790 hasil
Menampilkan 141–160 · 0,26 detik · RSS
-
Artikel Jurnal
The value of soil temperature data versus soil moisture data for state, parameter, and flux estimation in unsaturated flow model
Abstract This synthetic study explores the value of near‐surface soil moisture and soil temperature measurements for the estimation of soil moisture and soil temperature profiles, soil hydraulic and thermal parameters, and latent heat and sensible heat fluxes using data assimilation (ensemble…
-
Artikel Jurnal
New insights into the correlation between soil thermal conductivity and water retention in unsaturated soils
Abstract The heat transfer and water retention in soils, governed by soil thermal conductivity (λ) and soil water retention curve (SWRC), are coupled. Soil water content (θ) significantly affects λ. Several models have been developed to describe λ(θ) relationships for unsaturated soils. Ghanbarian…
-
Artikel Jurnal
Biochar modifies soil physical properties mostly through changes in soil structure rather than through its internal porosity
Abstract Besides its carbon sequestration potential, biochar application generally improves soil physical properties, but the magnitude of its impact and the underlying mechanisms remain debated and depend on soil type, biochar application rate, and age. The objective was therefore to determine the…
-
Artikel Jurnal
Importance of background threshold value development within risk‐based corrective action programs
Abstract Risk‐based corrective action (RBCA) programs employ conservative models to develop default values for soil screening, which simplify the risk assessment process. However, for several naturally occurring metals (e.g., arsenic and lead), these published screening values are often unrealistic…
-
Artikel Jurnal
Frequency domain‐based analytical solutions for one‐dimensional soil water flow in layered soils
Abstract Solutions of the linearized Richardson–Richards Equation (RRE) for one‐dimensional soil water flow in layered soils with sinusoidal flux in the frequency domain are derived. We evaluate the accuracy of our analytical and other analytical solutions by comparing them with results from a…
-
Artikel Jurnal
Soil pores in preferential flow terminology and permeability equations
Abstract Linkages between the micro‐scale of soil water and landscape scale of hydrological data could be improved with the analysis of soil factors in preferential flow rates. This rearrangement of the terminology on soil pore size from published literature focused on the relationship between…
-
Artikel Jurnal
Shear strength equation of soils in a wide suction range under various initial void ratios
Abstract Shear strength equation is a basic theory for solving many geotechnical engineering problems. Although the shear strength equation has received widespread attention, shear strength of clay under wide suction range and different initial void ratio e conditions cannot be well predicted. This…
-
Artikel Jurnal
A generalized van Genuchten model for unsaturated soil hydraulic conductivity
Abstract The hydrodynamics of variably saturated soils or porous media in general are described via nonlinear functions of water retention and hydraulic conductivity, which facilitate the simulation of various mass and energy transport processes (e.g., water, heat, contaminants, colloids) within…
-
Artikel Jurnal
A simple infiltrometer automated with a user‐friendly pressure datalogger
Abstract We have constructed a new, simplified constant‐head infiltrometer automated with a self‐contained water level datalogger (HOBO U20L‐01) repurposed to measure changes in gas pressure inside an inverted bottle reservoir. Our field tests of six of these infiltrometers confirmed that recorded…
-
Artikel Jurnal
Quantitative experimental study on the apparent contact angle of unsaturated loess and its application in soil–water characteristics curve modeling
Abstract Advancing and receding water contact angles, often denoted as the maximum and minimum apparent water contact angles, are crucial parameters reflecting a soil's water holding capacity. These parameters play an important role in establishing theoretical soil–water characteristic curves…
-
Artikel Jurnal
Bailout test, HYDRUS‐2D, and analytical modeling for estimating permeability of ephemeral stream bed
Abstract Accurate estimation of effective saturated hydraulic conductivity (Ksat) of a vadose zone with an underlying shallow perched aquifer is challenging. Standard pumping tests and double‐ring infiltrometers are unsuitable for this purpose. Therefore, a bailout test (BOT) was conducted in nine…
-
Artikel Jurnal
Simulating controlled drainage and hydrological connections in a cultivated peatland field
Abstract Cultivated peatlands are increasingly regarded as hot spots due to climate change and other environmental concerns. Flexible water management, such as controlled drainage, is proposed to optimize cultivation and reduce environmental risks in peatland fields. The hydrological and…
-
Artikel Jurnal
Quantifying the effects of size exclusion on colloidal particle transport in porous media at a pore scale and column scale
Abstract Colloid‐facilitated transport has been widely acknowledged as a significant contributor to surface water and groundwater pollution. Compared to water‐dissolved solutes, colloids are subject to a size exclusion effect (SEE) due to their inherent size when transported through porous media…
-
Artikel Jurnal
Inverse analysis of soil hydraulic parameters of layered soil profiles using physics‐informed neural networks with unsaturated water flow models
Abstract Information about the spatial distribution of soil hydraulic parameters is necessary for the accurate prediction of soil water flow and the coupled movement of chemicals and heat at the field scale using a process‐based model. Physics‐informed neural networks (PINNs), which can provide…
-
Artikel Jurnal
Soil hydraulic property maps for the contiguous United States at 100‐m resolution and seven depths: Code design and preliminary results
Abstract Estimates of the van Genuchten (1980, abbreviated as VG) parameters and saturated hydraulic conductivity (Ks) were made for the contiguous United States at a resolution of 100 m and seven soil depths by combining the SoilGrids+ (SG+) soil property maps of Ramcharan et al. with the R3H3…
-
Artikel Jurnal
Mechanistically derived macroscopic root water uptake functions: The α and ω of root water uptake functions
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…
-
Artikel Jurnal
Vadose zone flushing of fertilizer tracked by isotopes of water and nitrate
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 (NO3−). Understanding mechanisms for soil N retention below the rooting zone and leaching to groundwater is essential for our ability…
-
Artikel Jurnal
Modeling N fertilization impact on water cycle and water use efficiency of maize, finger‐millet, and lablab crops in South India
Abstract The understanding of the impact of nitrogen (N) fertilization on the field water cycle and corresponding water use efficiency (WUE) is very important for optimizing fertilization rates and conserving stressed water resources. We modeled soil moisture dynamics of maize (Zea mays L.), finger…
-
Artikel Jurnal
Temporal covariance of spatial soil moisture variations: A mechanistic error modeling approach
Abstract When estimating field‐scale average soil moisture from sensors measuring at fixed positions, spatial variability in soil moisture leads to “measurement errors” of the spatial mean, which may persist over time due to persistent soil moisture patterns resulting in autocorrelated measurement…
-
Artikel Jurnal
Preferential flow of phosphorus and nitrogen under steady‐state saturated conditions
Abstract Repeated broiler litter application on agricultural lands can cause nutrient enrichment of subsurface effluent, especially with the existence of preferential flow through soil macropores. Previous studies quantifying soil macropores have not attempted to establish a connection of soil…