Chin J Plant Ecol ›› 2013, Vol. 37 ›› Issue (6): 492-502.DOI: 10.3724/SP.J.1258.2013.00051

• Research Articles • Previous Articles     Next Articles

Coupling simulation of water-carbon processes for catchment―calibration and validation of the WaSSI-C model

LIU Ning1,SUN Peng-Sen1,*(),LIU Shi-Rong1,SUN Ge2   

  1. 1Key Laboratory of Forest Ecology and Environment of the State Forestry Administration, Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China
    2Eastern Forest Environmental Threat Assessment Center, USDA Forest Service, Raleigh, NC 27606, USA
  • Received:2013-01-09 Accepted:2013-03-27 Online:2013-01-09 Published:2013-06-05
  • Contact: SUN Peng-Sen

Abstract:

Aims The water-carbon coupling model has become a major approach of eco-hydrology study under the complicated situation of climate changes. Our objective was to explore the applicability of the WaSSI-C model for the humid region in southwestern China.
Methods We focused on a large watershed, the upper Zagunao River watershed, situated in the upper reach of the Minjiang River, Yangtze River Basin. Applicability of the WaSSI-C model was assessed by evaluating the modeling results with two indexes: determination coefficient (R2) and Nash-Sutcliffe efficiency coefficient (NS). In order to make it better suited for the study area, two main improvements were introduced regarding to the snowmelt and evapotranspiration (ET) calculation. The calibration period was set as 1988-1996, and the validation period was set as 1997-2006. We validated the model using observed runoff and gross ecosystem productivity (GEP) and ET production of moderate resolution imaging spectroradiometer (MODIS) in the calibration and validation periods, respectively.
Important findings There was a good performance of our application of the WaSSI-C model in the study area. The R2of calibration period and NS for the total runoff of the study watershed were 0.86 and 0.82, respectively, and 0.78 and 0.67, respectively, for the validation period. Moreover, the R2 of the GEP and ET were 0.89 and 0.78, respectively. We discussed the modeling process and results, and the future direction of improvements of the ET calculation in the end.

Key words: eco-hydrological model, model calibration, model validation, WaSSI-C model