Acta Geographica Sinica ›› 2007, Vol. 62 ›› Issue (7): 753-763.doi: 10.11821/xb200707008

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The Mean Annual Water Balance in the Hekou- Longmen Section of the Middle Yellow River : Testing of the Regional Scale Water Balance Model and Its Calibr ation

ZHANG Xiaoping1,2, ZHANG Lu3, MU Xingmin1,2, LI Rui1,2   

  1. 1. Institute of Soil and Water Conservation, Northwest Agriculture and Forest University, Yangling, 712100, Shaanxi, China;
    2. Institute of Soil and Water Conservation, CAS, Yangling 712100, Shaanxi, China;
    3. CSIRO Land and Water, Christian Laboratory, GPO Box 1666, Canberra, ACT, 2601, Australia
  • Received:2006-11-28 Revised:2007-03-23 Online:2007-07-25 Published:2007-07-25
  • Supported by:

    The West Bright Project of CAS (2005); ACIAR funded international cooperated project with Australia, No.LWR/2002/018

Abstract:

Ecosystem health and sustainability of social and economic development in arid and semi-arid regions depends on water availability. To study the responses of water balance components to the different land cover types on mean annual scale, the data of streamflow, precipitation and Epan from 1980 to 2000 in the He-Long section (briefly for Hekou-Longmen section) of the middle reaches of the Yellow River, were used to test and calibrate the water balance model set up by Zhang in 2001. The results showed that the model was able to accurately simulate mean annual evapotranspiration, but not mean annual streamflow when compared with streamflow measurements from 38 hydrologic stations in the study area. Using the optimized parameters, the index of agreement between modeled and observed evaporation increased from 0.89 to 0.94, and the relative error and root mean square error decreased from 3.6% and 17.2 mm to 1.5% and 7.9 mm. The index of agreement for streamflow increased from 0.21 to 0.63 and the relative error decreased from 42.7% to 18.0%. Hierarchical cluster analysis showed that 3 types of water cycles exist due to the different land cover types. The parameter optimization showed that due to the effects of forest interception, the evaporation coefficient (ET/P) in the southern part of the He-Long section is fairly high so the region is suitable for the parameter w 1.61. For the influence of sandy soil and high groundwater, the evaporation coefficient in the northwestern region is low, so that for this region the parameter value of 0.10 was used. In the middle part of the He-Long section, it is fit for the parameter value of 0.45.

Key words: catchment scale water balance model, water cycle principle, land cover, the middle reaches of the Yellow River