Extreme hydrological events in karst areas of Slovenia,the case of the Unica River basin     

《Geodinamica Acta》2013,26(1-3):89-100

The study presents natural hazards in Slovenia's karst, focusing on flooding in karst poljes. A specific study was done on the flood dynamics of two typical and connected karst poljes (Cerknica and Planina) of the Classical Karst region. In the case of particularly extreme hydrological conditions in the autumn of 2008, detailed analyses of the recharge-discharge regime and the interrelationship of flooding on the two poljes were done. Daily precipitation, discharge, and water level values from several monitoring sites were analyzed and cross-correlated, and additional hydrological analyses were done using a digital elevation model in order to acquire water level increase and decrease intensity, flood water volumes, and the extent of flooding and to understand the conditions controlling karst flooding. The results reveal that the hydrological functioning of the studied karst poljes is influenced by the hydrogeological and temporary hydrological conditions in the catchment area. The response of the binary karst system (i.e., the influence of autogenic and allogenic recharge) is especially distinct. The study shows that during extremely intense recharge, the reactions of karst aquifer systems to precipitation are as rapid as the response of surface waters (the water level of Cerknica Lake increased with an intensity of 38-63 cm/day or 55 m3/s respectively) while retention capacities are negligible. In contrast to flash floods, floods in karst areas may last from several weeks to several months. For the observed period a three-dimensional simulation of the flooding was made. At the maximum recorded water level, the volume of water on the Cerknica polje was 51 million m³, and 26 million m³ on the Planina polje. The maximum extent of flooding on the Cerknica polje was 23 km² and on the Planina polje 9.5 km². On the basis of the study, information was provided regarding future hazard mitigation. However, the study demonstrated that a sufficiently dense monitoring network is necessary to predict the occurrence and duration of floods with greater certainty.  相似文献   

Déjà vu or something new? The adaptation concept in the climate change literature     

《Geoforum》2013

This paper reflects on the resurgence and meaning of the adaptation concept in the current climate change literature. We explore the extent to which the early political economic critique of the adaptation concept has influenced how it is used in this literature. That is, has the current conceptualization been enriched by the political economic critique of the 1970s and 1980s and thus represent something new? Or is the concept used in a way today that echoes previous debates; that is, is this a déjà vu experience? To answer this question, we review the early political economic critique of the natural hazards school’s interpretations of vulnerability and adaptation. We then examine the revival of the adaptation concept in the climate change literature and discuss its main interpretations. For the purposes of this paper, the climate change literature encompasses the four IPCC reports and adaptation-focused articles in four scholarly journals: Global Environmental Change, Climatic Change, Climate and Development, and Mitigation and Adaptation Strategies for Global Change. Our content analysis shows the dominance (70%) of “adjustment adaptation” approaches, which view climate impacts as the main source of vulnerability. A much smaller percentage (3%) of articles focus on the social roots of vulnerability and the necessity for political–economic change to achieve “transformative adaptation.” A larger share (27%) locates risk in both society and the biophysical hazard. It promotes “reformist adaptation,” typically through “development,” to reduce vulnerability within the prevailing system. We conclude with a discussion of continuity and change in the conceptualization of adaptation, and point to new research directions.  相似文献   

数字流域与雨量站网论证技术的集成应用研究          下载免费PDF全文

李春红  王建平  陈建  谢小燕 《水文》2013,33(6):58-62

针对传统站网论证方法难以与降雨分布的影响因素相关的局限性,将数字流域引入站网论证方法中,阐述了数字流域建设和信息提取的相关技术,并将数字流域与站网密度、相关分析、雨量等值线、历史洪水预报分析4种站网论证技术进行集成和应用研究。研究结果表明,数字流域与雨量站网论证技术的集成考虑了地形等因素影响,论证结果更合理,其基本思想可为类似的站网论证分析提供借鉴。  相似文献   

云南山区水库溃坝洪水及其演进分析     

刘新有  李自顺  朱俊  尹炳槐 《水文》2013,33(3):61-64

受地形影响,西南山区水源以水库为主,由于大部分水库修建时间较早,在西南季风气候降水集中影响下,存在较大的溃坝风险。溃坝洪水突发性与破坏性极强,进行水库溃坝洪水计算及洪水演进分析,是在水库大坝发生突发性安全事故时科学应对的基础。结合西南山区实际,优选溃坝洪水计算与洪水演进模型,并以云南省昌宁县河西水库为例,分析确定相关参数,分析指出了西南山区水库溃坝形态以全溃为主,具有溃坝洪水量极大、洪水演进迅速的特点。研究不仅可为河西水库制定大坝安全管理应急预案提供技术支撑,也能为该地区水库溃坝洪水及其演进分析提供参考借鉴。  相似文献   

