scholarly journals Analysis of Hydraulic Properties of Indian Forest Soil

2018 ◽  
Vol 7 (1) ◽  
pp. 12
Author(s):  
Shwetha Prasanna

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.

Soil Research ◽  
2016 ◽  
Vol 54 (8) ◽  
pp. 914 ◽  
Author(s):  
N. Pahlevan ◽  
M. R. Yazdani ◽  
A. A. Zolfaghari ◽  
M. Ghodrati

Physical and hydraulic properties of soil are variable at different spatial scales. This indicates the necessity of understanding spatial patterns of soil properties. Scaling analysis, such as multifractal analysis, has been used to determine the spatial variability of soil properties. There are however limited numbers of studies concerning the applications of multifractal techniques applied to characterise spatial variability of soil properties in arid lands. The objective of this study was to quantify the scaling patterns of soil properties measured across a transect and to apply multifractal analysis in arid land areas. A transect with a length of 4.80km was selected, and soil properties were measured at 0–20cm depth every 145m along the transect. The soil properties analysed were: texture (sand, silt, clay), pH, electrical conductivity (EC), bulk density (BD), soil hydraulic properties (saturated hydraulic conductivity Ks and the van Genuchten soil water-retention equation’s parameters nv and αv), saturated water content (θs), and the slope of the soil water-retention curve at its inflection point (S). Results showed that the variability of pH and BD was characterised by quasi-monofractal behaviour. Results showed that soil hydraulic properties such as Ks, αn, nv, S, and θs were characterised by higher multifractal indices in the transects. EC showed the highest tendency to a multifractal type of scaling or the higher degree of multifractality.


Biologia ◽  
2006 ◽  
Vol 61 (19) ◽  
Author(s):  
Csilla Farkas ◽  
Csaba Gyuricza ◽  
Márta Birkás

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.


2018 ◽  
Vol 66 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Camila R. Bezerra-Coelho ◽  
Luwen Zhuang ◽  
Maria C. Barbosa ◽  
Miguel Alfaro Soto ◽  
Martinus Th. van Genuchten

AbstractMany soil, hydrologic and environmental applications require information about the unsaturated soil hydraulic properties. The evaporation method has long been used for estimating the drying branches of the soil hydraulic functions. An increasingly popular version of the evaporation method is the semi-automated HYPROP©measurement system (HMS) commercialized by Decagon Devices (Pullman, WA) and UMS AG (München, Germany). Several studies were previously carried out to test the HMS methodology by using the Richards equation and the van-Genuchten-Mualem (VG) or Kosugi-Mualem soil hydraulic functions to obtain synthetic data for use in the HMS analysis, and then to compare results against the original hydraulic properties. Using HYDRUS-1D, we carried out independent tests of the HYPROP system as applied to the VG functions for a broad range of soil textures. Our results closely agreed with previous findings. Accurate estimates were especially obtained for the soil water retention curve and its parameters, at least over the range of available retention measurements. We also successfully tested a dual-porosity soil, as well as an extremely coarse medium with a very high van Genuchtennvalue. The latter case gave excellent results for water retention, but failed for the hydraulic conductivity. In many cases, especially for soils with intermediate and highnvalues, an independent estimate of the saturated hydraulic conductivity should be obtained. Overall, the HMS methodology performed extremely well and as such constitutes a much-needed addition to current soil hydraulic measurement techniques.


2020 ◽  
Author(s):  
Mirko Castellini ◽  
Simone Di Prima ◽  
Anna Maria Stellacci ◽  
Massimo Iovino ◽  
Vincenzo Bagarello

