The impact mechanism of vegetation on slope soil water infiltration and stability in the loess areas of the northeastern Qinghai-Tibet Plateau remains unclear.Understanding this mechanism is crucial for regional ecolo...The impact mechanism of vegetation on slope soil water infiltration and stability in the loess areas of the northeastern Qinghai-Tibet Plateau remains unclear.Understanding this mechanism is crucial for regional ecological restoration and shallow geological disaster prevention.This study investigated slopes covered by Caragana korshinskii Kom.by employing double-ring infiltration tests to explore the permeability characteristics and influencing factors of root-containing soils and to propose an appropriate infiltration model.Considering the synergistic effects of the canopy and roots,the hydrological response and stability of vegetation-covered slopes under rainfall infiltration conditions were evaluated through numerical simulation analysis.The results revealed that within the main root distribution layer(0-0.5 m),the initial and average infiltration rates and the permeability coefficient of the root-soil composite were significantly higher than those of bare land.Coarse roots with diameters of>5 mm were the key contributors to enhancement of the infiltration capacity.The dry density,fine particle content,and initial water content of the soil around the roots were negatively correlated with the infiltration process.The Horton model effectively reproduced the infiltration process under the canopy and on bare land.The roots significantly accelerated the advance of the slope wetting front during rainfall infiltration,whereas the canopy delayed its onset and progression.The rainfall infiltration process on vegetation-covered slopes was divided into three stages:the equilibrium infiltration stage,optimal infiltration stage beneath the canopy,and secondary equilibrium stage.Vegetation enhances slope stability through coupling of the canopy and root,with an order of canopy-root mode>root mode>bare slope.Under heavy rainfall conditions,the direct contribution of canopy interception to slope stability is limited,and its primary role is to delay the occurrence of instability.During this period,the mechanical effect of roots becomes the dominant mechanism in slope protection.展开更多
[Objective] The aim was to study the effect of salt solution on characteristics of soil infiltration, and to provide references for the further studies on the effect of water quality on soil infiltration characteristi...[Objective] The aim was to study the effect of salt solution on characteristics of soil infiltration, and to provide references for the further studies on the effect of water quality on soil infiltration characteristics and its mechanism. [Method] With the NaCl, CaCl2 solutions as the main test materials, the effect of different water quality and salt solution concentration on soil infiltration was studied under one-dimensional vertical ponded water infiltration at laboratory. [Result] The solution concentration could affect the infiltration performance. The trends of the infiltration rates, cumulative infiltrations and wetting front migration distances were all 50 mg/L 100 mg/L 10 mg/L. At the same concentration, the effect of NaCl solution on soil infiltration characteristics was more significant than CaCl2 solution： in the same time, cumulative infiltration and wetting front migration distance of NaCl solution were greater than CaCl2 solution; compared with NaCl solution, CaCl2 solution took longer time to infiltrate the same amount of water. The dynamic changes of infiltration rate, wetting front and cumulative infiltration were well fitted to the Philip model. [Conclusion] This study only conducted indoor experiment to the infiltration of salt solutions, involving in low concentration and small range. Although it provided some references for the study on the effect of water quality on soil infiltration characteristics and its mechanism, studies in larger areas and with bigger concentrations are demanding.展开更多
Detailed knowledge about soil characteristics and site-specific final steady infiltration rate could help to increase the irrigation water use efficiency and decrease water losses in agricultural system.The experiment...Detailed knowledge about soil characteristics and site-specific final steady infiltration rate could help to increase the irrigation water use efficiency and decrease water losses in agricultural system.The experiments were conducted on Agricultural Research Farm of Bahauddin Zakariya University,Multan,Pakistan during 2016.The cumulative infiltration depth was measured using double ring infiltrometer at selected six points of the study area.Most commonly used infiltration models such as Kostikov’s,Philip’s and Horton’s were fitted to the field infiltration data for determination of model parameters and to find the best fit model for the study area.Kostikov’s infiltration model’s parameters such as empirical constant‘c’and infiltration decay constants‘k’were obtained in the ranges of 0.140-0.290 and 0.307-0.433,respectively.Philip’s infiltration model’s parameters such as sorptivity‘S’and conductivity constant‘A’were found in the ranges of 0.167-0.288 cm/min1/2 and-0.001 to-0.009 cm/min,respectively.Similarly,the Horton’s model’s‘parameter‘k’was obtained in the range of-1.619 to-1.238.The value of infiltration capacity at onset of infiltration(fo)was obtained as 1.744 to 3.491 for all the six points.The analysis showed that the infiltration models using the estimated parameters have satisfactory prediction capability at all the selected points.Horton’s model provided the lowest mean values for RMSE(0.235)and highest mean values for ME(94%);and the lowest mean values for MPD(0.127).This indicated that infiltration can be well-described by the Horton’s model at the selected site.展开更多
基金funded by Science and Technology Program of Qinghai Province of China(2024-SF-129)the National Natural Science Foundation of China(42002283).
