The Experts below are selected from a list of 24330 Experts worldwide ranked by ideXlab platform
Wanjun Zhang - One of the best experts on this subject based on the ideXlab platform.
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effects of hillslope position on soil water infiltration and Preferential Flow in tropical forest in southwest china
Journal of Environmental Management, 2021Co-Authors: Ashutosh Kumar Singh, Chunfeng Chen, Xiai Zhu, Wanjun Zhang, Xin Zou, Bin YangAbstract:Abstract The hillslope is an essential natural spatial gradient that influences hydrological processes by affecting water distribution, surface Flow, soil erosion, and groundwater recharge. To date, few studies have addressed only the hydrological processes of tropical forest hillslopes. To reveal the effect of hillslope on soil hydrological functioning—including water distribution and exchange, infiltration capacity, and Flow behaviour—we conducted 36 field infiltration and nine dye-tracer investigations of different hillslope locations in the natural rainforest of Xishuangbanna, southwest China. The soil physical properties—including soil noncapillary and total porosity, saturated water capacity, and field water capacity—decreased with decreasing elevation from hilltop to middle slope and the valley bottom. The water infiltration capacity—including the initial infiltration rate, saturated soil hydraulic conductivity, and average infiltration rate—decreased from the hilltop to the valley bottom. Preferential Flow dominated soil water movement more in the upper locations than in the valley bottom. The infiltration capacity parameters and Preferential Flow were significantly correlated with soil water content, noncapillary and total porosity, root biomass, and termite holes. These results indicated that along with the soil physical properties, root systems, animal activity, cracks, and stones affected the soil infiltration capacity and Preferential Flow. Differences in the hydraulic processes of each hillslope position contributed to the redistribution, transportation, and storage of surface and belowground water, resulting in differing availabilities of soil water resources and utilisation by plants. The findings of this study can help understand eco-hydrological processes in the context of water resources management in tropical mountain ecosystems.
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can complementary Preferential Flow and non Preferential Flow domains contribute to soil water supply for rubber plantation
Forest Ecology and Management, 2020Co-Authors: Xiaojin Jiang, Sissou Zakari, Ashutosh Kumar Singh, Chunfeng Chen, Xiai Zhu, Wanjun ZhangAbstract:Abstract Preferential Flow has always been hotspot of research regarding soil water Flow, biological activity, and carbon and nitrogen dynamics. However, the mechanism of water Flow exchange between two adjacent zones (with and without root system) and the pattern of soil water supply for rubber are still unclear. In the present study, we considered two plots experiencing similar farming history: in the first plot we measured soil physical properties and soil volumetric water content (VWC) during rainfall, and the second plot was used to visualise water Flow path and to measure root biomass. Besides, a model was developed on Preferential Flow domain (PFD, matching the root zone) and on non-Preferential Flow domain (NPFD, matching the remote root zone) to compute differences in soil properties between the PFD and NPFD. The results revealed that the dominant Flow type in the PFD was Preferential Flow and the one in the NPFD was capillary Flow. Dye stained area and wetting front rate negatively correlated with bulk density, while they positively correlated to non-capillary porosity and root biomass. Accordingly, PFD showed a quick response to rainfall. Indeed, during the rain, a lateral Flow (driven by water gravity and pressure head gradient) predominantly carried water (0.95, 0.27, and 0.44 cm3 cm−3 for various rainfall events 1, 2, and 3, respectively) from PFD to NPFD. During the soil drainage stage, the lateral Flow direction changed, and water (about 0.63, 0.30, and 0.39 cm3 cm−3 for rainfall events 1, 2, and 3, respectively) Flowed from NPFD to PFD. As a result, PFD presented low storage and high Flow characteristics compared with NPFD, suggesting this complementary relationship for water interaction between the two domains could be beneficial for rubber plants growth and development.
