Urbanization process and induced environmental geological hazards in China

Urbanization is a common development trend of countries all over the world, which is a mark of civilization and progress of human beings. The number of urbanization-induced environmental geological hazards has grown steadily in recent years and is receiving increased attention throughout the world. The purpose of this paper is to generalize China’s urbanization process and induced environmental geological hazards. Driving forces and characteristics of urbanization are briefly introduced in this study; specifically, the distribution of urban agglomerations is principally related to water resources, transportation and energy. Common geological hazards and particular ones in mountain city, mining city and coastal city are also summarized. The type and severity of hazards are different due to the differences of natural conditions and various urban functions. Main environmental geological hazards in cities are land subsidence, landslide and seawater intrusion, etc. Accordingly, reasons for these urbanization-induced geological hazards in different type of cities are analyzed and discussed. The research results may provide a clear perspective for urban geological hazard prevention, and suggestions for urban geological hazard control are pointed out.     

重庆市矸石山环境地质灾害效应及稳定性分析

煤矸石是我国排放量及积存量最大的工业废弃物。我国现有矸石山1500余座,累计存量约34亿t。矸石排放量的持续增加造成严重的地质灾害隐患。论文分析了矸石山的污染效应、自燃效应、占地效应、爆炸效应、结构侵蚀效应、失稳效应及景观破坏效应系列环境地质灾害效应。为避免矸石山失稳所造成的危害,对重庆地区的矿区进行现场调研踏勘。根据其结果对影响矸石山稳定的因素及几种失稳模式进行了分析,并在此基础上,依据塑性极限分析原理,针对矸石山边坡失稳主要形式,利用极限分析上限定理推出了矸石山边坡稳定堆积高度的计算公式,并采用在重庆地区矿区调研踏勘及现场直剪试验所得到的参数进行计算,做出对应表格及曲线。其结果可作为确定矸石山实际堆放高度的理论依据。     

Overexploitation status of groundwater and induced geological hazards in China

During the process of urbanization and industrialization, groundwater has been extensively overexploited, with the direct result of continuously decreasing groundwater level, followed by the appearance of large scale of depression cones, which is furthermore followed by land subsidence, seawater intrusion, and increasing difficulties in subsequent groundwater exploitation. This paper makes an analysis on the geological disasters caused by overexploitation of groundwater. The consumption and overexploitation status of groundwater in representative regions in China is discussed first, with the distribution and development of depression cones elaborated the next. And the problems of land subsidence, seawater intrusion, and increasing difficulties caused by overexploitation of groundwater are analyzed at last. Results show that overexploitation of groundwater is positively related to economic development. Moreover, geological disasters such as land subsidence and seawater intrusion caused by long term of overexploitation also aggregate, posing threats, and losses to people’s lives and production. According to the analysis, the fundamental resolution for overexploitation of groundwater as well as consequential geological damages is to properly control city size and to utilize groundwater rationally and efficiently.     

Evolution of major environmental geological problems in karst areas of Southwestern China

Karst terrains are generally regarded as a fragile and vulnerable environment. China’s karst is mainly developed in pre-Triassic, old-phase, hard, compact carbonate rock. The lack of soil cover in bare karst land can enhance desertification. Its underground drainage system can aggravate both drought and flooding problems; the interconnected surface and subsurface conditions allow for easy contamination by pollutants. Moreover, karst terrains quite often suffer from a series of engineering problems, such as water infiltrating into mines or transportation tunnels, leakage from reservoirs, and failure of building foundations. As resources and energy exploitation intensified in recent years, karst areas in Southwest China faced some severe geo environmental problems. In order to find out how the problems action and evolution in recent years, field and laboratory investigations were conducted in Guangxi autonomous region, Guizhou, Yunnan, Guangdong, Hunan, Hubei provinces, and Chongqing municipality. About 100 experts from the Provincial Geological Survey and graduate students took part in this project. Several symposiums were held during those 3 years. Besides the in situ survey, data were collected from hydrogeological survey results since 2000 when the new round of land resources investigation began. After analyzing these data, rock desertification, drought and flooding, and contamination and engineering geological environmental problems were considered the most prevalent problems in karst areas in Southwestern China. The status of each problem is elaborated upon in this paper and should be considered for future sustainable development.     

