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1.
G. Y. Wang Greg Guanlin You B. Shi S. L. Wu J. Q. Wu 《Environmental Earth Sciences》2010,61(5):1085-1093
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
2.
Jichun Wu Xiaoqing Shi Yuqun Xue Yun Zhang Zixin Wei Jun Yu 《Environmental Geology》2008,55(8):1725-1735
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
3.
由于长期过量开采地下水,苏州、无锡和常州（苏锡常）的局部地区地裂缝发育,在深层地下水禁采十多年后的今天有些地裂缝还在发展。地裂缝的发育及发展受到诸多因素的影响,其具体力学机制尚不明确。为了查明影响地裂缝发育的因素、确定各因素对地裂缝的影响程度,本文在苏锡常地裂缝发育现状的基础上,利用基于确定性系数计算权重法对苏锡常地裂缝发育危险性进行预测分区。模型考虑了基岩埋深、基岩坡度、累计地面沉降量、沉降坡度、第二含水层厚度、第二含水层厚度变化梯度、第二含水层水位降深、第四纪沉积相等8个主要影响因素,分析结果显示苏锡常地区北部地裂缝易发,东南部发生地裂缝的危险性较小。计算结果与苏锡常地裂缝的分布及发育情况基本一致,验证了该方法在地裂缝预测方面的有效性。本研究对苏锡常地区地下水开采及城市建设规划具有一定的指导意义。 相似文献
4.
Excessive groundwater withdrawal from an aquifer system leads to three-dimensional displacement, causing changes in the states of stress and strain. Often, land subsidence and sometimes earth fissures ensue. Field investigation indicates that land subsidence and earth fissures in Wuxi, a city in eastern China, are mainly due to excessive groundwater withdrawal, and that they are temporally and spatially related to groundwater pumping. Groundwater withdrawal may cause tensile strain to develop in aquifer systems, but tensile strain does not definitely mean tensile stress. Where earth fissures are concerned, the stress state should be adopted in numerical simulations instead of the strain state and displacement. The numerical simulation undertaken for the Wuxi area shows that the zone of tensile strain occupies a large area on the ground surface; nevertheless, the zone of tensile stress is very limited. The zone of tensile stress often occurs near the ground surface, beneath which the depth to the bedrock surface is relatively small and has considerable variability. Earth fissures often initiate near the ground surface where tensile stress occurs. Tensile stress and earth fissures rarely develop at the centers of land subsidence bowls, where compressive stress is dominant. 相似文献
5.
Earth fissures triggered by groundwater withdrawal and coupled by geological structures in Jiangsu Province,China 总被引：3，自引：0，他引：3
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
6.
过量开采地下水诱发的地裂缝("采水型"地裂缝)灾害对社会造成严重损失,受到人们普遍关注。近几十年来,国内外学者对其成因机制进行了大量研究,取得了丰硕成果。本文系统分析了前人的研究成果,归纳出"采水型"地裂缝的差异沉降成因、拉张性水平应变成因和四种成因模式;然后针对中国三个典型的"采水型"地裂缝发育区,即汾渭盆地、华北平原、苏锡常地区,阐述了各地地裂缝分布、发育特征和成因机理,并选择典型地段地裂缝进行成因分析,认为汾渭盆地和华北平原地区部分地裂缝属于"先期断层模式",而苏锡常地区地裂缝总体属于"基岩起伏模式",并阐述了该模式下导致地裂缝发育的差异性变形、水平应变作用机理。 相似文献
7.
1995年以来,针对严重的区域性地面沉降和地裂缝灾害,苏锡常地区地下水资源保护和管理工作逐渐加强,特别是从2000年开始,江苏省政府分阶段实施限期禁止开采工作,首先在超采区实行地下水禁采,到2005年底,在苏锡常地区全面禁止开采地下水,全区地下水环境、地面沉降状况出现明显好转,地下水水位普遍回升,地面沉降速率逐渐减缓。根据近年来苏锡常地区地面沉降基岩标、分层标的系统监测资料,对地下水禁采后地质环境的效应特别是地面沉降的变化特征进行了初步分析、研究,并对该区今后地质环境保护工作提出了对策和建议。 相似文献
8.
Earth Fissuring and Land Subsidence in Western Saudi Arabia 总被引：4，自引：0，他引：4
The present investigation deals with the engineering geological evaluation of earth fissuring associated with land subsidence in Wadi Al-Yutamah. The investigations include surface mapping and sampling, in situ and laboratory soil testing, water well inventory, geophysical survey, and monitoring of open fissures and the level of the wadi floor.The earth fissures in the area developed as a result of land subsidence due to man-induced water level declines caused by pumping water from the wadi aquifer above a safe yield. This situation has produced a compaction of underlying unconsolidated sediments and formed hair fissures above ridges and steps of buried surface bedrock. These hair fissures enlarged later after flood erosion and possible enhancement with hydrocompaction.The wadi soil in the study area consists mainly of silt of low plasticity, low density and high void ratio and it was classified as loess like material and collapsing soil. The settlement in the area is greatly increased by excessive wetting under constant pressures. The calculated coefficients of subsidence (collapse) show that the wadi soils were considered to pose moderate problems when wetted.Monitoring of the existing open earth fissures using extensometers indicates that the width of the fissure increases after flooding or rain falls. Monitoring of the ground level using GPS techniques, shows a good relation between the declination of the water table and the subsidence of the ground of the wadi floor. 相似文献
9.
