Vadose Zone Journal最新文献

{"title":"Measuring and modeling soil moisture and runoff at solar farms using a disconnected impervious surface approach","authors":"David Mulla, Jake Galzki, Aaron Hanson, Jirka Simunek","doi":"10.1002/vzj2.20335","DOIUrl":"https://doi.org/10.1002/vzj2.20335","url":null,"abstract":"Ground-mounted photovoltaic sites are often treated as impervious surfaces in stormwater permits. This ignores the pervious soils beneath and between solar arrays and leads to an overestimation of runoff. Our objective was to improve solar farm stormwater hydrology models by explicitly considering the disconnected impervious nature of solar design and site characteristics. Experimental sites established on utility scale solar farms in Colorado, Georgia, Minnesota, New York, and Oregon had perennial vegetative plantings with mean precipitation ranging from 40.6 to 124.5 cm, and soil texture ranging from loamy sand to clay. Soil moisture measurements were collected beneath arrays, under drip edges, and in the vegetated area between arrays at each site. Hydrus-3D models for soil moisture and stormwater hydrology were developed that accounted for precipitation falling on solar panels, drip edge redistribution of rainfall, infiltration, and runoff in the pervious areas between solar arrays and beneath panels. Drip edge runoff averaged 3- to 10-times incident precipitation at the New York and Minnesota sites, respectively. Root mean square error values between measured sub-hourly soil moisture and predicted moisture for large measured single storm events averaged 0.029 across all five sites. Predicted runoff depths were strongly affected by precipitation depth, soil texture, soil profile depth, and soil bulk density. Runoff depths across the five experimental sites averaged 13%, 25%, and 45% of the 2-, 10-, and 100-year design storm depths, clearly showing that these solar farms do not behave like impervious surfaces, but rather as disconnected impervious surfaces with substantial infiltration of runoff in the vegetated areas between and beneath solar arrays.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":"16 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140578529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling water flow and volumetric water content in a degraded peat comparing unimodal with bimodal porosity and flux with pressure head boundary condition","authors":"Mariel F. Davies, Ottfried Dietrich, Horst H. Gerke, Christoph Merz","doi":"10.1002/vzj2.20328","DOIUrl":"https://doi.org/10.1002/vzj2.20328","url":null,"abstract":"Degraded peatlands release large amounts of greenhouse gases. The development of effective mitigation and management measures requires an understanding of relevant site‐specific biogeochemical and hydraulic processes. However, the simulation of water fluxes and vadose zone state variables of degrading peatlands relies on proper process description, parameterization of hydraulic functions, and representation of the boundary conditions. The objective of this study was to analyze the effects of unimodal versus bimodal soil hydraulic functions and pressure head versus flux‐type lower boundary conditions (LBCs) on the calculated hydraulic characteristics of a degraded peat profile. HYDRUS‐1D was used to study the hydraulic flow dynamics parameterized with data from a weighable groundwater lysimeter for the period from May 1 to December 31, 2019. Simulations comparing uni‐ and bimodal hydraulic functions showed only minor differences. Simulations of soil water pressure at a depth of 30 cm using a flux‐type LBC (RMSE: 27 cm, where RMSE is root mean square error) performed better than simulations using a pressure head LBC (RMSE: 48 cm). The pressure head LBC performed better at simulating volumetric water contents in 30‐cm depth than the flux LBC variant (RMSE: 0.05 vs. 0.09 cm<jats:sup>3</jats:sup> cm<jats:sup>−3</jats:sup>). For specific site conditions with a shallow, fluctuating groundwater table and temporary air entrapment, the choice of LBC was important for a more accurate simulation of soil water fluxes and volumetric water content.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":"44 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140578527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unsaturated hydraulic property measurements of subtropical anthropogenic (purple) soils in China","authors":"Luwen Zhuang, Hao Chen, Ping Yan, Xingmei Liang, Wenceslau G. Teixera, Martinus Th. van Genuchten, Kairong Lin","doi":"10.1002/vzj2.20334","DOIUrl":"https://doi.org/10.1002/vzj2.20334","url":null,"abstract":"Many anthropogenic soils, often referred to as red bed or purple soils, are distributed in various areas of southern China. Purple soils typically are highly weathered and often lead to natural and engineering hazards because of their relatively poor water retention properties. Knowledge of the unsaturated soil hydraulic properties of purple soils is crucial for their optimal management and various assessment studies. In this work, the hydraulic properties of purple soils from southern China were