Environmental Impact Analysis:
Scoping, Screening, Assessment
    EIA - Environmental Impact Assessment:   A Coastal Water Quality Example

    Lebanon Chemical Fertilizer Factory, Selaata:   release of phosphogypsum sludge
    The primary model domain extend over 5 by 5 km, simulated with a horizontal resolution of 20 m and ten (terrain following) vertical layers.

    For the initial screening, a number of scenarios were run with different resolutions (100, 50, and 20 m) and with different configurations;
    these are described below, with links to the on-line model system.
    Please note: vertical layers include one extra layer for the vertical average concentrations.

    The scenarios include:

    Scenario Description of the scenario configuration  
    ROMS 20m winter,
    initial sediment layer

    20/120/11
    Winter-period, February 16-20, modelling of point source pollutant discharge at rate 0.75 m3/s with temperature 40C near Selaata coast. Initial bed sediments thickness 1m at the pollutant source and 0.5m in the cells around source. Bed sediments initially contain pollutant's sediments in equal proportions. Pollutant components:
    • Passive contaminant -- conc. in pollutant 8kg/m3
    • Non-cohesive sediment (sand) -- medium grain diameter 0.125mm, density 2650kg/m3, conc. 0.43kg/m3. settling velocity 5.4 mm/s
    • Coarse cohesive sediment (mud) -- 0.032 mm, 2650 kg/m3, 1.92 kg/m3, 0.353 mm/s
    • Fine cohesive sediment (mud) -- 0.008 mm, 2400 kg/m3, 1.92 kg/m3, 0.018 mm/s
    Hydrology: Tidal currents from western boundary (0.5 m amplitude with period 12 h), constant northward current from the southern boundary (0.2 m/s), open W/N/S lateral boundary, radiative conditions. MM5 atmospheric forcing, downscaled NCEP/NCAR reanalysis for the period 16-20 February 2008. Surface fluxes calculated with bulk formulae
    ROMS 20m summer,
    initial sediment layer

    20/120/11
    Summer-period, September 7 - 11, modelling of point source pollutant discharge at rate 0.75 m3/s with temperature 40C near Selaata coast. Initial bed sediments thickness 1m at the pollutant source and 0.5m in the cells around source. Bed sediments initially contain pollutant's sediments in equal proportions. Pollutant components:
    • Passive contaminant -- conc. in pollutant 8kg/m3
    • Non-cohesive sediment (sand) -- medium grain diameter 0.125mm, density 2650kg/m3, conc. 0.43kg/m3. settling velocity 5.4 mm/s
    • Coarse cohesive sediment (mud) -- 0.032 mm, 2650 kg/m3, 1.92 kg/m3, 0.353 mm/s
    • Fine cohesive sediment (mud) -- 0.008 mm, 2400 kg/m3, 1.92 kg/m3, 0.018 mm/s
    Hydrology: Tidal currents from western boundary (0.5 m amplitude with period 12 h), constant northward current from the southern boundary (0.2 m/s), open W/N/S lateral boundary, radiative conditions. MM5 atmospheric forcing, downscaled NCEP/NCAR reanalysis for the period 7-11 September 2008. Surface fluxes calculated with bulk formulae.
    ROMS 50m SED,
    initial sediment layer

    50/120/8
    Medium-term modelling of point source pollutant discharge at rate 0.4 m3/s near Selaata coast. Initial bed sediments thickness 1m at the pollutant source and 0.5m in the cells around source. Bed sediments initially contain pollutant's sediments in equal proportions. Pollutant components:
    • Passive contaminant -- concentration in pollutant 8kg/m3
    • Non-cohesive sediment (sand) -- medium grain diameter 0.125mm, density 2650kg/m3, concentration 0.8kg/m3. settling velocity 0.5 mm/s
    • Coarse cohesive sediment (mud) -- 0.032 mm, 2650 kg/m3, 3.6 kg/m3, 0.1 mm/s
    • Fine cohesive sediment (mud) -- 0.008 mm, 2400 kg/m3, 3.6 kg/m3, 0.01 mm/s
    Hydrology: Tidal currents from western boundary (0.5 m amplitude with period 12 h), constant northward current from the southern boundary (0.2 m/s), no surface forcing, open W/N/S lateral boundary, radiative conditions.
    ROMS 50m SED,
    no initial sediment layer

    50/120/8
    Medium-term modelling of point source pollutant discharge at rate 0.4 m3/s near Selaata coast. No initial bed sediments. Pollutant components:
    • Passive contaminant -- concentration in pollutant 8kg/m3
    • Non-cohesive sediment (sand) -- medium grain diameter 0.125mm, density 2650kg/m3, concentration 0.8kg/m3. settling velocity 0.5 mm/s
    • Coarse cohesive sediment (mud) -- 0.032 mm, 2650 kg/m3, 3.6 kg/m3, 0.1 mm/s
    • Fine cohesive sediment (mud) -- 0.008 mm, 2400 kg/m3, 3.6 kg/m3, 0.01 mm/s
    Hydrology: Tidal currents from western boundary (0.5 m amplitude with period 12 h), constant northward current from the southern boundary (0.2 m/s), no surface forcing, open W/N/S lateral boundary, radiative conditions.

    Case study: LCC, Selaata Model implementation Input data Scenario analysis On-line demo system


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