基于多源遥感信息的人为热排放量空间化——以浙江省为例

基于自上而下能源清单法,主要考虑工业、交通、建筑和人体新陈代谢这4个热源对人为热的贡献,估算了2010年浙江省68个县市的人为热排放总量.使用DMSP/OLS遥感夜间灯光数据以及阈值法提取出人为热排放的主要区域,并有效减少夜灯像元溢出效应的影响.利用夜间灯光数据和增强型植被指数(EVI)构建人居指数,基于各市县人为热排放总量与其行政区范围内人居指数累计值之间很强的相关关系建立人为热排放量空间化模型,获得了250m分辨率下浙江省2010年城市人为热通量的空间分布.结果显示浙江省各县市的平均人为热排放通量为5.5W/m²,城市高值区一般介于10~40W/m².栅格化的人为热数据可以为城市气候环境的数值模拟研究提供基础数据支持.     

真空联合堆载预压法在加固软土路基中的应用

真空联合堆载预压法已经广泛应用于处理高等级公路的软土地基,与常规的堆载预压法对比,该方法能有效降低工后沉降,节约工期,并能保证路基的稳定性.笔者通过工程实例,阐述了真空联合堆载法的加固机理,并通过对现场监测资料的分析,说明该方法用于加固软土路基所取得的良好效果.     

Full scale amendment of a contaminated wood impregnation site with iron water treatment residues

Iron water treatment residues are a free by-product with high concentration of iron oxides Iron water treatment residues has a large potential for arsenic sorption Soils are highly contaminated by arsenic at wood preservation sites Iron water treatment residues were added to hot spots contaminated with arsenic The addition led to significant decrease in leaching of arsenic from the contaminated soil Iron water treatment residues (Fe-WTR) are a free by-product of the treatment of drinking water with high concentration of iron oxides and potential for arsenic sorption. This paper aims at applying Fe-WTR to a contaminated site, measuring the reduction in contaminant leaching, and discussing the design of delivery and mixing strategy for soil stabilization at field scale and present a cost-effective method of soil mixing by common contractor machinery. Soil contaminated by As, Cr, and Cu at an abandoned wood impregnation site was amended with 0.22% (dw) Fe-WTR. To evaluate the full scale amendment a 100 m² test site and a control site (without amendment) were monitored for 14 months. Also soil analysis of Fe to evaluate the degree of soil and Fe-WTR mixing was done. Stabilization with Fe-WTR had a significant effect on leachable contaminants, reducing pore water As by 93%, Cu by 91% and Cr by 95% in the upper samplers. Dosage and mixing of Fe-WTR in the soil proved to be difficult in the deeper part of the field, and pore water concentrations of arsenic was generally higher. Despite water logged conditions no increase in dissolved iron or arsenic was observed in the amended soil. Our field scale amendment of contaminated soil was overall successful in decreasing leaching of As, Cr and Cu. With minor improvements in the mixing and delivery strategy, this stabilization method is suggested for use in cases, where leaching of Cu, Cr and As constitutes a risk for groundwater and freshwater.     

污染场地土壤中Cd人体可给性影响因素及对筛选值的影响

采用Unified bioaccessibility model (UBM) 模拟胃肠消化的方法测试了来自湖南、广西和大连12个污染土壤样品中Cd的人体可给性.结果显示,Cd在胃提取阶段的可给性为12.24%~81.10%,平均值为53.60%,肠提取阶段的可给性为2.01%~43.30%,平均值为19.74%.胃提取阶段的可给性浓度仅与总镉(TCd) (P<0.000, n=12)和总锰(TMn) (P=0.04, n=12)显著正相关,肠提取阶段的可给性浓度与TCd (P<0.001, n=12)、胃阶段Cd的可给性浓度(P<0.001, n=12)以及TMn(P=0.05, n=12)均显著正相关.胃阶段基于土壤中TCd和TP含量能较好的预测Cd在胃阶段的可给性浓度,模型决定系数(R2)达到0.992,肠阶段基于Cd在胃阶段的可给性浓度及土壤pH值能较好的预测其在肠阶段的可给性浓度,R2达到0.999.考虑土壤中Cd在胃中的可给性时,居住及工商业情形下土壤筛选值分别提升至未考虑可给性时的1.8倍(以可给性平均值计算)和1.2倍(以可给性最大值计算).考虑土壤中Cd在肠阶段的可给性时,居住及工商业情形下土壤筛选值分别提升至未考虑可给性时的5.0倍(以可给性平均值计算)和2.3倍(以可给性最大值计算).     