&lt;p&gt;Testing new experimental procedures to assess the effects of the drops impact on the soil sealing formation is a main topic in soil hydrology.&lt;/p&gt;&lt;p&gt;In this field investigation, the methodological approach proposed first by Bagarello et al. (2014) was extended to account for a greater soil infiltration surface (i.e., about 3.5 times higher), a higher range and number of heights of water pouring and to evaluate the different impact on soil management. For this purpose, the effects of three water pouring heights (low, L=3 cm; medium, M=100 cm; high, H=200 cm) on both no-tilled (NT) and conventionally tilled (CT) loam soil were investigated by Beerkan infiltration runs and using the BEST-procedure of data analysis to estimate the soil hydraulic properties.&lt;/p&gt;&lt;p&gt;Final infiltration rate decreased when perturbing runs (i.e., M and H) were carried out as compared with the non-perturbing (L) ones (by a factor of 1.5-3.1 under NT and 3.4-4.4 under CT). Similarly, the water retention scale parameter, h&lt;sub&gt;g&lt;/sub&gt;, increased (i.e., higher in absolute terms) by a factor 1.6-1.8 under NT and by a factor 1.7 under CT. Saturated hydraulic conductivity, K&lt;sub&gt;s&lt;/sub&gt;, changed significantly as a function of the increase of water pouring height; regardless of the soil management, perturbing runs caused a reduction in soil permeability by a factor 5 or 6. Effects on hydraulic functions (i.e., soil water retention curve and hydraulic conductivity function), obtained with the BEST-Steady algorithm, were also highlighted. For instance, differences in water retention curve at fixed soil pressure head values (i.e., field capacity, FC, and permanent wilting point, PWP) due to perturbing and non-perturbing runs, were estimated as higher under NT (3.8%) than CT (3.4%) for FC, and equal to 2.1% or 1.6% for PWP.&lt;/p&gt;&lt;p&gt;Main results of this investigation confirm that a recently tilled loamy soil, without vegetation cover, can be less resilient as compared to a no-tilled one, and that tested water pouring heights methodology looks promising to mimic effects of high energy rainfall events and to quantify the soil sealing effects under alternative management of the soil.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Acknowledgments&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;The work was supported by the project &amp;#8220;STRATEGA, Sperimentazione e TRAsferimento di TEcniche innovative di aGricoltura conservativA&amp;#8221;, funded by Regione Puglia&amp;#8211;Dipartimento Agricoltura, Sviluppo Rurale ed Ambientale, CUP: B36J14001230007.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;&amp;#160;&lt;/strong&gt;&lt;strong&gt;References&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Bagarello, V., Castellini, M., Di Prima, S., Iovino, M. 2014. Soil hydraulic properties determined by infiltration experiments and different heights of water pouring. Geoderma, 213, 492&amp;#8211;501. https://doi.org/10.1016/j.geoderma.2013.08.032&lt;/p&gt;


2021 ◽  
Author(s):  
Ifeoma Edeh ◽  
Ondřej Mašek

&lt;p&gt;The physical properties of biochar have been shown to dramatically influence its performance as a soil amendment. Biochar particle size is one of key parameters, as it controls its specific surface area, shape, and pore distribution. Therefore, this study assessed the role of biochar particle size and hydrophobicity in controlling soil water movement and retention. Softwood pellet biochar in five particle size ranges (&gt;2 mm, 2 &amp;#8211; 0.5 mm, 0.5 &amp;#8211; 0.25 mm, 0.25 &amp;#8211; 0.063mm and &lt;0.063 mm) was used for the experiment. These particle sizes were tested on 2 soil types (sandy loam and loamy sand) at four different application rates (1, 2, 4 and 8%).&amp;#160; Our results showed that biochar hydrophobicity increased with decreasing biochar particle size, leading to a reduction in its water retention capacity. The effect of biochar on soil hydraulic properties varied with different rate of application and particle sizes. With increasing rate of application, water retention increased while hydraulic conductivity decreased. Water content at field capacity, permanent wilting point, and the available water content increased with increasing biochar particle size. The soil hydraulic conductivity increased with decreasing particle sizes apart from biochar particles &lt;0.063mm which showed a significant (p&amp;#8804;0.05) decrease compared to the larger particle sizes. The results clearly showed that both biochar intra-porosity and inter-porosity are important factors affecting soil hydraulic properties. Biochar interpores affected mainly hydraulic conductivity, both interpores and intrapores controlled soil water retention properties. Our results suggest that for a more effective increase in soil water retention in sandy loam and loamy sand, the use of hydrophilic biochar with high intra-porosity is recommended.&lt;/p&gt;


Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2383
Author(s):  
Hatma Suryatmojo ◽  
Ken’ichirou Kosugi

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.


