堰塞湖应急处置实践与认识

堰塞湖是由于山体滑坡、崩塌、泥石流等堵塞河道形成的没有经过专门设计、没有专门的泄水设施的湖泊,一旦溃决,容易给下游造成巨大的灾难。分析了堰塞湖的成因、溃决机理与风险判断,提出堰塞湖应急处置的原则、理念、阶段与处置方法,总结了堰塞湖应急处置中的一些经验和认识。以四川省汶川特大地震形成的堰塞湖应急处置为例,从可能溃决方式、溃坝洪水、应急除险总体方案、开渠引流方案和除险效果等方面,介绍了唐家山堰塞湖的应急处置实践,并简要介绍了其它一些堰塞湖应急处置。     

河道疏浚底泥堆土镉污染修复技术分析

城市生活垃圾中重金属Cd污染修复是我国亟待解决的环境问题之一。为了确定最佳Cd污染修复技术,探究了多种镉修复技术在河道治理中的适用性。以华东地区城市河道疏浚底泥堆土修复工程为例,对重金属镉污染土壤的修复工艺进行了对比和分析。拟选定土壤稳定化修复技术、土壤淋洗技术和植物修复技术三种修复工艺对受污染土壤进行治理。实验结果表明,稳定化修复技术可以使土壤中镉的浸出率从33.3%降低到14.3%,能有效降低其在环境中的生物毒性,但镉的总量并不会降低;采用柠檬酸和草酸的土壤淋洗技术,能够使镉的去除率达到90.1%和92.4%;相比而言,植物修复技术具有更为突出的高效性、易操作和二次污染少的特点,但修复周期较长。从技术、经济、环境安全等多方面出发,分别对三种修复工艺进行了分析讨论,综合考虑了研究场地的现状和未来规划,最终确定土壤淋洗技术为治理河道底泥堆土镉污染的最佳选择。      

福建永泰旗山小区后山滑坡应急处置实例分析

主要介绍了永泰县旗山小区后山滑坡地质灾害的特征和应急处置措施,由于应急处置措施有效合理、行动及时,有效地防止了滑坡的大规模向下滑移,避免了一次可能发生的滑坡地质灾害的破坏。     

多年冻土区天然气管道建设关键技术

多年冻土地区天然气资源丰富,资源勘探开发和天然气外输管道建设日益受到重视。温带地区传统、常规的天然气管道设计、施工、运维方法、技术在多年冻土区遇到很大的挑战。因此,以管道工程设计者的角度,总结多年冻土区天然气管道的设计、施工和项目风险管理3个大项14个子项关键技术,主要包括管土水、热、力耦合系列的管输气冷却技术和传热计算技术,材料、应力系列的管道断裂控制技术和基于应变的管道设计技术,公用配套系列的连续多年冻土接地技术、不连续冻土区阴极保护技术、冻土区站场基础、管道支撑设计技术和建筑物模块化和设备撬装化技术,施工系列的特殊施工装备、冰雪公路修建、低温焊接和焊缝100%检测技术,以及自然环境、社会人文和技术等风险管理技术。希望能够为北极、高山和高原多年冻土区天然气管道建设提供新思路。     

Detection and delineation of glacial lakes and identification of potentially dangerous lakes of Dhauliganga basin in the Himalaya by remote sensing techniques

Glaciers are retreating and thinning in the high altitude of the Himalayas due to global warming, causing into formation of numerous glacial lakes. It is necessary to monitor these glacial lakes consistently to save properties and lives downstream from probable disastrous glacial lake outburst flood. In this study, image processing software ArcGIS and ERDAS Imagine have been used to analyse multispectral image obtained by Earth resource satellite Landsat for delineating the glacial lakes with the help of image enhancement technique like NDWI. Landsat data since 1972 through 2013 have been used and maximum seven glacial lakes (L1–L7) have been detected and delineated in Dhauliganga catchment, they are situated above 4000 masl. The Glacial Lake L2 (Lat 30°26′45″E and Long 80°23′16″N) is the largest whose surface area was 132,300 m² in Sept 2009, and L6 (Lat 30°23′27″E and Long 80°31′52″N) is highly unstable with variation rate ?55 to +145 % with increasing trend. Additionally, glacial lakes L2 (Lat 30°26′45″E and Long 80°23′16″N) and L6 (Lat 30°23′27″E and Long 80°31′52″N) have been identified as potentially hazardous. These lakes may probably burst; as a result, huge reserve of water and debris may be released all on a sudden. This may transform into hazardous flash flood in downstream causing loss of lives, as well as the destruction of houses, bridges, fields, forests, hydropower stations, roads, etc. It is to note that Dhauliganga river considered in this study is a tributary of Kaliganga river, and should not be confused with its namesake the Dhauliganga river, which is a tributary of Alaknanda river.     

