A framework of numerical simulation on moraine-dammed glacial lake outburst floods

Glacial outburst floods（GLOFs） in alpine regions tend to be relatively complicated, multi-stage catastrophes, capable of causing significant geomorphologic changes in channel surroundings and posing severe threats to infrastructure and the safety and livelihoods of human communities. GLOF disasters have been observed and potential hazards can be foreseen due to the newly formed glacial lakes or the expansion of existing ones in the Poiqu River Basin in Tibet, China. Here we presented a synthesis of GLOF-related studies including triggering mechanism（s）, dam breach modeling, and flood routing simulation that have been employed to reconstruct or forecast GLOF hydrographs. We provided a framework for probability-based GLOFs simulation and hazard mapping in the Poiqu River Basin according to available knowledge. We also discussed the uncertainties and challenges in the model chains, which may form the basis for further research.

Flooding(or breaching)of inter-connected proglacial lakes by cascading overflow in the arid region of Western Mongolia(Mt.Tsambagarav,Mongolian Altai)

This study investigates the glacial lake outburst flood(GLOF)hazards in the Tsambagarav mountain range in Western Mongolia,focusing on the Khukhnuruu Valley and its interconnected proglacial lakes.Over the last 30 years,significant glacier retreats,driven by rising temperatures and changing precipitation patterns,have led to the formation and expansion of several proglacial lakes.Fieldwork combined with satellite data and meteorological analysis was used to assess the dynamics of glacier and lake area changes,with particular focus on the flood events of July 2021.The research reveals a substantial reduction in glacier area,particularly in the Khukhnuruu E complex,where glacier area decreased by 19.3%.The study highlights the influence of increasing temperatures and summer precipitation,which have accelerated ice melt,contributing to the expansion and eventual breaching of lakes.Additionally,lake area changes were influenced by the steepness of the terrain,with steeper slopes exacerbating peak discharge during floods.Of the studied seven lakes(Lake 1 to Lake 7),Lake 1 experienced the most dramatic reduction,with a decrease in area by 73.51%and volume by 84.84%,followed by Lake 7.This study underscores the region's vulnerability to climate-induced hazards and stresses the need for a comprehensive early warning system and disaster preparedness measures to mitigate future risks.

Moraine-dammed glacial lake changes during the recent 40 years in the Poiqu River Basin,Himalayas

Glacier retreat is not only a symbol of temperature and precipitation change, but a dominating factor of glacial lake changes in alpine regions, which are of wide concern for high risk of potential outburst floods. Of all types of glacial lakes, moraine-dammed lakes may be the most dangerous to local residents in mountain regions. Thus, we monitored the dy- namics of 12 moraine-dammed glacial lakes from 1974 to 2014 in the Poiqu River Basin of central west Himalayas, as well as their associated glaciers with a combination of remote sensing, topographic maps and digital elevation models （DEMs）. Our results indicate that all monitored moraine-dammed glacial lakes have expanded by 7.46 km2 in total while the glaciers retreated by a total of 15.29 km2 correspondingly. Meteorological analysis indicates a warming and drying trend in the Nyalam region from 1974 to 2014, which accelerated glacier retreat and then augmented the supply of moraine-dammed glacial lakes from glacier melt. Lake volume and water depth changed from 1974 to 2014 which indicates that lakes Kangxico, Galongco, and Youmojanco have a high potential for outburst floods and in urgent need for continuous moni- toring or artificial excavation to release water due to the quick increase in water depths and storage capacities. Lakes Jialongco and Cirenmaco, with outburst floods in 1981 and 2002, have a high potential risk for outburst floods because of rapid lake growth and steep slope gradients surrounding them.

The Two Main Mechanisms of Glacier Lake Outburst Flood in Tibet,China

With the global warming,the disasters of Glacier Lake Outburst Flood(GLOF) have taken place frequently in Tibet in recent years and attracted more and more attention.A systematic survey was conducted on the 19 GLOFs in Tibet to study their two main mechanisms.Investigations indicated that all the events occurred in end-moraine lakes,and the outburst occurred partially and instantly.And the breach had the shape of an arc or a trapezoid in overflow outburst and its top width was 3-5 times more than the height.The two main mechanisms of GLOFs in Tibetan end-moraine Lake were overflow and piping,and the overflow mechanism caused by iceberg collapse was dominated in most cases.A formula was proposed to calculate the critical thickness of iceberg tongue that determines the collapse.Granular analysis of the moraine materials revealed that seepage deformation is crucial in the outburst process.Finally,we conducted a case study of the Guangxiecuo Lake to show its possible process of outburst and estimated the peak discharge of the resulted flood.

