Assessing Impacts of Projected Climate Change on the Streamflow of Kesinga Catchment, India using the SWAT Model

Author: P. Chinna Vani, B.C. Sahoo, J.C. Paul, A.P. Sahu and A.K.B. Mohapatra

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Abstract

Climate change has significantly affected the hydrological cycle and future climate projections. Understanding the impacts of climate change on streamflow necessitates the examination of various climate scenarios using hydrological models. The present study used the Soil and Water Assessment Tool (SWAT) model to predict and project streamflow in a catchment. High-resolution future climate data from CSIRO-QCCCE-CSIRO and CCCma-CanESM2 models obtained from CORDEX are generated for impact assessment. The hydrological response of the catchment is assessed by dividing the future time scales into mid-century (2021-2050) and end-century (2071-2099) with two scenarios: Representative Concentration Pathway (RCP) 4.5 and 8.5. The climate projection results indicate an increase in both maximum (up to 3.7℃) and minimum (up to 2.9℃) temperatures, along with an expected increase in precipitation of up to 14.8%. Additionally, streamflow is projected to increase by up to 21% to 172% in the mid-century and decrease by 28% or increase by 160% in the end-century under different streamflow scenarios. The results of this study highlight the impact of climate change on streamflow in the Kesinga catchment and provide a scientific basis for adaptive management.

Keywords

Precipitation, Temperature, CORDEX, Future scenarios, SWAT model, streamflow

Conclusion

This study adopted a methodology to enhance SWAT streamflow projections for future climate change scenarios at regional scales. The estimation of watershed-scale streamflow using the SWAT model involved the integration of climate change factors at the regional scale, including the use of Digital Elevation Models (DEMs). A DEM was generated by removing topographic elements from high-resolution data and replacing them at the Hydrologic Response Unit (HRU) level. The SWAT model was then employed to evaluate the effects of climate change using future scenarios from RCM models under two RCP scenarios. The average streamflow values over 30-year periods exhibited significant changes under the future projected RCP climate change scenarios derived from two CORDEX-RCM models, as predicted by the SWAT model. Consequently, the streamflow values for the end of the century were notably different from the observed values. Monthly average streamflow values typically increased during June and August, while they decreased in February and March. Changes in precipitation patterns, surface temperature, and streamflow primarily drove the hydrological changes within the catchment. Furthermore, the climate models developed in this study hold significant value for the formulation of effective watershed management and mitigation strategies for the middle and end of the century, aimed at minimizing the impacts of climate change.

References

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How to cite this article

P. Chinna Vani, B.C. Sahoo, J.C. Paul, A.P. Sahu and A.K.B. Mohapatra (2023). Assessing Impacts of Projected Climate Change on the Streamflow of Kesinga Catchment, India using the SWAT Model. Biological Forum – An International Journal, 15(9): 963-968.