GEOGRAPHICAL RESEARCH ›› 2014, Vol. 33 ›› Issue (9): 1658-1667.doi: 10.11821/dlyj201409007

• Orginal Article • Previous Articles     Next Articles

Variation of rainfall-runoff relationship and the driving factors identification in the Chaohe River Basin

Moyuan YANG1,2(), Yanfang SANG1, Zhonggen WANG1, Changming LIU1,3   

  1. 1. Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China
    3.College of Water Sciences, Beijing Normal University, Beijing 100875, China
  • Received:2013-07-16 Online:2014-09-20 Published:2014-11-10

Abstract:

The Chaohe River basin, located in the northeast area of Beijing district, is a very important water source for the water supply of Beijing. Under the great impacts of both climate variability and human activities, the rainfall-runoff relationship in the Chaohe River Basin has undergone significant changes during the past 40 years, which threats to the water supply security of Beijing. By using the daily rainfall and runoff series data, we mainly investigated the variation of the rainfall-runoff relationship in the Chaohe River Basin during the 1973-2010, and found that the rainfall-runoff relationship can be divided into three stages. The driving factors causing the rainfall-runoff relationship changes in each stage were identified. Double mass curve of rainfall-runoff, indexes of concentration degree and concentration period, the Mann-Kendall (M-K) test methods, together with the HIMS (Hydro-Informatic Modelling System) model are used for this study. The results show that: (1) two change points were identified in the variation of the rainfall-runoff relationship in the Chaohe River Basin, and the change processes can be divided into three stages: 1973-1983, 1984-1998, 1999-2010. The mean annual runoff in each stage decreased more significantly compared with the mean annual precipitation, which make the rainfall-runoff relationship changed dramatically; (2) the sum of precipitation in rainstorm days and the runoff depth are closely related, which means that the change in the sum of precipitation in rainstorm days is the main driving factor for the obvious change of rainfall-runoff relationship in the 1983; (3) by analyzing the HIMS simulation results, we found that the underlying surface of the Chaohe River Basin during the 1999-2010 has changed significantly compared with the period of the 1973-1998, therefore human activity is the main driving factor for the obvious change of rainfall-runoff relationship in the 1998; the runoff-reducing effects caused by human activity in the Chaohe River Basin increased from 14.93% in the second stage to 25.78% after the 1998. As a result, under the impacts of both precipitation variations and continuous changes of subsurface, the runoff and water resources in the Chaohe River Basin would more likely decrease. The unfavorable situation would further cause the water resources shortage in the Beijing City. More effective and urgent measures should be implemented for water supply safety of Beijing.

Key words: the Chaohe River Basin, rainfall-runoff relationship, hydrological model, climate variability, human activities

PACS: 

  • P333