Jiangbo Han
State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, China ( E-mail: jbhan@nhri.cn)
Based on observations in lysimeters with different water table depths, numerical simulations are conduced to obtain impacts of groundwater table on surface soil water content, temperature, and fluxes of vapor, radiation and heat. The observed soil water content and temperature data in the lysimeter for one year were used to compare with the simulated values. Results indicated simulated water contents and soil temperatures matched well the measured data in the lysimeter in Huaihe River basin of China. Under the same atmospheric forcing condition, the change of groundwater depth has an impact on the soil surface water content, temperature and the exchange of water and heat flux between land and air. There is a critical depth of 250 cm in our study site, in which groundwater can have strong effect on soil moisture content, temperature and heat flux. When the groundwater depth is deeper than the critical depth, the change of groundwater level will no longer affect these variables.