Modelling Chorabari Lake outburst flood, Kedarnath, India

In this study, the Glacier Lake Outburst Flood(GLOF) that occurred over Kedarnath in June 2013 was modeled using integrated observations from the field and Remote Sensing(RS). The lake breach parameters such as area, depth, breach, and height have been estimated from the field observations and Remote Sensing(RS) data. A number of modelling approaches, including Snow Melt Runoff Model(SRM), Modified Single Flow model(MSF), Watershed Management System(WMS), Simplified Dam Breach Model(SMPDBK) and BREACH were used to model the GLOF. Estimations from SRM produced a runoff of about 22.7 m3 during 16–17, June 2013 over Chorabari Lake. Bathymetry data reported that the lake got filled to its maximum capacity(3822.7 m3) due to excess discharge. Hydrograph obtained from the BREACH model revealed a peak discharge of about 1699 m3/s during an intense water flow episode that lasted for 10–15 minutes on 17 th June 2013. Excess discharge from heavy rainfall and snowmelt into the lake increased its hydrostatic pressure and the lake breached cataclysmically.

Overview of an early warning system for Glacial Lake outburst flood risk mitigation in Dudh-Koshi Basin, Nepal

Natural disasters inflict severe damage on almost the entire spectrum of social and natural habitats. This ranges from housing and shelter, water, food, health, sanitation to information and communication networks, supply of power and energy,transportation infrastructure, and others. Nepal is a risk prone country for Glacial Lake Outburst Flood(GLOF). GLOFs exist as major challenges as they repeatedly cause a heavy toll of life and property. During such a disaster, major challenges are indeed the protection of life, property and vital life-supporting infrastructure. Any delay or laxity in disaster relief can escalate the magnitude of distress for the victims. Thus, rather than trying to take curative measures, it is better to minimize the impacts of GLOF. These measures subsequently help in reducing the magnitude of death and casualties due to a GLOF event. This reduction of impact is often achieved by optimizing preventive measures. For applying necessary deterrent measures, it is essential to disseminate information about the danger beforehand. Early Warning System(EWS) is an important step for such information dissemination for GLOF disaster management and helps to anticipate the risk of disaster and disseminate information to lives at risk. It is impossible and impractical to reduce all GLOF risks, but it is possible to reduce several impacts of a GLOF through the implementation of the EWS. This paper presents the design and implementation of an EWS for monitoring potential outbursts of a glacier lake in the Dudh-Koshi Basin, Nepal.

Outburst mechanism of Yindapu Glacial Lake in Tibet

At present,the mechanism research on glacial lake outburst mainly focuses on the ice quake and ice landslide,etc. To some glacial lakes,the seepage deformation is the dominant factor in outburst process. Taking the Yindapu Glacial Lake in Tibet as an example,using SEEP/W module of FEM software (GEO-STUDIO),the authors analyzed seepage stability of terminal moraine ridge dam. The leading role of seepage deformation in some glacial lake outburst mechanism is proposed and proved.

Process-driven susceptibility assessment of glacial lake outburst debris flow in the Himalayas under climate change

Global warming is causing glaciers to retreat and glacial lakes to expand in the Himalayas,which amplifies the risk of glacial lake outburst debris flows(GLODFs)and poses a significant threat to downstream lives and infrastructures.However,the complex interplay between GLODF occurrences and associated indicators,coupled with the lack of a comprehensive susceptibility indicator system that considers the entire GLODF process,presents a substantial challenge in assessing GLODF susceptibility in the Himalayas.This study proposes a process-driven GLODF susceptibility assessment indicator system responding to climate change that considers the complete process of GLODF formation,incorporating relevant parameters about upstream,themselves,and downstream of glacial lakes.Furthermore,to mitigate subjective factors associated with traditional evaluation methods,we developed three novel hybrid machine-learning models by integrating classic machine-learning algorithms with the whale optimization algorithm(WOA)to delineate the distribution of GLODF susceptibility in the Himalayas.All the hybrid models effectively predicted the GLODFs occurrence,with the WOA-SVC model demonstrating the highest prediction accuracy.Approximately 34%of the catchments exhibit high and very high susceptibility levels,primarily concentrated along the north and south sides of the Himalayan ridge,particularly in the eastern and central Himalayas.Indicators capturing the physical formation process of hazards,such as topographic potential(highest relative importance value of 40%),can precisely identify GLODF.A total of 128 catchments pose potential transboundary threats,with 24 classified as having a very high susceptibility level and 25 as having a high susceptibility level.Notably,the border region between China and Nepal is a prominent hotspot for transboundary threats of GLODF.These findings can provide valuable clues for disaster prevention,mitigation,and cross-border coordination in the Himalayas.