measured in the laboratory over the full moisture range using a combination of evaporation (HYPROP) and psychrometer (WP4C) approaches. Measured data were analyzed in terms of four different unimodal and bimodal soil hydraulic models. The measurements and analyses showed that bimodality was not overly significant for most samples. The good fit of the Peters–Durner–Iden models furthermore suggested that corner and film flows were important under relative dry conditions. Existing soil pedotransfer functions were found to provide a fairly close match for the slope of water retention curves with the exception of near saturated water contents and the saturated conductivity. To the best of our knowledge, this is the first time that unsaturated hydraulic data of purple soils are provided over the full moisture range.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":"91 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140578313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanistically derived macroscopic root water uptake functions: The α and ω of root water uptake functions","authors":"Jan Vanderborght, Valentin Couvreur, Mathieu Javaux, Daniel Leitner, Andrea Schnepf, Harry Vereecken","doi":"10.1002/vzj2.20333","DOIUrl":"https://doi.org/10.1002/vzj2.20333","url":null,"abstract":"Water uptake by plant roots is an important component of the soil water balance. Predicting to what extent potential transpiration from the canopy, that is, transpiration demand, can be met by supply of water from the soil through the root system is crucial to simulate the actual transpiration and assess vegetation water stress. In models that simulate the dynamics of vertical soil water content profiles as a function of water fluxes and soil water potential gradients, the root water uptake (RWU) distribution is represented by macroscopic sink terms. We present RWU functions that calculate sink terms based on a mechanistic model of water flow in the soil–root system. Based on soil–root hydraulics, we define <jats:italic>α</jats:italic>‐supply functions representing the maximal uptake by the root system from a certain soil depth when the root collar water potential equals the wilting point, <jats:italic>ω</jats:italic>‐supply factors representing the maximal supply from the entire root system, and a critical <jats:italic>ω<jats:sub>c</jats:sub></jats:italic> factor representing the potential transpiration demand. These functions and factors are subsequently used to calculate RWU distributions directly from potential transpiration or demand and the soil water potentials. Unlike currently used approaches, which define <jats:italic>α</jats:italic>‐stress functions and <jats:italic>ω</jats:italic> factors representing ratios of actual uptake to uptake demand, the supply‐based formulations can be derived directly from soil and root hydraulic properties and can represent processes like root hydraulic redistribution and hydraulic lift.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":"22 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140578455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vadose zone flushing of fertilizer tracked by isotopes of water and nitrate","authors":"Julie N. Weitzman, J. Renée Brooks, Jana E. Compton, Barton R. Faulkner, R. Edward Peachey, William D. Rugh, Robert A. Coulombe, Blake Hatteberg, Stephen R. Hutchins","doi":"10.1002/vzj2.20324","DOIUrl":"https://doi.org/10.1002/vzj2.20324","url":null,"abstract":"A substantial fraction of nitrogen (N) fertilizer applied in agricultural systems is not incorporated into crops and moves below the rooting zone as nitrate (NO<jats:sub>3</jats:sub><jats:sup>−</jats:sup>). Understanding mechanisms for soil N retention below the rooting zone and leaching to groundwater is essential for our ability to track the fate of added N. We used dual stable isotopes of nitrate (δ<jats:sup>15</jats:sup>N–NO<jats:sub>3</jats:sub><jats:sup>−</jats:sup> and δ<jats:sup>18</jats:sup>O–NO<jats:sub>3</jats:sub><jats:sup>−</jats:sup>) and water (δ<jats:sup>18</jats:sup>O–H<jats:sub>2</jats:sub>O and δ<jats:sup>2</jats:sup>H–H<jats:sub>2</jats:sub>O) to understand the mechanisms driving nitrate leaching at three depths (0.8, 1.5, and 3.0 m) of an irrigated corn field sampled every 2 weeks from 2016 to 2020 in the southern Willamette Valley, Oregon, USA. Distinct periods of high nitrate concentrations with lower δ<jats:sup>15</jats:sup>N–NO<jats:sub>3</jats:sub><jats:sup>−</jats:sup> values indicated that a portion of that nitrate was from recent fertilizer applications. We used a mixing model to quantify nitrate fluxes associated with recently added fertilizer N versus older, legacy soil N during these “fertilizer signal periods.” Nitrate leached below 3.0 m in these periods made up a larger proportion of the total N leached at that depth (∼52%) versus the two shallower depths (∼13%–16%), indicating preferential movement of recently applied fertilizer N through the deep soil into groundwater. Further, N associated with recent fertilizer additions leached more easily when compared to remobilized legacy N. A high volume of fall and winter precipitation may push residual fertilizer N to depth, potentially posing a larger threat to groundwater than legacy N. Optimizing fertilizer N additions could minimize fertilizer losses and reduce nitrate leaching to groundwater.