Geospatial Approach for the Assessment and Analysis of Flood Risk in the region of Nanjangud town, Mysore District, Karnataka, India

Abstract

Flooding in urban and rural areas is one of the utmost challenges to human safety. Destruction of the properties is the main issue in urban areas and damage to the agriculture practices in the rural area. Flood risk is rising significantly all over the globe. The regional water cycle and water resource availability are governed by the rainfall event, which is a fundamental meteorological parameter. The objective of the study is to examine the rainfall variability for 25 years from the period from 1995 to 2020 for monthly and annual rainfalls in the part of Nanjangud taluk, Mysore district, Karnataka. During the last three years that is 2017 to 2019 during the southwest monsoon, it is noted that the severity of flood increased in the surrounding of Nanjangud town, due to the heavy rainfall and excess amount of water released has augmented the inflow source of flooding. The assimilation of Remotely Sensing (RS) and Geographical Information System (GIS) is capable to generate a sequence of thematic maps that were helpful to create geospatial data for demarcating flood hazard areas. This study discusses the probable flood risk-prone regions of the Kabini river basin near Nanjangud town based on the multi-ring buffered layer analysis. The buffered layers created for the radius of 250m, 500m 750m, and 1000m were overlaid on the Sentinel-2 satellite image and topographic map to delineate the flood-affected region. To calculate the slope and drainage density, the SRTM DEM data was used. Structural and nonstructural practices are proposed in this study can be implemented to reduce the probability of the effect of floods.