昆仑山北坡冰川湖变化及其溃决风险评估

探究昆仑山北坡冰川湖时空变化及冰川湖溃决洪水(Glacier lake outburst flood,GLOF)风险评估对区域水资源安全和生态发展具有重要意义。基于Google Earth Engine(GEE)遥感计算平台分析昆仑山北坡冰川湖近30 a的变化特征和GLOF风险评估模型对当前的冰碛湖进行灾害与风险评估。结果表明:(1)1990—2023年昆仑山北坡冰川湖呈显著增长趋势,冰川湖的数量从1990年的248个增加到2023年的925个(增加了2.73倍),面积从1990年的14.99 km^(2)增加到2023年的54.83 km^(2)(增加了2.66倍),冰川湖在昆仑山北坡西部高海拔山区增加显著。(2)通过对2023年GLOF风险评估分析得出,灾害水平在叶尔羌河流域最高(约占47.2%),其次是和田河流域(约占15.7%)。风险水平较高是叶尔羌河流域(约占50.8%),叶尔羌河流域高风险冰川湖占整个昆仑山北坡高风险冰川湖的60.7%。(3)1990—2023年冰川湖的增长趋势与区域气候变化相关,山区降水增加和冰川积雪消融是冰川湖扩张的主要原因。开展冰川湖溃决洪水风险评估可为干旱区水资源可持续利用,为下游地区防灾预警提供科学依据和支撑。

“11·03”金沙江白格堰塞湖溃决洪水沉积物粒度特征

【目的】探究堰塞湖溃决洪水沉积物粒度特征和理解金沙江溃决洪水泥沙沿程变化特征。【方法】分析了“11·03”金沙江白格堰塞湖溃决洪水沉积物样品颗粒组成,计算了粒度参数,论述了泥沙特征从上到下的变化及其原因,并对比讨论了本次洪水泥沙粒度特征与其他流域洪水及古洪水沉积物泥沙粒度特征。【结果】堰塞湖溃决洪水沉积物类型为粉砂、砂质粉砂、粉砂质砂;泥沙粒径中粉砂占55.18%,砂占32.86%,黏土占11.97%。泥沙中值粒径为41.34μm,平均粒径为31.73μm,两者随离白格堰塞湖距离的增加而逐渐变小;偏度值为0.27,属正偏;峰态值为0.94,属于中等尖锐;分选系数为0.57,分选性好;泥沙的粒度分布曲线双峰占52%,主峰高而窄,峰值为100μm,次峰低而宽;单峰占48%,峰态较窄,峰值为50μm。剖面泥沙粒径组成差别很小,以砂占优,粉砂含量略小于细砂,黏土含量大多在11.0%,中值粒径值大于其平均粒径值,分选系数均小于0.6,偏度为极正偏,峰态为中等。“11·03”溃决洪水与其他洪水相比,泥沙粒度组分较细,以粉砂为主,中值粒径和平均粒径较小,峰态更宽,偏度为正偏,分选性更好。【结论】研究结果对进一步认识堰塞湖溃决洪水的泥沙特征具有重要参考价值。

1990—2020年科西河流域冰川冰湖遥感监测

科西河流域冰川和冰湖较为发育,随着全球气候变暖,冰川融水成为冰湖扩张的重要补给,同时会引发冰湖溃决洪水(GLOF)等自然灾害,给当地居民生产生活带来巨大损失。因此,对该区域冰川冰湖的时空分布规律和变化特征的研究具有现实意义。本文基于Landsat系列遥感影像和数字高程模型,分析了1990—2020年科西河流域冰川冰湖面积时空分布与变化特征,并结合气象格点数据和GLOF事件,探究科西河流域冰川冰湖对气候变化响应及其与GLOF事件关系。结果表明:(1)1990—2020年科西河流域冰川面积呈加速退缩的趋势,近10年加速退缩趋势进一步加强。(2)科西河流域冰川主要分布在海拔4800~6800 m范围内,而在坡度上,主要分布在5°~20°。(3)1990—2020年科西河流域冰湖呈加速扩张的趋势,冰湖面积共扩张了26.09 km^(2),其中面积>0.25 km^(2)的冰湖扩张迅速;与冰川相连的冰湖面积扩张显著,面积增长率为49.39%。(4)1990—2020年科西河流域共11条冰湖发生溃决,溃决冰湖分布面积较小,介于0.02~0.7 km^(2)。(5)1990—2020年科西河流域气温和降水量呈波动增长趋势,降水增加不足以弥补温度引起的冰川退缩,致使科西河流域冰川加速退缩,冰湖加速扩张,冰湖溃决事件频发。

