Obtaining soil hydraulic properties for water balance and leaching models from survey data. 2. Hydraulic conductivity

1999 ◽  
Vol 50 (7) ◽  
pp. 1259 ◽  
Author(s):  
K. R. J. Smettem ◽  
K. L. Bristow
Keyword(s):  
Hydraulic Conductivity ◽  
Water Balance ◽  
Survey Data ◽  
Hydraulic Properties ◽  
Regional Scale ◽  
Saturated Hydraulic Conductivity ◽  
Soil Survey ◽  
Attractive Alternative ◽  
Soil Hydraulic Properties ◽  
Soil Hydraulic

Regional scale application of water and solute transport models is often limited by the lack of available data describing soil hydraulic properties and their variability. Direct measurement over large areas is expensive and time consuming. Physico-empirical models derived from soil survey data are therefore an attractive alternative. If the Marshall method of estimating the saturated hydraulic conductivity is simplified to depend primarily on the maximum pore radius, given by the bubbling pressure, then it is equivalent to the Campbell model of saturated hydraulic conductivity which relies entirely on an estimate of the bubbling pressure obtained from particle size data. We apply this simplified physico-empirical model to estimate the ‘matrix’, or textural saturated hydraulic conductivity, K m, using estimates of the bubbling pressure derived entirely from clay content data that are readily available in soil surveys. Model estimates are compared with in situ measurements on surface soils obtained using a disc permeameter with a negative pressure head at the supply surface of 40 mm. Results appear to be satisfactory for broad-scale water balance and leaching risk models that require specification of a matching point for the unsaturated hydraulic conductivity function and for modelling applications requiring generalised application of results from experimental sites.

scholarly journals Analysis of Hydraulic Properties of Indian Forest Soil

2018 ◽  
Vol 7 (1) ◽  
pp. 12
Author(s):  
Shwetha Prasanna
Keyword(s):  
Hydraulic Conductivity ◽  
Spatial Variability ◽  
Soil Properties ◽  
Forest Soil ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Saturated Hydraulic Conductivity ◽  
Soil Hydraulic Properties ◽  
Soil Hydraulic ◽  
High Degree

Soils are a product of the factors of formation and continuously change over the earth’s surface. The analysis of the spatial variability of soil properties is important for land management and construction of an ecological environment. Soils are characterized by high degree of spatial variability due to the combined effect of physical, chemical or biological processes that operate with different intensities and at different scales. The spatial variability of soil hydraulic properties helps us to find the subsurface flux of water. The most frequently used hydraulic properties are soil water retention curve and saturated hydraulic conductivity. Both these hydraulic properties exhibit a high degree of spatial and temporal variability. The primary objective of this study was to analyze the spatial variability of hydraulic properties of forest soils of Pavanje river basin. Correlation analysis technique has been used to analyze various soil properties. Spatial variability of the forested hillslope soils at different depths varied considerably among the soil hydraulic properties. The spatial variability of water retention at all the different pressure head is low at the top layers, and increases towards the bottom layers. The saturated hydraulic conductivity is almost same in the top layers, but more in the bottom layers of forest soil.

scholarly journals River Buffer Effectiveness in Controlling Surface Runoff Based on Saturated Soil Hydraulic Conductivity

Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2383
Author(s):  
Hatma Suryatmojo ◽  
Ken’ichirou Kosugi
Keyword(s):  
Hydraulic Conductivity ◽  
Surface Runoff ◽  
Hydraulic Properties ◽  
Canopy Cover ◽  
Selective Logging ◽  
Saturated Hydraulic Conductivity ◽  
Soil Hydraulic Properties ◽  
Near Surface ◽  
Soil Hydraulic Conductivity ◽  
Soil Hydraulic

