Current and Future Ecological Status Assessment: A New Holistic Approach for Watershed Management

Abstract

The Paiva River catchment, located in Portugal, integrates the Natura 2000 network of European Union nature protection areas. Resorting to topography, climate and land-use data, a semi-distributed hydrological model (Hydrological Simulation Program–FORTRAN) was run in order to simulate the hydrological cycle of the river and its tributaries. The model was calibrated over a 25-year period and validated within a 31-year period. Its performance was verified by comparing the recorded and simulated daily flows. The values of the Nash–Sutcliffe coefficient of efficiency of 0.95 and 0.76, and coefficient of determination of 0.95 and 0.82, were achieved for calibration and validation, respectively, thus showing a quite satisfactory model performance. Subsequently, the climate change impacts on temperature and precipitation, as well as their extremes, and on the flowrates were also assessed for a future period (2041–2070) under two anthropogenic forcing scenarios (representative concentration pathways 4.5 and 8.5). A procedure for selecting the most relevant metrics for assessing the ecological condition of the Paiva River was developed based upon a set of 52 invertebrate families sampled. Correspondence analyses were carried out for biological datasets (traits/metrics) with physicochemical and land use/land cover matrices separately. Out of all variables, water quality and flow and agriculture land use explained most of the variance observed. The integrated analysis undertaken in the present study is an important advance when compared to previous studies and it provides key information to stakeholders and decision-makers, particularly when planning suitable adaptation measures to cope with changing climates in the forthcoming decades.

Ethical issues and legal principles regarding joint management of shared river basins in the context of climate change and water scarcity in the Iberian Peninsula

“…Besides, differences in economic development, differences in demographic density on each side of the river basin lead to dissimilar impacts on river ecosystems (Fonseca et al 2020 ) and potential legal conflicts.…”

“…There are many examples of activities that, in the long run, can change the ecological conditions of superficial and groundwater masses 4 : slope deforestation causes soil erosion and silting up river beds; mining leachate runoff causes chemical contamination of water; intensive use of fertilizers in agriculture causes eutrophication; bad landfill management can cause contamination with microplastics; road construction and other soil sealing activities reduce the levels of the aquifers and lead to loss of habitats; atmospheric pollutant emissions from motorized traffic and housing, induce water acidification; and industrial accidents can lead to soil and water contamination. Besides, differences in economic development, differences in demographic density on each side of the river basin lead to dissimilar impacts on river ecosystems (Fonseca et al 2020) and potential legal conflicts.…”

The Impact of a Hydroelectric Power Plant on a Regional Climate in Portugal

“…Nevertheless, the damming of rivers represents one of the broadest human alterations of water flow from land to sea, substantially affecting ecological, sociocultural and, economic aspects in the surrounding area [6]. Furthermore, coupling high-resolution meteorological data [8,9] with calibrated and validated hydrological models is an important tool to determine the water quantity [10][11][12][13][14] and quality [15][16][17][18][19] of a basin, to investigate the hydroelectric potential it may deliver. In effect, although dams provide the above-mentioned benefits, they may affect the environment through damage to ecosystems [20][21][22] or changes in the local climate.…”