Infiltration is an important part of the hydrological cycle, and it is one of the main abstractions accounted for in the rainfall-runoff modeling. The main purpose of this study is to compare the infiltration models t...Infiltration is an important part of the hydrological cycle, and it is one of the main abstractions accounted for in the rainfall-runoff modeling. The main purpose of this study is to compare the infiltration models that were used to assess the infiltration rate of the Mitidja Plain in Algeria. Field infiltration tests were conducted at 40 different sites using a double ring infiltrometer. Five statistical comparison criteria including root mean squared error(RMSE), normalized root mean squared error(NRMSE), coefficient of correlation(CC), Nash-Sutcliffe efficiency(NSE), and Kling-Gupta efficiency(KGE) were used to determine the best performing infiltration model and to confirm anomalies between predicted and observed values. Then we evaluated performance of five models(i.e., the Philip model, Kostiakov model, Modified Kostiakov model, Novel model, and Horton model) in simulating the infiltration process based on the adjusted performance parameters cited above. Results indicated that the Novel model had the best simulated water infiltration process in the Mitidja Plain in Algeria. However, the Philip model was the weakest to simulate the infiltration process. The conclusion of this study can be useful for estimating infiltration rate at various sites using a Novel model when measured infiltration data are not available and are useful for planning and managing water resources in the study area.展开更多
The quantification of soil infiltration is necessary for the estimation of water accessibility in soils for plant growth and development. Field infiltration tests runs were conducted on agricultural soils in three irr...The quantification of soil infiltration is necessary for the estimation of water accessibility in soils for plant growth and development. Field infiltration tests runs were conducted on agricultural soils in three irrigation sites of Northern Ghana. The field data were fitted into Green and Ampt, Kostiakov, Philip, Holtan, Soil Conservation Service and Horton infiltration models for the determination of the unknown model parameters. Regression analysis at 95% confidence level using GraphPad Prism 8. Laboratory and field data on infiltration were used for the model fitting and the unknown parameters were determined using the calibrated models. The <i>k</i> and <i>n</i> parameters of Kostiakov model at Bontanga study site were found to be <i>k</i> = 28.0027 and <i>n</i> = 0.5902, <i>k</i> = 17.0294 and <i>n</i> = 0.4504 for Golinga and <i>k</i> = 23.0356 and <i>n</i> = 0.6339 for Libga. For all the models, the coefficient of determination ranged from 0.7612 to 0.9876 indicating strong relationships. Only Holtan model gave different values at all the three study sites. The parameter <i>GIa</i> and <i>i<sub>c</sub></i><i> </i>of the Holtan model drawn from hydrologic soil group were the same at all the study sites because of the same vegetative cover and surface conditions. The study observed the values of the parameters to have influenced the models’ performance.展开更多
Based on the principle of saturated infiltration and the Green-Ampt model,an unsaturated infiltration model for a soil slope surface was established for either constant moisture content,or depth-varying moisture conte...Based on the principle of saturated infiltration and the Green-Ampt model,an unsaturated infiltration model for a soil slope surface was established for either constant moisture content,or depth-varying moisture content and the slope.Infiltration parameters in the partially saturated slope were revealed under sustained rainfall.Through analysis of the variation of initial moisture content in the slope,the ponding time,infiltration depth,and infiltration rate were deduced for an unsaturated soil slope subject to rainfall infiltration.There is no ponded water on the surface of the slope under sustained low-intensity rainfall.The results show that the infiltration parameters of an unsaturated slope are influenced by the initial moisture content and the wetting front saturation,the soil cohesion and rainfall intensity under sustained rainfall.More short-term slope failures can occur with the decrease of cohesion of the soil of the slope.The ponding time and infiltration depth differ considering constant or different initial moisture content respectively in the soil slope.Then,best-fit curves of the infiltration rate,ponding time,and infiltration depth to the wetting front saturation were obtained with constant or different initial moisture contents.And the slope failure time is roughly uniform when subject to a rainfall intensity I>5 mm/h.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