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can intercrops improve soil water infiltrability and Preferential Flow in rubber based agroforestry system
Soil & Tillage Research, 2019Co-Authors: Chunfeng Chen, Xiai Zhu, Wanjun Zhang, Xin Zou, Jianbo YangAbstract:Abstract Land-use change due to the widespread practice of rubber-based agroforestry influences ecosystem services. However, little is known about their soil hydrological functioning associated with infiltration and water Flow behaviour which affects surface runoff, soil erosion, and groundwater recharge. In order to clarify whether the intercrop can promote soil water infiltrability and water movement in rubber-based agroforestry system, 66 field infiltration and 2 dye tracer experiments were performed in this study on undisturbed soil in a rubber-tea agroforestry system in Xishuangbanna, SW China. The results showed that the field saturated soil hydraulic conductivity (Ks) exhibited a high spatial heterogeneity. The Ks, initial infiltration rate (IIR), and actual steady-state infiltration rate (Is) were significantly higher in the tea tree planting zone (TT) than in the rubber tree planting zone (RT). The Ks decreased with distance from the trunks of tea trees, and the Ks between rubber trees in a row was lower than that between rubber rows. Along with improved soil physical properties, increased root and faunal activities, and more inhomogeneous cracks and stones, there was higher soil water infiltrability and more Preferential Flow in the TT than in the RT. Therefore, tea shrubs in rubber agroforestry systems may function as water harvesters, contributing to deeper drainage and recharge. In contrast, the rubber trees function as water consumers, causing soil desiccation and water scarcity. Differences in the soil hydraulic properties among different zones in a rubber-tea agroforestry system can lead to the spatial redistribution of surface and belowground water, increasing water availability for various plants with different root systems. Better infiltration and increased Preferential Flow beneath tea trees potentially reduce runoff generation and erosion risk, promote groundwater recharge, and increase water storage that may counteract the interception and transpiration losses from intercrops and rubber trees, thereby contributing to the management of water resources.
Xiai Zhu - One of the best experts on this subject based on the ideXlab platform.
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effects of hillslope position on soil water infiltration and Preferential Flow in tropical forest in southwest china
Journal of Environmental Management, 2021Co-Authors: Ashutosh Kumar Singh, Chunfeng Chen, Xiai Zhu, Wanjun Zhang, Xin Zou, Bin YangAbstract:Abstract The hillslope is an essential natural spatial gradient that influences hydrological processes by affecting water distribution, surface Flow, soil erosion, and groundwater recharge. To date, few studies have addressed only the hydrological processes of tropical forest hillslopes. To reveal the effect of hillslope on soil hydrological functioning—including water distribution and exchange, infiltration capacity, and Flow behaviour—we conducted 36 field infiltration and nine dye-tracer investigations of different hillslope locations in the natural rainforest of Xishuangbanna, southwest China. The soil physical properties—including soil noncapillary and total porosity, saturated water capacity, and field water capacity—decreased with decreasing elevation from hilltop to middle slope and the valley bottom. The water infiltration capacity—including the initial infiltration rate, saturated soil hydraulic conductivity, and average infiltration rate—decreased from the hilltop to the valley bottom. Preferential Flow dominated soil water movement more in the upper locations than in the valley bottom. The infiltration capacity parameters and Preferential Flow were significantly correlated with soil water content, noncapillary and total porosity, root biomass, and termite holes. These results indicated that along with the soil physical properties, root systems, animal activity, cracks, and stones affected the soil infiltration capacity and Preferential Flow. Differences in the hydraulic processes of each hillslope position contributed to the redistribution, transportation, and storage of surface and belowground water, resulting in differing availabilities of soil water resources and utilisation by plants. The findings of this study can help understand eco-hydrological processes in the context of water resources management in tropical mountain ecosystems.
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can complementary Preferential Flow and non Preferential Flow domains contribute to soil water supply for rubber plantation
Forest Ecology and Management, 2020Co-Authors: Xiaojin Jiang, Sissou Zakari, Ashutosh Kumar Singh, Chunfeng Chen, Xiai Zhu, Wanjun ZhangAbstract:Abstract Preferential Flow has always been hotspot of research regarding soil water Flow, biological activity, and carbon and nitrogen dynamics. However, the mechanism of water Flow exchange between two adjacent zones (with and without root system) and the pattern of soil water supply for rubber are still unclear. In the present study, we considered two plots experiencing similar farming history: in the first plot we measured soil physical properties and soil volumetric water content (VWC) during rainfall, and the second plot was used to visualise water Flow path and to measure root biomass. Besides, a model was developed on Preferential Flow domain (PFD, matching the root zone) and on non-Preferential Flow domain (NPFD, matching the remote root zone) to compute differences in soil properties between the PFD and NPFD. The results revealed that the dominant Flow type in the PFD was Preferential Flow and the one in the NPFD was capillary Flow. Dye stained area and wetting front rate negatively correlated with bulk density, while they positively correlated to non-capillary porosity and root biomass. Accordingly, PFD showed a quick response to rainfall. Indeed, during the rain, a lateral Flow (driven by water gravity and pressure head gradient) predominantly carried water (0.95, 0.27, and 0.44 cm3 cm−3 for various rainfall events 1, 2, and 3, respectively) from PFD to NPFD. During the soil drainage stage, the lateral Flow direction changed, and water (about 0.63, 0.30, and 0.39 cm3 cm−3 for rainfall events 1, 2, and 3, respectively) Flowed from NPFD to PFD. As a result, PFD presented low storage and high Flow characteristics compared with NPFD, suggesting this complementary relationship for water interaction between the two domains could be beneficial for rubber plants growth and development.