苏锡常地区地裂缝灾害危险性评价与预测 总被引：4，自引：1，他引：4
伍洲云 《水文地质工程地质》2004,31(1):28-31,51
苏锡常地区是我国近年来地裂缝灾害最为活跃的地区之一。作者在深入研究其灾害成因机理和形成过程的基础上 ,提取了基岩面起伏、浅部含水砂层差异、隐伏灰岩、浅部土层结构条件、累计地面沉降量、地面沉降速率和主采层水位共 7个主要影响因素 ,选用层次分析法确定权值 ,建立了苏锡常地裂缝危险性评价模型。以GIS软件Arcinfo为主要工具 ,利用其强大的空间分析功能 ,将各影响因素专题图层按照权重进行多重叠加操作 ,进行了不同时期地裂缝灾害危险性分区评价和发展趋势的预测。目前研究区地裂缝灾害危险性仍在增加 ,常州马杭镇与湖塘镇中间、武进横林镇铁路以北和无锡堰桥镇西北地区危险指数最大 ,是今后几年苏锡常地区防治地裂缝灾害的重点区域。 相似文献
10.
基于ANN的苏锡常地裂缝预测研究 总被引：5，自引：0，他引：5
伴随着地面沉降灾害的发生,地裂缝作为一种新的地质灾害出现在苏锡常平原上,已有十多年历史,给地区发展造成严重危害。作者在较详细地阐述区域地质背景基础上,着重分析了地下水位和地面沉降在地裂缝形成中的作用。确定了“起伏的基底外加地下水位和地面沉降作用”这一地裂缝成灾模式。研究认为地裂缝的发生与地下水及地面沉降之间不存在简单的线性关系。而是二者共同作用的结果,同时需要有量的配合。初步确定了水位埋深50m,地面沉降量达500mm这样一个苏锡常地区地裂缝的易发环境。通过文章的研究,使得苏锡常地区地裂缝的产生机制更加清晰。文中一些定性和半定量的分析结论将对该地区地裂缝防治区划产生指导作用。 相似文献
11.
长期过量开采地下水所引发的地面沉降是一个复杂的非线性变化过程,对其进行数值模拟时,如不考虑沉降发展过程中模型参数的非线性变化,会给预测带来很大误差。本文依据苏锡常地区实际资料,通过典型钻孔土力学试验,确定出土体在不同荷载条件下的弹塑性和蠕变特征方程以及土体渗透系数随孔隙度变化的关系式。在此基础上建立了研究区三维变系数地下水流模型及考虑土体垂向不同变化特征(弹塑变或蠕变)的一维区域沉降模型,并采用多尺度有限单元法对模型进行了真正意义上的耦合求解。 相似文献
12.
苏锡常地裂缝危险性分区 总被引：1，自引：0，他引：1
地裂缝作为苏锡常地区的一种地质灾害对该区的发展造成了严重危害。由于地裂缝孕育过程的非线性以及各影响因素作用关系的复杂性,使得难以用线性方法进行地裂缝危险性分区。在分析地裂缝发生的主要影响因素--古基岩面的起伏差异、第四纪沉积结构差异、地面沉降的不均一性和地下水的超采的基础上,将该4个因素的6项量化指标--基岩埋深、基岩起伏度、地下水位、地面沉降梯度、含水层导水系数以及粘性土层厚度作为输入量,采用遗传人工神经网络算法,建立了苏锡常地区地裂缝危险性分区模型。结果表明,苏锡常地区地裂缝危险区主要分布在常州东部、无锡中部和江阴南部地段,安全区主要分布在张家港的东北部、常熟市的东部、常州市的北部和西南部,较危险区和次安全区为危险区和安全区的过渡区。 相似文献
13.
