SCIENTIA GEOGRAPHICA SINICA ›› 2014, Vol. 34 ›› Issue (5): 621-626.doi: 10.13249/j.cnki.sgs.2014.05.621

• Orginal Article • Previous Articles     Next Articles

Variation Analysis of Flood Dynamic Risk in Huangpu River Basin

Fei SU1(), Jie YIN1(), Zhan-e YIN2, Da-peng YU3, Shi-yuan XU4   

  1. 1. School of Tourism and City Management, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, China
    2. Department of Geography, Shanghai Normal University, Shanghai 200234, China
    3. Department of Geography, Loughborough University, Leicestershire LE11 3TU, UK
    4. Department of Geography, East China Normal University, Shanghai 200062, China
  • Received:2014-02-17 Revised:2014-04-01 Online:2014-05-10 Published:2014-05-10

Abstract:

Huangpu River Basin has experienced rapid urbanization since “reform and opening up”. Increasing human activities greatly changed the natural environment and flood risk characteristics in this area. This article presented a scenario-based study that investigated the flood dynamic risk in Huangpu River floodplain during the transitional period (1979-2009). A 1D/2D coupled flood inundation model (Flood Map) was firstly used to simulate the designed flood scenarios with 5 a, 50 a and 500 a return periods in 1979, 1990, 2000 and 2009. The flow hydrographs at the boundary gauging stations (i.e. upstream Mishidu and downstream Wusong) were derived using a simplified algebraic subtraction of the water levels with different return period which have been calculated in our previous studies and the maximum water level during the 9711 flood event where hourly stage hydrograph was available. The flood processes are only represented with 24 h stage hydrographs, including two rising and falling phases. 175 rectangular cross-sections were used as the 1D river channel model. The DEMs of 1979, 1990, 2000 and 2009 were generated based upon the 2005 DEM and land subsidence data of 1980-2009 for the study area. Roughness parameters of river channel and floodplain were represented by varying manning's. These provided the boundary conditions and the calibrated parameters for the model simulations. Furthermore, land use maps of the study area in various time points were used for vulnerability analysis and then they were categorized into four classes. On the basis of some relevant national standards and expert judgments, a flood risk matrix, which comprehensively considerate the relationship between flood inundation and vulnerability, was constructed for the analysis of flood dynamic risk variation in Huangpu River Basin during the transitional period. The results shown that over the past 30 years, the flood dynamic risk of Huangpu River Basin slightly increased between 1979 and 1990 due to rapid urbanization and land subsidence in floodplain but significantly reduced afterwards particularly in city center because the floodwall system along Huangpu River has been largely extended and reinforced. As expected, the flood risk obviously increased with the increasing return periods. Spatially, the flood risk appeared in most of riparian regions in 1979 and then it was gradually restricted to mid- and upstream. Finally, uncertainties and limitations were analyzed and some suggestions were presented for future researches.

Key words: the transitional period, flood dynamic risk, change trend, Huangpu River Basin

CLC Number: 

  • X43