崩塌滑坡泥石流灾害链分类研究

为了科学预防应对跨越时空的灾害链锁效应,提高多灾种灾害链风险综合防御的科学性、针对性和效能性,作者基于自己多年研究体会和国内外研究案例,开展了崩塌滑坡泥石流灾害链分类研究。崩塌滑坡泥石流灾害链是指自然因素或人类活动更多的是两者迭加作用引发的冰雪岩土崩塌滑坡或泥石流灾害作为首环而接续产生的一系列灾害链式反应,后续环节表现为碎屑流、涌浪、洪流倾泻、堰塞湖淹没、溃决洪水冲击等不同组合,具有空间关联、时间接续、动力转换、灾情放大的基本特点。根据作者经验和国内外诸多典型案例的分析综合,作者提出了崩塌滑坡泥石流为首环的灾害链的基本认识、分类依据和包括5类21种的分类体系。第1类是自然崩塌滑坡接续灾害链,包括崩塌滑坡间歇级联、周期接续、多级顺直俯冲和多级折转冲击等4种灾害链。第2类是自然崩塌滑坡泥石流及其转化灾害链,包括崩塌滑坡导致激流倾泻、涌浪传播、涌浪-堰塞-淹没-溃决、转化为泥石流、沟道堵溃-泥石流淤堵河道、泥石流-淤堵-洪水和土体液化-泥土流灾害链等7种灾害链。第3类是工程土体滑坡泥石流及其转化灾害链,包括滑坡-滑坡、泥石流-堵河洪水、滑坡-泥石流和尾矿坝溃决-泥石流等4种灾害链。第4类是雪崩冰崩滑坡泥石流及其转化灾害链,包括雪崩-埋压-堵塞-洪水泥石流、冰崩岩崩-滑坡-涌浪-堰塞-溃决和冰崩滑坡-冰湖溃决-洪水泥石流等3种灾害链。第5类是火山或海域崩塌滑坡泥石流灾害链,包括火山滑坡-泥石流-堰塞、海岸崩塌滑坡-海啸和海底滑坡-泥石流等3种灾害链。本项研究试图为研究每一种类崩塌滑坡泥石流灾害链的静力学、动力学和运动学指明方向,为建立整体论与分割论相结合的地质灾害链预防应对工程技术体系和决策支持平台奠定理论基础。

堰塞湖风险处置研究现状与展望

科学认知堰塞湖基本特征、高效评估堰塞湖风险以及提升堰塞湖应急处置技术是缓和堰塞湖威胁和降低堰塞湖灾损的关键。从堰塞湖分布、成因、蓄水库容、生命周期以及堰塞湖灾害特点等方面系统分析了堰塞湖基本特征,从定性、定量以及灾害链角度系统总结了堰塞湖危险性评估方法,并结合堰塞湖溃决机理系统分析当前堰塞湖溃决应急监测困境、引流槽除险技术水平和疏通开挖机械设备现状。基于当前研究的局限性,凝炼堰塞湖应急处置研究未来应重点关注的5个问题:①堰塞体堆积形态分区机制;②强非恒定流输沙理论;③大尺度堰塞湖溃决模型试验;④堰塞湖应急处置专用机械设备研制;⑤堰塞湖溃决洪峰动态追踪。研究成果可为高风险堰塞湖风险评估、应急处置及区域防灾减灾规划提供有益参考。

Effects of seismic surge waves and implications for moraine-dammed lake outburst

Moraine dams usually collapse due to over- topping by the surge wave in the dammed lake, and the surge wave is most likely caused by an earthquake. The seismic water wave （SWW） is a major factor causing the dam to break in the earthquake zone. This paper focused on the SWW by model experiments with a shaking water tank under conditions of various water depths, seismic waves, and peak ground accelerations. Two empirical equations were obtained for estimating maximal wave height for the low and high frequency, respectively. Finally, we present the application of the empirical equations on Midui Glacier Lake in Tibet plateau.

