China's Coastal Lowland Population Distribution And Population Natural Disaster Vulnerability Research

Low Elevation Coastal Zone (LECZ) is defined as the contiguousarea along the coast which is less than10meters above sea level. InChina it is densely populated and developed economically, yet it isprone to natural hazards. So it is very important to research on thisspecial area in the context of climate change. Population size anddistribution are the key factors to analyzing the risk, especially in LECZ.Because of the greatly increased effect of flooding and storm surge,the dense population has the highest risk as the main disaster bearingbody, and the vulnerability of itself determines the influence of disaster.This paper defines the extent of the LECZ in China, and analyzes thespatial distribution of LECZ and its population in the administrative unitsof provincial level, county or city level and three major economic zones,using ArcGIS to combine ASTER GDEM, GPWv3, China’s populationstatistics and administrative division datasets. Since the Yangtze RiverDelta has the largest LECZ area and population, we selectedrepresentative indicators to build indicator system of its coastalsecond-level regions based on the vulnerability concept and structure,and in connect with spatial and statistical analysis techniques to assessthe population natural disaster vulnerability in LECZ.The results and conclusions of this thesis are as follows:（1）The total area of LECZ in China is193,938square kilometers,which accounts for2percent of China’s land area, and14.6percent ofall land area in Chinas coastal provincial level units. There are morethan164million people living in the LECZ, covering27.1percent of thetotal population in coastal China and12.0percent of the totalpopulation in China. There are nearly350counties or cities that havethe LECZ, and in which Jiangsu Province has the most. （2）Jiangsu Province has the largest LECZ of67,548squarekilometers and population of51,944,412, which stands at34.8percentof all LECZ and one third of all population in LECZ in China.（3）The LECZ in China are also concentrated in three majoreconomic zones, the Yangtze River Delta, the Pearl River Delta and theBeijing-Tianjin-Hebei Metropolis Circle, which account for64percent ofChina’s LECZ and77percent of all LECZ population in China. Especiallythe Yangtze River Delta has the highest disaster exposure with the mostLECZ area and highest population which covers40percent and50percent of the total in China.（4）The area and population of the LECZ distribution decreases asthe distance from coastline increases. More than a quarter of the LECZand one fifth of the LECZ population are located within10km from thecoastline, about half of the LECZ and population are distributed within40km from the coastline and85%of LECZ and90%of population arewithin100km from coastline. By building the Lorenz curve of populationspatial distribution in LECZ, it shows that the population is mostlydispersive within10km from coastline. From20km from the coastline,population becomes more and more agglomerative until70km fromthe coastline. Further than70km from coastline, the concentration ofpopulation begins to decline, and tends to be evenly distributed.（5）The natural disaster vulnerability of LECZ population in coastalsecond-level regions of Yangtze River Delta shows an obviousdifference, which has a close relationship with the socio-economicdevelopment, the imbalance of population structure and the directionof government policy. Overall, it shows an obvious grade-distribution ofpopulation vulnerability in the study area. The extremely high vulnerableareas are located in the northern second-level regions from Dafeng ofJiangsu Province. The highly vulnerable areas are distributed in the areaof Nantong, Yancheng in the North Jiangsu Campagna. Although the second-level regions in Changshu, Taicang, Shanghai and Zhejianghave higher disaster exposure, they have the lower vulnerability.Because of their developed economy, comprehensive medical andeducation system, reasonable structure and high quality of thepopulation, they can easily cope with and recover from the naturaldisaster.