The Impact Of Flood Disaster On Social Economy Under Climate Change Scenarios

The middle and lower reaches of the Yangtze River region is affected by the eastern Asian monsoon, and floods occur more frequently. Floods caused heavy loss of social economy in this region and created a great threat to human’s manufacture and life. Therefore, it has important theoretical and realistic significance on the research of the impact of flood disaster on social economy under Climate Change Scenarios. Based on the data of daily precipitation observed from the 90 weather stations(1961-2014) in the Yangtze River region and 405 grids(1961-2050) of a high-resolution (0.5°×0.5°) regional climate model CCLM (COSMO model in Climate Mode), the data of social and economic(1984-2013) and disastrous. The impact of flood disaster on social economy under Climate Change Scenarios are studied by the risk evaluation for flood disaster, the analysis of flood disaster exposure and vulnerability, the method of return periods, and the comparison of climate extreme indices. The main contents of the paper are:the impact of historical flood disaster on social economy; evaluate the CCLM’s ability of simulating extreme precipitation in Yangtze River region; the rainfall variation characteristics in the future; the impact of flood disaster on social economy under Climate Change Scenarios. The results show that:(1)The higher risk regions of 20 year frequency flood from 1961 to 2014 was located in north of Hunan province, many parts of Jiangxi province and coastal county (city, area) of Zhejiang province; The high risk regions of 50 year frequency flood was located in east of Hubei and Jiangxi province; The higher risk regions of 100 year frequency flood was located in center and south of Jiangxi province; There was no 1000 year frequency flood Happening.(2)The population exposure and economic exposure showed an increasing tendency in the provinces (municipality) of Yangtze River from 1984 to 2013. The average population exposure was 387 people per square kilometer and the average economic exposure was 0.06 million yuan/sq km.The maximum exposure was located in Shanghai and the minimum exposure was Jiangxi province. The population vulnerability and economic vulnerability showed the trend of decreasing after increasing first. The population vulnerability was 0.1 and the economic vulnerability was 0.01.The maximum vulnerability was located in Hunan and the minimum vulnerability was Shanghai.(3) From the point of view of the evaluation, the regional climate model CCLM had the ability of simulating extreme precipitation in Yangtze River region. The spatial correlation was better. It was better to simulating the spatial distribution characteristic of extreme precipitation.(4)The return period flood in T years showed an increasing trend in general under different climate change scenarios and in T years extreme precipition events for flood hazard-formative factors.In RCP2.6 scenario,the high risk regions of T years frequency flood from 2016 to 2050 is located in the east of Hubei province, northwestern Hunan and central of Jiangxi region; In RCP4.5 scenario, the high risk regions of T years frequency flood is located in the western Hubei, central of Jiangxi and southern Jiangsu Province; In RCP8.5 scenario, the higher risk regions of T years frequency flood is located in the west of Hubei and Hunan province, coastal areas of Jiangsu and Zhejiang province.(5) In 20 years extreme precipition events for flood hazard-formative factors, keeping the 2010 population and GDP unchanged,the larger population exposure is located in the south of Jiangsu and north of Zhejiang province form 2016 to 2050 in RCP2.6 scenario. There are 16.594 million people affected by flood disaster.The larger economic exposure is located in Hubei Wuhan and Jiangsu province.There are 661.8 billion yuan affected by flood disaster; In RCP4.5 scenario,the larger population exposure is located in the north of Hunan and Anhui province. There are 17.117 million people affected by flood disaster.The larger economic exposure is located in the east of Jiangsu province. There are 349.9 billion yuan affected by flood disaster; In RCP8.5 scenario, the larger population exposure is located in the Hubei and Anhui province. There are 18.532 million people affected by flood disaster. The larger economic exposure is located in the east of Hubei province and north of Anhui province. There are 273.7 billion yuan affected by flood disaster.