Outburst flood hazard: Case studies from the Tien-Shan Mountains, Kyrgyzstan   总被引：3，自引：0，他引：3  

Bohumír Janský  Miroslav Šobr  Zbyněk Engel 《Limnologica》2010,40(4):358-364

More than 2000 of mountain lakes covering more than 0.1 ha exist in a territory of Kyrgyzstan. Nearly 20% of them are dangerous because of instability of lake dams, frequent overflows and melting of buried ice inside the moraine dams. According to the Kyrgyz lake inventory, 328 lakes are at risk of outburst and 12 lakes are considered as actually dangerous. Since 1952 more than 70 disastrous cases of lake outbursts have occurred. The majority of the endangered lakes belong to one of the three genetic types: morainic-glacier, supraglacial and lake dammed by landslides and debris flows. Petrov, Adygine and Koltor lakes were selected and studied in the Tien-Shan Mountains as case studies of the most frequent genetic types of hazardous lakes. Observations were focused on the morphology of the lake basin and the surrounding relief, outflow pattern and processes controlling the development of lake. For the hazard assessment, evolution of glaciers and lakes was reconstructed using historical reports, aerial photographs and satellite images.  相似文献   

关中西部漆水河全新世特大洪水与环境演变   总被引：20，自引：6，他引：14  

查小春  黄春长  庞奖励 《地理学报》2007,62(3):291-300

古洪水水文学研究是全球变化研究的前沿课题。本文通过对漆水河流域深入调查研究, 在漆水河与湋河交汇的二级阶地全新世黄土-土壤剖面中发现古洪水沉积夹层, 利用沉积地貌学、沉积学、考古学和释光年代学方法, 确定了在全新世时期的11500 年内, 漆水河曾经在4650~4600a BP、4600~4300a BP、4300~4100a BP 和3100~3000a BP 发生了4 期20 次洪水事件。通过利用水位-流量关系模型, 计算出这4 期20 次特大洪水的洪峰流量, 大大延长了洪水水文数据序列, 并建立了漆水河全新世洪水频率曲线, 科学、系统地提高了漆水河洪水水文学计算精度, 增强了渭河流域防洪减灾和水资源开发当中洪水频率分析的可靠性。这项研究成果对于我国著名的农业科技城-杨凌的防洪减灾、水资源开发和生态环境建设具有重要的应用价值, 同时填补了渭河流域古洪水水文学研究的空白, 对于渭河流域生态环境综合治理具有重要的科学意义。  相似文献   

论太湖平原洪涝灾害与水利工程问题和发展趋势   总被引：5，自引：1，他引：4  

陈西庆  陈吉余 《湖泊科学》1994,6(4):364-374

在分析研究太湖流域洪涝灾害成因及以围圩、筑堤、建闸为特点的圩区经济基础上,论述了近几十年来流域下垫面变化对流域水情的影响。总结了近40年来流域水利工程规划设计的经验与不足之处;展望了未来几十年流域水情变化发展趋势,特别是全球海平面上升对流域洪水蓄、泄方面的重大影响。指出在流域十大骨干水利工程的基础上,今后流域中新建骨干工程的关键目标是提高长江南岸、杭州湾北岸闭闸时段的排洪能力及建设吴淞挡潮闸,从而大幅度提高各潮周期内黄浦江净泄洪量;同时运用非工程措施,确保与充分利用区内洪水调蓄能力。  相似文献   

三峡工程影响的初步评价     

Heike HARTMANN  Stefan BECKER 《湖泊科学》2003,15(Z1):249-254

全世界都在评论三峡工程的修建,这些评论经常是不太客观的.本文从正负两方面对三峡工程进行了讨论,重点在防洪工程和区域经济方面.作者认为修建三峡工程作为发电的功能远大于防洪的功能.尽管上游来的洪峰经过三峡水库调蓄后能够被削弱.但中游的洪水风险仍然很大.一般而言,中游地区的洪水是大降水事件的产物.三峡工程不可能完全控制中游的洪水.三峡水库发电对中国中部及周边地区经济的可持续发展将产生积极作用,也将能确保东部沿海地区尤其是上海市电能的供给.  相似文献   

Riverine export of water,sediment and carbon during flood events in the arid to semi-arid Wuding River on the Chinese Loess Plateau     

Lishan Ran  Xiankun Yang  Mingyang Tian  Hongyan Shi  Shaoda Liu  Ruihong Yu  Yuanyuan Zhou 《地球表面变化过程与地形》2020,45(8):1777-1788

