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1.
基于情景分析的天津市滨海新区地面沉降预测   总被引:2,自引:0,他引:2  
鉴于地面沉降演化的地质系统渐变性特征,从主要致灾因子考虑建立地面沉降数值模型。设计3种地下水开采情景,编译计算机程序预测地下水位动态变化过程中的地面沉降值。至2020年,在最不利、适中和最理想3种情景下天津市滨海新区最大累计沉降量分别达640 mm、520 mm和150mm;全区平均累计沉降量分别达268 mm、177 mm和95 mm。  相似文献   

2.
天津市地下水流-地面沉降耦合模型   总被引:6,自引:0,他引:6  
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。  相似文献   

3.
唐山沿海地区经济在迅速发展,沿海地区城市化规模在扩大,地下水开采量增大,地面沉降加剧.文中分析了唐山沿海地区的水文地质条件,概化为3个含水层、3个弱透水层,共6个压缩层.建立了三维地下水流和垂向一维压缩完全耦合模型.采用25a的观测资料校正模型,计算值与实测值拟合较好,模型具有较高的仿真性和适用性.预测了10a末的地面沉降;当地下水以现有开采量开采时,沉降中心累计达1192.3mm, 10a沉降352.3mm,沉降速率为35.23mma-1;当地下水的开采量在现有开采量的基础上增加10%时,沉降中心累计达1260.8mm, 10a沉降420.8mm,沉降速率为42.08mma-1; 当地下水的开采量在现有开采量的基础上减小10%时,沉降中心累计达1088.7mm, 10a沉降247.9mm,沉降速率为24.79mma-1.增大10%的地下水开采量, 10a地面沉降量增加68.5mm;减少10%的地下水开采量, 10a地面沉降量减少104.4mm.因此,控制地下水开采量是控制地面沉降的有效方法.  相似文献   

4.
Suzhou is located at the lower reaches of the Yangtze River in southeastern Jiangsu, China. It is part of the Su-Xi-Chang area including Suzhou, Wuxi and Changzhou. As one of the most developed areas in China, this region has suffered from severe land subsidence caused by extensive groundwater exploitation since 1980s. The land subsidence was controlled by prohibition of groundwater exploration in the past several years. However, the surface water pollution prompted a new task of how to sustainably utilize the groundwater resource, especially to satisfy the emergency demands of water supply. In this paper, we took Suzhou as a representative case to discuss how to develop groundwater resources while controlling the land subsidence. The relationship between the deformation and the groundwater level was analyzed, with focus on the deformation features after the period of groundwater exploitation ban. The results confirmed the conclusion by Shi et al. (2007, 2008a): even in the period of rising groundwater level, same units may manifest different deformation characteristics, such as elasticity, elasto-plasticity, and visco-elasto-plasticity, at different locations of the cone of depression. A land subsidence model that couples a 3-D groundwater model and a 1-D deformation model was developed to simulate the groundwater level and deformation. A high-resolution local grid (child model) for Suzhou was built based on the regional land subsidence model of Su-Xi-Chang area by Wu et al. (2009). The model was used for a number of predictive scenarios up to the year of 2012 to examine how to develop sustainable use of groundwater resources under the conditions of land subsidence control. Our results indicated that about 3.08 × 107 m3/a groundwater could be provided as emergency and standby water source while meeting the land subsidence control target of 10 mm/a.  相似文献   

5.
Unplanned exploitation of groundwater constitutes emerging water-related threats to MayoTsanaga River Basin. Shallow groundwater from crystalline and detrital sediment aquifers, together with rain, dams, springs, and rivers were chemically and isotopically investigated to appraise its evolution, recharge source and mechanisms, flow direction, and age which were used to evaluate the groundwater susceptibility to contamination and the basin’s stage of salinization. The groundwater which is Ca–Na–HCO3 type is a chemically evolved equivalent of surface waters and rain water with Ca–Mg–Cl–SO4 chemistry. The monsoon rain recharged the groundwater preferentially at an average rate of 74 mm/year, while surface waters recharge upon evaporation. Altitude effect of rain and springs show a similar variation of −0.4‰ for δ18O/100 m, but the springs which were recharged at 452, 679, and 773 m asl show enrichment of δ18O through evaporation by 0.8‰ corresponding to 3% of water loss during recharge. The groundwater which shows both local and regional flow regimes gets older towards the basins` margin with coeval enrichment in F and depletion in NO3 . Incidentally, younger groundwaters are susceptible to anthropogenic contamination and older groundwaters are sinks of lithologenic fluoride. The basins salinization is still at an early stage.  相似文献   

