Frequent Landslides in the central Western Ghats due to mismanagement of ecologically susceptible regions
Ramachandra T V, Bharath Setturu, Vinay S and Subash Chandran M D Cite
ENVIS[RP], Environmental Information System, Energy and Wetlands
Research Group,
Centre for Ecological Sciences, Indian Institute of Science -
560012
envis.ces@iisc.ac.in
tvr@iisc.ac.in Phone:
080 22933099/22933503
Introduction
Landslides occur when masses of rock, earth or debris move down a slope. Mudslides, debris flows or mudflows, are common type of fast-moving landslides that tend to flow in channels. These are caused by disturbances in the natural stability of a slope, which is triggered due to high intensity rains with the extensive changes in land cover. Mudslides usually begin on steep slopes and develop when water rapidly collects in the ground and results in a surge of water-soaked rock, earth, and debris. Causes are either preparatory (factors responsible for unstable slopes) or triggering causes (events initiating landslides / mudslides). Thus, a landslide is a complex dynamic system with preparatory causes making slopes vulnerable to failure, while the triggering causes initiates the movement. However, each ‘landslide’ characteristically involves diverse processes operating together, often with differing intensity during successive years. The objectives of the current research pertaining to landslides in the Western Ghats and coastal regions are to (i) understand the land cover dynamics using the temporal remote sensing data, (ii) evaluating temporal forest fragmentation and its adverse effects on landscape connectivity and (iii) alterations in climatic regime due to global warming with the large-scale land cover changes in the ecologically fragile regions.
Land use dynamics in the ecologically fragile districts of central Western Ghats in Karnataka have been analysed using temporal (2005, 2019) spatial data acquired through space borne sensors (remote sensing data) along with the collateral data (historical vegetation map, the Survey of India topographic maps, long time precipitation data, etc.) and field data compiled using pre-calibrated hand held GPS (Global Positioning system). Likely land uses for the year 2033 using hybrid constrained Cellular Automata (CA) integrated with Fuzzy Analytical Hierarchical Process (AHP). The analyses reveal of escalating landslide vulnerabilities in the ecologically fragile Western Ghats, due to:
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