| Title: | An integrated analysis of the eutrophication process in the Enxoé Reservoir within the DPSIR framework |
| Authors: | Ramos, T.B., H. Darouich, M.C. Gonçalves, D. Brito, M.A.C. Branco, J.C. Martins, M.L. Fernandes, F.P. Pires, M. Morais and R. Neves |
| Year: | 2018 |
| Journal: | Water |
| Volume (Issue): | 10(11) |
| Pages: | |
| Article ID: | 1576 |
| DOI: | 10.3390/w10111576 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic and pollutant |
| Primary Application Category: | nitrogen cycling/loss and transport |
| Secondary Application Category: | hydrologic assessment |
| Watershed Description: | 60.8 km^2 Enxoé River, a tributary of the Guadiana River located in the Alentejo region in southern Portugal. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | The Enxoé reservoir in southern Portugal has been exhibiting the highest trophic state
in the country since its early years of operation. The problem has attracted water managers’
and researchers’ attention as the reservoir is the water supply for two municipalities. Extensive
research was thus conducted over the last few years, including field monitoring and modelling
at the plot, catchment, and reservoir scales. This study now frames all partial findings within the
Driver-Pressure-State-Impact-Response (DPSIR) framework to better understand the eutrophication
process in the Enxoé reservoir. Agriculture and grazing were found to have a reduced role in the
eutrophication of the reservoir, with annual sediment and nutrient loads being comparably smaller or
similar to those reported for other Mediterranean catchments. Flash floods were the main mechanism
for transporting particle elements to the reservoir, being in some cases able to carry up three times the
average annual load. However, the main eutrophication mechanisms in the reservoir were P release
from deposited sediment under anoxic conditions and the process of internal recycling of organic
matter and nutrients. Reducing the P load from the catchment and deposited sediment could lead to
a mesotrophic state level in the reservoir. However, this level would only be sustainable by limiting
the P internal load ability to reach the photic zone. |
| Language: | English |
| Keywords: | catchment; eutrophication; modelling; nutrients; trophic level. |