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can intercrops improve soil water infiltrability and Preferential Flow in rubber based agroforestry system
Soil & Tillage Research, 2019Co-Authors: Chunfeng Chen, Xiai Zhu, Wanjun Zhang, Xin Zou, Jianbo YangAbstract:Abstract Land-use change due to the widespread practice of rubber-based agroforestry influences ecosystem services. However, little is known about their soil hydrological functioning associated with infiltration and water Flow behaviour which affects surface runoff, soil erosion, and groundwater recharge. In order to clarify whether the intercrop can promote soil water infiltrability and water movement in rubber-based agroforestry system, 66 field infiltration and 2 dye tracer experiments were performed in this study on undisturbed soil in a rubber-tea agroforestry system in Xishuangbanna, SW China. The results showed that the field saturated soil hydraulic conductivity (Ks) exhibited a high spatial heterogeneity. The Ks, initial infiltration rate (IIR), and actual steady-state infiltration rate (Is) were significantly higher in the tea tree planting zone (TT) than in the rubber tree planting zone (RT). The Ks decreased with distance from the trunks of tea trees, and the Ks between rubber trees in a row was lower than that between rubber rows. Along with improved soil physical properties, increased root and faunal activities, and more inhomogeneous cracks and stones, there was higher soil water infiltrability and more Preferential Flow in the TT than in the RT. Therefore, tea shrubs in rubber agroforestry systems may function as water harvesters, contributing to deeper drainage and recharge. In contrast, the rubber trees function as water consumers, causing soil desiccation and water scarcity. Differences in the soil hydraulic properties among different zones in a rubber-tea agroforestry system can lead to the spatial redistribution of surface and belowground water, increasing water availability for various plants with different root systems. Better infiltration and increased Preferential Flow beneath tea trees potentially reduce runoff generation and erosion risk, promote groundwater recharge, and increase water storage that may counteract the interception and transpiration losses from intercrops and rubber trees, thereby contributing to the management of water resources.
Chunfeng Chen - One of the best experts on this subject based on the ideXlab platform.
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effects of hillslope position on soil water infiltration and Preferential Flow in tropical forest in southwest china
Journal of Environmental Management, 2021Co-Authors: Ashutosh Kumar Singh, Chunfeng Chen, Xiai Zhu, Wanjun Zhang, Xin Zou, Bin YangAbstract:Abstract The hillslope is an essential natural spatial gradient that influences hydrological processes by affecting water distribution, surface Flow, soil erosion, and groundwater recharge. To date, few studies have addressed only the hydrological processes of tropical forest hillslopes. To reveal the effect of hillslope on soil hydrological functioning—including water distribution and exchange, infiltration capacity, and Flow behaviour—we conducted 36 field infiltration and nine dye-tracer investigations of different hillslope locations in the natural rainforest of Xishuangbanna, southwest China. The soil physical properties—including soil noncapillary and total porosity, saturated water capacity, and field water capacity—decreased with decreasing elevation from hilltop to middle slope and the valley bottom. The water infiltration capacity—including the initial infiltration rate, saturated soil hydraulic conductivity, and average infiltration rate—decreased from the hilltop to the valley bottom. Preferential Flow dominated soil water movement more in the upper locations than in the valley bottom. The infiltration capacity parameters and Preferential Flow were significantly correlated with soil water content, noncapillary and total porosity, root biomass, and termite holes. These results indicated that along with the soil physical properties, root systems, animal activity, cracks, and stones affected the soil infiltration capacity and Preferential Flow. Differences in the hydraulic processes of each hillslope position contributed to the redistribution, transportation, and storage of surface and belowground water, resulting in differing availabilities of soil water resources and utilisation by plants. The findings of this study can help understand eco-hydrological processes in the context of water resources management in tropical mountain ecosystems.
