LANDSLIDE SUSCEPTIBILITY MAPPING OF UTTARAKHAND REGION

Abstract

Landslides are transient and instantaneously happening and damaging natural hazard in mountains. However, landslides turn into a disaster mainly due to the immature geology connected with external triggering factors which causing landscape changes and indirect and direct losses. Based on the few reports, more than 15% of the total land area in India is to be affected by landslides. The studies of landslides are rapidly growing because of the urbanization and social economic effects on the terrain regions. The present study area uttarakhand which is covered with 86% hilly regions, which is highly prone to devastating landslides. Landslides cause heavy economic losses and human losses. Hence study to be carried in this mountainous region and identifying the factors controlling the occurrence of the landslides. The (LSZ) Landslide Susceptibility Zonation mapping plays a key role in future urbanization planning to reduce the risk of a potentially catastrophic event. These maps categorized an area according to stability and instability based on parameters which are used in the preparation of Landslide Susceptibility Zonation maps such as slope, aspect, relative relief, drainage, thrusts, and lineaments, lithology, etc. and also triggering factors like seismicity (Earthquake). The (LSZ) Landslide Susceptibility Zonation mapping study is carried for the Uttarakhand region and the process of identification of different zones of landslide susceptibility. A total of 2188 existing historical landslides identified using remote sensing techniques from Google earth pro. The different landslide causative parameters such as slope, aspect, relative relief, drainage, thrusts, and lineaments, lithology, and earthquake are finalized. The qualitative approach of Landslide Susceptibility Zonation mapping (LSZ) is used and the weights, rankings are assigned based on the causative effects for the occurrence of landslides. The data is collected from Google Earth, IMD (Indian Metrological Department), Aster GDEM and previously published maps used to prepare the landslide inventory and prepare thematic layers data integration in an Arc GIS platform. The final Landslide Susceptibility Zonation mapping prepared for the study area separates five different zones based on the susceptibility varying from very low to very high. The results of this dissertation work explain the slope angle, aspect, relative relief, drainage density, thrusts, and lineaments, lithology have the built-in implication of landslide susceptibility and local seismicity affect the landslide occurrence and distribution. These maps can incorporate the future landslide susceptibility in the Uttarakhand region