Creative spoil: Design concepts,construction techniques,and disposal of excavated materials

The author discusses some of the construction methods used in building the Tennessee-Tombigbee Waterway, the disposal of surplus excavated materials, and the reclamation of disposal areas along the waterway Emphasis is placed on the steps taken to assure protection of natural resources and to promote overall environmental quality.     

Physically based simulation of dam breach development for Tangjiashan Quake Dam,China

Physically based modeling approach has been widely developed in recent years for simulation of dam failure process resulting from overtopping flow. Due to the lack of field data, there exist few applications to natural quake dams with complex erosion mechanisms. This paper presents a physically based simulation of the failure process of the Tangjiashan Quake Dam formed as a result of the “May 12, 2008” Wenchuan earthquake in China. The one-dimensional model adopted features as cost saving but enables capturing the main characteristics of the failure process, where selective sediment transport and gravitational slope collapse are accounted for. The simulated flow hydrograph and breach progression process are generally in good agreement with the observed data. Unsteadiness and non-uniformity are found to be substantial characteristics of breach progression during the failure process of natural quake dams. Sensitivity analysis showed that the Manning resistance coefficient and the erodibility coefficient in Osman and Thorne’s (J Hydraul Eng 114(2):134–150, 1988) model significantly influences the flow peak discharge but has less influence on its occurrence time, while the velocity lag coefficient associated with bed-load transport may affect the two breaching parameters substantially.     

Multi-criteria analysis for the identification of waste disposal areas

The municipality of Cachoeiro de Itapemirim (ES) is currently the largest domestic producer and exporter of marble and granite in Brazil. The processing of the rock, especially the sawing results in a large volume of waste, including the abrasives used during sawing and the off-cut pieces. Presently these waste products are disposed of without proper environmental protection and cause pollution to surface water and groundwater resources, including silting, an increase in hardness and increased aluminium values in the groundwater. In order to minimize the harmful effects of these practices on the environment, a research project was undertaken to identify potential disposal sites for the generated waste. A multi-criteria approach was followed during which a database was compiled of all the companies generating waste products and also including a baseline environmental study of the region, integrated analysis (multi-criteria analysis) of the restriction factors and the preliminary identification of possible disposal sites. This revised version was published online in July 2006 with corrections to the Cover Date.     

Modeling the risk assessment of landslide-dammed lakes based on the emergency response measures in Wenchuan earthquake, 2008, China

With the rapid development of urbanization and climate change, the frequency and degree of the natural hazards and extreme weather events have increased, such as the earthquake, flood, and torrential rain. And the landslide-dammed lake as the secondary disaster of these hazards has become a major threat to many countries. So from twentieth century, many countries have begun to explore the effective emergency response method to reduce the danger of the landslide-dammed lake to the surrounded environment and people. Particularly in China, with successfully dealing with three high-risk landslide-dammed lakes in recent 10 years, the Chinese government has accumulated a great deal of experience in managing the landslide-dammed lakes. So in this paper, based on the Chinese and many other countries’ emergency response experience of successfully managing the landslide-dammed lakes, we build an outburst time–predicted model which can use the Dimensionless blockage index value to predict the outburst time of the landslide-dammed lakes. Based on the urgent time in the process of emergency response to the landslide-dammed lake, we build an integrated risk assessment model with the gray relational analysis and Technique for order preference by similarity to an ideal solution approach to evaluate the risk value and judge the risk level of the landslide-dammed lake from three aspects (the stability of the landslide-dammed lake, the hydrological environment, and the vulnerability factor of the surrounding environment). These two models can quickly and accurately determine the risk level of landslide-dammed lake in case of lack of complete and detailed data. So it would provide an important reference for government to make the scientific and effective emergency response plan to deal with the extremely high-risk landslide-dammed lake disasters in the future.     

