Earth, Atmosphere & Environment Sciences
Title : | Influence of Rainfall on Landslide Susceptibility of Soil-Rock Slopes |
Area of research : | Earth, Atmosphere & Environment Sciences |
Focus area : | Geotechnical Engineering |
Principal Investigator : | Dr. Nishant Roy, Birla Institute Of Technology and Science (BITS), Pilani, Rajasthan |
Timeline Start Year : | 2023 |
Timeline End Year : | 2026 |
Contact info : | nishant.roy@pilani.bits-pilani.ac.in |
Details
Executive Summary : | Landslides are a major natural hazard that result in loss of life, property damage, and economic losses. In India, nearly 12.6 percent of the land area, including 22 states and two union territories, is susceptible to landslide risks (NIDM 2002, NDMA 2019). On an annual basis, an average of 500 lives are lost and close to Rs. 300 crores in economic losses are incurred. Major triggers associated with catastrophic landslides include precipitation and temperature changes. While climate change has a significant impact on the intensity and frequency of precipitation, global warming is also responsible for temperature variations. Thus, landslide events are expected to rise in response to the effects imposed by climate change. This belief resonates in the special report of the Intergovernmental Panel on Climate Change (Seneviratne et al. 2012), where one reads, “There is a high confidence that changes in heat waves, glacial retreat, and/or permafrost degradation will affect slope instabilities in high mountains, and medium confidence that temperature-related changes will influence bedrock stability. There is also high confidence that changes in heavy precipitation will affect landslides in some regions.” It is therefore crucial to determine how the risk of landslides will evolve in the future in response to the constant threat posed by variations in climatic conditions. Extensive research have been conducted to understand the mechanisms of evolution of slope instability. Studies ranging from use of GIS based tools to physics based simulations have significantly improved our understanding of the causative factors and trigerring mechanisms for landslide events. However, a major gap in this area of research involves the identification of the threshold conditions for the trigerring of instabilities for different slope configurations. This is primarily due to the idealization of the ground either as soil or jointed rock mass which is simplistic. In the majority of the landslide events, the slide material is found to comprise of chaotic and heterogeneous mixture of soil-rock, which has seldom been considered in studies. Considering that the scale of instability, influence of triggering factors, and mechanisms of evolution of instability will be different for slopes comprising soil-rock mixtures, it is essential for a more realistic idealization of the soil-rock mixture in slope configurations. The present work envisages the laboratory characterization of soil-rock mixture and its integration in discrete element framework to study the evolution of slope instability. Additionally, the influence of climate change scenarios through the incorporation of extreme rainfall events on slopes comprising of soil-rock mixture is planned. The study intends to evaluate the threshold conditions for slope instability under rainfall in heterogeneous soil-rock slope. |
Total Budget (INR): | 18,83,910 |
Organizations involved