In tropical Indonesia, rainforests are managed by an intensive forest management system (IFMS). The IFMS has promoted selective logging for timber harvesting and intensive line planting to enrich the standing stock. The implementation of the IFMS has reduced the forest canopy cover, disturbed the surface soil, changed the soil hydraulic properties, and increased direct runoff and soil erosion. Investigation of the IFMS impact on soil hydraulic properties and the generation of surface runoff using a saturated hydraulic conductivity model is needed. Soil hydraulic properties were investigated on 11 plots, including one virgin forest plot and 10 plots at different operational periods of the IFMS. A two-dimensional saturated soil water flow simulation was applied to generate surface runoff from different periods of the IFMS. The main parameters of canopy cover, net rainfall, and saturated hydraulic conductivity were used in the simulations. A simulation scenario of a surface runoff hydrograph in different forest operations was used to analyze the river buffer effectiveness. The results showed that fundamental IFMS activities associated with mechanized selective logging and intensive line planting have reduced the soil hydraulic conductivity within the near-surface profile. The recovery time for near-surface Ks on non-skidder tracks was between 10 and 15 years, whereas on the skidder tracks it was more than 20 years. Forest disturbances have altered the typical surface hydrological pathways, thereby creating the conditions for more surface runoff on disturbed surfaces than on undisturbed surfaces. Maintaining the buffer area is an effective means to reduce the peak discharge and surface runoff in the stream channel.

scholarly journals A Comparative Investigation of Various Pedotransfer Functions and Their Impact on Hydrological Simulations

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1401
Author(s):  
Hadis Mohajerani ◽  
Sonja Teschemacher ◽  
Markus C. Casper
Keyword(s):  
Hydraulic Conductivity ◽  
Water Balance ◽  
Hydraulic Properties ◽  
Hydrological Model ◽  
Pedotransfer Functions ◽  
Balance Model ◽  
Baseline Scenario ◽  
Calibration Data ◽  
Soil Hydraulic Properties ◽  
Soil Hydraulic

Soil hydraulic properties, which are basically saturated and unsaturated hydraulic conductivity and water retention characteristics, remarkably control the main hydrological processes in catchments. Thus, adequate parameterization of soils is one of the most important tasks in physically based catchment modeling. To estimate these properties, the choice of the PTFs in a hydrological model is often made without taking the runoff characteristics of the catchment into consideration. Therefore, this study introduces a methodology to analyze the sensitivity of a catchment water balance model to the choice of the PTF. To do so, we define 11 scenarios including different combinations of PTFs to estimate the van Genuchten parameters and saturated hydraulic conductivity. We use a calibrated/validated hydrological model (WaSiM-ETH) as a baseline scenario. By altering the underlying PTFs, the effects on the hydraulic properties are quantified. Moreover, we analyze the resulting changes in the spatial/temporal variation of the total runoff and in particular, the runoff components at the catchment outlet. Results reveal that the water distribution in the hydrologic system varies considerably amongst different PTFs, and the water balance components are highly sensitive to the spatial structure of soil hydraulic properties. It is recommended that models be tested by careful consideration of PTFs and orienting the soil parameterization more towards representing a plausible hydrological behavior rather than focusing on matching the calibration data.

Seasonal changes of hydraulic properties of a Chromic Luvisol under different soil management

Biologia ◽  
2006 ◽  
Vol 61 (19) ◽  
Author(s):  
Csilla Farkas ◽  
Csaba Gyuricza ◽  
Márta Birkás
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Water ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Vegetation Period ◽  
Saturated Hydraulic Conductivity ◽  
Soil Hydraulic Properties ◽  
Soil Water Retention ◽  
Tillage Systems ◽  
Soil Hydraulic

AbstractIn the present work the effect of five tillage methods on the hydraulic properties and water regime of a brown forest soil was studied. In each treatment, measurements of bulk density and soil water retention characteristics were carried out 3 times (March, June and August) within the vegetation period. Near-saturated hydraulic conductivity and soil water content measurements were performed five and eight times, respectively. Statistically valuable differences were obtained between the soil properties, measured in different tillage treatments. The effect of the tillage treatments on the water retention curves was significant in the low suction range (pF < 2.0) only. Differences between the soil water retention curves, measured at the end of the vegetation period reflected the indirect effect of different tillage systems on soil hydraulic properties. The seasonal variability of both the soil hydraulic functions was proofed. Saturated hydraulic conductivity values, evaluated in the ploughing treatment at the beginning and end of the vegetation period differed up to 4-times. The near-saturated hydraulic conductivity values measured in March were nearly two times higher in all the treatments, except no till, than those, measured in August. The applied tillage systems did not influence the potential amount of water available for the plant; still, valuable differences between the soil water contents were measured. According to the soil hydraulic properties and measured soil water regime, ploughing and deep loosening created the most favourable soil conditions for the plants. The biological activity, however, was the highest in the no till treatment. Further studies on the application of the soil conserving tillage systems under Hungarian conditions are recommended.

