The Evaluation Of Disaster Loss In Coastal Zone Under Different Sea Level Rise Scene Simulation

Sea level rise and extreme weather events, which are caused by global climate change, has been aggravating coastal disasters, such as storm surge, coast erosion, salt water intrusion, land submergence, flooding, and pollution. And making China’s coastal cities face an increasing trend of marine disaster loss. Therefore, by precisely analyzing the coastal disaster loss induced by sea level rise, would be significant in providing the scientific support for coastal disasters prevention and damages reduction, and sustainable development strategy implementation. Choosing Yangtze River Delta as the research area, this paper focuses on China’s coastal disaster loss under different scenarios of sea level rise, through coupling the nested coupled tide-surge prediction model (NCTSM model), GIS, Nighttime imagery and mathematical statistical analysis. The main findings are as follows:(1) The uses of NCTSM model to simulate nine sea level rise scenarios, which respectively are THmax-0.3m, Hmax-0.3m, CHmax-0.3m, THmax-0.6m, Hmax-0.6m, CHmax-0.6m, THmax-1.0m, Hmax-1.0m and CHmax-1.0m.(2) The rank of GDP loss rate in Yangtze River Delta region from larger to less is: CHmax-1.0m scene, Hmax-1.0m scene, CHmax-0.6m scene, THmax-1.0m scene, Hmax-0.6m scene, CHmax-0.3m scene, Hmax0.3m and THmax-0.3m. The submerged land use area is similar with the scenario of GDP and population situation roughly.(3) GDP, population, land use area and traffic lines, which suffer the most serious damage is all in CHmax-1.0m scenario (a superposition of astronomic tide and storm surge scenarios when sea lever rise1.0meter. The loss is8188billion yuan,4362million person,3399km2and180000km respectively). In this scenarios, Shanghai and Wenzhou loss more than half of GDP (that loss is2168billion yuan in Wenzhou city,59.10%proportation).(4) Majority of the cities suffer from GDP, the people, land, and transport line loss, are located in coastal areas in the nine sea level rise scenarios. GDP and population loss of Shanghai Municipality is the most serious (GDP loss ranged from1459to18177billion yuan, the percentage ranging from2.00to90.23%. Population loss range from176to974hundred thousand, with the percentage ranging from7.39to82.00%). (5) The city land loss ranked from greatest to smallest:Wenzhou (the land loss is7124km2), Hangzhou (the land loss is6866km2), Nantong (land loss is5455km2), Ningbo and Shanghai, in the nine of sea level rise scenarios. Cultivated land in all scenarios are the most serious losses (the loss is ranged from401to23646km2). As high water level scenarios happen, construction land risk become greater, following by woodland in Yangtze River Delta.(6) Under the same grade of sea level rise, the rank of total land loss rate from larger to less is:superposition of astronomic tide and storm surge scenarios (CHmax scenarios), storm surge scenarios (Hmax scenarios) and the largest astronomic tide scenarios (THmax scenarios). Under the same tide level scenarios (THmax, Hmax or CHmax), the total land loss and the ascensional range would increase as the sea level rising from0.3m to1.0m, especially under the scenarios, which sea level rises from0.6m to1.0m. Besides, under the same tide level scenarios (THmax, Hmax or CHmax), with sea level rising from0.3m to1.0m especially rising from0.6m to1.0m, cultivated land is always the type of land use that shows the greatest ascensional range of loss, meanwhile the bare land and forest land show the smallest ascensional range of loss.(7) The urban traffic lanes is a type of transportation, which suffers the highest loss rate and the greatest accessional range of loss (ranged from10000to160000km, the percentage of the transport line in Shanghai is ranged from2to90.23%). The railway and the state’s main highways have the same rate of loss (ranged from0to10000km, the percentage of the total transport line is from0.01to3.90%). No matter under the same grade of sea level rise or under the same tide level scenarios (THmax, Hmax or CHmax), the urban traffic lanes is the type of transportation, which suffers the highest loss rate and the greatest ascensional range of loss. The railway and the state’s main highways have the same loss rate, but are significantly lower than the rate of urban traffic lanes.The research and the characteristics of innovation lies in:(1) Compared with many previous studies, this study uses the most quality of DEM and land use data to malke this reacher and increases the accuracy of the assessment for large scale disaster research.(2) Nighttime imagery remote sensing technology is applied to the assessment of disaster loss in coastal zone, providing new way for the research of this study in the future for the first time.(3) This study will combine NCTSM model with ArcGIS software to constructe submerged model under different sea level rise scenarios analysis process, provide new ideas for evaluation for the first time.