In the hilly regions of China, developing sustainable agriculture requires implementing conservation management practices that prevent soil erosion and conserve soil and water resources. In the semiarid northwest Loess Plateau, the primary conservation management practice is terracing. Numerical simulation of soil water dynamics in terraces is potentially an efficient means of investigating the effects of terrace design on moisture retention, but little information is available on the accuracy of such simulations. In this work, we evaluated the accuracy of HYDRUS-2D simulations of water infiltration and redistribution in fallow, level, dryland terraces located in the Loess Plateau. The simulated soil water content distributions were in good agreement with experimental data. Modeling analyses showed that about one-third of the evaporative water losses occurred from the terrace riser surface. To prevent such losses, it is advisable to mulch the riser and minimize the riser surface area. The simulations also demonstrated that with other dimensions equal, wide terraces retain more water on a percentage basis than narrow ones due to a lower evaporating surface area are per unit volume of water storage. With other design considerations being equal, wide beds and minimal riser surface areas will likely enhance water capture and retention. Future analyses of terrace moisture dynamics may additionally include simulations of root water uptake, surface ponding, and runoff.
[1]
X. Y. Li.
Soil and water conservation in arid and semiarid areas: the Chinese experience.
,
2000
.
[2]
Bojie Fu,et al.
Soil and water conservation on the Loess Plateau in China: review and perspective
,
2007
.
[3]
M. Schaap,et al.
ROSETTA: a computer program for estimating soil hydraulic parameters with hierarchical pedotransfer functions
,
2001
.
[4]
Mingan Shao,et al.
Soil and water loss from the Loess Plateau in China
,
2000
.
[5]
Q. Feng,et al.
Soft-riser bench terrace design for the hilly loess region of Shaanxi Province, China
,
2007
.
[6]
L. S. Pereira,et al.
Crop evapotranspiration : guidelines for computing crop water requirements
,
1998
.