A distributed hydrological model, Grid-based Integrated Surface-groundwater MODel (GISMOD), was developed to simulate hydrological processes by considering water interaction among different soil layers. The model integrates six modules. Basic information on catchment such as flow direction, drainage network can be obtained from DEM data automatically by using the preprocessing module, and three and eight kinds of methods are available in GISMOD to estimate precipitation and evapotranspiration in each grid, respectively. Infiltration excess flow, saturation flow, recharge flow from soil and groundwater are all considered by using a simplified method according to the three layers structure of GISMOD. A case study in the upper-middle reaches of the Heihe River was presented to evaluate the model performance. Results show that the change tendency of infiltrated water and recharged water is quite opposite in the study area, the surface water is mainly infiltrated to soil layer in the upper streams, and then discharged by groundwater in the middle reaches, which is more consistent with the actual situation of Heihe River basin. In addition, the simulated runoff of a river grid nearby Yingluoxia hydrological station is compared with the observed one and the results also demonstrate that GISMOD has a better performance in runoff estimation on both daily and monthly scales.
- Heihe River
- hydrological model
- surface water
- water interaction
- First received 4 January 2015.
- Accepted in revised form 23 September 2015.
- © IWA Publishing 2015