PROGRESS IN GEOGRAPHY ›› 2019, Vol. 38 ›› Issue (12): 1917-1932.doi: 10.18306/dlkxjz.2019.12.008

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Temporal and spatial features of precipitation and impact of urbanization on precipitation characteristics in flood season in Beijing

DING Kaixi1,2, ZHANG Liping1, SONG Xiaomeng1,2,*(), SHE Dunxian1, XIA Jun1   

  1. 1. State Key Laboratory ofWater Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072, China
    2. School of Resources and Geosciences, China University of Mining & Technology, Xuzhou 221116, Jiangsu, China
  • Received:2018-12-20 Revised:2019-06-20 Online:2019-12-28 Published:2019-12-28
  • Contact: SONG Xiaomeng E-mail:xmsong@cumt.edu.cn
  • Supported by:
    National Key Research and Development Program(2017YFA0603704);Visiting Scholars' Fund of State Key Laboratory of Water Resources & Hydropower Engineering Science(2015SWG02)

Abstract:

In the process of urbanization, the original landform is inevitably changed, which directly affects the dynamic characteristics of the underlying surface of cities. On the other hand, with the increase of population, high density of buildings, and the emission of all kinds of waste and heat to the atmosphere, the thermodynamic characteristics of the underlying surface and the air above the city, as well as the condensation nucleus of the atmospheric cloud induced rain are all changed, which directly affect rainfall. Beijing as the capital city of China has experienced rapid development of urbanization in the recent decades. Extreme rainfall events and heavy floods in flood seasons have become more frequent and the socioeconomic losses caused by floods have become increasingly serious. In this case, it is very necessary to study the relationship between urbanization and rainfall. Based on the precipitation data of 30 stations during 1963-2012, the temporal and spatial features of precipitation in Beijing flood season were analyzed by linear regression, sliding average, and ArcGIS spatial analysis. In addition, the data were used to research the impact of urbanization on precipitation characteristics in flood season by comparing the differences between urban and suburban areas. Land-use data of different urbanization stages in Beijing were used to analyze the effect of the change of urban underlying surface on rainfall. The results indicate that: 1) Precipitation in the flood season showed a downward trend and the overall spatial pattern is gradual decrease from east to west. 2) Light rain and moderate rain were most likely to occur in Beijing mountainous areas, while urban areas were more prone to moderate rain and heavy rain events, especially rainstorm and heavy rain. The frequency of light rain and moderate rain in the suburbs was close to that in the urban area, but the frequency of rainfall events above the heavy rain level was less than that in the urban area. The frequency of all grade rainfall events in the far suburbs was higher. 3) Compared with the northern suburb, the rainfall in the urban area was greater than that in the southern suburb at different stages of urbanization, but the effect of urbanization was also reflected in the rainfall difference between the urban area and the northern suburb. 4) With the development of urbanization, the area of urban construction land in Beijing and suburban areas continues to increase. However, because the urbanization of urban areas is faster than that of peri-suburbs, the situation of the underlying surface of urban areas also changes more, which makes the rainfall in flood season in urban areas higher than that in the suburbs and rainfall events above the grade of heavy rain are more likely to occur.

Key words: urbanization, flood season, precipitation characteristic, Beijing