6.
Large differential land subsidence and earth fissures in Jiangyin,China   总被引:1,自引:0,他引:1  
Jiangyin County is in the infamous Su–Xi–Chang land subsidence area caused by excessive groundwater withdrawal in Jiangsu province, China. The maximum accumulated land subsidence reached 1,310 mm near the centre of the subsiding trough in 2006 in southern Jiangyin, and earth fissures of significant vertical offsets have been observed at Changjing, Hetang and Wenlin which form an arc towards the subsidence trough. An ancient Yangtze River course is found underlying and passing through the depression in southern Jiangyin, forming a local basin surrounded by outcropped bedrock ridges in the north and south. The Quaternary stratigraphy demonstrates significant heterogeneities in the basin; the second confined aquifer is much thicker and deeper and encapsulated inside the basin and absent above the ridges. The development of earth fissures along the Changjing–Hetang–Wenlin arc might be a combination of an inward rotation of sediments due to a large differential subsidence, an inward movement driven by seepage force and a steeper slope along the south-eastern shoulder of the basin that facilitates the development of horizontal tensile strain and/or shear strain necessary for fissuring. The land subsidence has slowed down and no new earth fissure zone has occurred in the area after the banning of deep groundwater extraction was enacted in 2001.  相似文献   

7.
Hangzhou-Jiaxing-Huzhou Plain in northern Zhejiang Province, located between the Yangtze and Qiantang Rivers, is one of the regions where economic development is most rapid in China. Geological and hydrogeological surveys reveal a multi-layered aquifer system beneath the plain, which includes Holocene phreatic water layers and Pleistocene confined aquifers. Based on the historical records of groundwater extraction, groundwater levels, and ground settlement from 1964 to 2000, it is shown that ground subsidence has resulted from the continuously increasing extraction of groundwater from deep confined aquifers, and that the evolution of land subsidence can be characterized by a multifractal model. Based on this model, a set of empirical power-law relations have been established between: the land subsidence velocity and the annual groundwater extraction; groundwater drawdown and the annual land subsidence velocity; and the amount of land subsidence and the associated area of land. A set of indices are proposed for evaluating dynamic evolution of groundwater exploitation and land subsidence for the Hang-Jia-Hu Plain, from which the critical degree of evolution of land subsidence in the near future can be estimated using data on groundwater exploitation and water level changes.
Changjiang LiEmail: Phone: +86-571-85116129Fax: +86-571-87057826
  相似文献   

8.
Jakarta is the capital city of Indonesia with a population of about 9.6 million people, inhabiting an area of about 660 square-km. In the last three decades, urban development of Jakarta has grown very rapidly in the sectors of industry, trade, transportation, real estate, and many others. This exponentially increased urban development introduces several environmental problems. Land subsidence is one of them. The resulted land subsidence will also then affect the urban development plan and process. It has been reported for many years that several places in Jakarta are subsiding at different rates. The leveling surveys, GPS survey methods, and InSAR measurements have been used to study land subsidence in Jakarta, over the period of 1982–2010. In general, it was found that the land subsidence exhibits spatial and temporal variations, with the rates of about 1–15 cm/year. A few locations can have the subsidence rates up to about 20–28 cm/year. There are four different types of land subsidence that can be expected to occur in the Jakarta basin, namely: subsidence due to groundwater extraction, subsidence induced by the load of constructions (i.e., settlement of high compressibility soil), subsidence caused by natural consolidation of alluvial soil, and tectonic subsidence. It was found that the spatial and temporal variations of land subsidence depend on the corresponding variations of groundwater extraction, coupled with the characteristics of sedimentary layers and building loads above it. In general, there is strong relation between land subsidence and urban development activities in Jakarta.  相似文献   

