Articles | Volume 21, issue 7
Hydrol. Earth Syst. Sci., 21, 3359–3375, 2017

Special issue: Modeling hydrological processes and changes

Hydrol. Earth Syst. Sci., 21, 3359–3375, 2017

Research article 07 Jul 2017

Research article | 07 Jul 2017

Improving the Xin'anjiang hydrological model based on mass–energy balance

Yuan-Hao Fang1,2,5, Xingnan Zhang2,3,4, Chiara Corbari5, Marco Mancini5, Guo-Yue Niu6,7, and Wenzhi Zeng8,9 Yuan-Hao Fang et al.
  • 1School of Earth Sciences and Engineering, Hohai University, Nanjing, China
  • 2National Cooperative Innovation Center for Water Safety & Hydro-Science, Hohai University, Nanjing, China
  • 3College of Hydrology and Water Resources, Hohai University, Nanjing, China
  • 4National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety, Hohai University, Nanjing, China
  • 5Department of Civil and Environmental Engineering (D.I.C.A.), Politecnico di Milano, Milan, Italy
  • 6Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
  • 7Biosphere 2, University of Arizona, Oracle AZ, USA
  • 8State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, China
  • 9Crop Science Group, Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Bonn, Germany

Abstract. Conceptual hydrological models are preferable for real-time flood forecasting, among which the Xin'anjiang (XAJ) model has been widely applied in humid and semi-humid regions of China. Although the relatively simple mass balance scheme ensures a good performance of runoff simulation during flood events, the model still has some defects. Previous studies have confirmed the importance of evapotranspiration (ET) and soil moisture content (SMC) in runoff simulation. In order to add more constraints to the original XAJ model, an energy balance scheme suitable for the XAJ model was developed and coupled with the original mass balance scheme of the XAJ model. The detailed parameterizations of the improved model, XAJ-EB, are presented in the first part of this paper. XAJ-EB employs various meteorological forcing and remote sensing data as input, simulating ET and runoff yield using a more physically based mass–energy balance scheme. In particular, the energy balance is solved by determining the representative equilibrium temperature (RET), which is comparable to land surface temperature (LST). The XAJ-EB was evaluated in the Lushui catchment situated in the middle reach of the Yangtze River basin for the period between 2004 and 2007. Validation using ground-measured runoff data proves that the XAJ-EB is capable of reproducing runoff comparable to the original XAJ model. Additionally, RET simulated by XAJ-EB agreed well with moderate resolution imaging spectroradiometer (MODIS)-retrieved LST, which further confirms that the model is able to simulate the mass–energy balance since LST reflects the interactions among various processes. The validation results prove that the XAJ-EB model has superior performance compared with the XAJ model and also extends its applicability.

Short summary
Soil moisture and evapotranspiration (ET) are important to flood forecasting. An energy balance scheme based on the representative temperature (RET) was developed and coupled to the original mass balance scheme of the Xin'anjiang model. Validation against both runoff and land surface temperature confirmed the accuracy and applicability of the improved model (XAJ-EB). RET serves as a new constraint to the model and can be used for model calibration and validation.