20 6 2011 12 JOURNAL OF NATURAL DISASTERS Vol. 20 No. 6 Dec. 2011 1004-4574 2011 06-0094 - 05 200062 1949-1990 1949 1977 0. 8 0. 03345 0. 01243 30 100 P426. 616 A Risk analysis of flood disaster in Shanghai Municipality SUN A-li SHI Yong SHI Chun XU Shi-yuan WANG Jun Key Laboratory of Geographic Information Science of Ministry of Education East China Normal University Shanghai 200062 China Abstract This paper analyzes spatiotemporal distribution of flood disaster in suburb of shanghai Municipality according to the historical data from 1949 to 1990. Since planning for water resources development carried out in 1979 the index of area damaged by flood disaster has decreased significantly. In all districts and counties of the municipality considering two factors of flood disaster frequency ratio and area ratio Nanhui District is the highest. Because the historical data of flood disaster is not enough to be used for analysing the probability distribution the information diffusion method was introduced to change single sample observations into fuzzy sets and a quantitatively analyzing model of flood disaster risk was proposed. The results show that the flood disaster risk assessment values are higher in Nanhui District and Pudong District when the index of area damaged by flood disaster is lower However the flood disaster risk assessment values in Chongming Jinshan are always high in any case. When the index reaches 0. 8 the exceedance probability are 0. 03345 and 0. 01243 corresponding to 30-year return period and 50- year return period respectively. Key words flood disaster information diffusion risk analysis agriculture Shanghai Municipality 2010-04 - 16 2010-10 - 22 40730526 05DZ12007 1985 -. E-mail sunali@ ecnu. cn 1972 -. E-mail shi_chun@ 163. com
6 95 1 1001-1991 605 496 82% 3 1 2 3 2 GIS 3 1 1. 1 / / 1949-1990 1 1949-1990 1 Fig. 1 Characteristics of flood disaster variation in suburbs of Shanghai Municipality from 1949 to 1990 1 1977 2 1949-1959 1959-1979 1956 4 1979 1. 2 3 3 1949-1990 2 3 1 2 > > > > >
96 20 > > > > > > > 2 3 > > > > > > > > > > > > 2 3 2 1949-1990 3 1949-1990 Fig. 2 Distribution characteristics of the flood disaster frequency Fig. 3 Distribution characteristics of flood disaster-affected ratio in suburbs of Shanghai Municipalityy from 1949 to1990 area in suburbs of Shanghai Municipality from 1949 to 1990 2 2. 1 5 6-7 U U = u 1 u 2 u n u i i = 1 n n y j f j U u i [ ] 1 f j u i = h 槡 2π exp - y 2 j - u i i = 1 2 n j = 1 2 m. 1 2 2h m h b a m m < 10 h = 1. 4230 b - a / m - 1 m 10 h = 1. 4208 b - a / m - 1 C j = n f i u i i = 1 g j g j u i = f j u i /C j. u i q u i u i Q q u i = m j = 1 g j u i Q = m i = 1 q j u i u i p u i = q u i /Q u i 2 3
6 97 P u u i = i k = 1 p u k. u i P u i 2. 2 1949-1990 V = v 1 v 2... v 51 = 0 0. 02 0. 04... 1 1-4 1 0. 10 / 0. 10 Table 1 1 Risk assessment values of flood disaster in suburbs of Shanghai Municipality 0. 10 0. 338 06 0. 422 78 0. 333 59 0. 636 96 0. 609 52 0. 517 31 0. 428 37 0. 739 19 0. 404 29 0. 739 08 0. 20 0. 016 88 0. 193 39 0. 156 61 0. 320 64 0. 316 00 0. 321 89 0. 220 44 0. 310 19 0. 250 77 0. 494 44 0. 30 0. 000 01 0. 147 52 0. 113 08 0. 142 76 0. 178 59 0. 125 04 0. 148 77 0. 118 88 0. 145 72 0. 348 44 0. 40 0. 000 00 0. 091 26 0. 063 55 0. 095 11 0. 145 25 0. 059 93 0. 109 02 0. 056 41 0. 068 22 0. 275 77 0. 50 0. 000 00 0. 052 31 0. 014 92 0. 085 19 0. 141 63 0. 043 74 0. 087 90 0. 048 18 0. 012 01 0. 222 06 0. 60 0. 000 00 0. 046 81 0. 000 07 0. 058 76 0. 125 90 0. 004 95 0. 023 51 0. 006 38 0. 000 23 0. 162 34 0. 70 0. 000 00 0. 015 07 0. 000 00 0. 020 12 0. 066 55 0. 000 00 0. 000 27 0. 000 01 0. 000 00 0. 091 95 0. 80 0. 000 00 0. 000 26 0. 000 00 0. 002 54 0. 012 43 0. 000 00 0. 000 00 0. 000 00 0. 000 00 0. 033 45 0. 90 0. 000 00 0. 000 00 0. 000 00 0. 000 10 0. 000 59 0. 000 00 0. 000 00 0. 000 00 0. 000 00 0. 006 59 4 x 0. 1 x 0. 2 x 0. 3 x 0. 5 4 0. 1 4 a 1. 5a 3 a 0. 2 4 b 0. 494 44 0. 2 4 ~ 5 a 60 a 0. 3 4 c 0. 348 3 a 0. 5 4 d 0. 222 0. 14 5 a 7 a 100 a 3 1977
98 20 Fig. 4 4 Risk map of flood for different disaster-suffering indices 1. M. 1999 17-25. 2. J. 2001 16 3 70-75. 3. J. 2007 26 4 11-22. 4. J. 2001 2 12-15. 5. J. 2007 5 826-830. 6. J. 1998 7 2 1-8. 7. J. 2008 23 4 713-723.