Acta Geographica Sinica ›› 2019, Vol. 74 ›› Issue (7): 1374-1391.doi: 10.11821/dlxb201907008

• Climate Change and Surface Processes • Previous Articles     Next Articles

Spatial-temporal distribution and the influencing factors of mountain flood disaster in southwest China

XIONG Junnan1,2,LI Jin1,CHENG Weiming2(),ZHOU Chenghu2,GUO Liang3,4,ZHANG Xiaolei3,4,WANG Nan2,LI Wei1   

  1. 1.School of Civil Engineering and Architecture, SWPU, Chengdu 610500, China
    2.State Key Laboratory of Resources and Environmental Information System, Institute of Geographic and Natural Resources Research, CAS, Beijing 100101, China
    3.China Institute of Water Resources and Hydropower Research, Beijing 100038, China
    4.Research Center on Flood & Drought Disaster Reduction of the Ministry of Water Resources, Beijing 100038, China;
  • Received:2018-10-15 Revised:2019-05-19 Online:2019-07-25 Published:2019-07-23
  • Contact: CHENG Weiming E-mail:chengwm@lreis.ac.cn
  • Supported by:
    Strategic Priority Research Program of the Chinese Academy of Sciences(XDA20030302);National Mountain Flood Disaster Survey and Evaluation Project of IWHR(SHZH-IWHR-57);China Geological Survey Project(DD20190637);The Open Fund of Big Data Institute of Digital Natural Disaster Monitoring in Fujian(NDMBD2018003);Scientific and Technological Innovation Team Project of Southwest Petroleum University(2017CXTD09)

Abstract:

Studies on spatial-temporal characteristics and influencing factors of flash floods are key contents to the assessment and management of flash flood. Based on the historic flash flood data in southwest China from 1960 to 2015, the spatial and temporal distribution of flash flood and its influencing factors were analyzed by using the linear regression model, standard deviation ellipse, spatial autocorrelation, and logistic regression model. The results show that: (1) The annual frequency of flash floods in southwest China shows an exponential growth trend, and the annual variation reveals a stable, slow and rapid increase fluctuation during 1960-1980, 1981-1998 and 1999-2015, respectively; the monthly characteristics are obvious and precipitation is mainly concentrated in June, July and August. (2) The obvious spatial difference of flash flood is observed in the study area, and the high-density areas are mainly concentrated in central Yunnan plateau, Sichuan Basin and their surrounding mountainous areas. The flash flood distribution has a significant spatial positive correlation and spatial agglomeration (Moran's I index is 0.127, Z = 5.784, P = 0.007). (3) The gravity center of historical disasters has a distinct trend of moving to the west during the year. The standard deviation ellipse angle gradually weakens, the long axis gradually lengthens, and the short axis gradually shortens. (4) Rainfall factors have the maximum impact on flash floods, followed by human activity factors, and the minimal is surface environmental factors. Among the rainfall factors, the one-hour rainfall has the strongest impact on flash floods, and its dominant ratio reached 3.654. The results can provide techinical support for research on forming mechanism, monitoring and early warning, and implementation of disaster prevention and mitigation measures of flash floods.

Key words: southwest China, flash flood, spatial-temporal pattern, logistic regression