Geoenvironmental site investigation using different techniques in a municipal solid waste disposal site in Brazil

Different geoenvironmental site investigation techniques to assess contamination from a municipal solid waste disposal site in Brazil are presented here. Superficial geophysical investigation (geoelectrical survey), resistivity piezocone penetration tests (RCPTU), soil samples collected with direct-push samplers and water samples collected from monitoring wells were applied in this study. The application of the geoelectrical method was indispensable to identify the presence and flow direction of contamination plumes (leachate) as well as to indicate the most suitable locations for RCPTU tests and soil and water sampling. Chemical analyses of groundwater samples contributed to a better understanding of the flow of the contaminated plume. The piezocone presented some limitations for tropical soils, since the groundwater level is sometimes deeper than the layer which is impenetrable to the cone, and the soil genesis and unsaturated conditions affect soil behavior. The combined interpretation of geoelectrical measurements and soil and water samplings underpinned the interpretation of RCPTU tests. The interpretation of all the test results indicates that the contamination plume has already overreached the landfill’s west-northwest borders. Geoenvironmental laboratory test results suggest that contamination from the solid waste disposal site has been developing gradually, indicating the need for continuous monitoring of the groundwater.     

高光谱分辨率遥感在地质应用中的关键技术及前景

遥感技术应用于地质中的目的之一是分辨和识别出不同的岩石和矿物等地质体。宽波段遥感只能分辨不同岩石类型，而难以识别含不同成分的岩石和矿物。高光谱分辨率遥感则可通过诊断性光谱特征对岩石或矿物成分及结构进行识别。通过对高光谱分辨率遥感应用于地质中的关键技术进行分析，对未来高光谱分辨率遥感在地质中的应用进行了预测。     

Liner design for waste disposal sites

 Since the beginning of the 1980s waste disposal has become a particularly sensitive issue. This has led to the development of new legislations in the European Community and internationally which resulted in an array of regulations concerning landfill liner design. This paper comments on different "engineered" containment methods with particular reference to landfill liner design. Suggestions based on the review of the different methodologies are given and a case study is presented. Received: 25 February 1997 · Accepted: 16 December 1997     

Flow behaviour of tailings paste for surface disposal

Surface disposition of mine tailings in paste form is a new disposal technique, and to achieve a desired depositional geometry, it is necessary to characterize the paste's flow properties. This study investigates how water content affects the flow behaviour and depositional geometry of tailings and kaolinite pastes, which are shear-thinning, high solids content, mineral pastes. A stress-controlled rheometer and a strain-controlled viscometer with vane fixtures were used to characterize the yield behaviour of the pastes, and three types of yield stress were determined. A flume apparatus was used to simulate paste deposition under laboratory conditions. The depositional angle, determined from the flume tests, and the yield stresses, determined from the rheometers, decreased as the water content increased. For each type of yield stress, a linear relationship was found between the depositional angle and the Sofra–Boger dimensionless group (τ_y′Fr/Re), with the linear coefficient depending on paste type.     

湖泊及水库富营养化模型研究综述

以湖泊及水库的富营养化研究的发展为主线,着重介绍了三类富营养化模型,即:单一营养物质负荷模型,浮游植物与营养盐相关模型,生态动力学模型。通过对目前国内外常用富营养化模型的建立思路和应用实例进行概括和描述。对不同模型的优缺点和适用范围进行了分析比较,对水体富营养化研究的最新发展趋势进行了预测和展望,为湖泊水库综合管理提供了有效工具。     

