成了威胁,地面沉降与过量开采地下水造成的水位下降关系密切,为此有针对性地开展基于高速铁路的地下水动态与地面沉降相关关系研究对于高铁安全运行意义重大,特别是对于制定高铁沿线地下水开采方案、地面沉降减缓措施和工程措施至关重要。基于其对高速铁路的影响模式,本文将地面沉降分为区域沉降和局部沉降两种类型。针对区域沉降,利用Logistic方程,使用天竺、望京及王四营分层地面沉降和地下水位数据,构建了不同层位地下水水位变化与地面沉降之间的相关关系模型,通过ABAQUS计算局部地区,对于6m高路堤和15m CFG桩处理深度的地基而言,当渗透系数k=2m／d,距离线路边缘25m处浅层地下水下降10m将产生约61—85mm的沉降。     

Long term and seasonal ground deformation monitoring of Larissa Plain (Central Greece) by persistent scattering interferometry

The land subsidence which occurs at the Larissa Basin (Thessaly Plain, Central Greece) is due to various causes including aquifer system compaction. Deformation maps of high spatial resolution deduced by the Persistent Scattering Interferometry (PSI) technique (using radar scenes from ERS and ENVISAT satellites) for the period 1992–2006 were produced to study the spatial and temporal ground deformation. A developed GIS database (including geological, tectonic, morphological, hydrological, meteorological and watertable variation from wells in the area) offered the possibility of studying in detail the intense subsidence. The PSI based average deformation image clearly shows that subsidence generally takes place inside the Larissa Plain ranging from 5–250 mm. The largest amplitude rates (?25 mm/yr) are observed around the urban area of Larissa City (especially at Gianouli and Nikea villages), while the Larissa City center appears to be relatively stable with a tendency to subside. The rest of the plain regions seem to subside at moderate rates (about 5–10 mm/yr). The surrounding mountainous area is stable, or has slightly been uplifted with respect to the NE located reference point. It was found that there is a correlation between the seasonal water-table variation (deduced from wells data), the seasonal water demand for irrigation associated with specific types of cultivation (cotton fields), the monthly rainfall, and the observed subsidence rate in the rural regions of the Thessaly Plain.     

Influence of South to North Water Transfer on groundwater dynamic change in Beijing plain

Beijing is a city of severe water shortage. The groundwater plays a key role in the water supply. However, the groundwater level has been gradually descending due to extensive pumping in consecutive drought years. How to satisfy the water demand and recover the groundwater level is an urgent work. With the implementation of the South to North Water Transfer Project, an opportunity has been provided for restoration of groundwater under over exploitation. On the basis of hydrogeology conditions of the Beijing plain, as well as the high-performance parallel computing platforms, a groundwater flow numerical model was established. And dynamic monitoring data of groundwater levels were used to calibrate the numerical model. The calculation results fit well with the measured data in the calibrated model. Therefore, the calibrated model can be used to predict the dynamic change of groundwater levels in the Beijing plain. The results show that several obvious depression cones of groundwater have been formed because of the rapid decline of groundwater levels in the Beijing plain in recent years. After the implementation of the South to North Water Transfer project and due to the restrictions on groundwater exploitation, the area of cone of depression will be reduced to different degrees, the central water level of depression cone will increase, and some cones of depression around wellhead will disappear. It is a benefit to relieve water shortage and control the development of land subsidence and the deterioration of the ecological environment.     

北京潮白河冲洪积扇地面沉降时空异质性特征及驱动因素分析

为了研究地面沉降的时空分布模式、机理机制,选择北京典型沉降区——潮白河冲洪积扇为研究区,采用PS-InSAR技术、莫兰指数及地理探测器,分析了研究区地面沉降的空间异质性特征,探测了不同特征下的地面沉降的主要驱动因素。结果表明：2017-01—2019-01研究区内地面沉降时空分布特征以一般沉降为主,沉降速率为[-133,3] mm/a,最大累积沉降量为261 mm,呈北部轻微、中部较严重、南部较轻的分布状态,其中,严重、极严重等级地面沉降主要分布在中游顺义后沙峪东部等地区及中下游交界地带的潞城镇;不同地区地面沉降呈现不同的空间异质性特征,即不均匀地面沉降分布特征明显,中游、下游均表现为低—低集聚;不同分布特征下地面沉降主要驱动因素不同,中游地区主要驱动因素为第二承压水水位变化和可压缩层厚度,下游主要驱动因素为浅层地下水水位变化和第一承压水水位变化。莫兰指数能够有效分析地面沉降空间异质性,识别集聚特征;地理探测器可以探明沉降空间异质性成因,获得其主要驱动因素。     

北京平原区地面沉降水准监测网点位优化

长期超量开采地下水所诱发的地面沉降已经成为北京平原区最主要的地质灾害。文中针对现有水准监测网点位布设存在的不足,分别选取水文地质单元分区、主要开采层地下水位下降速率、可压缩层总厚度3类影响要素图件,基于GIS空间分析平台,划分北京平原区地面沉降综合影响因素分区,共划分448个分区。在此基础上,进行地面沉降水准监测网点位优化设计,新增水准点220个。同时,采用地质统计学中克里金插值误差的方差作为精度评价指标,分别绘制监测网优化前后标准差分布等值线图,发现优化后的标准差明显小于优化之前,证明以地质环境背景为依托,利用地面沉降综合影响因素分区图进行水准监测网点位优化设计的方法是可行的,可以作为今后地面沉降监测点布设的基础依据。     

