Landslide Susceptibility Screening using Wind-Driven Rainfall

Abstract

Rainfall is one of the most significant triggering factors for shallow landslides, raveling, and erosion of over-steepened slopes, especially in steeply inclined mountainous regions, such as the western Greater Himalayan Mountains of northern Pakistan. The influence of wind-driven rainfall is usually neglected in comparisons between rainfall and mass wasting. Winddriven rain falls with an angle of incidence influenced by prevailing wind direction and velocity. The need to include considerations of incident rainfall distribution with respect to mass wasting processes is long overdue. The idea of coupling "wind-driven" rainfall based on directional monsoon with regional topography (slope aspect) was analyzed to ascertain the actual distribution of rainfall upon slopes exhibiting varying inclinations and slope aspect. Regional-level landslide susceptibility maps were prepared for the entire Indus River watershed using widely accepted methods including GIS heuristic weighted overlay and fuzzy logic techniques by including traditional rainfall distribution maps as one of the triggering factors. The results of that analysis were then compared with current research to examine whether an oblique/ inclined rainfall correction map would aid in assessing landslide susceptibility by considering the impacts of slope inclination and aspect on the effective rainfall being "caught" by those slopes facing the prevailing wind directions. The susceptibility maps produced bythis method were found to be more reasonable than others yet produced of such a large study area (~75,000 km2).

Department(s)

Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

GIS; Landslide; Slope Aspect; Susceptibility Mapping; Wind-Driven Rainfall; Air Pollution Control; Fuzzy Logic; Geographic Information Systems; Heuristic Methods; Landslides; Fuzzy Logic Techniques; Landslide Susceptibility; Mountainous Regions; Prevailing Wind Directions; Rainfall Distribution; Slope Aspect; Susceptibility Mapping; Erosion; Fuzzy Mathematics; Mass Wasting; Monsoon; Mountain Region; Vulnerability; Watershed; Wind Direction; Wind Forcing; Wind Velocity; Himalayas; Indus River; Pakistan

International Standard Serial Number (ISSN)

1078-7275

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2016 Geological Society of America (GSA), All rights reserved.

Publication Date

01 Nov 2016

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