The purpose of this study is to advance our current understanding of soil moisture storage in subsurface and water infiltration rate in loess soil. Therefore, a set of experiments was conducted on two soil columns fil...The purpose of this study is to advance our current understanding of soil moisture storage in subsurface and water infiltration rate in loess soil. Therefore, a set of experiments was conducted on two soil columns filled with silty clay loam, with and without applying cavity technical method. For the soil column applied with loess cavity, the ponding infiltration was simulated using HYDRUS-2D/3D, version 2.x and the simulated results were verified by those of observation. The results show that 1) the loess cavity significantly decreased the infiltration rates when the flux permeated through it (varying from 0.358 to 0.208 cm·min-1) as compared with no cavity soil column (varying from 0.408 to 0.241 cm·min-1);2) similarly, the total cumulative infiltration and at the termination of wetting front advancement of soil column with cavity were 66 cm and 69 cm lower than that of no cavity soil column (76 and 78 cm), respectively. Consequently, the soil moisture at the subsurface and surrounding the loess cavity was effectively ameliorated;3) the model was capable of predicting water infiltration processes in the soil column with loess cavity, and the root mean square error of simulated water contents, wetting front advancements, cumulative infiltrations, and infiltration rates were from 0.22 to 3.63 cm3·cm-3, 1.6 to 3.63 cm, 3.44 cm, and 0.026 cm·min-1, respectively. Overall, the findings in this study indicate that loess cavity can effectively increase soil moisture storage at shallow surface and the HYDRUS-2D/3D model is capable of simulating and predicting scenarios to help achieve stable shallow soil surface with loess cavity.展开更多
The applicability of Tropical Rainfall Measuring Mission (TRMM3B42V7) precipitation data in the region was evaluated using the measured daily precipitation data in 16 hydrological stations in Shaanxi Province from 199...The applicability of Tropical Rainfall Measuring Mission (TRMM3B42V7) precipitation data in the region was evaluated using the measured daily precipitation data in 16 hydrological stations in Shaanxi Province from 1998 to 2014. The evaluation process with several statistical error metrics was applied to daily, monthly, and annual timescale. The results show that the satellite and gauge stations show good consistency for monthly and annual timescale, but rather worse accuracy of daily timescale. All timescales produced the overestimated result of average precipitation measurement. The spatially statistical distribution shows a slight correlation between the observation and satellite estimation, especially at the higher elevation area such as Taibai. The TRMM precipitation value is closer to the gauge station precipitation value at a place with lower elevation, whether the timescale is daily, monthly or annual. At the same time, the smaller timescale leads to closer relations between elevation and metrics. The research results are important value of the research study of meteorological process in the Qinba mountain area.展开更多
文摘The purpose of this study is to advance our current understanding of soil moisture storage in subsurface and water infiltration rate in loess soil. Therefore, a set of experiments was conducted on two soil columns filled with silty clay loam, with and without applying cavity technical method. For the soil column applied with loess cavity, the ponding infiltration was simulated using HYDRUS-2D/3D, version 2.x and the simulated results were verified by those of observation. The results show that 1) the loess cavity significantly decreased the infiltration rates when the flux permeated through it (varying from 0.358 to 0.208 cm·min-1) as compared with no cavity soil column (varying from 0.408 to 0.241 cm·min-1);2) similarly, the total cumulative infiltration and at the termination of wetting front advancement of soil column with cavity were 66 cm and 69 cm lower than that of no cavity soil column (76 and 78 cm), respectively. Consequently, the soil moisture at the subsurface and surrounding the loess cavity was effectively ameliorated;3) the model was capable of predicting water infiltration processes in the soil column with loess cavity, and the root mean square error of simulated water contents, wetting front advancements, cumulative infiltrations, and infiltration rates were from 0.22 to 3.63 cm3·cm-3, 1.6 to 3.63 cm, 3.44 cm, and 0.026 cm·min-1, respectively. Overall, the findings in this study indicate that loess cavity can effectively increase soil moisture storage at shallow surface and the HYDRUS-2D/3D model is capable of simulating and predicting scenarios to help achieve stable shallow soil surface with loess cavity.
文摘The applicability of Tropical Rainfall Measuring Mission (TRMM3B42V7) precipitation data in the region was evaluated using the measured daily precipitation data in 16 hydrological stations in Shaanxi Province from 1998 to 2014. The evaluation process with several statistical error metrics was applied to daily, monthly, and annual timescale. The results show that the satellite and gauge stations show good consistency for monthly and annual timescale, but rather worse accuracy of daily timescale. All timescales produced the overestimated result of average precipitation measurement. The spatially statistical distribution shows a slight correlation between the observation and satellite estimation, especially at the higher elevation area such as Taibai. The TRMM precipitation value is closer to the gauge station precipitation value at a place with lower elevation, whether the timescale is daily, monthly or annual. At the same time, the smaller timescale leads to closer relations between elevation and metrics. The research results are important value of the research study of meteorological process in the Qinba mountain area.