Prediction of ground subsidence in Samcheok City,Korea using artificial neural networks and GIS

This study shows the construction of a hazard map for presumptive ground subsidence around abandoned underground coal mines (AUCMs) at Samcheok City in Korea using an artificial neural network, with a geographic information system (GIS). To evaluate the factors governing ground subsidence, an image database was constructed from a topographical map, geological map, mining tunnel map, global positioning system (GPS) data, land use map, digital elevation model (DEM) data, and borehole data. An attribute database was also constructed by employing field investigations and reinforcement working reports for the existing ground subsidence areas at the study site. Seven major factors controlling ground subsidence were determined from the probability analysis of the existing ground subsidence area. Depth of drift from the mining tunnel map, DEM and slope gradient obtained from the topographical map, groundwater level and permeability from borehole data, geology and land use. These factors were employed by with artificial neural networks to analyze ground subsidence hazard. Each factor’s weight was determined by the back-propagation training method. Then the ground subsidence hazard indices were calculated using the trained back-propagation weights, and the ground subsidence hazard map was created by GIS. Ground subsidence locations were used to verify results of the ground subsidence hazard map and the verification results showed 96.06% accuracy. The verification results exhibited sufficient agreement between the presumptive hazard map and the existing data on ground subsidence area. An erratum to this article can be found at     

北京平原区地面沉降分布特征及影响因素

地面沉降是北京平原区主要地质灾害之一。文中采用永久散射体差分干涉测量(PS-InSAR)技术获取平原区地面沉降空间分布特征,基于GIS空间分析平台,将多种地面沉降影响因素分别与PS-InSAR获取的地面沉降场形变信息进行耦合研究,查明地面沉降与多种影响因素之间的响应关系。研究发现:(1)北京市地面沉降发育较为严重的地区主要出现在平原区东部、北部以及南部等地,存在多个沉降中心,最大沉降速率达到152mm/a,区域不均匀沉降现象明显,并且有连成一片的趋势。(2)地面沉降分布具有明显的构造控制特性,沉降区多位于几大活动断裂交接部位的沉积凹陷地区,与第四纪沉积凹陷十分吻合。地面沉降的发展趋势与活动断裂的走向具有明显的对应关系,在有活动断裂通过的区域,地面沉降剖面线上表现出明显的转折或突变,断裂两侧区域不均匀沉降十分明显。(3)地面沉降分层沉降量与对应层位上黏性土占比呈正比例关系,其空间分布特征及变化趋势与平原区的地层结构及可压缩黏性土层厚度具有很好的一致性,沉降范围整体由北西向的单一结构区向南东方向的多层结构区扩张。沉降速率大于50 mm/a的沉降区大多分布在黏性土层厚度大于100 m的地区,几大沉降中心与黏性土层厚度较大地区吻合较好。(4)第二承压含水层(顶底板埋深100~180 m)地下水开采对地面沉降影响最大,沉降中心与该层位地下水位降落漏斗区高度吻合,是地面沉降的主要贡献层位。     

Numerical simulation of groundwater flow and contamination transport in Nahavand plain aquifer,west of Iran

Numerical simulation of groundwater flow used for the estimation of hydraulic and hydrologic parameters which is an important tool for the management of aquifers. This study presents the results of a mathematical model developed for the simulation of groundwater flow in Nahavand plain aquifer in the southwest Hamadan province. For this purpose Groundwater Modeling Software (GMS) was used which supports the MODFLOW-2000 code. After gathering required data such as the hydrological, hydrogeological and topography maps, a 3D hydrogeological model of plain was constructed with borehole and surface elevation data. Then MODFLOW was used for simulation of flow. After initial simulation of the flow, the model was calibrated in steady state with trial-and-error and parameter estimation methods the observed head of groundwater table monitoring data of 1997. Results of calibration show that error between observed head and computed head is in allowable range. Also results of computed head with model show that groundwater flow is in the direction of the dominate slope (southeast to northwest). Finally MODPATH code which simulates advective transport of particles was used for estimation of flow path and source of contaminants.     

浙江温州市永强平原地面沉降分析与趋势预测

温州市永强平原经济发达,工业化的发展和地下水无计划的开采,使永强平原地面沉降较为严重,永中累计沉降量超过300mm。为了更好地对永强平原地面沉降做出分析预测,本文通过研究区域地质环境、地下水开采量、地下水位的动态变化特征及2005～2010年的地面沉降监测资料,分析地面沉降速率、范围、沉降量,从而进一步探讨地面沉降与地层结构、地下水动态的关系,同时采用年开采量和年平均沉降速率预测2015年的地面沉降量。分析结果对深化永强平原地面沉降研究具有一定意义。