Research and Application of Rainstorm Disaster Risk Assessment along the Middle and Lower Reaches of Yangtze River

摘要

We explored and studied rainstorm disaster impact grade. Firstly,we selected average precipitation,precipitation intensity,coverage and duration during rainstorm process,and economic losses,the number of deaths and total casualties in rainstorm disaster situation as the pre-assessment indexes of rainstorm process impact grade along the middle and lower reaches of Yangtze River. Then,normalized and dimensionless processing of each index was conducted. By using gray correlation method,we established rainstorm process grade and rainstorm disaster impact grade. At last,we conducted regression analysis of relevancy degree between rainstorm process grade and rainstorm disaster situation grade,and established a linear relationship between the two,thereby getting a rainstorm disaster pre-assessment method. On this basis,using rainstorm hazard factors in independent sample,we carried out pre-assessment test of disaster impact grade. The results show that this pre-assessment method is quick and easy,and the effect is better.