Lake inventory and potentially dangerous glacial lakes in the Nyang Qu Basin of China between 1970 and 2016

There are a large number of glaciers and lakes developed in the Nyang Qu Basin of China. Recent climate change has significant impacted on the high-mountain glacial environment. Rapid melting of glaciers contributes to the formation and expansion of moraine-dammed lakes which increase the probability of glacial lake outburst floods(GLOFs). We calculated a multi-temporal lake inventory based on(1) topographic maps in the 1970 s,(2) satellite imageries from 1990 to 2016,(3) First Chinese Glacier Inventory(FCGI),(4) Glacier Inventory of Southeastern Tibet(GIST) and(5) meteorological data. A total of 880 lakes(>0.01 km^2) have been mapped in 2016, with 318 being glacial lakes(GLs) and 462 non-glacier lakes(NGLs). Most of the lakes were mainly located at 4500 m a.s.l. and the lakes dominated by small lakes(<0.1 km^2) where the change of their actual sizes are more significant compared to the larger ones. Meanwhile, we found that there were 178 newly formed GLs and 51 of them had disappeared between 1970 and 2016. During the same period, there can be identified 157 newly formed GLs and 226 had disappeared. We additionally performed a hazard and risk assessment for GL in 2016 and exposed 14 potentially dangerous morainedammed lakes(PDMDLs), covering a total area of 5.88 km2 in the Nyang Qu Basin. There can be found 4 GLs with very high risk, 3 GLs with high risk, 4 GLs with medium risk and 4 GLs with low risk of GLOFs susceptibility. The findings of this study can be used for the future policy of risk management and also be adapted for promoting water resources management.

Can a dam type of an alpine lake be derived from lake geometry?A negative result

Glacial lake outburst floods(GLOFs)represent one of the most serious hazard and risk in deglaciating high mountain regions worldwide and the need for GLOF hazard and risk assessment is apparent.As a consequence,numerous region-and nation-wide GLOF assessment studies have been published recently.These studies cover large areas and consider hundreds to thousands of lakes,prioritizing the hazard posed by them.Clearly,certain simplification is required for executing such studies,often resulting in neglecting qualitative characteristics which would need manual assignment.Different lake dam types(e.g.,bedrock-dammed,moraine-dammed)are often not distinguished,despite they control GLOF mechanism(dam overtopping/dam breach)and thus GLOF magnitude.In this study,we explore the potential of easily measurable quantitative characteristics and four ratios to approximate the lake dam type.Our dataset of 851 lakes of the Cordillera Blanca suggests that while variances and means of these characteristics of individual lake types differ significantly(F-test,t-test),value distribution of different geometrical properties can’t be used for the originally proposed purpose along the spectra.The only promising results are obtained for extreme values(selected bins)of the ratios.For instance,the low width to length ratio indicates likely morainedammed lake while the high value of ratio indicating round-shape of the lake indicates increased likelihood of bedrock-dammed lake.Overall,we report a negative result of our experiment since there are negligible differences of relative frequencies in most of the bins along the spectra.

Paleo-shoreline changes in moraine dammed lake Khagiin Khar, Khentey Mountains, Central Mongolia

The formation and evolution of glacier moraine-dammed lakes are closely related to past glacier expansion and retreat. Geomorphic markers such as lacustrine terraces and beach ridges observed in these lakes provide important evidence for regional paleoenvironment reconstruction. We document the magnitude of paleo-shoreline fluctuations and timings of highstands of lake water by using cosmogenic 10Be surface exposure dating and optically stimulated luminescence(OSL) dating on samples collected from lacustrine sediment and bedrock strath in Lake Khagiin Khar. The lake was initially impounded by glacier moraine at the Global Last Glacial maximum(gLGM;21–19 ka), and the lake reached its maximum paleo-shoreline level of 1840 m at sea level(a.s.l.). At that time, the stored lake water amount was up to seven times greater and the surface area was three times larger than the present values. The paleolake experienced higher shoreline levels at 1832, 1822, and 1817 m a.s.l. and reached the present lake level after 0.4 ka. We interpret that decrease in the paleolake level was caused by spillover. The increase in melt water after the gLGM and the Late Glacial exceeded the storage threshold of the lake, and the paleolake water overflowed across the lowest drainage divides. The lake spilled over across the lowest bedrock ridge at 15.9 ± 0.6 ka, and the outlet was incised since that time at a rate of 3.72 ± 0.15 mm/yr. The initial stream of the Khiidiin Pass River was disturbed by LGM moraine damming and was rerouted into the present course running through moraine after the spillover at 15.9 ± 0.6 ka.

