城市灾害对城市土地利用的影响

随着城市的不断扩张，对城市土地利用的需求量也在不断增加。地震、火灾、风灾、地质破坏是现代城市的主要灾害，城市灾害在一定程度上制约着土地利用的类型。充分运用GIS的空间分析功能，研究了城市灾害对城市土地利用的影响，所得结果可为城市土地利用规划提供辅助决策参考。     

基于事故理论的城市轨道交通风险评价模型研究

笔者分析了城市轨道交通事故,在分析我国其他行业事故分类的基础上,确定城市轨道交通事故分类标准,即重大事故、大事故、险性事故和一般事故,并将不同事故分类情况及专家判断评分,按事故的大小不同换算成可以计算的计算尺度,根据事故种类不同计算出事故折算因子,根据风险理论的评价方法,建立了地铁风险评价模型,对地铁的危险性进行量化定级,并通过具体实例进行综合分析评价,该风险评价模型具有一定的工程意义。     

城市海岸带环境管理模式优化研究——以青岛市胶州湾为例

我国的海洋污染日益严重,政府加大海洋环境保护力度势在必行。科学、有效的海洋环境管理对保护环境、提高资源利用效率起着非常重要的作用。但海洋环境并不是一维线性的系统,涉及系统的多维耦合,而海岸带又是与人类活动息息相关的重要部分。本文尝试以青岛市胶州湾海岸带环境管理模式为例,构建包含有"经济-人口-资源-环境-安全-行政(EPRESA)"六个子系统的多维耦合系统模型,并绘制出总流图,然后以此为管理模式的优化提供前提性分析,提出海岸带综合管理模式优化的对策建议。本研究认为,要改善现有的海岸带环境管理体系,应该制定综合性管理政策,建立可持续的融资机制,推进海岸带灾害与风险管理以及引导利益相关者参与管理。     

THE IMPACT OF HIGH INTEREST RATES ON OPTIMUM MULTIPLE OBJECTIVE DESIGN OF SURFACE RUNOFF URBAN DRAINAGE SYSTEMS1

ABSTRACT. This research examines the impact of high rates of interest upon the least cost system design for urban drainage systems when water quality is a critical parameter. Results of examination of twelve alternative system designs in a case study watershed indicate the least cost study design is highly sensitive to the rate of interest, but not sensitive to the water quality parameters. When the high rates of interest currently prevalent are introduced into the model those systems which contain open channel collection components are selected as the least cost system. At low rates of interest pipeline collection components are selected as the least cost system. Holding pond components of system design are cost effective at several levels of water quality. They are neutral to the rate of interest so they are incorporated in least cost systems at all the levels of interest rates. The results of the study indicate that at the current high rates of interest open channel collection systems and holding ponds are cost effective system components to achieve selected levels of water quality in urban drainage system design.     

COMPARATIVE EVALUATION OF THREE URBAN RUNOFF MODELS1

ABSTRACT: Three urban runoff models, namely, the Road Research Laboratory Model (RRLM), the Storm Water Management Model (SWMM) and the University of Cincinnati Urban Runoff Model (UCURM), were examined by comparing the model simulated hydrographs with the hydrographs measured on several instrumented urban watersheds. This comparison was done for the hydrograph peak points as well as for the entire hydrographs using such statistical measures as the correlation coefficient, the special correlation coefficient and the integral square error. The results of the study indicated that, when applying the three selected non-calibrated models on small urban catchments, the SWM model performed marginally better than the RRL model and both these models were more accurate than the UCUR model. On larger watersheds, the comparisons between the SWM model and the other two models would be likely even more favourable for the SWM model, because it has the most advanced flow routing scheme among the studied models.     