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":"80 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140578356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coupled hydro‐mechanical pore‐scale modeling of biopore‐coated clods for upscaling soil shrinkage and hydraulic properties","authors":"Luis Alfredo Pires Barbosa, Horst H. Gerke","doi":"10.1002/vzj2.20325","DOIUrl":"https://doi.org/10.1002/vzj2.20325","url":null,"abstract":"Earthworms and plant roots are vital for macropore formation and stabilization. The organo‐mineral coating of biopore surfaces also regulates macropore‐matrix mass exchange during preferential flow. The influence of finer‐textured burrow coatings on macroscopic soil properties during shrinkage could potentially be assessed by upscaling pore‐scale hydraulic and mechanical simulations. The aim was to investigate the influence of micro parameters (particle size, stiffness, and bond strength) on macro parameters (i.e., shrinkage curve and soil hydraulic properties). Drainage experiments and simulations were carried out using biopore‐coated clod‐size samples compared to those without coating. Simulations were performed using a two‐phase pore‐scale finite volume coupled with discrete element model (DEM‐2PFV). The structural dynamics was characterized by analyzing the pore volume and soil shrinkage curve obtained from numerically determined data. The soil hydraulic parameters were described using uni‐ and bimodal van Genuchten (vG) functions. The drainage simulations revealed hydro‐mechanical dynamics characterized by Braudeau‐shrinkage curve subdomains: The matrix‐only samples, with lower particle bond strength, exhibited relatively higher shrinkage. The coated samples, with higher particle stiffness and bond strength, displayed greater hydro‐mechanical stability. The numerically determined initial value of the saturated hydraulic conductivity (<jats:italic>K<jats:sub>s</jats:sub></jats:italic>) was about 70 times larger for matrix‐only samples than for coated samples. As expected, for the nonrigid soil structures, constant <jats:italic>K<jats:sub>s</jats:sub></jats:italic>, <jats:italic>α</jats:italic>, and <jats:italic>n</jats:italic> values for bimodal vG model resulted in prediction errors. Upscaling DEM‐2PFV pore‐scale model outcomes quantifies micro‐coating effects on macro hydro‐mechanics. This yields void ratio‐based soil water retention and hydraulic conductivity functions, advancing macroscopic soil hydraulic models and enhancing structured soil flow and transport descriptions.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":"6 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140578354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Implementation of the Brunswick model system into the Hydrus software suite","authors":"Efstathios Diamantopoulos, Jirka Simunek, Tobias K. D. Weber","doi":"10.1002/vzj2.20326","DOIUrl":"https://doi.org/10.1002/vzj2.20326","url":null,"abstract":"The Brunswick modular framework for modeling unsaturated soil hydraulic properties (SHP) over the full moisture range was implemented in the Hydrus suite. Users can now additionally choose between four different variants of the Brunswick model: (i) van Genuchten–Mualem (VGM), (ii) Brooks–Corey, (iii) Kosugi, and (iv) modified van Genuchten. For demonstration purposes, simulation results for two different setups, (i) bare soil evaporation and (ii) root water uptake, are presented, along with a comparison of the original VGM model and its Brunswick variant. Results show that the original VGM model underestimates the simulated cumulative evaporation and cumulative transpiration due to the inconsistent representation of the SHP in the dry moisture range. We also implemented a two‐step hydro‐PTF (pedotransfer function) into the Hydrus suite that converts the parameters of the original VGM model (from Rosetta) to the corresponding Brunswick variant. In that way, physically comprehensive simulations are ensured if no data on SHP are directly available, but information on physical soil properties (e.g., texture and bulk density) exists.