Single-ring Infiltrometer Research Articles

Woody species alongside earth contour bunds enhance the soil water‐infiltration capacity in the Sahel, West Africa

AbstractLand degradation, including the loss of tree, forest and vegetation cover, and its related loss of water availability are the main constraints affecting the rainfed agricultural systems in West African Sahel and dry savanna. Therefore, farmers are implementing various soil and water conservation techniques such as zaï pits, half‐moons, contour stone and earth bunds to improve crop production through reduced erosion and enhanced water retention. This study explores the effect of woody and herbaceous vegetation established along earth contour bunds on soil infiltration capacity in southern Mali. The soil infiltration measurements were carried out from September to December 2019 using single ring infiltrometers up‐slope and down‐slope of the bunds built on contour lines in 2015 and 2016 with four types of vegetation: (1) natural annual herbaceous vegetation; (2) planted Andropogon gayanus (perennial grass); (3) planted Gliricidia sepium (woody species) and (4) planted Acacia colei (woody species). The field‐saturated hydraulic conductivity (Kfs) was estimated from the infiltration data and subjected to statistical analysis to compare the effect of the four types of vegetation on soil infiltration capacity. The results revealed significant differences in infiltration rate and Kfs between the four vegetation types. The highest infiltration rate and Kfs were observed for earth contour bunds reinforced with woody species G. sepium (299.5 ± 0.6; 45.3 ± 1.4 mm h−1), followed by A. colei (232.2 ± 2; 38.2 ± 1.6 mm h−1). These were followed by the grass A. gayanus (189.4 ± 2.5; 33.0 ± 1.7 mm h−1) and natural annual herbaceous vegetation (132 ± 2.3; 20.7 ± 1.9 mm h−1). In addition, soil water‐infiltration rate and Kfs were higher for down‐slope compared to up‐slope areas for the two woody species. In practice, it is appropriate for farmers to reinforce contour bunds with woody species and perennial herbs given the beneficial effect on soil water infiltration and retention capacity and the expected socio‐economic benefit they can get from them.

Infiltration performance evaluation of a 15-year-old concrete grid paver parking area (Italy)

Abstract The management of urban stormwater needs a wide array of environmentally friendly solutions to safeguard water resources and improve the quality of the urban environment. In that, permeable pavements, a type of sustainable drainage system, are designed to reduce the volume and peak flow of stormwater on-site, improve infiltrating water quality, and combat the urban heat island phenomena. In this study, we tested the infiltration capacity of 15-year-old concrete grid pavers (CGPs) using single ring infiltrometer tests. We investigated how various factors, including location within the parking space, affect infiltration rates. Despite no maintenance and 15 years of operation, the infiltration capacity of the CGPs still exceeds the minimum infiltration capacity of 1.62 mm/min as required in many European regions. This may be due to the presence of soil cracks and the development of plant roots and insect/microorganism activities within the pavement voids. Indeed, this ‘living soil system’ continuously develops and counteracts the formation of clogging, interacting with the compaction process. Our study demonstrates that incorporating CGPs is effective in addressing emerging challenges associated with urban hydrology. Due to effectiveness and limited maintenance requirements, CGPs could be successfully included in long term climate adaptation measures.

Clog-Resistant Permeable Pavement: Methods of Performance Measurement

Permeable pavements are considered to be one of the effective measures for LID (i.e. Low Impact Development) and SUDS (i.e. Sustainable Urban Drainage System) globally. The major three types of permeable pavements are (a) pervious concrete (PC), (b) previous asphalt (PA), and (c) permeable interlocked concrete paver (PICP). The performance of all types of permeable is satisfactory at the start of the service life but greatly reduced if not maintained on time. Considering the long lengths of the pavements, measurement of permeability at different locations is a cumbersome and tedious task. Therefore, ease of performance and realistic results are of vital importance. In this study, ASTM C1701/C1701M—17a single ring infiltrometer, Stormwater Infiltration Field Test (SWIFT), and NCAT permeameter Methods are discussed in detail and examined for their relative ease of setting-up, versatility and performance. It is concluded that ASTM C1701/C1701M—17a single ring infiltrometer is the most versatile, easy to set up and produces accurate results.

Water retention and infiltration affected by conventional and conservational tillage on a maize plot; rainfall simulator and infiltrometer comparison study

Tillage practices have a profound influence on the propensity for overland flow formation. The hydrological behavior of nine experimental plots was investigated by means of saturated hydraulic conductivity (Ks) and water retention analysis provided by single-ring infiltrometer (INF) and rainfall simulator (RS) infiltration measurements. The applied management practices encompassed no-tillage, reduced tillage and several forms of conventional tillage methods. Specifically, the influence of wide and narrow sowing rows and the use of cover crops were examined. Finally, the applicability of INF and RS for overland flow formation evaluation on cropped plots was compared. The reduced tillage practices resulted in the Ks and water retention increase, implying a lower propensity for overland flow formation. The Ks in the reduced tillage plots were higher by 30–50% compared to conventionally tilled and by 20% compared to no-tilled plots, respectively. The differences in water retention were less straightforward as the reduced tilled plots exhibited higher retention than conventionally tilled plots (by >20%) but lower values compared to no-tilled plots in June (by 15%). The utilization of narrow sowing rows generally resulted in higher Ks and enhanced water retention compared to wide rows. The use of cover crops in the conventionally tilled plots led to a 40% increase in Ks and a 90% increase in water retention. Hence, the use of reduced tillage, narrow sowing rows or cover crops in the conventionally tilled plots were found desirable for the mitigation of soil erosion, flash flood occurrence and sufficient groundwater recharge. Eight times higher variance of Ks using a single-ring infiltrometer compared to RS indicated the incomparability of these two methods. Therefore, the RS should be considered as a benchmark for evaluating the propensity to overland flow formation on cropped plots.

