Methodological Framework for the Evaluation of Climate Change Impacts on Rural Basins Using the GR2M Model

Abstract The goal of the present work is to introduce a framework to assess climate change impacts on water resources in rural basins. The proposed framework was applied and tested in the Platanovrisi river basin, located in Northern Greece. A hydrological model for the basin was developed and implemented using the GR2M, and calibrated-validated using observed rainfall, temperature and streamflow data. Climate change projections from three climate models and two Shared Socioeconomic Pathways (SSP) scenarios were used as drivers to the calibrated-validated hydrological model to assess the impact of climate change on the hydrological regime of the basin. Climate change impacts were assessed in terms of precipitation, temperature, evapotranspiration, and meteorological drought. Results indicated that, for the period 2015–2050, the annual precipitation and discharge will decrease by 13–23% and 32–47%, respectively, while temperature will increase on an average of about 13% (about 1 °C) compared to the reference period (historical period spanning from 1974 to 2014). The results revealed significant changes in the annual and seasonal water flow, with a net reduction in the river flow during winter and spring and a slight increase during autumn and summer. Therefore, difficulties may arise for ensuring hydropower production and storage, agricultural needs and ecological flows. The results revealed significant sensitivity and variability of rainfall, evapotranspiration and river flows based on the climate model and the climate scenario examined. Overall, the proposed framework constitutes a robust approach for the assessment of climate change impacts on water resources in different hydrological regimes, and can be easily modified and applied to diverse watersheds worldwide. In addition, the proposed methodology can help and guide practitioners and decision makers towards adaptation and mitigation efforts for sustainable water management under climate change conditions.