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121.
基于河网水系变化的水灾危险性评价——以永定河流域京津段为例 总被引:2,自引:0,他引:2
城市化过程中不合理的土地利用导致河道填塞、河网缩减现象普遍,城市水灾增加。基于灾害系统思想,构建了基于河网水系变化的水灾危险性评价体系,并以永定河京津段为例进行了实证分析。结果表明:(1)近40年来研究区水系结构简单化趋势明显,河道长度减少了20.5%,条数减少了36.4%,水系调蓄能力下降,在同样的致灾强度下水灾危险性加大;(2)在假设暴雨重现期为50年的条件下,经济密度差异决定了水灾潜在危险区的空间格局,居民用地将成为水灾重度危险区;平原段水灾重度危险区占5.7%,中度危险区占33.1%,滨海段重度危险区占13.9%,中度危险区占26.8%。研究结果可为区域综合减灾、水灾预报提供依据。 相似文献
122.
Brain M. Reich Kenneth G. Renard 《Journal of the American Water Resources Association》1981,17(1):67-74
ABSTRACT: Flood frequency analyses are frequently being made using widely available computer programs. Serious errors can result from blind acceptance of such results. Visual interpretation of observed flood series can be used for evaluation on frequency paper with compatible scales. Such frequency papers are presented in the paper. In ephemeral streams, more infrequent floods may constitute a separate set from the more frequent floods because (a) runoff producing storms cover only a portion of the contributing area, (b) transmission losses in the normally dry streambed may reduce the peak flow, and (c) some runoff may be stored in stock water ponds which therefore leads to partial area runoff. The Cunnane plotting position used in this paper is superior to the more widely used Weibull equation, having a mathematically sound basis for locating observed floods on an assumed probability. 相似文献
123.
124.
震害预测的软件程序一般都是基于结构分析的原理,大都采用FORTRAN语言来编写,而震害预测工作中又大量用到分组和排序,这又是数据库语言的特长。本文介绍了在震害预测工作中应用数据库语言的一些体会,主要讨论了两种语言的接口问题。 相似文献
125.
为了迅速、合理地预测和评估洪涝灾害造成的经济损失,为防汛决策提供科学依据,从江苏省洪涝灾害防治的实际需求出发,进行了江苏省洪涝灾情评估系统的总体设计,并阐明了系统的特点,结构和功能。 相似文献
126.
127.
《Environmental Hazards》2013,12(1):3-11
Abstract During the past two decades it has become increasingly common to attribute “naturala” disasters and other damaging environmental events to proximate or underlying causes that are socially produced. Through an examination of three cases, two of them historical, this paper demonstrates that underlying causes within the geophysical domain are also important. Few types of environmental damage or disaster stem from unalloyed human causes or geophysical ones; complex intermixtures are the rule. 相似文献
128.
TaWei Soong William H. Ettinger 《Journal of the American Water Resources Association》2000,36(1):105-121
ABSTRACT: Effects of the 1993 flood on river water and sediment quality were investigated using historical data and data collected from the Illinois River and Upper Mississippi River in a post‐flood period. Overall the post‐flood results showed systematic reductions and individual changes in the water and sediment constituents. The reductions in sediment metals and nutrients were most obvious at the Keokuk and Lock and Dam 26 stations. By analyzing and comparing the physical changes to the changes in water and sediment constituents at each station, it was found that physical processes such as sediment entrainment and, more importantly, the removal of fine sediment to be the main causes for the reduced concentrations in sediment constituents. On the other hand, sediment redistribution and associated secondary contamination could have caused the emergence of several water and sediment constituents that were undetected before the flood. 相似文献
129.
Chao‐Hsien Liaw Yao‐Lung Tsai Mow‐Soung Cheng 《Journal of the American Water Resources Association》2006,42(2):311-322
The Keelung River Basin in northern Taiwan lies immediately upstream of the Taipei metropolitan area. The Shijr area is in the lower basin and is subject to frequent flooding. This work applies micromanagement and source control, including widely distributed infiltration and detention/ retention runoff retarding measures, in the Wudu watershed above Shijr. A method is also developed that combines a genetic algorithm and a rainfall runoff model to optimize the spatial distribution of runoff retarding facilities. Downstream of Wudu in the Shijr area, five dredging schemes are considered. If 10‐year flood flows cannot be confined in the channel, then a levee embankment that corresponds to the respective runoff retarding scheme will be required. The minimum total cost is considered in the rule to select from the regional flood mitigation alternatives. The results of this study reveal that runoff retarding facilities installed in the upper and middle parts of the watershed are most effective in reducing the flood peak. Moreover, as the cost of acquiring land for the levee embankment increases, installing runoff retarding measures in the upper portion of the watershed becomes more economical. 相似文献
130.