陕西省宝鸡市渭滨区地质灾害风险评价

在渭滨区地质灾害详细调查的基础上,通过统计分析确定了各类地质灾害危险性和易损性的主要影响因素,采用模型方法和定性评价方法分别进行了地质灾害的危险性评价和易损性评价,在此基础上进行了地质灾害风险评价。渭滨区地质灾害类型主要为滑坡、崩塌、泥石流3种,共发育地质灾害隐患点123个,其中有16个点直接威胁人民的生命和财产。分别统计了渭滨区各乡镇地质灾害的多少和危害程度,总结了区域内地质灾害的分布特征,分析了地质灾害的形成条件,建立了地质灾害风险评价的指标体系,确定了地质灾害危险性、易损性和风险的判别标准,进行了地质灾害风险性评价与区划。共划分为极高风险区、高风险区、中风险区、低风险区和极低风险区5个等级。     

陕西省宝鸡市渭滨区地质灾害风险评价

在渭滨区地质灾害详细调查的基础上,通过统计分析确定了各类地质灾害危险性和易损性的主要影响因素,采用模型方法和定性评价方法分别进行了地质灾害的危险性评价和易损性评价,在此基础上进行了地质灾害风险评价。渭滨区地质灾害类型主要为滑坡、崩塌、泥石流3种,共发育地质灾害隐患点123个,其中有16个点直接威胁人民的生命和财产。分别统计了渭滨区各乡镇地质灾害的多少和危害程度,总结了区域内地质灾害的分布特征,分析了地质灾害的形成条件,建立了地质灾害风险评价的指标体系,确定了地质灾害危险性、易损性和风险的判别标准,进行了地质灾害风险性评价与区划。共划分为极高风险区、高风险区、中风险区、低风险区和极低风险区5个等级。     

中国西南地区主要地质灾害及常用监测方法

我国西南部地区山地面积比例高,地质灾害尤为突出,发生频繁。主要灾害类型为崩塌、滑坡及泥石流。目前的滑坡、泥石流监测工作主要有以工程减灾为目的的专业监测,城镇居民点的综合减灾监测,而广大农村则以群测群防为主监测。国土资源部建立了全国性的内容包括滑坡、泥石流的中国地质环境监测体系,特别是在三峡水库区,地质灾害专业监测由中央主管部门统一指挥、专业技术人员配以相关监测方法及仪器进行。目前使用的主要监测方法有地表位移监测、滑坡体深部位移监测、滑坡体应力应变监测、地下水监测、3S技术综合应用I、nSar技术应用、基于现代通讯技术的实时自动化监测等。通过这些监测,对三峡水库区的移民迁建、经济建设及构建和谐社会起到了重要作用。     

Evaluation of karst collapse risks induced by over-pumping and karst groundwater resource protection in Zaozhuang region,China

Based on the comprehensive analysis of factors influencing karst collapse in the Zaozhuang Shili Spring Area, China, this paper establishes a karst collapse risk evaluation model by means of the fuzzy comprehensive evaluation method. Application of the model led to division of the study area into very high risk area, high risk area, average risk area and low risk area; therefore, the karst collapse risk evaluation map of Zaozhuang Shili Spring Area is completed. As preventive measures of karst collapse, the different karst water resource protection areas of Zaozhuang Shili Spring Area are established, and the map for karst water resource protection area of Zaozhuang Shili Spring Area is compiled. The results will be helpful for the strategic planning and decision-making processes associated with exploitation of karst water resources and with prevention and control of karst collapse hazards of this region.     

徐州市地质灾害特征与防治研究

徐州市矿产资源和地下水资源开采历史悠久,诱发了崩塌、地面塌陷、地面沉降等多种类型的地质灾害.为摸清徐州市地质灾害发育特征、发展趋势及其危险程度,更好地指导地质灾害防治工作,在徐州市地质调查和徐州市矿山地质环境调查的基础上,结合徐州市近年来的地质灾害调查与防治工作,阐述了各种地质灾害的类型,分析了徐州市各种地质灾害的形成机理、成因特征及其空间分布,并结合灾害地质环境条件,预测了各种地质灾害的发展趋势,提出了相应的防治措施.目前,徐州市地质灾害防治工作取得了一定的成效,可为其他区域的地质灾害防治工作提供参考.     

