TY - JOUR
T1 - Thermal stratification of Portuguese reservoirs
T2 - Potential impact of extreme climate scenarios
AU - Almeida, Manuel C.
AU - Coelho, Pedro Simões
AU - Rodrigues, António Carmona
AU - Diogo, Paulo A.
AU - Maurício, Rita
AU - Cardoso, Rita M.
AU - Soares, Pedro M. M.
N1 - The authors thank the Portuguese Water Institute (INAG), Energias de Portugal (EDP) and the Alqueva Development and Infra-structure Company (EDIA). The ENSEMBLES data used in this work was funded by the EUFP6 Integrated Project ENSEMBLES (contract GOCE-CT-2003-505539) whose support is acknowledged; we also acknowledge the Danish Meteorological Institute for hosting the RCM repository. Two reviewers provided valuable comments to improve the manuscript. We thank both of them.
PY - 2015/9/18
Y1 - 2015/9/18
N2 - Changes in water temperature and stratification dynamics can have a significant effect on hydrodynamics and water quality in reservoirs. Therefore, to assess future climate impacts, projections of three regional climate models for Europe, under the IPCC A1B emission scenario (2081-2100), were used with the CE-QUAL-W2 water quality model to evaluate changes in the thermal regime of 24 Portuguese reservoirs, representing different geographic regions, morphologies, volumes and hydrological regimes. Simulation results were compared with reference simulations for the period 1989-2008 and changes in water temperature and thermal stratification characteristics were evaluated. Future inflow scenarios were estimated from precipitation-runoff non-linear correlations and outflows were estimated considering present water uses, including hydropower, water supply and irrigation. Results suggest a significant increment in the mean water temperature of the reservoirs for the entire water volume and at water surface of 2.3 and 2.5 WC, respectively, associated with a runoff reduction of approximately 23%. Overall, variations in annual stratification patterns are characterized by changes in the mean annual length of stratification anomaly that ranged from -21 to +39 days. Results also show the influence of depth and volume over the reservoir’s temperature anomaly, highlighting the importance of future water uses and operation rule curves optimization for reservoirs.
AB - Changes in water temperature and stratification dynamics can have a significant effect on hydrodynamics and water quality in reservoirs. Therefore, to assess future climate impacts, projections of three regional climate models for Europe, under the IPCC A1B emission scenario (2081-2100), were used with the CE-QUAL-W2 water quality model to evaluate changes in the thermal regime of 24 Portuguese reservoirs, representing different geographic regions, morphologies, volumes and hydrological regimes. Simulation results were compared with reference simulations for the period 1989-2008 and changes in water temperature and thermal stratification characteristics were evaluated. Future inflow scenarios were estimated from precipitation-runoff non-linear correlations and outflows were estimated considering present water uses, including hydropower, water supply and irrigation. Results suggest a significant increment in the mean water temperature of the reservoirs for the entire water volume and at water surface of 2.3 and 2.5 WC, respectively, associated with a runoff reduction of approximately 23%. Overall, variations in annual stratification patterns are characterized by changes in the mean annual length of stratification anomaly that ranged from -21 to +39 days. Results also show the influence of depth and volume over the reservoir’s temperature anomaly, highlighting the importance of future water uses and operation rule curves optimization for reservoirs.
KW - Climate change
KW - Modeling
KW - Reservoir thermal regime
KW - Water quality
UR - http://www.scopus.com/inward/record.url?scp=84941643685&partnerID=8YFLogxK
U2 - 10.2166/wcc.2015.071
DO - 10.2166/wcc.2015.071
M3 - Article
AN - SCOPUS:84941643685
VL - 6
SP - 544
EP - 560
JO - Journal of Water and Climate Change
JF - Journal of Water and Climate Change
SN - 2040-2244
IS - 3
ER -
