Characteristic analysis of typhoon disaster chains in the Yangtze River Delta region of China

Based on the frequency of historical typhoons,the typhoon tracks that struck the Yangtze River Delta region were divided into three main types: westward,traverse and northward,and one special track in this paper.Then with the digital elevation model(DEM) data and geographical environment,the Yangtze River Delta region was divided into three areas: coastal area in the east,hilly area in the south and plain area in the north.Finally,the characteristics of typhoon disaster chains in the combinations of typhoon tracks and environment were analyzed with the typical cases of "Ranan","Winnie" and "Agnes".Results show that typhoon-strong wind-high wave /storm surge disaster chain are easily to form in the coastal area,typhoon-rainstorm-flash flood,landslide and debris flow disaster chain are easily to form in the hilly area and typhoon-rainstorm-plain flood and inundation disaster chain are easily to form in the plain area.The westward type of typhoon mainly affects the coastal area and the hilly area is prone to induce the relative typhoon disaster chain in these two areas;The traverse typhone mainly affect the whole Yangtze River Delta region and would cause the above mentioned three chains;and the northward typhoon mainly affect the coastal area and would easily induce high wave or storm surge disasters.