Floods have become increasingly important in fluvial export of water, sediment and carbon (C). Using high-frequency sampling, the export of water, sediment and C was examined in the Wuding River catchment on the Chinese Loess Plateau. With groundwater as an important contributor to runoff all year round, floods were relatively less important in the export of water. However, large floods were disproportionately important in exporting sediment and inorganic C (DIC) and organic C (DOC and POC). The three largest floods in each year transported 53.6–97.3 and 41.4–77% of the annual sediment and C fluxes, respectively. An extreme flood in 2017 alone contributed 94.6 and 73.1% of the annual sediment and C fluxes, respectively, in just 7 days, which included 20.3, 92.1 and 35.7% of the annual DOC, POC and DIC fluxes, respectively. A stable carbon isotope (δ¹³C) analysis of POC indicated that modern soils and C3 plants were its primary source. Furthermore, floods greatly accelerated CO₂ degassing due to elevated gas transfer velocity, although stream water CO₂ partial pressure (pCO₂) exhibited a decreasing trend with flow discharge. Although these results illustrated that increasing runoff diluted pCO₂, the timing and magnitude of floods were found to be critical in determining the response of pCO₂ to flow dynamics. Low-magnitude floods in the early wet season increased pCO₂ because of enhanced organic matter input, while subsequent large floods caused a lower pCO₂ due to greatly reduced organic matter supply. Finally, continuous monitoring of a complete flood event showed that the CO₂ efflux during the flood (2348 ± 664 mg C m^–2 day^–1) was three times that under low-flow conditions (808 ± 98 mg C m^–2 day^–1). Our study suggests that infrequent, heavy storm events, which are predicted to increase under climate change, will greatly alter the transport regimes of sediment and C. © 2020 John Wiley & Sons, Ltd.  相似文献   

Studies on changes in extreme flood peaks resulting from land-use changes need to consider roughness variations     

Wei Qi 《水文科学杂志》2019,64(16):2015-2024

ABSTRACT

The impacts of changes in forest coverage on extreme floods have drawn much attention globally. This study quantifies the sensitivity of flood peaks to forest coverage and roughness changes. With this objective, a framework is first introduced that includes a variance-based sensitivity analysis approach and a water and energy budget-based distributed hydrological model with a vegetation module. The influence of forest coverage changes is simulated by altering land-use types that are based on physical parameters. A variance decomposition approach is used to quantify the contribution of influential factors, i.e. event size, forest coverage and roughness changes, to extreme flood peak variations. The results in a medium-sized river basin show forest coverage changes have little influence: variations in canopy interception, ground surface water retention, soil moisture and groundwater table resulting from changing forest coverage did not alter flood peaks considerably. In contrast, it is found that flood peaks are more sensitive to roughness variations.  相似文献   

鄱阳湖流域过去1000 a径流模拟以及对气候变化响应研究   总被引：1，自引：1，他引：0  

张小琳  李云良  于革  张奇 《湖泊科学》2016,28(4):887-898

为研究过去千年尺度径流变化及其对气候变化的响应,以长江中游鄱阳湖流域为研究区,运用气候模式CCSM4和ECHAM5模拟过去1000 a气候数据,空间降尺度后驱动水文模型模拟了鄱阳湖流域过去近千年流域径流序列.利用快速傅里叶变换、小波分析等手段,分析流域极端径流变化特征、周期和该流域旱涝事件发生频率.结果表明:2种气候模式均能反映出中世纪暖期及小冰期阶段的干湿交替变化,且小冰期内中干旱状态维持时间较长;径流的丰枯变化与降水量变化具有较好的对应关系.CCSM4和ECHAM5模式下发生旱涝灾害与极大极小降水事件发生频率基本相同,径流丰枯变化与降水变化周期相近,均具有30 a左右的主周期,10~15、7 a左右的子周期.小波系数模平方图中30 a左右显著的能量信号揭示了该周期与北太平洋气候的主要环流机制的太平洋年代际振荡周期相近,因此,大气环流涛动是造成气候-水文变化的主要原因.研究结果拓展了基于近代60 a观测记录的流域水文变化的认识,探讨了千年时间长度下流域干湿变化特征和水文对气候响应的动力机制,有助于全面系统认识长江中游在全球气候暖化背景下旱涝极端水文事件的发生机制与变化规律.  相似文献