Journal of Geographical Sciences ›› 2007, Vol. 17 ›› Issue (3): 327-338.doi: 10.1007/s11442-007-0327-z

• Climate and Environmental Change • Previous Articles     Next Articles

Research on runoff variations based on wavelet analysis and wavelet neural network model: A case study of the Heihe River drainage basin (1944?2005)

WANG Jun, MENG Jijun   

  1. College of Environmental Sciences, Peking University|Key Laboratory of Analysis and Simulation of Earth Surface Processes, Ministry of Education|Beijing 100871, China
  • Received:2007-02-02 Revised:2007-03-20 Online:2007-09-25 Published:2007-09-25
  • Supported by:

    National Natural Science Foundation of China, No.40335046

Abstract:

The Heihe River drainage basin is one of the endangered ecological regions of China. The shortage of water resources is the bottleneck, which constrains the sustainable development of the region. Many scholars in China have done researches concerning this problem. Based on previous researches, this paper analyzed characteristics, tendencies, and causes of annual runoff variations in the Yingluo Gorge (1944–2005) and the Zhengyi Gorge (1954–2005), which are the boundaries of the upper reaches, the middle reaches, and the lower reaches of the Heihe River drainage basin, by wavelet analysis, wavelet neural network model, and GIS spatial analysis. The results show that: (1) annual runoff variations of the Yingluo Gorge have principal periods of 7 years and 25 years, and its increasing rate is 1.04 m3/s·10y; (2) annual runoff variations of the Zhengyi Gorge have principal periods of 6 years and 27 years, and its decreasing rate is 2.25 m3/s·10y; (3) prediction results show that: during 2006–2015, annual runoff variations of the Yingluo and Zhengyi gorges have ascending tendencies, and the increasing rates are respectively 2.04 m3/s·10y and 1.61 m3/s·10y; (4) the increase of annual runoff in the Yingluo Gorge has causal relationship with increased temperature and precipitation in the upper reaches, and the decrease of annual runoff in the Zhengyi Gorge in the past decades was mainly caused by the increased human consumption of water resources in the middle researches. The study results will provide scientific basis for making rational use and allocation schemes of water resources in the Heihe River drainage basin.

Key words: annual runoff variations, wavelet analysis, wavelet neural network model, GIS spatial analysis, Heihe River drainage basin