武江“2006·07”洪水的分析与研究          下载免费PDF全文

陈斯伦  朱维科 《水文》2013,33(1):94-96

阐述了武江“2006·07”洪水的成因、规模、灾害以及对这场洪水的查测、资料整理和分析研究等情况,并就这些成果的价值在学术上、实际应用上作出了评价.  相似文献   

区域滑坡灾害风险评估——以长江三峡库区秭归县为例     

彭令  牛瑞卿  赵艳南  邓清禄 《吉林大学学报(地球科学版)》2013,43(3):891-901

以滑坡灾害突出的三峡库区秭归县为研究区。在深入分析滑坡孕灾环境、诱发因素、滑坡编录和承灾体信息的基础上,利用Logistic回归模型和统计分析方法相结合进行了滑坡危险性评价。通过滑坡灾害致灾强度与承灾体抗灾能力分析了人口、建筑物、生命线工程和土地资源的易损性。采用成本价值核算法对各类承灾体进行了价值核算,最后通过风险模型预测了研究区内未来10年滑坡灾害的生命与经济风险。生命和经济高风险区分别占整个研究区面积的1.11%和2.71%,主要分布在集镇和学校、企事业单位等人口密集区以及交通建设用地等经济价值大的地区;中风险区分别占13.21%和20.66%,主要分布于农村居民生活居住和耕地活动区;低风险区分别占85.68%和76.63%,则分布在经过地质灾害治理和人类活动较为稀少的未利用地及林地等区域。通过实地调查分析与对比验证,发现预测结果与实际灾情较吻合。研究表明,集镇和学校、企事业单位等人口集中区和交通建设用地区是今后减灾防灾部署工作的重中之重。  相似文献   

变化环境下武江超定量洪水门限值响应规律及影响   总被引：2，自引：0，他引：2       下载免费PDF全文

叶长青  陈晓宏  张丽娟  庞园  张家鸣 《水科学进展》2013,24(3)

世界众多江河洪水超定量(POT)系列门限值已发生变化,门限值选取不当会影响频率分析合理性.结合历史洪水资料,采用洪水POT理论分析变化环境下武江门限值响应规律及影响.结果表明:武江流域下垫面植被和径流系数在1991年明显改变,变化环境下不仅洪水门限值显著增大,且超过特定量级洪水的发生次数也在增加,POT模型能捕捉洪水在量级和发生次数方面的变化信息.分别选用变化环境前后门限值来推算设计洪峰,当重现期大于200年时,坪石站差异度达19.21％,犁市站达8.12％以上.选用变化环境后高门限值可有效提高线型对大洪水的拟合程度和设计洪水计算精度.  相似文献   

下荆江二元结构河岸土体特性及崩岸机理          下载免费PDF全文

夏军强  宗全利  许全喜  邓春艳 《水科学进展》2013,24(6):810-820

三峡水库蓄水后下荆江河段河床冲刷下切, 局部河段崩岸险情频繁发生。为研究下荆江二元结构河岸的土体特性及崩岸机理,结合近期该河段崩岸情况,现场查勘了6个崩岸点,并对河岸土体进行了室内土工试验。试验结果表明下荆江河岸土体的垂向组成具有典型的二元结构特征:下部非粘性土（沙土）层较厚,上部粘性土（低液限粘土）层较薄且松散。以河岸崩塌过程分析为基础,提出了二元结构河岸发生绕轴崩塌时上部土层稳定性的计算方法。结合近岸水动力条件计算及土工试验结果,定量分析了二元结构河岸的崩塌机理及其影响因素:① 下部沙土层的起动流速比近岸流速小得多,故该土层容易受水流冲刷;②上部粘性土层崩塌前抗冲强度很大,但多为低液限粘土且相对松散,崩塌后堆积在岸边容易分解并被水流带走;③ 河岸稳定安全系数在一个水文年内呈周期性变化,落水期安全系数最小,故容易引发崩岸,该计算结果与近期崩岸实际统计结果一致。  相似文献   

自适应网格在复杂地形浅水方程求解中的应用          下载免费PDF全文

周建中  张华杰  毕胜  严凡  赵越 《水科学进展》2013,24(6):861-868

计算域内地形的概化精度对模拟结果有较大影响,针对实际地形中同时存在狭长河谷与广阔泛洪区的问题,在层次自适应网格模型的基础上,研究了网格快速加密与合并的步骤,并以水位梯度与局部弗劳德数为基础设计了网格自适应准则,当水流运动情势变化时网格密度自动调整,实现计算精度与效率的平衡。在此网格模型基础上,采用有限体积法求解二维浅水方程,利用梯度限制器技术及龙格-库塔法提高模型的空间、时间计算精度。算例表明,层次自适应网格模型既能实现随水流运动动态变化并捕获水位计算敏感区,也能对局部区域进行静态固定加密,自适应性良好,具有较好的推广应用价值。  相似文献   

山洪灾害临界雨量研究综述   总被引：2，自引：0，他引：2       下载免费PDF全文

程卫帅 《水科学进展》2013,24(6):901-908

临界雨量是一个关键的山洪灾害预警指标。按其技术原理将临界雨量推求方法划分为数据驱动的统计归纳法和基于灾变物理机制的水文水力学法分别进行评述,并介绍了临界雨量指标的两个拓展:动态临界雨量和暴雨临界曲线,综述了临界雨量不确定性分析的研究进展。通过综述发现:中国目前主要应用的是较简单的统计归纳法;临界雨量推求主要考虑前期降雨量（前期土壤饱和度）和时段累积降雨量两个因素的影响或仅后者一个;临界雨量指标难以反映山洪灾害的规模;考虑临界雨量不确定性有助于提高预警质量,但如何充分考虑其影响仍然是一个挑战。  相似文献