117-35 Analysis of Soil-Water Movement by Using HYDRUS-1D In a Maize Field In the Arid Region of China.



Monday, October 17, 2011
Henry Gonzalez Convention Center, Hall C, Street Level

Kenta Tagawa1, Hiroyuki Cho1, Masaharu Kitano2 and Weizhen Wang3, (1)Saga University, Saga, JAPAN
(2)Kyushu University, Fukuoka City, Japan
(3)Cold and Arid Regions Environment and Engineering Research Institute, Lanzhou, China
One-dimensional analysis of water movement in a maize field in the arid region of China during 2008-2009 was done by using HYDRUS-1D software package. The potential values of evaporation and transpiration from the evapotranspiration calculated by the FAO Penman-Monteith method were separated by the FAO dual crop coefficient method. The evaporation part was assigned as a surface boundary and the transpiration part as an intake term. The hydrostatic pressures measured at a fixed depth in a well at the center of the field were dispensed as the bottom boundary. The simulated soil-water content at 0.1, 0.2 and 0.4 m below the soil surface agreed well with the measured values when the soil profile was divided into three layers: a top silt layer with high hydraulic conductivity, a middle silt layer with low hydraulic conductivity and a bottom sandy loam layer. The two silt layers with different hydraulic conductivity could reveal the truth of crack formation at the surface layer. In addition to soil-water content, the actual evapotranspiration calculated by the HYDRUS-1D was compared with that calculated by Bowen-ratio method. Under the order of ten days’ values, both evapotranspiration values agreed very well during the two years of investigation.
See more from this Division: S01 Soil Physics
See more from this Session: General Soil Physics: II (Includes Graduate Student Competition)