Reference material for the measurement of soil hydraulic properties

2021 ◽  
Author(s):  
Axel Lamparter ◽  
C. Florian Stange
Keyword(s):  
Quality Control ◽  
Hydraulic Conductivity ◽  
Reference Material ◽  
Hydraulic Properties ◽  
Saturated Hydraulic Conductivity ◽  
Water Retention Curve ◽  
Soil Hydraulic Properties ◽  
Retention Curve ◽  
Sintered Glass ◽  
Soil Hydraulic

&lt;p&gt;Quality control of the measurement of soil hydraulic properties (water retention curve, saturated hydraulic conductivity) using soil cores is not very common in soil physics laboratories. The missing quality control in the labs might be due to the lack of a suitable reference material for the measurement of soil hydraulic properties (SHP). However, a standardized quality of these measurements is needed, especially when generated data from different laboratories are used.&lt;/p&gt;&lt;p&gt;So far no satisfying reference material has been presented that can be used for quality control during the measurement of SHP. Reference material should have a rigid pore system and pore surfaces properties that do not change over time. Additionally, the reference material should be very sensitive to provide a sufficient quality control for the measurement of SHP.&lt;/p&gt;&lt;p&gt;We present sintered glass cylinders with a defined pore size distribution that were tested in the laboratory for reproducibility. After a standardized cleaning procedure of the glass cylinders, water contents after equilibration at -63 hPa (field capacity) showed reasonably low standard deviations. Thus, it seems promising that these cylinders can be used as reference material for the measurement of the water retention curve.&lt;/p&gt;&lt;p&gt;First Results of repeated saturated hydraulic conductivity measurements (Ks) of the same sintered glass cylinders showed larger variability and an increasing trend over the time. Currently the reason for this trend is unknown. Therefore, it is worked on standardizing procedures of using the reference cylinders and on cleaning the cylinders to improve the reproducibility. The results show how sensitive the measurement of saturated hydraulic conductivity is and that we need to put more emphasis on quality control in our work.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

Hyphal colonization of Rhizophagus irregularis increases unsaturated hydraulic conductivity of a loamy sand distant from roots

2021 ◽  
Author(s):  
Michael Bitterlich ◽  
Richard Pauwels
Keyword(s):  
Hydraulic Conductivity ◽  
Water Content ◽  
Hydraulic Properties ◽  
Volumetric Water Content ◽  
Rhizophagus Irregularis ◽  
Loamy Sand ◽  
Soil Hydraulic Properties ◽  
Unsaturated Hydraulic Conductivity ◽  
Soil Hydraulic ◽  
Root Exclusion

&lt;p&gt;Hydraulic properties of mycorrhizal soils have rarely been reported and difficulties in directly assigning potential effects to hyphae of arbuscular mycorrhizal fungi (AMF) arise from other consequences of AMF being present, i.e. their influence on growth and water consumption rates of their host plants that both also influence soil hydraulic properties.&lt;/p&gt;&lt;p&gt;We assumed that the typical nylon meshes used for root-exclusion experiments in mycorrhizal research can provide a dynamic hydraulic barrier. It is expected that the uniform pore size of the rigid meshes causes a sudden hydraulic decoupling of the enmeshed inner volume from the surrounding soil as soon as the mesh pores become air-filled. Growing plants below the soil moisture threshold for hydraulic decoupling would minimize plant-size effects on root-exclusion compartments and allow for a more direct assignment of hyphal presence to modulations in soil hydraulic properties.&lt;/p&gt;&lt;p&gt;We carried out water retention and hydraulic conductivity measurements with two tensiometers introduced in two different heights in a cylindrical compartment (250 cm&amp;#179;) containing a loamy sand, either with or without the introduction of a 20 &amp;#181;m nylon mesh equidistantly between the tensiometers. Introduction of a mesh reduced hydraulic conductivity across the soil volumes by two orders of magnitude from 471 to 6 &amp;#181;m d&lt;sup&gt;-1&lt;/sup&gt; at 20% volumetric water content.&lt;/p&gt;&lt;p&gt;We grew maize plants inoculated or not with Rhizophagus irregularis in the same soil in pots that contained root-exclusion compartments while maintaining 20% volumetric water content. When hyphae were present in the compartments, water potential and unsaturated hydraulic conductivity increased for a given water content compared to compartments free of hyphae. These differences increased with progressive soil drying.&lt;/p&gt;&lt;p&gt;We conclude that water extractability from soils distant to roots can be facilitated under dry conditions when AMF hyphae are present.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