Severe soil erosion and drought are the two main factors affecting the ecological security of the Loess Plateau,China.Investigating the influence of drought on soil conservation service is of great importance to regio...Severe soil erosion and drought are the two main factors affecting the ecological security of the Loess Plateau,China.Investigating the influence of drought on soil conservation service is of great importance to regional environmental protection and sustainable development.However,there is little research on the coupling relationship between them.In this study,focusing on the Jinghe River Basin,China as a case study,we conducted a quantitative evaluation on meteorological,hydrological,and agricultural droughts(represented by the Standardized Precipitation Index(SPI),Standardized Runoff Index(SRI),and Standardized Soil Moisture Index(SSMI),respectively)using the Variable Infiltration Capacity(VIC)model,and quantified the soil conservation service using the Revised Universal Soil Loss Equation(RUSLE)in the historical period(2000-2019)and future period(2026-2060)under two Representative Concentration Pathways(RCPs)(RCP4.5 and RCP8.5).We further examined the influence of the three types of drought on soil conservation service at annual and seasonal scales.The NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP)dataset was used to predict and model the hydrometeorological elements in the future period under the RCP4.5 and RCP8.5 scenarios.The results showed that in the historical period,annual-scale meteorological drought exhibited the highest intensity,while seasonal-scale drought was generally weakest in autumn and most severe in summer.Drought intensity of all three types of drought will increase over the next 40 years,with a greater increase under the RCP4.5 scenario than under the RCP8.5 scenario.Furthermore,the intra-annual variation in the drought intensity of the three types of drought becomes smaller under the two future scenarios relative to the historical period(2000-2019).Soil conservation service exhibits a distribution pattern characterized by high levels in the southwest and southeast and lower levels in the north,and this pattern has remained consistent both in the historical and future periods.Over the past 20 years,the intra-annual variation indicated peak soil conservation service in summer and lowest level in winter;the total soil conservation of the Jinghe River Basin displayed an upward trend,with the total soil conservation in 2019 being 1.14 times higher than that in 2000.The most substantial impact on soil conservation service arises from annual-scale meteorological drought,which remains consistent both in the historical and future periods.Additionally,at the seasonal scale,meteorological drought exerts the highest influence on soil conservation service in winter and autumn,particularly under the RCP4.5 and RCP8.5 scenarios.Compared to the historical period,the soil conservation service in the Jinghe River Basin will be significantly more affected by drought in the future period in terms of both the affected area and the magnitude of impact.This study conducted beneficial attempts to evaluate and predict the dynamic characteristics of watershed drought and soil conservation service,as well as the response of soil conservation service to different types of drought.Clarifying the interrelationship between the two is the foundation for achieving sustainable development in a relatively arid and severely eroded area such as the Jinghe River Basin.展开更多
Single or multi-layer infiltration rate models describe water penetration into soil porous zone at a variety of comparable complexity levels. Commonly, those models are indicating a route leading from general to more ...Single or multi-layer infiltration rate models describe water penetration into soil porous zone at a variety of comparable complexity levels. Commonly, those models are indicating a route leading from general to more specific case depending on the mathematical structure and the simulated ongoing phenomenon. For the purpose of wastewater flow quantification through porous media, an algorithmic procedure was developed which includes certain interconnected activity stages and decision nodes. Furthermore, a schematic cross shaped representation of the infiltration rate models’ ontology is presented within a route, leading from general to more specific models and evaluation criteria are introduced to determine highest ranking and thus the best model amid those placed on the horizontal axis of the cross shaped scheme, via a simple Multi-Criteria Analysis Decision Making.展开更多
Some Swedish school buildings built in the 1960s and 1970s experience indoor air quality problems,where the contaminants are suspected to come from the crawl space underneath the building.The poor indoor air quality c...Some Swedish school buildings built in the 1960s and 1970s experience indoor air quality problems,where the contaminants are suspected to come from the crawl space underneath the building.The poor indoor air quality causes discomfort among pupils and teachers.Installing an exhaust fan to maintain a negative pressure difference in the crawl space relative to indoors or increasing the ventilation in the classroom are two examples of common measures taken to improve the indoor air quality.However,these measures are not always effective,and sometimes the school building has to be demolished.The relation between pressure distribution,contaminant concentration in the classroom,outdoor temperature,wind,mechanical ventilation,and air leakage distribution is complex.A better understanding of these relations is crucial for making decisions on the most efficient measure to improve the indoor air quality.In this paper,a model for contaminant infiltration from the crawl space is used together with the Monte Carlo method to study these relations.Simulations are performed for several cases where different building shapes,building orientations,shielding conditions,and geographical locations are simulated.Results show,for example,that for a building with an imbalanced ventilation system,air is leaking from the crawl space to the classroom for the majority of cases and that concentration levels in the classroom are usually the highest during mild and calm days.展开更多
