Impact assessment of climate change on future soil erosion and SOC loss

Abstract

Soil organic carbon (SOC) is an important component of soil fertility and agricultural production that also controls the atmospheric CO2 which affects the global carbon cycle. Soil erosion is a major hazard which is directly affected by the rainfall change caused by the climate change. SOC is depleted through soil erosion affected by a change in the rainfall pattern. This study aims at quantifying the impact of climate change on future soil erosion and SOC with respect to the different controlling parameters (slope, soil and landuse) of soil erosion. The study area is a part of the Narmada river basin in India. Future rainfall is estimated by least square support vector machine method using Hadley Centre coupled model, version 3 data of A2 scenario. Revised universal soil loss equation has been used to estimate the soil erosion spatially, and field data collection is done to estimate SOC. Regression–kriging (RK) method is used for spatial interpolation of SOC on the top surface considering ancillary information of the land. Results show that sediment load has changed by −5.33, 17.97 and 58.37 % in the 2020s, 2050s and 2080s, respectively, from current erosion rate. Soil erosion and SOC loss rate are higher in a high degree of slope (>20), while SOC stock is low here (5.77 gm/kg). Again, SOC stock (1.27 gm/kg) is high in the clay soil, but soil erosion and SOC loss are less, while sandy loam indicates the opposite. Agricultural land and fallow lands have higher rate of soil erosion and SOC loss, while stock SOC is 12.24 and 9.65 gm/kg, respectively. Results show that soil erosion and SOC loss will be increased in the future and steeper slopes, sandy soil and fallow lands are more vulnerable to the loss.