2021 ◽  
Author(s):  
Brigitta Szabó ◽  
Melanie Weynants ◽  
Tobias Weber

&lt;p&gt;We present improved European hydraulic pedotransfer functions (PTFs) which now use the machine learning algorithm random forest and include prediction uncertainties. The new PTFs (euptfv2) are an update of the previously published euptfv1 (T&amp;#243;th et al., 2015). With the derived hydraulic PTFs soil hydraulic properties and van Genuchten-Mualem model parameters can be predicted from easily available soil properties. The updated PTFs perform significantly better than euptfv1 and are applicable for 32 predictor variables combinations. The uncertainties reflect uncertainties from the considered input data, predictors and the applied algorithm. The euptfv2 includes transfer functions to compute soil water content at saturation (0 cm matric potential head), field capacity (both -100 and -330 cm matric potential head) and wilting point (-15,000 cm matric potential head), plant available water content computed with field capacity at -100 and -330 cm matric potential head, saturated hydraulic conductivity, and Mualem-van Genuchten parameters of the moisture retention and hydraulic conductivity curves. The influence of predictor variables on predicted soil hydraulic properties is explored and suggestions to best predictor variables given.&lt;/p&gt;&lt;p&gt;The algorithms have been implemented in a web interface (https://ptfinterface.rissac.hu) and an R package (https://doi.org/10.5281/ZENODO.3759442) to facilitate the use of the PTFs, where the PTFs&amp;#8217; selection is automated based on soil properties available for the predictions and required soil hydraulic property.&lt;/p&gt;&lt;p&gt;The new PTFs will be applied to derive soil hydraulic properties for field- and catchment- scale hydrological modelling in European case studies of the OPTAIN project (https://www.optain.eu/). Functional evaluation of the PTFs is performed under the iAqueduct research project.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;This research has been supported by the Hungarian National Research, Development and Innovation Office (grant no. KH124765), the J&amp;#225;nos Bolyai Research Scholarship of the Hungarian Academy of Sciences (grant no. BO/00088/18/4), and the German Research Foundation (grant no. SFB 1253/12017). OPTAIN is funded by the European Union&amp;#8217;s Horizon 2020 Program for research and innovation under Grant Agreement No. 862756.&lt;/p&gt;


2021 ◽  
Author(s):  
Budiman Minasny ◽  
Rudiyanto Rudiyanto ◽  
Federico Maggi

&lt;p&gt;To study the effect of drought on soil water dynamics, we need an accurate description of water retention and hydraulic conductivity from saturation to complete dryness. Recent studies have demonstrated the inaccuracy of conventional soil hydraulic models, especially in the dry end. Likewise, current pedotransfer functions (PTFs) for soil hydraulic properties are based on the classical Mualem-van Genuchten functions.&lt;/p&gt;&lt;p&gt;This study will evaluate models that estimate soil water retention and unsaturated hydraulic conductivity curves in full soil moisture ranges. An example is the Fredlund-Xing scaling model coupled with the hydraulic conductivity model of Wang et al. We will develop pedotransfer functions that can estimate parameters of the model. We will compare it with existing PTFs in predicting water retention and hydraulic conductivity.&lt;/p&gt;&lt;p&gt;The results show that a new suite of PTFs that used sand, silt, clay, and bulk density can be used successfully to predict water retention and hydraulic conductivity over a range of moisture content. The prediction of hydraulic properties is used in a soil water flow model to simulate soil moisture dynamics under drought. This study demonstrates the importance of accurate hydraulic model prediction for a better description of soil moisture dynamics.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;


2020 ◽  
Author(s):  
Patrizia Hangele ◽  
Katharina Luise Müller ◽  
Hannes Laermanns ◽  
Christina Bogner

&lt;p&gt;The need to study the occurrence and effects of microplastic (MP) in different ecosystems has become apparent by a variety of studies in the past years. Until recently, research regarding MP in the environment has mainly focused on marine systems. Within terrestrial systems, studies suggest soils to be the biggest sink for MP. Some studies now started to explore the presence of MP in soils. However, there is a substantial lack of the basic mechanistic understanding of the behaviour of MP particles within soils.&lt;/p&gt;&lt;p&gt;This study investigates how the presence of MP in soils affects their hydraulic properties. In order to understand these processes, experiments are set up under controlled laboratory conditions as to set unknown influencing variables to a minimum. Different substrates, from simple sands to undisturbed soils, are investigated in soil cylinders. MP particles of different sizes and forms of the most common plastic types are applied to the surface of the soil cylinders and undergo an irrigation for the MP particles to infiltrate. Soil-water retention curves and soil hydraulic conductivity are measured before and after the application of MP particles. It is hypothesised that the infiltrated MP particles clog a part of the pore space and should thus reduce soil hydraulic conductivity and change the soil-water retention curve of the sample. Knowledge about the influence of MP on soil hydraulic properties are crucial to understand transport and retention of MP in soils.&lt;/p&gt;


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