ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
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Volume IV-5/W2
ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., IV-5/W2, 1–8, 2019
https://doi.org/10.5194/isprs-annals-IV-5-W2-1-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., IV-5/W2, 1–8, 2019
https://doi.org/10.5194/isprs-annals-IV-5-W2-1-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

  05 Dec 2019

05 Dec 2019

ASSESSING THE IMPACTS OF CLIMATE CHANGE ON THE HYDROLOGY OF THE INDRAWATI RIVER BASIN, NEPAL

B. Bade1, D. R. Gyawali2, and S. Timilsina3 B. Bade et al.
  • 1GIS Developer, International Maize and Wheat Improvement Center (CIMMYT), Lalitpur, Nepal
  • 2Data Analyst (Spatial Modeling), United Nations World Food Programme (UNWFP), Kathmandu, Nepal
  • 3GIS Analyst, Nepal Development Research Institute (NDRI), Lalitpur, Nepal

Keywords: Climate change, Arc SWAT, Indrawati River, Hydrological Modelling

Abstract. This study details climate change assessment of the hydrological regime of Indrawati basin of Nepal. The study uses Soil and Water Assessment Tool (SWAT) model to delineate, discretize and parameterize the Indrawati basin to compute model’s input parameters. The model was then run for 1990–2014 to simulate the discharge at the outlet (Dholalghat). The coefficient of determination R2 and Nash-Sutcliffe (ENS) were used to evaluate model calibration and validation. The results found were satisfactory for the gauging station R2 = 0.951 and ENS = 0.901 for calibration and R2 = 0.937 and. ENS = 0.906 for validation. The calibrated hydrological model was run for the future climate change scenario using the RegCM4-LMDZ4 data and the relative changes with the baseline scenarios were analyzed. The comparison suggests that the historical trend of flow is decreasing at the rate of 0.55 m3/s per year. According to RegCM4-LMDZ4 simulations, the trend is going to continue but at a flatter rate. The decreasing trend is observed to be very less. The characteristic peak flow month in the historical scenario is August but the RegCM4-LMDZ4 led simulated flows suggest a shift in monthly peak to October suggesting decrease in monsoon flows and a subsequent significant increase in flows from October to January.