13-Modelling of Stream Flow In Himalayan Basin Under Climate Change.

Abstract

Stream flow modelling is vital for agricultural watershed management and its effect on many aspects of change in climate variability. For Soil and Water Assessment Tool (SWAT) model has been used to simulate stream flows in Bhuntar River basin which is located Himachal Pradesh in N-W Himalaya region, India. Daily stream flow was simulated for the period of 1990-2000, and validated for 2001-2010. As it is difficult to manually calibrate such a complex model with many parameters, the sensitivity analysis have been carried out to find the sensitive parameter which is used as a input for the model calibration and the Sequential Uncertainty Fitting (SUFI2) algorithm was used for calibration and to quantify uncertainty. Performance SUFI2 was evaluated to reach the objective of the Bhuntar Basin. For the calibration period, the values of P-factor and R-factor, R2, NS, bR2 and PBIAS were found to be 0.27, 0.11, 0.6, 0.6, 0.352 and 3.7 respectively in Bhuntar basin. For validation data, values are found to be 0.14, 0, 0.57, 0.48, 0.258 and 25.3 respectively at the Bhuntar outlet. It demonstrates the efficiency and suitability of the SUFI2 method for the Bhuntar catchment. Investigation the potential changes in climatic variability, The predictors of two global climate models (GCMs) that are used to predict Present and future time. The data contains series of temperature minimum and maximum, precipitation. The simulation values were generated and investigated climate change effect for the year 1992 to 2060s. The results of climate change prediction in present and future scenario were estimated. The simulated stream flow is continuously increased with the time. In the end of 2040's to 2060's the stream flow will increase which shows the instability in climate. The study shows the changes in climate condition. hence, The climate is continuously changing due to instability in the climate as the glacier and snow are continuously shrinking and melting down in the downstream and effect the water budget component etc.