Numerical investigation of thermal discharge to coastal areas using TELEMAC-3D: A case study for South Italy

Maria-Gabriella Gaeta, Achilleas Samaras, Renata Archetti, Alberto Lamberti

Thursday 2 july 2015

16:00 - 16:15h at Asia (level 0)

Themes: (T) Hydro-environment, (ST) Impacts of pollutants on the water environment

Parallel session: 13G. Environment - Impact

Thermal pollution is defined as the degradation of water quality by any process that alters the ambient water temperature. Although thermal pollution may refer to the decrease of water temperature as well (e.g. release of cold water from reservoirs to rivers), the term is usually associated with the adverse effects of the increase in water temperature in rivers, lakes and coastal areas, as the consequent decrease of the concentration of dissolved oxygen (DO) in the water disturbs the ecological balance in the affected areas. The industrial use of water as a cooling agent is identified as the main cause of thermal pollution. Industries and power plants typically use water from nearby water bodies to cool their machinery, discharging it back to the environment at an elevated temperature. The present work investigates thermal discharge to coastal areas using TELEMAC-3D to simulate nearshore hydrodynamics, both standalone and coupled with TOMAWAC in order to include the effect of wave-current interactions as well. The study area is located in South Italy and comprises the vicinity of power plant at Cerano, near the city of Brindisi. The effect of thermal discharge is investigated through distinct scenarios for a combination of (a) tidal and wave conditions, (b) water temperature stratification in the coastal field, and (c) operational characteristics of the power plant (in terms of water discharge / temperature at its outlet). The model results of this representative array of scenarios are intercompared and evaluated on the basis of meeting basic standards of respective environmental regulations, providing with useful insights on the numerical simulation of the phenomenon and the potential effects for the specific coastal area.