Characteristics, Impacts and Risks of Dammed Lakes Induced by Debris Flows at the Wenchuan Earthquake Areas

After the Wenchuan Earthquake, many large-scale debris flows blocked rivers, generated dammed lakes, and produced outburst flood at the seriously hit areas. This paper mainly discussed the formation, outburst, impacts and risks of debris flow dammed lakes. The field investigation showed that the dammed lakes were created by debris flows from gullies and hill-slopes as well as the combination of debris flow and landslides, and also distributed along rivers step-by-step. The height of dams and the length of dammed lakes along river channel varied from 4 m to 18 m and from 400 m to 5000 m, respectively, and the reservoir capacity of dammed lakes were from 1.5 × 105 m3 to 3 × 106 m3. Due to geomorphological impact, dammed lakes commonly partially outburst along their front of debris flow deposition dams (1/4 - /3 outburst) or the suture between debris flow and landslide, and hardly completely outburst. Moreover, the subsequent debris flows continuously increased the magnitude and height of dams, not only increasing the stability of a single dam, but also improving the risks of outburst flood induced by intensive rainstorm. Dammed lakes produced steep rage in the sites of dams with the 4% - 9% of slope and rapidly raised river channel in the upstream due to a mass of alluvial sediment. As a result, the landscapes of step-dams and step-lakes dominate driver channels, significantly increasing the hazards of floods. Then the hazards, impacts and risk of debris flow dammed lakes along Min River from Dujiangyan to Wenchuan were analyzed. In order to mitigate dammed lakes induced by debris flows, the identification model of debris flow blocking rivers, the process of the formation, outburst and evolvement of dammed lakes, and the model of risk assessment for step-dammed lakes were strongly suggested to explore, and be used at the rivers of Min, Yuzi, Caopo, Longxi, Mianyuan, Jian, Shiting, Baishui and Jushui.

青藏高原冰湖溃决灾害隐患识别、发育规律及危险性评价

青藏高原是全球冰湖溃决灾害发生最频繁的区域之一,冰湖溃决对人类及工程建设安全造成严重威胁。以2015-2018年Landsat 8 OLI_TIRS等遥感影像及数据为基础,对青藏高原40000余条冰川10 km范围内且面积大于900 m^(2)的冰湖进行了遥感解译,分析了冰湖分布与发育特征,建立了冰湖溃决隐患的识别指标体系,利用突变级数法(CPM)对隐患点进行了危险性分级评价。结果表明:①青藏高原发育冰湖16481处,海拔分布在5000~5500 m之间的冰湖占总量的43.69%;面积集中在100~500 km^(2)之间的占总量的47.40%;行政分布上主要分布在西藏自治区,有12664个,占总量的76.84%;流域上主要分布在雅鲁藏布江流域,有8321个,占总量的50.49%。②识别出冰湖灾害隐患点369个,其中低危险点126个,中危险点177个,高危险点66个。③冰湖溃决隐患点面积多为0.1~0.2 km^(2);海拔主要分布在5000~5500 m之间;与母冰川距离大多小于100 m;冰碛坝宽度一般小于300 m,背水坡坡度大多小于50°;冰湖溃决隐患点的母冰川冰舌端坡度分布在10°~20°之间;绝大多数冰湖溃决的方向朝向北方。

冰川崩塌冰湖溃决引发的洪涝灾害调查及应对策略

我国冰川资源主要分布在青藏高原及周边地区,在全球变暖背景下,青藏高原及周边地区冰川整体上处于快速消融状态。冰川的快速变化降低冰川自身的稳定性,进而导致冰川灾害的发生风险增加,冰湖溃决洪水是冰川灾害中影响最大的自然灾害,21世纪以来冰湖溃决灾害发生频率明显上升。未来气温升高和降水的增加将加速冰川的退化,气温升高、冰川融水增加、降水量增加、极端天气条件增多,必将造成冰湖溃决风险增大。通过梳理典型历史灾害事件和气候变化下冰湖溃决洪水风险发展趋势,提出了冰川冰湖灾害应对建议,即部署排查普查,建立重点区域清单;建立多部门长效合作机制,做好协同协作;加强重点区域风险预警;研究冰湖溃决和漫溢溃坝洪水机理和风险;做好应急处置,指导地方编制预案。