Soil structure, soil hydraulic properties and the soil water balance

Soil Research ◽  
1992 ◽  
Vol 30 (3) ◽  
pp. 265 ◽  
Author(s):  
HP Cresswell ◽  
DE Smiles ◽  
J Williams
Keyword(s):  
Hydraulic Conductivity ◽  
Water Balance ◽  
Soil Water ◽  
Soil Structure ◽  
Hydraulic Properties ◽  
Rainfall Regime ◽  
Soil Hydraulic Properties ◽  
Matric Potential ◽  
Moisture Characteristic

We review the influence of soil structural change on the fundamental soil hydraulic properties (unsaturated hydraulic conductivity and the soil moisture characteristic) and utilize deterministic modelling to assess subsequent effects on the soil water balance. Soil structure is reflected in the 0 to -100 kPa matric potential section of the soil moisture characteristic with marked changes often occurring in light to medium textured soils' (sands, sandy-loam, loams and clay-loams). The effect of long-term tillage on soil structure may decrease hydraulic conductivity within this matric potential range. The 'SWIM' (Soil Water Infiltration and Movement) simulation model was used to illustrate the effects of long-term conventional tillage and direct drilling systems on the water balance. The effects of plough pans, surface crusts and decreasing surface detention were also investigated. Significant structural deterioration, as evidenced by substantially reduced hydraulic conductivity, is necessary before significant runoff is generated in the low intensity rainfall regime of the Southern Tablelands (6 min rainfall intensity <45 mm h-1). A 10 mm thick plough pan (at a depth of 100 mm) in the A-horizon of a long-term conventionally tilled soil required a saturated hydraulic conductivity (K,) of less than 2.5 mm h-1 before runoff exceeded 10% of incident rainfall in this rainfall regime. Similarly, a crust K, of less than 2.5 mm h-1 was necessary before runoff exceeded 10% of incident rainfall (provided that surface detention was 2 or more). As the crust K, approached the rainfall rate, small decreases in Ks resulted in large increases in runoff. An increase in surface detention of 1 to 3 mm resulted in a large reduction in runoff where crust K, was less than 2-5 mm h-1. Deterministic simulation models incorporating well established physical laws are effective tools in the study of soil structural effects on the field water regime. Their application, however, is constrained by insufficient knowledge of the fundamental hydraulic properties of Australian soils and how they are changing in response to our land management.

Soil hydraulic properties of an Orthic Black Chernozem under long-term tillage and residue management

1996 ◽  
Vol 76 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Baldev Singh ◽  
D. S. Chanasyk ◽  
W. B. McGill
Keyword(s):  
Hydraulic Conductivity ◽  
Pore Size ◽  
Hydraulic Properties ◽  
Total Porosity ◽  
Residue Management ◽  
Soil Hydraulic Properties ◽  
Transmission Characteristics ◽  
Hordeum Vulgare L ◽  
No Till ◽  
Soil Hydraulic

The effects of tillage on soil hydraulic properties are unclear from the literature and residue effects are little reported. The hydraulic properties of an Orthic Black Chernozem under three tillage-residue systems in central Alberta — tillage with straw incorporated (till+straw) or removed (till−straw) — and no tillage with straw on the surface (no till+straw) — were studied for 2 yr. Measurements began in the 9th year of continuous barley (Hordeum vulgare L.).Plant-available water capacity differed among treatments only in the 0–2.5 cm layer, due to differences in water retention at −1500 kPa. Pore size partitioning revealed relatively high macroporosities (14–18% of total porosity) and residual porosity (34–41% of total porosity), but no treatment differences in the tillage layer. Saturated hydraulic conductivity (Ksat), infiltration rate and cumulative infiltration at 1 h followed the trend: no till+straw > till+straw > till−straw. Infiltration characteristics and hydraulic conductivity had considerable temporal variation. Interestingly, field and laboratory measurements gave the same order of magnitude of transmission characteristics. The common similarity of the no till+straw and the till+straw treatments and their usual difference from the till−straw treatment, especially in the water transmission characteristics, indicate the importance of the return of residue to the soil. The influence of straw on soil hydraulic properties does not appear to depend on whether it was incorporated or not. Key words: tillage, straw, residue, soil hydraulic properties, infiltration, pore size distribution

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