The Research On Method Of Ecological Damage Assessment For Marine Oil Spills Based On SIMAP

With the expanding of oil drilling activity and the growing of marine oil trade,oil spill accidents occur frequently.Oil spills can cause serious damage to marine ecological environment,due to the lack of objective and reasonable assessment method,the loss caused by vast majority of oil spill accidents in our country couldn't get the compensation that should have.In this thesis the major ecological damage assessment method for marine oil spill are summarized,and the widely used Spill Impact Model Application Package is analyzed,the major parts of SIMAP—Physical Fates Model and Biological Effect Model are extracted.The algorithms of transport and weathering of oil in Physical Fates Model and the assessment methods of biological losses in Biological Effect Model are studied.An ecological damage assessment method for marine oil spill is established based on the frame of SIMAP.Given the different toxicity and fates of different components in oil,the method established evaluate the biological loss via the concentration of dissolved aromatic “pseudo-components” by drawing from SIMAP,rather than ther concentration of “whole oil”.The method established introduces MIKE 21 to simulate the fates of oil in 2-dimensional surface,then deduce the concentration of dissolved aromatic “pseudo-components” in water column.Considering the impact of different exposure time and temperature of sea water to evaluate the mortality of aquatic organisms based on the toxicology parameters provided by OilToxEx model.The HEA is also introduced to evaluate the loss of habitat resources.A 500 t condensate oil spill is simulated in nearby waters of Gulei working area in Dongshan Bay,Fujian Province.Four operating modes are set,including: spill at high tide with zero wind,spill at low tide with zero,SSE3.1m/s and NE5.4m/s wind,respectively.Two of them which cause more servere damage in Dongshan Bay(spill at low tide with zero and SSE3.1m/s wind)are choosed to evaluate the ecological damage cause by the simulated accident by using the method established.The biological resources loss include fishes,shrimps,crabs,and the habitat resources loss include mangrove,coral are taken into account.Results show that after 72 h of spill at low tide with zero wind,the loss of biological resources is about 67.30 t,and the loss value of habitat resources is about 19.5682 million yuan.After 72 h of spill at low tide with SSE3.1m/s wind,the loss of biological resources is about 56.03 t,and the loss value of habitat resources is about 26.2963 million yuan.The study on evaluating this simulated accident by lays the foundation for the establishment of the scientific and reasonable methods in our country and provides scientific evidence on the oil spill contingency response in the bay.