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51.
Flood seasonality and generating conditions in the Tay catchment, Scotland from 1200 to present 总被引:1,自引:0,他引:1
Lindsey J McEwen 《Area》2006,38(1):47-64
The new maximum recorded river flows in Scotland since 1988 have triggered widespread interest in whether floods are becoming more frequent and in the conditions that generate floods of different magnitudes and frequencies. There are questions about the longer-term variability in flood-generating characteristics, and whether there are past analogues for present hydroclimatic variability. The present paper builds on previous work reconstructing a detailed historic flood chronology for the Tay, the largest catchment in Scotland, and its tributaries over the past 800 years, extending the gauged discharge record (1952 onwards). It categorizes flood-generating factors in the Tay catchment and analyses the hydro-meteorological conditions that have generated extreme and moderate floods over a historical period. This work is placed in a broader literature context of historical 'climaxes of storminess', periods of higher storm frequency, flood patterns observed in Scotland and Europe during the Little Ice Age and longer-term rainfall and temperature patterns. The paper concludes that the variability in flood-generating characteristics is highly dependent on the timescale of observation. Inevitably the relative dominance of winter and early spring flooding can vary from year to year and within specific time-periods, but so can the level of augmentation of the flood series with summer and autumn floods to produce notable 'flood years' and flood clusters. The Tay provides a good 'all-Scotland surrogate' for historical flood patterns, reflecting its gathering areas in eastern and western Scotland. The value of a historical approach to the assessment of flood seasonality and generating characteristics is clearly demonstrated. 相似文献
52.
GIS-based flood hazard mapping at different administrative scales: A case study in Gangetic West Bengal, India 总被引:4,自引:0,他引:4
This paper addresses the need for an efficient and cost-effective methodology for preparing flood hazard maps in data poor countries, particularly those under a monsoon regime where floods pose a recurrent danger. Taking Gangetic West Bengal, India, as an example and using available historical data from government agencies, the study compiled a regional map indicating hazard prone subregional areas for further detailed investigation, thereby isolating actual high risk localities. Using a GIS (Geographical Information System), a composite hazard index was devised incorporating variables of flood frequency, population density, transportation networks, access to potable water, and availability of high ground and maximum risk zones were mapped accordingly. A digital elevation model derived from high resolution imagery available in the public domain was used to calculate elevated areas suitable for temporary shelter during a flood. Selecting administrative units of analysis at the lowest possible scales – rural development blocks (regional) and revenue villages (subregional) – also ensures that hazard mapping is prepared in line with the existing rural planning and administrative authorities responsible for remedial intervention. 相似文献
53.
54.
Midstream of the Keelung River Basin in Northern Taiwan has become highly urbanized and densely populated area. Flood inundation
along riversides frequently occurred during typhoons or rainstorms. Three protection measures, including constructions of
high-level protection levees, a diversion channel, and a detention reservoir, were proposed for flood mitigation. The main
purpose of this study is to evaluate the flood mitigation performance of the three proposed structural measures by using combined
hydrologic analyses and hydraulic routings. A semi-distributed parallel-type linear reservoirs rainfall-runoff model was used
for estimating the surface runoff. Furthermore, a 1-D dynamic channel routing model was coupled with a two-dimensional inundation
model to simulate the hydraulic characteristics of river flooding and overland flow. Simulation results of flood stages, runoff
peak discharges, and inundation extent under design rainfall scenarios were chosen as the criteria for evaluation. The results
showed a diversion channel is superior to the other two measures for flood mitigation of the study area. After the process
of environmental impact assessment, a revised diversion channel approach has been approved for construction as the major structural
measure. 相似文献
55.
A debris flow originating from the Alcamayo River on 10th April 2004 destroyed a part of the town of Aguas Calientes, resulting
in 11 victims, and with serious affects to the tourist flow to the Machupicchu inka citadel. On the same day, as well as in
January and March 2004, other similar phenomena occurred on the Cedrobamba and Leonchayoq Rivers, affecting the railway and
an electrical tower, and disrupting the train service. 相似文献
56.
57.
华北平原东部淡水资源短缺,旱涝碱成灾害限制了农业生产的可持续发展。海河的治理,解决了排洪排涝排咸出路。春季开发利用地下水包括微咸水和半咸水抗旱灌溉。夏季利用伏雨洗盐排咸,增大降雨入渗,减少径流流失,防治渍涝灾害,把降雨转化为地下水资源。秋冬引蓄河水,回灌地下水补源。以土壤与潜水的地层空间作为调节大气降水、土壤水、地下水、地表水的地下水库,以调控地下水埋深在临界动态为指标,最大限度地把时空分布不均的天然降雨转化为可持续利用的水资源。地表水地下水联合运用,促使水资源采补平衡,降雨灌溉淋洗脱盐强于干旱蒸发积盐过程,地下水淡化强于矿化过程。实现旱涝碱咸综合治理,水土资源可持续利用,经济社会可持续发展,生态环境良性循环。 相似文献
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59.
煤矿水害多源信息预测方法研究 总被引:1,自引:0,他引:1
基于MAPGIS平台,用Visual C++对其进行二次开发,研制了煤矿水害多源信息预测系统.通过对地震、电法、水文地质等多源数据进行处理后,在MAPGIS系统下进行成图、配准和空间定量分析,建立了预测模型.用该系统对煤矿实际资料进行了处理,结果表明其预测结果较传统方法更为准确. 相似文献
60.
国道108线广元段由于地质地貌条件复杂、重载作用及施工质量未能保证,桥梁裂缝病害较为普遍。文章简要介绍了沿线工程地质条件,按裂缝病害的成因将其分为3种类型:即桥台填土上部不密实引起的裂缝病害、桥台填土整体不密实引起的裂缝病害及地基土不均匀引起的裂缝病害。分别提出3种加固对策:即压浆、预应力对穿锚索锚梁及高压旋喷技术对上述病害进行治理。通过工程实例证明了这3种措施的有效性,为公路桥梁类似裂缝灾害提供了实践经验。这3种治理措施的优点为工艺简单、成本较低。但是桥梁病害的治理往往为隐蔽工程,施工难度较大、检测困难。对于压浆和高压旋喷加固工程,必须进行取芯检测,而预应力对穿锚索锚梁在施工过程中必须严格控制水平孔的倾斜度,保证施工质量。 相似文献