6 TWO CHEMICAL SPILL PATTERNS IN TIDALLY DOMINATED SAN DIEGO BAY

A coupled hydrodynamic-chemical spill model is used to investigate the chemical spill in the San Diego Bay. The hydrodynamic model shows that the San Diego Bay is tidally dominated. The chemical spill model shows the existence of two different patterns of chemical spill for pollution (methanol, benzene, liquefied ammonia, etc.) released at 0.5 m depth in the north (32o43’N, 117o13.05 ’ W) and the south bays (32o39’N, 117o07.92 ’ W). For the north-bay release, the chemical spill in the whole basin with a fast speed of spill in the northern part (12 hours) and a slow speed of spill in the southern part (20 days) with very small concentration. For the south-bay release, the chemical pollutants are kept in the southern part. Very few pollutants reach 32o41’N parallel (the boundary between the north and south bays). San Diego Bay (Figure 1) is located near the west coast of southern California. It is a relatively small basin (43-57 km2) nearly 25 km long and 1-4 km wide. It shapes a flipped-type and extends to the north to the city of San Diego and to the south to Coronado Island and Silver Strand, with a northwest to southeast orientation. It is a natural harbo