Simulating debris flow deposition using a two-dimensional finite model and Soil Conservation Service-curve number approach for Hanlin gully of southern Gansu (China)

Nat. Hazards Earth Syst. Sci.

Wang

Bao

et al. 2019

132

Abstract. Shaanxi Province, located in northwest China and spanning multiple hydroclimatic and geological zones, has many areas largely suffering from rainfall-induced landslide and debris flow. The objectives of this study are to reveal the spatiotemporal characteristics of the two hazards and identify their major controlling factors in this region based on a region-wide, comprehensive ground-survey-based hazard inventory dataset from 2009 to 2012. We investigated the spatiotemporal characteristics of the two hazards and quantified the relationships between the occurrence rates of the two hazards and their influencing factors, including antecedent rainfall amount, rainfall duration, rainfall intensity, terrain slope, land cover type and soil type. The results show that landslide has a higher occurrence rate and more extensive distribution than debris flow in this region, while the two hazards are both concentrated in the south with ample rainfall and steep terrains. Both of the hazards show clear seasonalities: July–September for landslide and July for debris flow. Rainfall characteristics (amount, duration and intensity) and slope are the dominant factors controlling slope stability across this region. Debris flow is more sensitive to these rainfall metrics on the high-value ranges than landslide in this region. Land cover is another influencing factor but soil type does not appear to impose consistent impacts on the occurrence of the two hazards. This study not only provides important inventory data for studying the landslide and debris flow hazards but also adds valuable information for modeling and predicting the two hazards to enhance resilience to these hazards in this region.

Section: Introductionmentioning

confidence: 99%

Characteristics and influencing factors of rainfall-induced landslide and debris flow hazards in Shaanxi Province, China

Nat. Hazards Earth Syst. Sci.

Wang

Bao

et al. 2019

132

“…FLO-2D developed by O'Brien [23] is an effective way for debris flow simulation and has been widely applied in previous case studies [30][31][32][33][34]. In this work, the flow velocity and flow depth of the Boshuigou debris flow under the 100-year return-period rainfall and 50-year return-period rainfall were investigated.…”

Section: Fluid Feature Of the Debris Flowmentioning

confidence: 99%

Hazard Zonation and Risk Assessment of a Debris Flow under Different Rainfall Condition in Wudu District, Gansu Province, Northwest China

Sun

et al. 2022

Water

Debris flows induced by heavy rainfall are a major threat in Northwest and Southwest China, due to its abrupt occurrence and long runout. In light of this, this work presents the runout simulation and risk assessment of the Boshuigou debris flow under different rainfall conditions in Wudu district, Gansu Province, Northwest China. Based on field reconnaissance, the geomorphological feature and main source of the Boshuigou debris flow were described. With the application of the FLO-2D simulation, the potential flow depth and flow extent of the Boshuigou debris flow under 100-year return-period rainfall and 50-year return-period rainfall were calculated. The maximum flow velocities of the Boshuigou debris flow under the 100-year return-period rainfall and 50-year return-period rainfall were 5.46 and 5.18 m/s, respectively. Accordingly, the maximum flow depths were 5.85 and 5.57 m. Then, the hazard zonation was conducted in combination of the construction and other properties within the potential impact zone, and the risk assessment of the Boshuigou debris flow under the 100-year return-period rainfall and 50-year return-period rainfall was finally completed. This work presents a method for debris flow risk assessment considering the solid source and water flow, which can provide a basic reference for mitigation and reduction of geohazards induced by torrential rainfall.

“…Eventos destrutivos de fluxos de detritos foram reportados na China, na parte alta das montanhas no Paquistão, no Afeganistão, na Índia, na zona montanhosa no Japão, nas zonas altas da Nova Zelândia, entre outros lugares (Hewitt, 2004;Li;Nakano, 1974;Selby, 1993;Xu;Zhang;Li, 2011).…”

Section: Histórico De Fluxos De Detritosunclassified

“…Fluxos de detritos são movimentos de massa catastrófico, constituídos por sedimentos (finos e grossos) e água, que se move como um fluido contínuo e viscoso impulsionado pela gravidade (Takahashi, 2007). Devido as suas características físicas e de movimento, os fluxos de detritos estão intimamente ligados à processos hidrológicos dentro de bacias hidrográficas (Zhang et al, 2014).…”

Section: Delimitação Da áRea De Estudounclassified

“…Esse conceito de estudar fluxo de detritos tomando como base a bacia hidrográfica como um todo pode ser observado nos trabalhos de (Alexander, 2008;Armas et al, 2013;Carrara et al, 1991;Gong et al, 2020;Lee;Park, 2016;Li et al, 2019;Ray;Smedt, 2009;Zhang et al, 2014;Zhou et al, 2014). Essa forma de análise, muito usada em hidrologia e hidráulica, permite observar eventuais interações entre as áreas afetadas da bacia com as áreas vizinhas levando a uma análise mais abrangente do problema.…”

Section: Delimitação Da áRea De Estudounclassified

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Mapeamento De Áreas De Risco De Fluxo De Detritos Com Base Em Modelo Gis

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