9.
Land subsidence in China occurs predominantly in 17 provinces (cities) situated in the eastern and middle regions of the country, including Shanghai, Tianjin and Jiangsu, and Hebei provinces. It is primarily caused by groundwater overpumping. One of the areas most severely affected by land subsidence is the Yangtze Delta, most of which consists of Shanghai City, the Su-Xi-Chang area (Suzhou, Wuxi and Changzhou cities) of Jiangsu Province, and the Hang-Jia-Hu area (Hangzhou, Jiaxing and Huzhou cities) of Zhejiang Province. The excessive exploitation of groundwater forms in a large regional cone of depression and, consequently, land subsidence is also regional, currently centered in the Shanghai and Su-Xi-Chang areas. In 2002, the maximum cumulative subsidence of Shanghai, Su-Xi-Chang and Hang-Jia-Hu were 2.63 m, 2.00 and 1.06 m, respectively. The land subsidence area is continuing to expand throughout the Yangtze Delta. To study the characteristics and the pattern of this land subsidence, the government has implemented a monitoring system involving the placement of 37 groups of extensometers (layers marks) and drilling of more than 1000 observation wells. These provide an invaluable historical record of deformation and pore water pressure and facilitate studies on the special features of soil deformation when the groundwater level changes due to pumping. Several measures have been taken in recent years to control the development of the land subsidence in the different areas; these include groundwater injection, prohibition of pumping deep confined groundwater, and an adjustment of the pumping depth and magnitude of the groundwater withdrawn. At present, although the subsidence area is still increasing slowly, the subsidence rate is controlled.  相似文献   

10.
Evaluation of groundwater environment of Kathmandu Valley   总被引:1,自引:1,他引:0  
Kathmandu Valley aquifer in central Nepal is continuously under stress since the commencement of mechanized extraction of groundwater resources in early 1970s. Many wells have been drilled in shallow and deep aquifers of the valley; and numerous studies have been made in last four decades to understand the aquifers. However, up-to-date information on well inventory, water extraction, water quality and overall situation of groundwater environment are not yet known in the absence of institutional responsibility in groundwater management. This study attempts to evaluate current state of the groundwater environment considering natural and social system together; to better understand origin of stresses, their state, expected impact and responses made/needed to restore healthy groundwater environment. The analysis reveals increasing population density (3,150–4,680 persons/km2), urbanization (increase in urban population from 0.61 to 1.29 million) and increasing number of hotels due to tourism (23–62 hotels) during a decade are acting as driving forces to exceed groundwater extraction over recharge (extraction = 21.56 and recharge = 9.6 million-cubic meter-a-year), decrease in groundwater levels (13–33 m during 1980–2000 and 1.38–7.5 m during 2000–2008), decline in well yield (4.97–36.17 l/s during mid-1980s to 1998) and deterioration in water quality. In the absence of immediate management intervention with institutional responsibility for groundwater development, regulation and knowledgebase management (i.e. to facilitate collection, integration and dissemination of knowledge); situation of groundwater environment are expected to deteriorate further. Groundwater modeling approach may help to suggest appropriate management intervention under current and expected future conditions.  相似文献   

11.
Land subsidence in Bangkok, Thailand   总被引:9,自引:0,他引:9  
Land subsidence from deep well pumping has been affecting Bangkok for the past 35 years. Its impact is particularly critical because of the flat low-lying topography and the presence of a thick soft clay layer at the ground surface that augment flood risk and foundation engineering problems, respectively. The subsidence reached its most critical state in the early 1980s when it occurred at a rate as high as 120 mm/year. The rate decreased in the subsequent period but the subsidence-affected area expanded following the growth of the city. Despite various attempts implemented to remedy the crisis, groundwater pumping from the thick aquifer system underneath the city continued to increase from 1.2 million m3/day in the early 1980s to more than 2.0 million m3/day at the turn of the century. Piezometric levels in the main aquifer layers had been drawn down by as much as 65 m. Monitoring data showed a clear correlation between the subsidence and piezometric drawdown. The data suggested that for 1 m3 of groundwater pumped out in Bangkok Plain, approximately 0.10 m3 of ground loss occurred at the surface. Significant development has been made in numerical methods for prediction of differential settlements between building foundations caused by the piezometric drawdown in the aquifers. The strict mitigation measures adopted recently, comprising a pricing policy for groundwater management, an expansion of tap water supply, and strict enforcement of groundwater laws, have resulted in a marked drop in groundwater use. However, the land subsidence will continue for a long while owing to the time-dependent consolidation behavior of the soft clay layer and clay aquitards.  相似文献   

12.
天津市地面沉降及地下水位监测自动化系统的设计与应用   总被引:2,自引:0,他引:2  
于强  王威  易长荣 《地下水》2007,29(5):101-104
地面沉降是天津市当前最为主要的环境地质问题之一,影响着各类城市基础设施的建设 和维护,不利于城市的快速发展.天津地面沉降研究结果业已表明地下水超采是导致沉降的主要原因,大范围、长时间监测地面沉降发展过程及地下水开采状况是进一步开展地面沉降机理分析、预测地面沉降趋势并采取合理防治措施地基础.本文将详细介绍天津市一项地面沉降和地下水位监测自动化系统的设计和应用情况,为我国地面沉降监测与防治工作摸索新方法.  相似文献   