Brian D. Conway 《Hydrogeology Journal》2016,24(3):649-655
Land subsidence due to groundwater overdraft has been an ongoing problem in south-central and southern Arizona (USA) since the 1940s. The first earth fissure attributed to excessive groundwater withdrawal was discovered in the early 1950s near Picacho. In some areas of the state, groundwater-level declines of more than 150 m have resulted in extensive land subsidence and earth fissuring. Land subsidence in excess of 5.7 m has been documented in both western metropolitan Phoenix and Eloy. The Arizona Department of Water Resources (ADWR) has been monitoring land subsidence since 2002 using interferometric synthetic aperture radar (InSAR) and since 1998 using a global navigation satellite system (GNSS). The ADWR InSAR program has identified more than 25 individual land subsidence features that cover an area of more than 7,300 km2. Using InSAR data in conjunction with groundwater-level datasets, ADWR is able to monitor land subsidence areas as well as identify areas that may require additional monitoring. One area of particular concern is the Willcox groundwater basin in southeastern Arizona, which is the focus of this paper. The area is experiencing rapid groundwater declines, as much as 32.1 m during 2005–2014 (the largest land subsidence rate in Arizona State—up to 12 cm/year), and a large number of earth fissures. The declining groundwater levels in Arizona are a challenge for both future groundwater availability and mitigating land subsidence associated with these declines. ADWR’s InSAR program will continue to be a critical tool for monitoring land subsidence due to excessive groundwater withdrawal. 相似文献
14.
通过地球物理勘探和地下水动态研究,认为柏乡地裂缝主要是过量开采地下水引起的。过量开采地下水导致了该地区大面积的地面沉降,地层的差异沉降诱发了地裂缝;大量降水造成表层土软化,有些表层土随雨水流入下面的裂缝中,使地裂缝显现出来。 相似文献
15.
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
16.
金沙洲可溶性灰岩分布面积广,岩溶洞隙发育,洞隙及地下水的连通性强,上覆第四系松散土体中软土广泛分布,客观存在岩溶地面塌陷及地面沉降的地质环境条件。2007年4月起,受某高铁隧道施工抽排地下水的影响,金沙洲地下水出现异常波动,引发了地面塌陷及地面沉降。文章根据监测数据,经对比分析结果表明,区内岩溶地面塌陷及地面沉降受控于地下水位的变化,地下水位波动至基岩面附近时,是地面塌陷较活跃的时期,地面沉降与地下水位变化呈正向相关。文章进一步对地面沉降与地下水位变化关系的机理进行了探讨,认为目前地下水位尚未恢复正常的区域仍存在地面塌陷及地面沉降的隐患。 相似文献
17.
根据江苏省徐州市睢宁县城区内可压缩土层的类型、空间分布特点及压缩变形等特征,建立了本区地面沉降计算地质模型。利用该模型计算出城区2013年累计地面沉降量3.08~380.60 mm,平均为162.41 mm,最大沉降量发生在城区西北部,该区域可压缩土层、黏性土的累计厚度大,地下水水位下降幅度较大。根据预测2030年地下水位埋深条件,采用地面沉降地质模型计算得出城区累计地面沉降量,在此基础上对区内地面沉降危险性进行分区,从而为地下水开采总量的控制及地面沉降监测控制提供相关建议措施,以避免城区2030年后地面沉降地质灾害逐步发展为特大型地质灾害。 相似文献
18.
衡水地区地裂缝空间发育特征与地下水位降深关系 总被引：1，自引：0，他引：1
通过浅层地震法及高密度电阻率法物探对河北衡水地区最近发现的3条地裂缝调查，探明了地裂缝地下发育深度、宽度、倾向等，发现地裂缝在地表与地下发育特征有明显不同：地表以一条地裂缝存在，在地下深处则以裂缝带发育，裂缝带两侧裂缝埋深不同，地下裂缝形态表现为上窄下宽。对该地区深层钻探、水文地质和多年地下水开采等资料分析表明，该地区的地裂缝是地质历史时期地质构造活动产物，开采深层地下水等资源则是促使地裂缝发展的主要原因。通过对不同地点地裂缝发育深度与近36年以来地下水水位降深的关系分析，结果显示：不同地区地裂缝发育深度与相应深层地下水水位降深呈线性关系。研究成果对地裂缝机理研究及预防开采深层地下水对地质环境的影响具有指导作用。 相似文献
19.
江苏松散沉积层厚度大、结构复杂、容易发生固结压缩,地下水可采资源量评价具有较大的不确定性,容易造成重复或缺失,地下水的过量开采又容易引发地面沉降地质灾害。针对以上问题,提出了地下水资源评价的地下水渗流三维数学模型及其地下水渗流与地面沉降耦合模型。地下水渗流三维数学模型可以将整个松散沉积层作为一个统一的水文地质体进行计算,对不同水力性质的含水层同时进行刻画描述,克服了以往二维或准三维模型将各含水层之间的粘性土层概化为越流层给评价结果带来的重复或缺失。地下水渗流与地面沉降耦合模型可以结合地面沉降环境控制,评价出地下水的可采资源量,尤其是以比奥固结理论为基础,考虑了土体的非线性特征及土的渗透性随应力状态的动态变化的全耦合模型,使评价结果更趋科学、合理。 相似文献