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

Poster Number 220

See more from this Division: S01 Soil Physics
See more from this Session: General Soil Physics: II (Includes Graduate Student Competition)
Monday, October 17, 2011
Henry Gonzalez Convention Center, Hall C
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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)