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

作　　者：Adam EMMER Vojtěch CURIN 

机构地区：[1]University of Graz,Institute of Geography and Regional Science,Cascade|The Mountain Processes and Mountain Hazards Group,Graz 8010,Austria [2]Czech Academy of Sciences,Prague 16500,Czechia [3]Global Change Research Institute,Czech University of Life Sciences Prague,Faculty of Environmental Sciences,Brno 60300,Czechia

出　　处：《Journal of Mountain Science》2021年第3期614-621,共8页山地科学学报（英文）

基　　金：the financial support by the University of Graz;partly supported by the Ministry of Education,Youth and Sports of the Czech Republic within the National Sustainability Programme I(NPU I),grant number LO1415;Supporting perspective human resources Programme of the Czech Academy of Sciences,project"Dynamics and spatiotemporal patterns of glacial lakes evolution and their implications for risk management and adaptation in recently deglaciated areas"awarded to AE。

摘　　要：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.

关 键 词：Alpine lake High mountain lake GLOFs Glacial lake Moraine-dammed Bedrock-dammed Negative result Cordillera Blanca 

分 类 号：TV122.4[水利工程—水文学及水资源]