Predictions
in Ungauged Basins: Promise and Progress (Proceedings of symposium S7 held during the
Seventh IAHS Scientific Assembly at Foz do Iguaçu, Brazil, April 2005). IAHS
Publ. 303, 2006, 153-163.
Evaluation of the Xinanjiang model structure by
observed discharge and gauged soil moisture data in the HUBEX/GAME Project
LILIANG REN, QIONG HUANG, FEI YUAN, JIXIN WANG, JING XU, ZHONGBO YU & XINREN LIU
State Key
Laboratory of Hydrology, Water Resources and Hydraulic Engineering, Hohai
University,
No.1 Xikang Road, Nanjing 210098, China
Abstract Based
upon the sense that the use of an inadequate model structure may be more
problematic than the use of sub-optimal parameter values, the experience and
progress in the HUaihe River Basin EXperiment (HUBEX) during the intensified
observation period from 1998 to 1999, as a component of the GEWEX (Global
Energy and Water Cycle EXperiment) Asian Monsoon Experiment (GAME) Project, is
reported in this paper. It focuses on the realism of the Xinanjiang model
structure evaluated not only by discharge hydrographs observed upstream
(Huangnizhuang station) and downstream (Jiangji station), but also by
volumetric soil moisture data gauged at three sites, Meishan, Nianyushan, and
Jiangji. The Xinanjiang model was applied to subcatchments derived from the
digital elevation data for runoff generation. The Muskingum method was used for
the routing of discharge from the outlet of each subcatchment to the outlet of
the whole studied catchment. Soil tension water storage at each time interval
computed by the Xinanjiang model, in millimetres is in good agreement with soil
moisture data time series gauged in the field. Their correlation coefficients
range from 0.810 to 0.867. The results show that the values of soil tension
water storage in the Xinanjiang model can represent temporal variability of the soil moisture state variable
within the subcatchments, reflecting wet or dry situations in the real world. That,
to some extent, answers the question of how far the internal model state
relates to real world variables.
Key words
digital elevation model; discharge hydrograph; model structure; runoff generation; soil moisture;
Xinanjiang model