JOURNAL OF NATURAL RESOURCES ›› 2012, Vol. ›› Issue (5): 766-777.doi: 10.11849/zrzyxb.2012.05.006

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Study on Spatial and Temporal Characteristics of Rainstorm in Taihu Lake Basin

YU Wen-jin1,2, YAN Yong-gang1, ZOU Xin-qing3   

  1. 1. Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information & Technology, Nanjing 210044, China;
    2. Key Laboratory of Coastal Disaster, Hohai University, Nanjing 210098, China;
    3. Ministry of Education Key Laboratory of Coastal and Island Development, Nanjing University, Nanjing 210093, China
  • Received:2011-05-19 Revised:2011-09-19 Online:2012-05-20 Published:2012-05-20

Abstract: Rainstorm disaster is a major meteorological disaster, this paper, taking the economic developed Taihu Lake Basin as a study area, uses wavelets, simulation of linear trend, P-Ⅲ type probability density function, Mann-Kendall and other methods to study and analyze temporal and spatial variation and trend of storms in Taihu Lake Basin. The results showed: 1) Taihu Lake Basin had an annual average rainfall days of 2.9 in the past 55 years with also more intense annual variation rate. The period 1991-2000 witnessed frequent occurrence days of heavy rain while the years of 1959, 1968 and 1978 had fewer days of heavy rain, presenting a weak "inverted U-shaped" pattern. The spatial distribution of storm frequency means was high in the south and west and low in the north and east. Taihu Lake has a total annual average rainfall between 202.1-238.3 mm, but the spatial distribution of rainstorm quantity and rain days is uneven, appearing more in the north and east, and less in the south and west. 2) The study showed that P-Ⅲ curve method of precipitation extremes in the region has a good effect, the maximum precipitation trend in the Taihu Lake region showed a "U-shaped" pattern, which is inconsistent with the evolution characteristics of the number of days with heavy rain in the region. In the last 55 years, the maximum rainfall occurred in Taihu Lake Basin is no more than 250 mm, namely, a 200-year occurred rainstorm flood disaster in the region is of modern extreme value. 3) The typical site of torrential rain has an increasing trend to varying degrees, to three sites south of the central lake, i.e., Dongshan, Hangzhou and Cixi are most significant, the point mutations exist to different degrees, but the abrupt time differs. 4)The wavelet spectrum results show that the aummer rainfall in Taihu Lake Basin presents multi-scale changes of 2 a, 9 a, 13 a and 25 a, but the stability and significance of the wave period differ.

Key words: Taihu Lake, rainstorm, precipitation extremes

CLC Number: 

  • P426.62