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can complementary Preferential Flow and non Preferential Flow domains contribute to soil water supply for rubber plantation
Forest Ecology and Management, 2020Co-Authors: Xiaojin Jiang, Sissou Zakari, Ashutosh Kumar Singh, Chunfeng Chen, Xiai Zhu, Wanjun ZhangAbstract:Abstract Preferential Flow has always been hotspot of research regarding soil water Flow, biological activity, and carbon and nitrogen dynamics. However, the mechanism of water Flow exchange between two adjacent zones (with and without root system) and the pattern of soil water supply for rubber are still unclear. In the present study, we considered two plots experiencing similar farming history: in the first plot we measured soil physical properties and soil volumetric water content (VWC) during rainfall, and the second plot was used to visualise water Flow path and to measure root biomass. Besides, a model was developed on Preferential Flow domain (PFD, matching the root zone) and on non-Preferential Flow domain (NPFD, matching the remote root zone) to compute differences in soil properties between the PFD and NPFD. The results revealed that the dominant Flow type in the PFD was Preferential Flow and the one in the NPFD was capillary Flow. Dye stained area and wetting front rate negatively correlated with bulk density, while they positively correlated to non-capillary porosity and root biomass. Accordingly, PFD showed a quick response to rainfall. Indeed, during the rain, a lateral Flow (driven by water gravity and pressure head gradient) predominantly carried water (0.95, 0.27, and 0.44 cm3 cm−3 for various rainfall events 1, 2, and 3, respectively) from PFD to NPFD. During the soil drainage stage, the lateral Flow direction changed, and water (about 0.63, 0.30, and 0.39 cm3 cm−3 for rainfall events 1, 2, and 3, respectively) Flowed from NPFD to PFD. As a result, PFD presented low storage and high Flow characteristics compared with NPFD, suggesting this complementary relationship for water interaction between the two domains could be beneficial for rubber plants growth and development.
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can intercrops improve soil water infiltrability and Preferential Flow in rubber based agroforestry system
Soil & Tillage Research, 2019Co-Authors: Chunfeng Chen, Xiai Zhu, Wanjun Zhang, Xin Zou, Jianbo YangAbstract:Abstract Land-use change due to the widespread practice of rubber-based agroforestry influences ecosystem services. However, little is known about their soil hydrological functioning associated with infiltration and water Flow behaviour which affects surface runoff, soil erosion, and groundwater recharge. In order to clarify whether the intercrop can promote soil water infiltrability and water movement in rubber-based agroforestry system, 66 field infiltration and 2 dye tracer experiments were performed in this study on undisturbed soil in a rubber-tea agroforestry system in Xishuangbanna, SW China. The results showed that the field saturated soil hydraulic conductivity (Ks) exhibited a high spatial heterogeneity. The Ks, initial infiltration rate (IIR), and actual steady-state infiltration rate (Is) were significantly higher in the tea tree planting zone (TT) than in the rubber tree planting zone (RT). The Ks decreased with distance from the trunks of tea trees, and the Ks between rubber trees in a row was lower than that between rubber rows. Along with improved soil physical properties, increased root and faunal activities, and more inhomogeneous cracks and stones, there was higher soil water infiltrability and more Preferential Flow in the TT than in the RT. Therefore, tea shrubs in rubber agroforestry systems may function as water harvesters, contributing to deeper drainage and recharge. In contrast, the rubber trees function as water consumers, causing soil desiccation and water scarcity. Differences in the soil hydraulic properties among different zones in a rubber-tea agroforestry system can lead to the spatial redistribution of surface and belowground water, increasing water availability for various plants with different root systems. Better infiltration and increased Preferential Flow beneath tea trees potentially reduce runoff generation and erosion risk, promote groundwater recharge, and increase water storage that may counteract the interception and transpiration losses from intercrops and rubber trees, thereby contributing to the management of water resources.
Xiaojin Jiang - One of the best experts on this subject based on the ideXlab platform.