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":"48 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140578256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Averaging or adding domain conductivities to calculate the unsaturated soil hydraulic conductivity","authors":"Gerrit H. de Rooij","doi":"10.1002/vzj2.20329","DOIUrl":"https://doi.org/10.1002/vzj2.20329","url":null,"abstract":"Recent models of the unsaturated hydraulic conductivity curve (UHCC) are the sum of separate UHCCs for domains of capillary water, film water, and water vapor. This requires parallel, noninteracting domains. A theoretical framework for aggregating domain conductivities to a bulk soil UHCC is presented to identify and possibly relax implicit assumptions about domain configuration. The paper develops arithmetic, harmonic, and geometric averages of the liquid-water conductivities that can be arithmetically averaged with the vapor conductivity. However, current models for capillary and film conductivities are intrinsic, that is, valid within their respective domain. The vapor conductivity is a bulk conductivity, that is, it gives the conductivity of the gaseous domain as it manifests itself in the soil. Conversion relationships use the domain volume fractions as approximations of the as-yet unknown weighting factors to convert between intrinsic and bulk conductivities. This facilitates consistent averaging of domain conductivities. Even with consistent averaging, a truly physically accurate model of the UHCC based on domain conductivities is fundamentally elusive. Nevertheless, models based on the three averages and the unweighted sum of the domain conductivities produce good fits to data for two soils but diverge in the dry range. The fitted curves for the capillary and film water depend on the averaging (or adding) method. Hence, they are not strictly characteristic of their respective domains. The true intrinsic domain conductivity functions may be impossible to determine.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":"144 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140324490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rien van Genuchten: A short autobiography","authors":"Martinus Th. van Genuchten","doi":"10.1002/vzj2.20322","DOIUrl":"https://doi.org/10.1002/vzj2.20322","url":null,"abstract":"<h2>1 INTRODUCTION</h2>\u0000<p>I am extremely honored to receive the 2023 Wolf Prize in the field of agriculture for “groundbreaking work in understanding water flow and predicting contaminant transport in soils,” and for that reason, being invited to contribute an autobiography to this special section of <i>Vadose Zone Journal</i>. Receiving the Wolf Prize reflects the guidance, support, and input I received from so many over the years, starting from the very beginning from my parents who instilled in me the beauty of the natural environment through their careful management of a small family farm in the Netherlands. They encouraged me to pursue my MS studies in Holland, after which I went to the United States, subsequently to Brazil, and back to the Netherlands. Throughout my life, I enjoyed enormous freedom to pursue whatever I felt was important to better describe fluid flow and contaminant transport processes in the near-surface environment. I could interact with a large number of colleagues from all over the world. This collaboration made me see not only the important gaps in science but also the difficulties of applying what we know to the many environmental and socio-economic problems facing this planet. As such, my appreciation goes to the Wolf Foundation for recognizing, through this award, the importance of us taking care of this planet and its inhabitants.</p>","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":"93 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140298857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Downscaling SMAP soil moisture product in cold and arid region: Incorporating NDSI and BSI into the random forest algorithm","authors":"Mingxing Gao, Kui Zhu, Yanjun Guo, Xuhang Han, Dongsheng Li, Shujian Zhang","doi":"10.1002/vzj2.20323","DOIUrl":"https://doi.org/10.1002/vzj2.20323","url":null,"abstract":"Soil moisture (SM) is a critical element of the hydrological cycle, land surface processes, and surface energy balance. However, the low spatial resolution of commonly used SM products limits the application of SM in agriculture and eco‐hydrology in cold and arid regions. In this study, the normalized difference soil index (NDSI) and bare soil index (BSI) were added to traditional downscaling factors including land surface temperature, normalized difference vegetation index, digital elevation mode, apparent thermal inertia, Albedo, and temperature vegetation dryness index, as they are more strongly correlated with surface SM in the bare soil‐vegetation alternation zone of such region. Using the random forest algorithm, a downscaling model of SM was constructed for such region. The accuracy of the downscaled SM estimates was validated by comparing them with the original SM data collected from May to September 2021, which is the non‐freezing period of the soil. The findings indicate that the newly added NDSI and BSI have good correlation with SM. Incorporating NDSI and BSI to construct the downscaled model enhances the accuracy by over 19% compared to excluding them, while also providing a more comprehensive representation of SM information. NDSI and BSI can be well applied to the downscaled research of SM in the bare soil‐vegetation alternation zone, which is of great value for the study of eco‐hydrology and agricultural drought monitoring in cold and arid regions.","PeriodicalId":23594,"journal":{"name":"Vadose Zone Journal","volume":"30 1","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140200877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}