Assessing water renewal time scales, based on the distribution of hypothetical contamination for Chabahar Bay using three-dimensional modeling

In this work we present the application of numerical investigations to compute water renewal time scales based on tracing the hypothetical contamination distribution for Chabahar Bay, amiddle size coastal embayment situated off the northern of Arabian Sea, south eastern coast ofIran (Fig.1). A three-dimensional hydrodynamic finite-difference multi-purpose model COupledHydrodynamical Ecological model for REgioNal Shelf seas (COHERENS) is applied, whichincorporates biological, resuspension and contaminant and sediment transport features and resolves mesoscale to seasonal scale processes [1].Water renewal time scales are not directly observable easily but is derived indirectly from this computational model. The model is forced by considering tidal constituents and alongshorecurrent speed at open sea boundary, surface stress as a function of wind speed, air temperature, relative humidity and heat flux through sea surface (Fig.2). Enhanced knowledge of renewal time scales can be useful in evaluating the water quality of coastal environments and can be utilized in sustainable marine resource management. Huge long term transportation plans for this baybeside the striking environmental characteristic of this domain make it crucial to pay attention to the industrial side effect hazards that could threaten the bay and may endanger aquatic plants, animals and local economy which depends on the fishery. Apparently, this is the first hydrodynamical computer modeling for this region.

Keywords:

Chabahar Bay , Water renewal , contaminant distribution , COHERENS