基金the framework of the SWATCH project (Prima project) funded by the DGRSDT, Algeria
文摘Infiltration is an important part of the hydrological cycle, and it is one of the main abstractions accounted for in the rainfall-runoff modeling. The main purpose of this study is to compare the infiltration models that were used to assess the infiltration rate of the Mitidja Plain in Algeria. Field infiltration tests were conducted at 40 different sites using a double ring infiltrometer. Five statistical comparison criteria including root mean squared error(RMSE), normalized root mean squared error(NRMSE), coefficient of correlation(CC), Nash-Sutcliffe efficiency(NSE), and Kling-Gupta efficiency(KGE) were used to determine the best performing infiltration model and to confirm anomalies between predicted and observed values. Then we evaluated performance of five models(i.e., the Philip model, Kostiakov model, Modified Kostiakov model, Novel model, and Horton model) in simulating the infiltration process based on the adjusted performance parameters cited above. Results indicated that the Novel model had the best simulated water infiltration process in the Mitidja Plain in Algeria. However, the Philip model was the weakest to simulate the infiltration process. The conclusion of this study can be useful for estimating infiltration rate at various sites using a Novel model when measured infiltration data are not available and are useful for planning and managing water resources in the study area.
文摘The quantification of soil infiltration is necessary for the estimation of water accessibility in soils for plant growth and development. Field infiltration tests runs were conducted on agricultural soils in three irrigation sites of Northern Ghana. The field data were fitted into Green and Ampt, Kostiakov, Philip, Holtan, Soil Conservation Service and Horton infiltration models for the determination of the unknown model parameters. Regression analysis at 95% confidence level using GraphPad Prism 8. Laboratory and field data on infiltration were used for the model fitting and the unknown parameters were determined using the calibrated models. The <i>k</i> and <i>n</i> parameters of Kostiakov model at Bontanga study site were found to be <i>k</i> = 28.0027 and <i>n</i> = 0.5902, <i>k</i> = 17.0294 and <i>n</i> = 0.4504 for Golinga and <i>k</i> = 23.0356 and <i>n</i> = 0.6339 for Libga. For all the models, the coefficient of determination ranged from 0.7612 to 0.9876 indicating strong relationships. Only Holtan model gave different values at all the three study sites. The parameter <i>GIa</i> and <i>i<sub>c</sub></i><i> </i>of the Holtan model drawn from hydrologic soil group were the same at all the study sites because of the same vegetative cover and surface conditions. The study observed the values of the parameters to have influenced the models’ performance.
基金sponsored by the Zhejiang Provincial Natural Science Foundation of China(Grant No.LY19E080007,No.LY19E080008)the Natural Science Foundation of China(Grant No.51578356)the Science and Technology Fund of Yunnan Provincial Communication Department of China(Grant No.2010(A)06-b)。
文摘Based on the principle of saturated infiltration and the Green-Ampt model,an unsaturated infiltration model for a soil slope surface was established for either constant moisture content,or depth-varying moisture content and the slope.Infiltration parameters in the partially saturated slope were revealed under sustained rainfall.Through analysis of the variation of initial moisture content in the slope,the ponding time,infiltration depth,and infiltration rate were deduced for an unsaturated soil slope subject to rainfall infiltration.There is no ponded water on the surface of the slope under sustained low-intensity rainfall.The results show that the infiltration parameters of an unsaturated slope are influenced by the initial moisture content and the wetting front saturation,the soil cohesion and rainfall intensity under sustained rainfall.More short-term slope failures can occur with the decrease of cohesion of the soil of the slope.The ponding time and infiltration depth differ considering constant or different initial moisture content respectively in the soil slope.Then,best-fit curves of the infiltration rate,ponding time,and infiltration depth to the wetting front saturation were obtained with constant or different initial moisture contents.And the slope failure time is roughly uniform when subject to a rainfall intensity I>5 mm/h.
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.
基金supported by the National Natural Science Foundation of China(42071285,42371297)the Key R&D Program Projects in Shaanxi Province of China(2022SF-382)the Fundamental Research Funds for the Central Universities(GK202302002).
