Chapter 8 - Critical soil erosion prone areas identification and effect of climate change in soil erosion prioritization of Kosi river basin

Abstract

The Kosi River is called the “Sorrow of Bihar” due to frequent flood and high sediment yield and hence it is essential to estimate the soil erosion. In this chapter, the annual soil erosion has been estimated for the present as well as for the projected years. Apart from this, the change intensity of the soil erosion has also been estimated between the years 2019 and 2070. The rainfall data have been taken from the India Meteorological Data, Pune, for a period of 33 years (1985–2017) and four General Circulation Models (CAN-ESM2, MPI-ESM-MR, CSIRO, CMCC-CMS) with three Representative Concentration Pathways (RCP2.6, RCP4.5, and RCP8.5) for the projected period. The Revised Universal Soil Loss Equation model has been utilized for the estimation of soil loss. The soil erosion level has been prioritized into seven levels based on the standard deviation and histogram distribution from the obtained map using ArcGIS10.3. It was observed from the map that the eastern area of the Kosi basin is severely affected and comes under the first priority level. Change Intensity (CI) of soil erosion from the present year (2019) to the projected year (2070) has been evaluated and they have also been grouped as intensive decrease, moderate decrease, mild decrease, stable, mild increase, moderate increase, and intensive increase. From the results of CI, it was observed that majority of area (43.642%) in the Kosi river basin is under stable zone. The results of this chapter provide a notable implication to water resources experts for the planning of soil conservation measures in the Kosi river basin.