Hydrogeologic studies for nuclear-waste disposal in Sweden

Safety Report 1997 (SR 97) of the Swedish Nuclear Fuel and Waste Management Company is a comprehensive performance assessment of three hypothetical radioactive waste repositories in Sweden. It includes hydrogeologic studies (data compilation, parameter synthesis, and groundwater flow modeling) to determine groundwater flow and the associated uncertainties for the three sites. This report reviews and compares the hydrogeologic characterization programs, the site characteristics, and the groundwater flow models used in the SR 97 performance assessment. Although differences in site-characterization programs tend to mask differences in site characteristics, the sites do have notable differences that affect the results of the performance assessment. The effects of model uncertainties evaluated by the variant cases appear to be smaller than the variability of results for the base case (best estimate of site conditions) of each site. Electronic Publication     

Long-term prediction for seismic hazard for radioactive waste disposal

We consider possible approaches to the long-term prediction for seismic hazard in relation to the practical need for the safety of geological disposal of long-lived radioactive waste. The required period of prediction significantly exceeds the one reflected in the set of maps of General Seismic Zoning of the territory of the Russian Federation (GSZ-97). The first geological repository in Russia is planned to be set up in the Nizhnii Kan granite massif in the Krasnoyarsk Krai. This region is an intraplate territory with a relatively high seismic activity. We summarize the analysis of the known empirical generalizations and theoretical principles underlying the seismic hazard prediction. Real seismic events constantly violate forward-looking statements even for relatively short periods of time. These and other arguments suggest that the hypothesis of stationarity of the seismic regime, which is the basis of long-term prediction today, has limited and uncertain applicability in time. Intraplate earthquake prediction is especially uncertain because of the uncertainty in the factor responsible for generating tectonic stresses in these regions. The short horizon of the prediction, based on statistical methods, can be attributed to the nonlinearity of seismic geodynamic processes. Fundamental laws of tectonic processes should be used as the scientific basis for long-term predictions for seismic hazard at the sites chosen for geological disposal of long-lived radioactive waste. These processes can be reflected in models for the migration of the seismically active boundaries of lithospheric plates and the occurrence of seismic activity in intraplate regions.     

Taming the killer lakes of Cameroon

A chain of volcanoes, some of them still active, extends from the Atlantic Ocean into the highlands of Cameroon. Mount Cameroon, located at the edge of the continent, erupted in 1999 and 2000 and spewed lava part-way down its flanks, cutting off a coastal road. A number of the now extinct (or dormant) volcanic craters on the continental part of the line are filled with water, forming crater lakes. These lakes have achieved mythical status in local tribal lore. Lacking a written history, prior to the arrival of the colonial powers, much of our understanding of past natural phenomena relating to the lakes is based on these myths.     

柴达木盆地盐湖物质来源识别

柴达木盆地是我国重要的盐矿资源战略基地,深入认识其物质来源具有重要的科学及社会意义。本研究根据柴达木盆地盐湖水、晶间卤水,以及格尔木河流域地表水、地下水化学组成,利用多元统计方法,探讨盆地区盐湖物质来源。结果显示:从山前到湖区,水体溶解性总固体逐渐增大,微量组分含量也逐渐升高,二者均表现为晶间卤水盐湖水格尔木河流域水体;阳离子变化趋势为:补给源头由昆仑山雪融水以Ca2+为主过渡到格尔木河流域以Na+为主;再到盐湖区以Mg2+为主;阴离子则从以HCO-3为主逐步过渡到以Cl-为主;盐湖水和晶间卤水的化学组成差异显著。因子分析表明,对于格尔木河流域河水和地下水,岩石风化淋滤是其化学组分的主要来源。而岩石风化淋滤来源和深部水来源对柴达木盆地不同盐湖区化学组成的贡献率差异很大,该差异取决于周围岩石的化学组成和深部水的存在及其化学组成,以及断层是否导通为深部水补给盐湖提供了通道。     

Site selection criteria for the disposal of spent nuclear fuel in Romania

 Common opinion today is that the only practicable way for the disposal of hazardous waste is in deep-laying bedrock deposits. A set of general site selection criteria for spent nuclear fuel were developed, and are presented and discussed in this paper. Four widespread geological formations in Romania appropriate as geological barriers for underground disposal (salt, granite, volcanic tuff and green schists) were analyzed, and sites were proposed on the basis of the geological criteria defined for each of the four formations. Received: 18 July 1996 · Accepted: 27 September 1996