Alok K. Sikka

Streamflow Response to Climate Change in the Brahmani River Basin, India

Climate change can significantly affect the water resources availability by resulting changes in hydrological cycle. Hydrologic models are usually used to predict the impacts of landuse and climate changes and to evaluate the management strategies. In this study, impacts of climate change on streamflow of the Brahmani River basin were assessed using Precipitation Runoff Modeling System (PRMS) run under the platform of Modular Modeling System (MMS). The plausible hypothetical scenarios of rainfall and temperature changes were used to assess the sensitivity of streamflow to changed climatic condition. The PRMS model was calibrated and validated for the study area. Model performance was evaluated by using joint plots of daily and monthly observed and simulated runoff hydrographs and different statistical indicators. Daily observed and simulated hydrographs showed a reasonable agreement for calibration as well as validation periods. The modeling efficiency (E) varied in the range of 0.69 to 0.93 and 0.85 to 0.95 for the calibration and validation periods, respectively. Simulation studies with temperature rise of 2 and 4°C indicated 6 and 11% decrease in annual streamflow, respectively. However, there is about 62% increase in annual streamflow under the combined effect of 4°C temperature rise and 30% rainfall increase (T4P30). The results of the scenario analysis showed that the basin is more sensitive to changes in rainfall as compared to changes in temperature.

Climate Change and Water Resources in India: Impact Assessment and Adaptation Strategies

Climate change and climate variability has received considerable attention from the scientific community and has been the focus of a multitude of scientific investigation over past two decades (e.g., Gleick, 1986; Lettenmaierand Gan, 1990; Arnell, 1992; Xu, 1999; Nijssen etal., 2001; Rosenzweig et al., 2004; Brumbelow and Georgakakos, 2007; Akhtar et al., 2008). The Third and Fourth Assessment Reports of the Intergovernmental Panel on Climate Change (IPCC) have clearly shown that the earth’s climate system has demonstrably changed on both global and regional scales since the pre-industrial era. Thus, the earth’s climate system is experiencing a warmer phase. Changes in temperature and precipitation under climate variation have serious impacts on hydrologie processes and water resources availability. Improved understanding of climatic causes of hydrological variability is of paramount importance for developing strategies for the sustainable development and management of vital water resources.