Economic Loss Assessment of Upstream Inundation under Time-Varying Water Levels in Landslide-Dammed Lakes:A Case Study of Tangjiashan Dammed Lake
Li Bo
Bai Zewen
Sun Rui
Peng Ming
Shi Zhenming
Ji Sitong
Abstract：The upstream backwater inundation triggered by landslide dam formation often leads to severe destruction of fixed assets such as buildings.Due to the dynamic nature of upstream water levels,traditional loss assessment methods exhibit significant uncertainty.To address this,in this paper it proposes a dynamic water level inundation loss assessment method that integrates the impacts of both inundation depth and duration.Taking the Tangjiashan landslide dam as a case study,this research first utilizes time series analysis and the DABA model to simulate the dynamic water level fluctuation process.Subsequently,a dual-factor(water depth-duration)vulnerability function for buildings under varying temporal water depth conditions is constructed.Finally,a quantitative assessment of economic losses is achieved.The results demonstrate that elevation is the key factor determining the inundation sequence of buildings,while terrain type and flood release velocity dominate the loss accumulation rate and its spatial distribution pattern.Specifically,losses accumulate rapidly in flat,low-elevation areas(e.g.,Xuanping Township)during the initial inundation phase(first 100 hours),whereas sloping,higher-elevation areas(e.g.,Yuli Town)exhibit a slow,linear increase trend.Artificially excavated drainage channels significantly reduce total losses in sloping areas(e.g.,approximately 40%reduction in Yuli Town),but their mitigating effect is limited in low-lying areas.Compared to the fixed water level model,the time-varying water level model proposed herein demonstrates superior accuracy in loss assessment within topographically complex regions.Artificially induced flood release shows significant disaster mitigation benefits compared to the natural dam breach mode.This study provides a theoretical foundation and technical pathway for the dynamic assessment of economic losses due to upstream inundation caused by landslide dams,and offers a quantitative decision support tool for emergency response engineering.
Keywords：landslide daminundation losstime-varying water levelbuilding vulnerabilitytime series analysisDABA modelengineering geology
Publication Date：2025-10-30
Online Publishing Date：2025-11-11(First online date of this platform, not the publication date of the document)
Pages：12( 3873-3884 )