文摘Severe soil erosion and drought are the two main factors affecting the ecological security of the Loess Plateau,China.Investigating the influence of drought on soil conservation service is of great importance to regional environmental protection and sustainable development.However,there is little research on the coupling relationship between them.In this study,focusing on the Jinghe River Basin,China as a case study,we conducted a quantitative evaluation on meteorological,hydrological,and agricultural droughts(represented by the Standardized Precipitation Index(SPI),Standardized Runoff Index(SRI),and Standardized Soil Moisture Index(SSMI),respectively)using the Variable Infiltration Capacity(VIC)model,and quantified the soil conservation service using the Revised Universal Soil Loss Equation(RUSLE)in the historical period(2000-2019)and future period(2026-2060)under two Representative Concentration Pathways(RCPs)(RCP4.5 and RCP8.5).We further examined the influence of the three types of drought on soil conservation service at annual and seasonal scales.The NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP)dataset was used to predict and model the hydrometeorological elements in the future period under the RCP4.5 and RCP8.5 scenarios.The results showed that in the historical period,annual-scale meteorological drought exhibited the highest intensity,while seasonal-scale drought was generally weakest in autumn and most severe in summer.Drought intensity of all three types of drought will increase over the next 40 years,with a greater increase under the RCP4.5 scenario than under the RCP8.5 scenario.Furthermore,the intra-annual variation in the drought intensity of the three types of drought becomes smaller under the two future scenarios relative to the historical period(2000-2019).Soil conservation service exhibits a distribution pattern characterized by high levels in the southwest and southeast and lower levels in the north,and this pattern has remained consistent both in the historical and future periods.Over the past 20 years,the intra-annual variation indicated peak soil conservation service in summer and lowest level in winter;the total soil conservation of the Jinghe River Basin displayed an upward trend,with the total soil conservation in 2019 being 1.14 times higher than that in 2000.The most substantial impact on soil conservation service arises from annual-scale meteorological drought,which remains consistent both in the historical and future periods.Additionally,at the seasonal scale,meteorological drought exerts the highest influence on soil conservation service in winter and autumn,particularly under the RCP4.5 and RCP8.5 scenarios.Compared to the historical period,the soil conservation service in the Jinghe River Basin will be significantly more affected by drought in the future period in terms of both the affected area and the magnitude of impact.This study conducted beneficial attempts to evaluate and predict the dynamic characteristics of watershed drought and soil conservation service,as well as the response of soil conservation service to different types of drought.Clarifying the interrelationship between the two is the foundation for achieving sustainable development in a relatively arid and severely eroded area such as the Jinghe River Basin.
文摘Single or multi-layer infiltration rate models describe water penetration into soil porous zone at a variety of comparable complexity levels. Commonly, those models are indicating a route leading from general to more specific case depending on the mathematical structure and the simulated ongoing phenomenon. For the purpose of wastewater flow quantification through porous media, an algorithmic procedure was developed which includes certain interconnected activity stages and decision nodes. Furthermore, a schematic cross shaped representation of the infiltration rate models’ ontology is presented within a route, leading from general to more specific models and evaluation criteria are introduced to determine highest ranking and thus the best model amid those placed on the horizontal axis of the cross shaped scheme, via a simple Multi-Criteria Analysis Decision Making.
基金The project has been funded by FORMAS,the Swedish Research Council for Environment,Agricultural Sciences and Spatial Planning and supported by Gothenburg Premises Administration.
文摘Some Swedish school buildings built in the 1960s and 1970s experience indoor air quality problems,where the contaminants are suspected to come from the crawl space underneath the building.The poor indoor air quality causes discomfort among pupils and teachers.Installing an exhaust fan to maintain a negative pressure difference in the crawl space relative to indoors or increasing the ventilation in the classroom are two examples of common measures taken to improve the indoor air quality.However,these measures are not always effective,and sometimes the school building has to be demolished.The relation between pressure distribution,contaminant concentration in the classroom,outdoor temperature,wind,mechanical ventilation,and air leakage distribution is complex.A better understanding of these relations is crucial for making decisions on the most efficient measure to improve the indoor air quality.In this paper,a model for contaminant infiltration from the crawl space is used together with the Monte Carlo method to study these relations.Simulations are performed for several cases where different building shapes,building orientations,shielding conditions,and geographical locations are simulated.Results show,for example,that for a building with an imbalanced ventilation system,air is leaking from the crawl space to the classroom for the majority of cases and that concentration levels in the classroom are usually the highest during mild and calm days.