STORM WATER MANAGEMENT: THE CONCEPT AND ITS APPLICATION1

ABSTRACT: Storm water management is a concept being applied in many urban areas to deal with the increasing problems of storm runoff control and flood damage prevention. This paper introduces the concept and describes the recently completed storm water management program in Columbus, Georgia. Columbus has spent five years and over $200,000 in the development of their problem which includes several basic elements: soils inventory and analysis, hydrologic data collection, sediment and erosion control ordinance, storm water management handbook, urban flood simulation model, interdepartment coordination study, drainage problem categorization study, and a pilot basin study. The results of the pilot basin study are presented including example output from the urban simulation model. The computer output illustrates both the hydrologic-hydraulic and economic capabilities of the model.     

FLOODING PROBLEMS IN A SMALL URBAN WATERSHED-DOAN BROOK,CLEVELAND, OHIO1

ABSTRACT: Analysis of a small urban watershed's flooding was undertaken to determine causes and solutions to this serious environmental hazard affecting University Circle, the cultural heart of Greater Cleveland. Doan Brook is a small, highly disturbed urban stream draining 11.3 square miles. Much of the stream coridor and associated park land is owned by the public. The upper watershed lies in the communities of Shaker Heights and Cleveland Heights who lease park land from Cleveland. Two 50-year floods seriously affected the Circle area in August 1975 generating over $1 million in damages. These events resulted from excessive rainfall triggering rapid earth movement of valley walls in the upper watershed, decreased basin lag time from the infilling of several small upland lakes, a seriously undersized stream channel and storm culvert (at University Circle), and complex institutional arrangements between the three communities in the watershed. Suggestions are presented for a methodology to resolve the technical aspects of the flooding problem.     

OBSERVATIONS ON KINEMATIC RESPONSE IN URBAN RUNOFF MODELS1

ABSTRACT: This paper first discusses the results of sensitivity analyses conducted on various parameters of the San Francisco Stormwater Model ta version of WREM) and the Penn State Runoff Model in terms of their impact on outflow hydrographs. The parameters considered within a idealized catchment include: basin shape, imperivous fraction, overland roughness and slope: deterntion depth; infiltration capacity; and hyetograph timing. Second, the results for the hypothetical catchment are extended to the lazzard laboratory surfaces (asphalt, grass, roofing material) as a mean of illustrating the need for changes in model structure, as opposed to continued parameter adjustment Finally the effect of altering the scale of hydraulic representation in the surface runoff and sewer transport calculations are demonstrated for two gaged watersheds in Hamburg, West Germany.     

DECISION-MAKING IN THE DEVLOPMENT OF URBAN WATERFRONTS FOR PARK/BUSINESS USE1

Abstract: Opportunities for the development of an amalgam of park and leisure-oriented commercial establishments in urban-core waterfont settings exist in many U.S. cities. Public awareness of the need to enhance the environmental quality of these waterfont areas has resulted in a demand for planning and implementation action. However, the lack of understanding of urban political systems has been an inhibiting factor in the development of this park/ business concept. The major factors that influence the decision-making process leading to the development of urban-core waterfronts for park/business use are identified inthis paper. Understanding this decision-making process can aid project implementation and avoid waste of planning effort in time, dollars, and productivity.     

EFFECTS OF THE URBAN ENVIRONMENT ON HEAVY RAINFALL DISTRIBUTION1

ABSTRACT: A network of 225 recording raingages was operated over an area of 5200 km² in the St. Louis region during 1971-1975, in conjunction with an extensive investigation of urban effects on precipitation. Study of urban-induced effects on the frequency of heavy rainstorms has revealed a pronounced increase in the occurrence of storms producing 25 mm (1 inch) or more of rain. The increase is greatest in an area that is frequently in the path of storms passing across two urban-industrial regions. Analyses of raincells (rain intensity centers) within heavy convective storms shows a pronounced increase in water yield from cells exposed to potential urban effects, compared with those exposed only to the surrounding rural environment. Naturally-occurring heavy cells tend to undergo the greatest enhancement from urban exposure. Other analyses indicate an above-average frequency of excessive rain rates for periods of five minutes to two hours downwind of the urban-industrial complex. It is concluded that urban-induced intensification of short-duration rainstorms is sufficient to merit inclusion in the design and operation of urban-area hydrologic systems that control the flow of surplus storm water.