Author(s): alvaro Sordo-Ward, I. Gabriel-Martin, Luis Garrote de Marcos, mariadolores bejarano
Linked Author(s): Álvaro Sordo-Ward, Luis Garrote de Marcos, Maria Dolores Bejarano Carrion
Keywords: Environmental flow; Water resources management; Climate change; Continental approach;
Abstract: This study presents a regional assessment of the effect of different ecological flow regimes by accounting both current (1960-1999) and future water availability (2020-2059 and 2060-2099) in Europe. Water availability was understood as the amount of water that can be supplied at a certain point of the river network to satisfy a regular demand under specified reliability requirements and environmental flows constrains. The methodology was based on the use of the geospatial high resolution WAAPA model. WAAPA is a simple model that simulates the operation of a water resources system comprising river network topology, streamflow, reservoir storage, evaporation and environmental flow. It was built accounting for 2,300 reservoirs characterized by a capacity of more than 5 hm3 and included Hydro 1k sub-basins, considering almost 4.000 sub-basins in Europe, which belong to 620 large basins draining to the sea (total area under study is over 6,000,000 km2). Hydrologic scenarios were taken from the Inter-Sectoral Impact Model Intercomparison Project where several hydrological models were applied using forcing from five global climate models under the Representative Concentration Pathways scenarios. Results show that water availability in a system is very sensitive to environmental flows changes. Also, higher water availability reduction rates for low percentile ranges of environmental flows were found. The ratio between the water availability reductions and environmental flows values is unevenly distributed over Europe, suggesting that the implications of increasing water allocation to environmental flows may vary, depending on hydrologic regime and available storage.
Year: 2019