13.
北京地下水系统演化与地面沉降过程   总被引:2,自引:0,他引:2  
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。  相似文献   

14.
《China Geology》2021,4(3):455-462
The Luanhe River Delta is located in the center of the Circum-Bohai Sea Economic Zone. It enjoys rapid economic and social development while suffering relatively water scarcity. The overexploitation of groundwater in the Luanhe River Delta in recent years has caused the continuous drop of groundwater level and serious environmental and geological problems. This study systematically analyzes the evolution characteristics of the population, economy, and groundwater exploitation in the Luanhe River Delta and summarizes the change patterns of the groundwater flow regime in different aquifers in the Luanhe River Delta according to previous water resource assessment data as well as the latest groundwater survey results. Through comparison of major source/sink terms and groundwater resources, the study reveals the impacts of human activities on the groundwater resources and ecological environment in the study area over the past 30 years from 1990 to 2020. The results are as follows. The average annual drop rate of shallow groundwater and the deep groundwater in the centers of depression cones is 0.4 m and 1.64 m, respectively in the Luanhe River Delta in the past 30 years. The depression cones of shallow and deep groundwater in the study area cover an area of 545.32 km2 and 548.79 km2, respectively, accounting for more than 10% of the total area of the Luanhe River Delta. Overexploitation of groundwater has further aggravated land subsidence. As a result, two large-scale subsidence centers have formed, with a maximum subsidence rate of up to 120 mm/a. The drop of groundwater level has induced some ecological problems in the Luanhe River Delta area, such as the zero flow and water quality deterioration of rivers and continuous shrinkage of natural wetlands and water. Meanwhile, the proportion of natural wetland area to the total wetland area has been decreased from 99% to 8% and the water area from 1776 km2 to 263 km2. These results will provide data for groundwater overexploitation control, land subsidence prevention, and ecological restoration in plains and provide services for water resources management and national land space planning.© 2021 China Geology Editorial Office.  相似文献   

15.
为了准确模拟评价沧州市地下水开采对地面沉降的影响,为沧州市政规划和地下水资源管理提供决策依据,基于比奥固结理论,建立了地下水开采与地面沉降三维全耦合数学模型。在对模型进行识别和校正的基础上,模拟预测了在地下水现状开采情况下,从2010年12月31日至2025年12月31日逐年的地面沉降变化趋势,并根据地面沉降速率对地面沉降进行了地质灾害预警分区。结果表明,到2025年12月31日,沧州市累计最大地面沉降量为466.82 mm,最小地面沉降量为241.54 mm,大部分地区为四级预警区和五级预警区,仅肃宁县为三级预警区。  相似文献   

16.
众所周知,引起天津市地面沉降的主要因素是地下流体的开采导致的地层压缩。实际上,自然因素引起的地面沉降在总沉降量中也占有一定比重。引起天津市地面沉降的自然因素包括构造运动、地震活动以及欠固结土的大面积分布。论述了天津市与地面沉降相关的地质环境背景,并对引起地面沉降的自然因素逐一分析。构造运动引起地面沉降量在沧县隆起、冀中坳陷构造单元为1.41~1.53mm/a,在黄骅坳陷为1.90~2.15mm/a,全市平均1.5mm/a;地震发生前后时间段内,是地震导致地面沉降量变化影响最大的时期;天津市欠固结土(第一海相层)分布区(外环线以东)软土引起平均沉降量1.0mm/a。该研究对地面沉降的防治工作起到一定的参考价值。  相似文献   

17.
雄安新区地下水资源概况、特征及可开采潜力   总被引:1,自引:0,他引:1       下载免费PDF全文
地下水资源在中国社会经济发展中发挥重要作用,特别是在地表水资源相对匮乏的北方地区。掌握一个地区地下水资源状况、动态变化特征及可开采潜力,对该地区的供水安全保障至关重要。本文选择雄安新区,在近年来开展的区域水文地质调查、监测及综合研究等成果基础上,结合前人研究,对雄安新区区域水文地质条件、地下水动态变化特征等进行分析总结;以恢复地下水降落漏斗为地下水可持续开采利用方案的目标,从白洋淀流域平原区尺度,设置现状开采条件、河流补水、工农业节水及地下水禁(限)采等不同情景方案,采用地下水数值模拟技术,综合分析不同情景30年后的预测结果,提出白洋淀流域平原区地下水可持续开采利用方案;在流域地下水可持续开采利用方案基础上,分析雄安新区地下水可开采的最大资源量,进而评价雄安新区地下水可开采潜力。结果显示,雄安新区区域水文地质条件相对简单,浅层富水性中等,深层富水性较强;地下水位为多年下降状态,近年来,浅、深层地下水整体呈企稳或回升状态,局部地区仍有所下降;地下水质量总体良好,且较为稳定。根据评价结果,雄安新区地下水可开采潜力约为1.80×10~8m~3/a,其中,浅层地下水可开采潜力约为1.50×10~8m~3/a,深层地下水可开采潜力约为0.30×10~8m~3/a。  相似文献   