西南地区地质灾害调查工作的思考

本文根据近年来开展的1∶10万县(市)地质灾害调查与区划、1∶5万地质灾害详细调查等工作所取得的大量成果,对西南地质地质灾害调查工作进行总结,提出几大方面的建议。     

中国矿山地质灾害分布特征

矿山地质灾害是人类矿业活动和自然地质作用作用于地质环境造成的灾害事件。近几年,随着矿产资源开发力度的不断加大,矿山地质灾害发生频率呈加剧趋势,对矿业正常生产和人居生态环境构成严重的威胁,甚至造成重大的群死群伤灾难。依据2002—2005年全国31个省（自治区、直辖市）矿山地质环境调查与评估的成果资料,利用数据统计、分析、总结的方法,按不同省区市、不同地质环境背景区、不同类型矿产、不同规模的矿山、不同开采方式,简述了中国矿业开发引发的崩塌、滑坡、泥石流、地面塌陷、地裂缝5种地质灾害的时空分布特征和危害,为矿山地质灾害监测、防治提供基础信息。     

中国矿山地质灾害分布特征

矿山地质灾害是人类矿业活动和自然地质作用作用于地质环境造成的灾害事件。近几年,随着矿产资源开发力度的不断加大,矿山地质灾害发生频率呈加剧趋势,对矿业正常生产和人居生态环境构成严重的威胁,甚至造成重大的群死群伤灾难。依据2002—2005年全国31个省（自治区、直辖市）矿山地质环境调查与评估的成果资料,利用数据统计、分析、总结的方法,按不同省区市、不同地质环境背景区、不同类型矿产、不同规模的矿山、不同开采方式,简述了中国矿业开发引发的崩塌、滑坡、泥石流、地面塌陷、地裂缝5种地质灾害的时空分布特征和危害,为矿山地质灾害监测、防治提供基础信息。     

临沂市城区岩溶塌陷危险性控制

通过分析临沂市城区岩溶塌陷与地下水活动的关系,确定了岩溶塌陷的主控因子为地下水水位。借助已建立的地下水流模型,提出控制岩溶塌陷的方法,即使岩溶水水位不低于控制水位。以此为目标在研究区选定若干具有代表性的水位控制点,并设计了三种地下水规划开采方案,将其带入地下水流模型演算,最终获得合理的地下水开采方案,即未来城区岩溶水开采量与现状开采相比减少了11.65×104m3/d,减少的水量由临沂市岸堤水库地表水工程解决。该方案实施后可在一定程度上控制岩溶塌陷发生的危险。     

中国矿山地质灾害分布特征

矿山地质灾害是人类矿业活动和自然地质作用作用于地质环境造成的灾害事件。近几年,随着矿产资源开发力度的不断加大,矿山地质灾害发生频率呈加剧趋势,对矿业正常生产和人居生态环境构成严重的威胁,甚至造成重大的群死群伤灾难。依据2002—2005年全国31个省（自治区、直辖市）矿山地质环境调查与评估的成果资料,利用数据统计、分析、总结的方法,按不同省区市、不同地质环境背景区、不同类型矿产、不同规模的矿山、不同开采方式,简述了中国矿业开发引发的崩塌、滑坡、泥石流、地面塌陷、地裂缝5种地质灾害的时空分布特征和危害,为矿山地质灾害监测、防治提供基础信息。     