文摘The impact mechanism of vegetation on slope soil water infiltration and stability in the loess areas of the northeastern Qinghai-Tibet Plateau remains unclear.Understanding this mechanism is crucial for regional ecological restoration and shallow geological disaster prevention.This study investigated slopes covered by Caragana korshinskii Kom.by employing double-ring infiltration tests to explore the permeability characteristics and influencing factors of root-containing soils and to propose an appropriate infiltration model.Considering the synergistic effects of the canopy and roots,the hydrological response and stability of vegetation-covered slopes under rainfall infiltration conditions were evaluated through numerical simulation analysis.The results revealed that within the main root distribution layer(0-0.5 m),the initial and average infiltration rates and the permeability coefficient of the root-soil composite were significantly higher than those of bare land.Coarse roots with diameters of>5 mm were the key contributors to enhancement of the infiltration capacity.The dry density,fine particle content,and initial water content of the soil around the roots were negatively correlated with the infiltration process.The Horton model effectively reproduced the infiltration process under the canopy and on bare land.The roots significantly accelerated the advance of the slope wetting front during rainfall infiltration,whereas the canopy delayed its onset and progression.The rainfall infiltration process on vegetation-covered slopes was divided into three stages:the equilibrium infiltration stage,optimal infiltration stage beneath the canopy,and secondary equilibrium stage.Vegetation enhances slope stability through coupling of the canopy and root,with an order of canopy-root mode>root mode>bare slope.Under heavy rainfall conditions,the direct contribution of canopy interception to slope stability is limited,and its primary role is to delay the occurrence of instability.During this period,the mechanical effect of roots becomes the dominant mechanism in slope protection.
基金Supported by the National Natural Science Foundation of China(40801100,50179035,50609022)the State Key Laboratory Fund Project of Soil Erosion and Dryland Faming on Loess Plateau(10501-177,10501-220)+1 种基金the Discipline Construction Fund of Ludong Universitythe Open Fund for Key Laboratory of Soil,Water and Environmental Conservation in Shandong Province(STKF201011)~~
文摘[Objective] The aim was to study the effect of salt solution on characteristics of soil infiltration, and to provide references for the further studies on the effect of water quality on soil infiltration characteristics and its mechanism. [Method] With the NaCl, CaCl2 solutions as the main test materials, the effect of different water quality and salt solution concentration on soil infiltration was studied under one-dimensional vertical ponded water infiltration at laboratory. [Result] The solution concentration could affect the infiltration performance. The trends of the infiltration rates, cumulative infiltrations and wetting front migration distances were all 50 mg/L 100 mg/L 10 mg/L. At the same concentration, the effect of NaCl solution on soil infiltration characteristics was more significant than CaCl2 solution： in the same time, cumulative infiltration and wetting front migration distance of NaCl solution were greater than CaCl2 solution; compared with NaCl solution, CaCl2 solution took longer time to infiltrate the same amount of water. The dynamic changes of infiltration rate, wetting front and cumulative infiltration were well fitted to the Philip model. [Conclusion] This study only conducted indoor experiment to the infiltration of salt solutions, involving in low concentration and small range. Although it provided some references for the study on the effect of water quality on soil infiltration characteristics and its mechanism, studies in larger areas and with bigger concentrations are demanding.
文摘Detailed knowledge about soil characteristics and site-specific final steady infiltration rate could help to increase the irrigation water use efficiency and decrease water losses in agricultural system.The experiments were conducted on Agricultural Research Farm of Bahauddin Zakariya University,Multan,Pakistan during 2016.The cumulative infiltration depth was measured using double ring infiltrometer at selected six points of the study area.Most commonly used infiltration models such as Kostikov’s,Philip’s and Horton’s were fitted to the field infiltration data for determination of model parameters and to find the best fit model for the study area.Kostikov’s infiltration model’s parameters such as empirical constant‘c’and infiltration decay constants‘k’were obtained in the ranges of 0.140-0.290 and 0.307-0.433,respectively.Philip’s infiltration model’s parameters such as sorptivity‘S’and conductivity constant‘A’were found in the ranges of 0.167-0.288 cm/min1/2 and-0.001 to-0.009 cm/min,respectively.Similarly,the Horton’s model’s‘parameter‘k’was obtained in the range of-1.619 to-1.238.The value of infiltration capacity at onset of infiltration(fo)was obtained as 1.744 to 3.491 for all the six points.The analysis showed that the infiltration models using the estimated parameters have satisfactory prediction capability at all the selected points.Horton’s model provided the lowest mean values for RMSE(0.235)and highest mean values for ME(94%);and the lowest mean values for MPD(0.127).This indicated that infiltration can be well-described by the Horton’s model at the selected site.