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can complementary Preferential Flow and non Preferential Flow domains contribute to soil water supply for rubber plantation
Forest Ecology and Management, 2020Co-Authors: Xiaojin Jiang, Sissou Zakari, Ashutosh Kumar Singh, Chunfeng Chen, Xiai Zhu, Wanjun ZhangAbstract:Abstract Preferential Flow has always been hotspot of research regarding soil water Flow, biological activity, and carbon and nitrogen dynamics. However, the mechanism of water Flow exchange between two adjacent zones (with and without root system) and the pattern of soil water supply for rubber are still unclear. In the present study, we considered two plots experiencing similar farming history: in the first plot we measured soil physical properties and soil volumetric water content (VWC) during rainfall, and the second plot was used to visualise water Flow path and to measure root biomass. Besides, a model was developed on Preferential Flow domain (PFD, matching the root zone) and on non-Preferential Flow domain (NPFD, matching the remote root zone) to compute differences in soil properties between the PFD and NPFD. The results revealed that the dominant Flow type in the PFD was Preferential Flow and the one in the NPFD was capillary Flow. Dye stained area and wetting front rate negatively correlated with bulk density, while they positively correlated to non-capillary porosity and root biomass. Accordingly, PFD showed a quick response to rainfall. Indeed, during the rain, a lateral Flow (driven by water gravity and pressure head gradient) predominantly carried water (0.95, 0.27, and 0.44 cm3 cm−3 for various rainfall events 1, 2, and 3, respectively) from PFD to NPFD. During the soil drainage stage, the lateral Flow direction changed, and water (about 0.63, 0.30, and 0.39 cm3 cm−3 for rainfall events 1, 2, and 3, respectively) Flowed from NPFD to PFD. As a result, PFD presented low storage and high Flow characteristics compared with NPFD, suggesting this complementary relationship for water interaction between the two domains could be beneficial for rubber plants growth and development.
Wei Shao - One of the best experts on this subject based on the ideXlab platform.
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analysis of plant root induced Preferential Flow and pore water pressure variation by a dual permeability model
Canadian Geotechnical Journal, 2017Co-Authors: Wei Shao, Anthony Kwan LeungAbstract:Vegetation can affect slope hydrology and stability via plant transpiration and induced matric suction. Previous work suggested that the presence of plant roots would induce Preferential Flow, and ...
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the influence of Preferential Flow on pressure propagation and landslide triggering of the rocca pitigliana landslide
Journal of Hydrology, 2016Co-Authors: Wei Shao, Thom Bogaard, Mark Bakker, Matteo BertiAbstract:Abstract The fast pore water pressure response to rain events is an important triggering factor for slope instability. The fast pressure response may be caused by Preferential Flow that bypasses the soil matrix. Currently, most of the hydro-mechanical models simulate pore water pressure using a single-permeability model, which cannot quantify the effects of Preferential Flow on pressure propagation and landslide triggering. Previous studies showed that a model based on the linear-diffusion equation can simulate the fast pressure propagation in near-saturated landslides such as the Rocca Pitigliana landslide. In such a model, the diffusion coefficient depends on the degree of saturation, which makes it difficult to use the model for predictions. In this study, the influence of Preferential Flow on pressure propagation and slope stability is investigated with a 1D dual-permeability model coupled with an infinite-slope stability approach. The dual-permeability model uses two modified Darcy-Richards equations to simultaneously simulate the matrix Flow and Preferential Flow in hillslopes. The simulated pressure head is used in an infinite-slope stability analysis to identify the influence of Preferential Flow on the fast pressure response and landslide triggering. The dual-permeability model simulates the height and arrival of the pressure peak reasonably well. Performance of the dual-permeability model is as good as or better than the linear-diffusion model even though the dual-permeability model is calibrated for two single pulse rain events only, while the linear-diffusion model is calibrated for each rain event separately. In conclusion, the 1D dual-permeability model is a promising tool for landslides under similar conditions.
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quantification of the influence of Preferential Flow on slope stability using a numerical modelling approach
Hydrology and Earth System Sciences, 2015Co-Authors: Wei Shao, Thom Bogaard, Mark Bakker, Roberto GrecoAbstract:The effect of Preferential Flow on the stability of landslides is studied through numerical simulation of two types of rainfall events on a hypothetical hillslope. A model is developed that consists of two parts. The first part is a model for combined saturated/unsaturated subsurface Flow and is used to compute the spatial and temporal water pressure response to rainfall. Preferential Flow is simulated with a dual-permeability continuum model consisting of a matrix domain coupled to a Preferential Flow domain. The second part is a soil mechanics model and is used to compute the spatial and temporal distribution of the local factor of safety based on the water pressure distribution computed with the subsurface Flow model. Two types of rainfall events were considered: long-duration, low-intensity rainfall, and short-duration, high-intensity rainfall. The effect of Preferential Flow on slope stability is assessed through comparison of the failure area when subsurface Flow is simulated with the dual-permeability model as compared to a single-permeability model (no Preferential Flow). For the low-intensity rainfall case, Preferential Flow has a positive effect on drainage of the hillslope resulting in a smaller failure area. For the high-intensity rainfall case, Preferential Flow has a negative effect on the slope stability as the majority of rainfall infiltrates into the Preferential Flow domain when rainfall intensity exceeds the infiltration capacity of the matrix domain, resulting in larger water pressure and a larger failure area.