甘肃定西地区地质灾害危险性评价

识别地质灾害聚集的热点区及驱动力对于区域灾害预警具有重要意义。以甘肃定西地区为研究区,选取坡度、坡向、土地利用等7个评价因子,利用确定系数与逻辑回归耦合模型、空间自相关方法分析地质灾害的空间集聚特征及驱动因素。结果表明：定西地区地质灾害危险性呈现中部高,南北两侧低的特征,其主要受降水、坡向、工程岩组等因子的影响;地质灾害与降水、坡向和工程岩组的空间关系为高高聚集;地质灾害危险性存在较强的空间自相关性,在3 km的空间尺度上呈显著正相关,且随距离阈值增加而降低;距离阈值为5 km时,正相关高高聚集与低低聚集以团块的形式存在,而高低聚集与低高聚集多以零星状分布。研究可为区域地质灾害监测与防控提供参考。     

三峡库区重庆市丰都县滑坡灾害危险性评价

在对三峡库区丰都县滑坡灾害调查和统计分析的基础上,初步概括了滑坡灾害的分布特征和主要影响因素,进而利用综合信息模型评价了丰都县滑坡灾害的危险性,将丰都县滑坡灾害的危险性划分为高危险区、中危险区、低危险区和基本安全区4个等级。其中,高危险区和中危险区分别占全县总面积的2.6%和23.2%,主要分布在长江干流及其支流两岸的居民相对集中区,不同规模的滑坡灾害经常发生,因此潜在危害也很大;低危险区占全县总面积的47.5%,偶有小规模的滑坡灾害发生;基本安全区占全县总面积的25.5%,在人为因素的诱发下可能偶有小规模的滑坡灾害发生,适合于大型工程建设和城镇居民点建设。     

西南岩溶石山区断陷盆地岩溶水系统分类及供水意义

笔者根据岩溶区水文地质条件及特征的差异，以地下水循环的特征为纲，应用系统分析方法，将岩溶水系统分为三级，对各级系统进行了分类。第一级为岩溶水系统，第二级分为浅循环和深循环岩溶水系统、第三级分别进一步分为裸露型、裸露-覆盖型、裸露-埋藏型、滞水型及层控型和断裂带型6类基本的岩溶水文地质单元。并论述了各类型的水文地质特征，指出了各类系统的供水意义，对断陷盆地岩溶水资源的勘查和开发有较大的参考价值。     

三峡库区泥灰质岩石斜坡带构造对岩溶地质灾害的控制机理

三峡库区三叠系巴东组(T26)泥灰质岩石岩溶是移民迁建中发现的重大工程地质问题。泥灰质岩石中的构造非常复杂，包括老构造、新构造和表生构造，它们共同控制了岩溶作用。老构造中，褶皱和断裂带等局部构造控制着岩溶的重要部位和重要层位，节理和层理等小构造使岩溶普遍存在。新构造时期地表隆升和河流切割使岩体卸荷松动，岩溶通道扩宽。表生岩溶构造加密了岩溶通道，使岩溶作用增强。三峡库区泥灰质岩石斜坡带地质灾害形成的机理遵循着构造控制下岩溶发育的规律性，致使岩溶地质灾害具有范围广、规模大和结构复杂的特点。岩溶地质灾害的形式包括地面不均匀沉降、地裂缝、滑坡、崩塌、泥石流和地面塌陷。     

Application of seismic velocity tomography in investigation of karst collapse hazards,Guangzhou, China

This paper describes seismic velocity tomography applied to the investigation and assessment of karst collapse hazards to facilitate accurate characterization of geological conditions of karst sinkhole formation. In the survey areas of Xiamao, Guangzhou, China, and Huangchi, Foshan, China, seismic velocity tomography was used to explore the structures of rock and soil associated with karst collapse. The results show that sand intercalated with clay or clay intercalated with soft soil dominates the cover of these two areas. The overburden is 20–33 m thick and underlain by Carboniferous limestone. In the limestone, there are well-developed karst caves and cracks as well as highly fluctuating bedrock surfaces. The seismic velocities are less than 2500 m/s in the cover, 2500–4500 m/s in the karst fracture zones and caves of Xiamao, and 1500–2000 m/s in the Huangchi collapse area. The karst fracture zones, relief of bedrock surfaces, and variations of soil thicknesses revealed by seismic velocity tomography are well constrained and in agreement with those in the drilling borehole profiles. This paper demonstrates that seismic velocity tomography can delineate anomalies of rock and soil with the advantages of speed, intuitive images, and high resolution.