Assessment of Ecological Risk Based on Projected Hydrological Alteration

It is widely accepted that changes in river flows related to Climate Changes (CCs) may result in several impacts on ecosystems. The main goal of this paper is to assess the ecological risk associated with projected/future flow alteration in the Portuguese Guadiana River Basin. Thus, five climate change scenarios were defined based on bias corrected and spatially downscaled climate projections. These projections were used to run a hydrological model (Temez) for the assessment of potential hydrological impacts. Ecologically relevant hydrological indicators were calculated for the baseline hydrological conditions and for each of five hydrological future scenarios (for selected future periods). By way of the evaluation of the potential hydrological changes (based on the comparison between baseline and future metrics), it was possible to assess the likely ecological risk due to flow alteration. This evaluation was performed based on the ecological risk due to flow alteration (ERFA) screening method. This methodology was developed based on the Range of Variability Approach (RVA), a technique used to define ecological limits of hydrologic alteration. The ERFA methodology enables the aggregation of information as colour-coded risk classifications, which allows for the assessment of the locations with higher or lower ecological risk. It was concluded that the selected ecologically-relevant indicators could translate and synthesize the flow alteration resulting from CC. The projected climate change was observed to have the potential to increase the ecological risk of the Guadiana River Basin, a region for which projections indicate increased future mean temperatures and decreased mean precipitation. © 2016, Springer International Publishing Switzerland.