黄土湿陷过程下埋地油气管道力学行为有限元模拟

针对黄土遇水后湿陷产生陷穴并引起埋地管道悬空这一过程中管道的力学行为,以基于弹塑性地基的黄土湿陷区悬空管道力学模型为基础,从湿陷原因和机理出发,建立三维有限元实体模型,模拟了土体湿陷过程和沉降变形,模拟计算结果与理论值和实测值进行了比对验证;进一步的计算和回归分析得到了管道最大位移、最大von Mises应力与地表土体湿陷沉降量的变化规律,同时也得到了最终湿陷情况下管道的von Mises应力分布和湿陷区范围的影响。结果表明:土体湿陷沉降是管道和土体共同作用的结果,湿陷前期管道与土体一起运动,位移和应力增加较快,而管道下方土体脱离管道产生陷穴后则增长较慢;管道最大位移和土体湿陷沉降量间呈对数函数关系,而管道最大von Mises应力和土体湿陷量呈指数函数关系; 湿陷区管段向下弯曲变形会在3个位置形成应力集中区,湿陷区范围增大会引起管道应力和变形的明显增加,且3个区域的最值分布有所不同。     

基坑降水引起的地面沉降机理探讨

分析了基坑降水引起坑周边地面沉降的机理、影响范围,探讨了基坑降水引起地面沉降的影响因素及减少地面沉降的措施。以“上海某钢铁公司1780mm热轧厂旋流池超深基坑的深井降水”工程为例,指出之所以出现周边环境安全问题,多因抽水中含砂量高引起。     

Overview of waste disposal and landfills/dumps in Asian countries

Many cities in developing Asian countries face serious problems in managing solid wastes. The annual waste generation increases in proportion to the rises in population and urbanization. Asian countries with greater rural populations produce more organic waste, such as kitchen wastes, and fewer recyclable items, such as paper, metals, and plastics. Reliable data on solid waste compositions are difficult to obtain, and even if available, they are often not updated. We report the most recent waste composition data in some developing Asian countries. We suggest that a better classification system for landfills is needed to address inconsistencies in data for sanitary landfill sites versus waste dumps. We also discuss the information on waste disposal trends and problems associated with general solid waste management in developing Asian countries.     

Can David and Goliath Get Along? Federal Land in Local Places

It is often unclear what the role of a local jurisdiction is with regard to land use management on nearby federal properties. Yet federal lands clearly impact nearby local communities. The US Department of Energy (DOE), with over 100 sites across the United States with varying degrees of environmental contamination, may be in a very difficult position with regard to relationships with local government about land use. Yet few, if any, studies have examined DOE land use issues. This study asks: (1) In general, how do local planners feel about federal government relationships with them? (2) Do local planners feel differently about the DOE than they do about other federal agencies? (3) What reasons explain any differences observed in answer to the second question? To answer these questions, local planners were interviewed from communities adjacent to non-DOE federal properties, and their responses compared to those of planners located near DOE facilities in the same regions. Findings showed that compared to other federal agencies that own land in the same regions, the DOE is relatively poorer at actively involving local officials in land use decisions at its sites. Primary reasons are the historic legacy of a culture of secrecy, focus on mission, and especially the lack of experience, training, or mandates in local planning cooperation. Findings also suggest that this attitude is markedly stronger in areas west of the Rocky Mountains. Recommendations for improved federal–local communications include the development of a vision for local government involvement that is supported by top levels of management and filtered effectively to the site level.     

SELECTION OF WASTE DISPOSAL SITES USING GIS1

ABSTRACT: Geographic Information Systems (GIS) technology is used to identify candidate sites for a solid waste disposal facility in the Gölbasi region of Turkey that has suffered from the negative impact of a current but poorly-located open-dump site on the environment. The municipality of Gölbasi has noticed its deleterious effect on the environment, and has thus decided to dismiss this open-dump site and search for new landfill sites. In this study, the procedure followed under a GIS framework rejects the unacceptable sites considering environmental factors exclusively, other than economic and political issues, contained in the form of multiple layers of attribute information to select the candidate sites for landfilling wastes through an overlay analysis performed by GIS software, ARC/INFO V 7.1. For the spatial data requirements of GIS, a number of thematic map layers (ground water, wetlands and swamp areas, surface water, roads, topographic contours, ecological features, settlements, erosion susceptibility zones, and soil type) are prepared in digital form. In this application, GIS is considered as a screening tool in a site selection process to narrow the number of candidate sites, subsequently leading to one or more sites for detailed investigation. Preliminary ranking for a group of potential sites is done on the basis of simple calculations coupled with on-site field studies.     

Nontraditional settlement patterns and typhoon hazard on contemporary Majuro atoll,Republic of the Marshall Islands

Low-lying islands and atolls are particularly prone to storm surges created by tropical depressions and typhoons. This paper presents a case study of traditional and contemporary settlement patterns of Majuro, the capital of the Republic of the Marshall Islands, and discusses its vulnerability to such storm surges. The paper shows that the application of traditional knowledge extends to the realm of urban planning and that, in fact, ignoring this traditional knowledge as expressed in pre-World War II settlement patterns, exposes urban development to increased flood hazards, a risk which may exact a price too high in life and property.