18.
Land subsidence is a serious problem in Taiwan’s Yunlin area due to groundwater overpumping. There are safety risks in the high-speed railway structures in the areas of Siluo, Huwei, Tuku, and Yuanchang towns that run from north to south in the Yunlin area. Therefore, it is important to increase the groundwater recharge and to remedy the land subsidence in this area. The purpose of this study is to use the stream-flow estimation model (SF) and the groundwater flow numerical software MODFLOW (MF) to estimate the stream infiltration with consideration to the variation of the river water level in the Hsinhuwei River. The Ferris analytical model (FA) and MF are used to estimate the increased stream infiltration after the water level of the river rises. The hydraulic parameters required for each model are obtained from field observations and laboratory experiments. The results indicate that the assessment of the stream infiltration obtained through the SF and MF models are 264.2 × 104 and 170.9 × 104 m3/year, respectively. When the river water level increases by about 2.5 m, the annual stream infiltration obtained through the FA and MF models significantly increases by 31.6 × 104 and 26.4 × 104 m3/year, respectively. Taken together, the stream storages estimated using these two models indicate that an increasing efficiency of groundwater recharge is within the range of 10.0–18.5%.  相似文献   

19.
济宁市区地面沉降及防冶措施研究   总被引:1,自引:1,他引:0  
地面沉降是近年来我国和世界上许多城市出现的重要的地质灾害之一,济宁城区1988年发现地面沉降,并以25.2mm/a沉降速度发展。本文从新构造运动、地下水开采、第四系砂土特征等方面,分析了济宁城区地面沉降的产生原因,指出新构造运动与超量抽取地下水是造成济宁城区地面沉降主要原因;通过对地下水开采量的变化趋势,中、深层地下水的补给条件的分析,对地面沉降变化趋势作出了预测;根据济宁市地处济宁矿区的特点,提出了综合利用地下水、防治济宁城区地面沉降进一步发展的对策。  相似文献   

20.
Earth fissures in Jiangsu Province, China have caused serious damages to properties, farmlands, and infrastructures and adversely affected the local or regional economic development. Under the geological and environmental background in Jiangsu Province, this paper presents the earth fissures caused by excessive groundwater withdrawal and coupled by distinctive geological structures such as Ancient Yellow River Fault in Xuzhou karst area, and Ancient Yangtze River Course and bedrock hills in Suzhou, Wuxi, and Changzhou area. Although all the earth fissures are triggered by groundwater exploitation, the characteristics are strongly affected by the specific geological and hydrogeological settings. In particular, in the water-thirsty Xuzhou city, the cone of depression caused by groundwater extraction enlarged nearly 20 times and the piezometric head of groundwater declined 17 m over a decade. As groundwater is extracted from the shallowly buried karst strata in the Ancient Yellow River Fault zone, the development of earth fissures is highly associated with the development of karstic cavities and sinkholes and their distribution is controlled by the Ancient Yellow River Fault with all the 17 sinkholes on the fault. On the other hand, in the rapidly developing Southern Jiangsu Province, groundwater is mainly pumped from the second confined aquifer in the Quaternary, which is distributed neither homogeneously nor isotropically. The second confined aquifer comprises more than 50 m thick sand over the Ancient Yangtze River Course, but this layer may completely miss on the riverbank and bedrock hills. With a typical drawdown rate of 4–6 m per annum, the piezometric head of groundwater in the second confined aquifer has declined 76 m at Maocunyuan since 1970s and 40 m at Changjing since mid-1980s, and a large land subsidence, e.g., 1,100 mm at Maocunyuan, is triggered. Coupled with the dramatic change of the bedrock topography that was revealed through traditional geological drilling and modern seismic reflection methods, the geological-structure-controlled differential settlement and earth fissures are phenomenal in this area.  相似文献   

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