Susceptibility mapping and estimation of rainfall threshold using space based input for assessment of landslide hazard in Guwahati city in North East India
Other literature type
Kundu, S. S.
(issn: 2194-9034, eissn: 2194-9034)
Slopes are the most common landforms in North Eastern Region (NER) of India and because of its relatively immature topography,
active tectonics, and intense rainfall activities; the region is susceptible to landslide incidences. The scenario is further aggravated
due to unscientific human activities leading to destabilization of slopes. Guwahati, the capital city of Assam also experiences similar
hazardous situation especially during monsoon season thus demanding a systematic study towards landslide risk reduction. A
systematic assessment of landslide hazard requires understanding of two components, "where" and "when" that landslides may occur.
Presently no such system exists for Guwahati city due to lack of landslide inventory data, high resolution thematic maps, DEM,
sparse rain gauge network, etc. The present study elucidates the potential of space-based inputs in addressing the problem in absence
of field-based observing networks. First, Landslide susceptibility map in 1 : 10,000 scale was derived by integrating geospatial
datasets interpreted from high resolution satellite data. Secondly, the rainfall threshold for dynamic triggering of landslide was
estimated using rainfall estimates from Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis. The 3B41RT data
for 1 hourly rainfall estimates were used to make Intensity-Duration plot. Critical rainfall was estimated for every incidence by
analysing cumulative rainfall leading to a landslide for total of 19 incidences and an empirical rainfall intensity-duration threshold
for triggering shallow debris slides was developed (Intensity = 5.9 Duration-0.479).