Search results for " Infiltration"

Laboratory testing of Beerkan infiltration experiments for assessing the role of soil sealing on water infiltration

2018

Abstract Soil surface sealing is a major cause of decreased infiltration rates and increased surface runoff and erosion during a rainstorm. The objective of this paper is to quantify the effect of surface sealing on infiltration for 3 layered soils with different textures for the upper layer and investigate the capability of BEST procedure to catch the formation of the seal and related consequences on water infiltration. Rainfall experiments were carried out to induce the formation of the seal. Meanwhile, Beerkan infiltration runs were carried out pouring water at different distances from the soil surface (BEST-H versus BEST-L runs, with a High and Low water pouring heights, respectively) f…

Estimating saturated soil hydraulic conductivity by the near steady-state phase of a Beerkan infiltration test

2017

Abstract Single-ring infiltration experiments carried out in the field, such as the Beerkan runs, allow easy and inexpensive characterization of soil hydraulic properties, and specifically saturated soil hydraulic conductivity, Ks, by maintaining the functional connection of the sampled soil volume with the surrounding soil. However, a single infiltration experiment is not enough to determine Ks. The simplest way to obtain the necessary additional data is based on the assessment of the soil texture and structure characteristics. In this investigation, a simplified method, named SSBI (Steady version of the Simplified method based on a Beerkan infiltration run), was developed to estimate Ks b…

Influence of soil surface sealing and hydrophobicity on water infiltration

Nella tesi viene affrontato lo studio dell’impatto dei fenomeni di sealing superficiale e di idrofobicità sui processi di infiltrazione dell’acqua nel suolo. A tal fine vengono utilizzati diversi tipi di esperimenti infiltrometrici che consentono di determinare le modificazioni delle proprietà idrauliche del suolo indotte da questi due fenomeni permettendo di valutare così le loro ripercussioni negative sui processi idrologici. The thesis aims at investigating the effects of soil sealing and hydrophobicity on the water infiltration process. Different field infiltrometric techniques are applied at this end due to their ability to characterize modifications of soil hydraulic properties that d…

Comparing two methods to perform a beerkan infiltration run in a loam soil at different dates

2023

<p>Performing beerkan infiltration runs with different heights of water pouring could help to obtain saturated soil sorptivity, <em>S</em>, and hydraulic conductivity, <em>K<sub>s</sub></em>, data usable to explain and simulate hydrological processes. However, most of the available information on the L (low height of water pouring, nearly 3 cm) - H (high height, 1-2 m) methodology refers to runs making use of a relatively limited number of water volumes and there is some sign that a few water volumes could yield an incomplete description of soil alteration phenomena induced by wetting. For a lo…

Using Beerkan experiments to estimate hydraulic conductivity of a crusted loamy soil in a Mediterranean vineyard

2019

Abstract In bare soils of semi-arid areas, surface crusting is a rather common phenomenon due to the impact of raindrops. Water infiltration measurements under ponding conditions are becoming largely applied techniques for an approximate characterization of crusted soils. In this study, the impact of crusting on soil hydraulic conductivity was assessed in a Mediterranean vineyard (western Sicily, Italy) under conventional tillage. The BEST (Beerkan Estimation of Soil Transfer parameters) algorithm was applied to the infiltration data to obtain the hydraulic conductivity of crusted and uncrusted soils. Soil hydraulic conductivity was found to vary during the year and also spatially (i.e., ro…

Analytical Solution of the Richards Equation under Gravity-Driven Infiltration and Constant Rainfall Intensity

2020

In the field of soil hydrology, the Richards equation is commonly used to model water flow in unsaturated soils. The high nonlinearity of the Richards equation makes it very challenging to solve analytically for situations that are meaningful in practical applications. In this paper, an exact and simple analytical solution of the Richards equation under gravity-driven infiltration and constant rainfall intensity is derived. First, the solution is presented under Torricelli's law, which mimics the soil hydraulic conductivity function and describes the emptying or filling process of a nonlinear water reservoir. Then, following a similar approach, the solution is extended to the Brooks and Cor…

Application of minidisk infiltrometer to estimate soil water repellency

2016

Soil water repellency (SWR) reduces affinity of soils to water resulting in detrimental implication for plants growth as well as for hydrological processes. During the last decades, it has become clear that SWR is much more widespread than formerly thought, having been reported for a wide variety of soils, land uses and climatic conditions. The repellency index (RI), based on soil-water to soil-ethanol sorptivity ratio, was proposed to characterize subcritical SWR that is the situation where a low degree of repellency impedes infiltration but does not prevent it. The minidisk infiltrometer allows adequate field assessment of RI inherently scaled to account for soil physical properties other…

EVALUATION OF THE EFFECTS OF CONTI- NUOUS PREPERITONEAL WOUND INFILTRATION ON POSTOPERATIVE RESPIRATORY PERFORMANCE IN PATIENTS WHO UNDERWENT MAJOR A…

2013

Aim. According to the recent literature, continuous pre-perito- neal wound infiltration with local anaesthetics (CPWI) is an effective analgesic therapy in patients who undergo major abdominal surgery 1. Although it is not inferior to other com- monly used techniques in postoperative analgesia, many studies report conflictive results about its efficacy compared to them 2. The aim of our study was to evaluate the effects of CPWI on the postoperative respiratory performance in patients after major abdominal surgery. Materials and methods. From June 2011 to July 2012, a total of 14 patients have been evaluated. All patients were treated using the protocol generally used in our Department for t…

Source shape and data analysis procedure effects on hydraulic conductivity of a sandy-loam soil determined by ponding infiltration runs

2017

Performing ponding infiltration runs with non-circular sources could represent a good means to sample completely an area of interest. Regardless of the shape of the source, predicting the expected reliability of the collected data by infiltrometers should facilitate soil hydraulic characterisation and also allow a more conscious use of the field data. The influence of the shape of the infiltration source (i.e., circular or square) and the analysis procedure of the steady-state infiltration data on the saturated hydraulic conductivity, Ks, of a sandy-loam soil was tested in this investigation. Circular and square surfaces sampled with the pressure infiltrometer (PI) yielded similar estimates…

Discussion of "Hydraulic Model of Transition of Transient to Steady Flows in the Vadose Zone" by Yaguo Zhang, Tonglu Li, Wei Shen, and Yu Wang

2020

The authors wrote an interesting article dealing with a simple hydraulic model to illustrate the transition mechanism of transient to steady flows in the vadose zone. The soil behavior is described by a set of nine vertically aligned cylinders, each opened at the top and with a small outlet at the bottom. The water level dynamic of each cylinder, associated with an intermittent constant rainfall applied to the top cylinder, C0, was analyzed and numerical simulations were performed. The only objective of this discussion is to show that results similar to those proposed by the authors could be obtained by using the recently introduced Richards equation analytical solution, under gravity-drive…