Evaluating the Field Performance of Permeable Concrete Pavers

The benefits of using permeable interlocking concrete pavement systems (PICPs) have not translated into widespread adoption in Australia, where their uptake has been slow. This paper communicates the actual performance of PICPs installed in the field by providing evidence of their long-term efficiency. There are currently no Australian standards for design, specification and installation of PICPs. In this study, field measurements were conducted to determine the infiltration capacity of PICPs in Sydney and Wollongong, New South Wales, applying the single ring infiltrometer test (SRIT) and the stormwater infiltration field test (SWIFT). A strong correlation was found between the results of the two tests in a previous study, which was verified in this study. The long-term performance of PICPs is demonstrated by their high infiltration rates (ranging from 125 mm/h to 25,000 mm/h) measured in this study at field sites under a diverse range of conditions. The influences of conditions such as age of installation, slope and tree cover on infiltration rates were explored.

PENGARUH PERBEDAAN TUTUPAN LAHAN TERHADAP INFILTRASI TANAH PADA KAWASAN UB FOREST KARANGPLOSO MALANG

Changes in land cover of forest provide different soil organic matter which affects soil infiltration through soil porosity. The purpose of this study was to determine the effect of differences in land cover on soil infiltration at UB Forest of Karangploso Malang. The study area was divided into six plots, namely protected area plots, mahogany production forests, pine production forests intercropped with coffee plants that have three different canopy densities (tenuous, sufficient and tight) and pine production forests intercropped with seasonal crops. Field observations were carried out to analyze the characteristics of vegetation with a sample plot measuring 20x20 m. The parameters observed were canopy density, basal area, plant density, litter and understorey. The taking of soil samples was done by making minipit which was repeated four times; the parameters observed were organic matter, texture, bulk density, particle density and soil porosity. Infiltration measurements were carried out with two methods i.e. single ring infiltrometer and rainfall simulator, each of which was repeated three times. Observation data were subjected to Analysis of Variance (ANOVA) and followed by with LSD test with a significant level of 5%. The results showed that differences in land cover can affect soil infiltration (F-count > F-table 3.33). The effect of land cover on infiltration occurs through litter which is a source of organic material which will then affect the physical properties of the soil, namely soil porosity. Soil porosity is a very influential factor in soil infiltration. The highest soil infiltration reta of 131.33 cm hour-1 was found in protected areas. Meanwhile, the lowest infiltration rate of 12 cm hour-1 was found in pine production forest plots intercropped with annual crops.

A perennial living mulch substantially increases infiltration in row crop systems

Poor infiltration in annual row crop systems can cause a range of problems, including sediment and nutrient loss in runoff, diminished trafficability, anaerobic soil conditions, and reduced precipitation use efficiency. Soils covered by perennial vegetation generally sustain much higher infiltration rates, and consequently are less prone to these problems. Kura clover (<i>Trifolium ambiguum</i> Bieb.) living mulch (KCLM) is a management system that seeks these environmental benefits of perenniality, while allowing continued production of annual row crops like maize (<i>Zea mays</i> L.) and soybean (<i>Glycine max</i> [L.] Merr.). This is done by planting them into tilled or killed strips within a perennial stand of kura clover. Our objective was to compare the hydrologic performance of long-term KCLM systems (in place for at least five years) against adjacent fields or plots in conventional row crop production on the same soil types. Measured variables included field-saturated hydraulic conductivity (K_fs), moisture release curves, and bulk density. K_fs was measured with a constant head single ring infiltrometer, and moisture release curves were determined with the evaporation method. Bulk density was measured on 5 cm diameter cores extracted from the surface horizon of each treatment. None of the long-term sites contained appreciable sloped land, so supporting runoff measurements were made on a third field in Minnesota where the KCLM had only been in place for two years, using lined plots with flumes and tipping buckets. Results revealed substantial and significant differences in K_fs at the long-term sites. At one site the mean value was 11 times greater in the living mulch than in the conventional fields, while at the other site it was 19 times greater. The runoff plots showed a 93% reduction in sediment loss for the KCLM relative to conventional production over the course of a year that included 10 runoff-inducing storms. These results suggest that KCLM may confer similar hydrologic benefits to prairie strips if strategically placed in fields or watersheds.

Estimation of soil hydraulic and solute transport properties from field infiltration experiments

To model water flow and solute transport in soils, hydrodynamic and hydrodispersive parameters are required as input data in the mathematical models. This work aims to estimate the soil hydraulic and solute transport properties using a ponded axisymmetric infiltration experiment using a single-ring infiltrometer along with a conservative tracer (Cl-) in the field. Single ring infiltration experiments were accomplished on an Oxisol in Areia in the state of Paraíba, Brazil (6o 58' S, 35o 41' W, and 645 m), in a 50 x 50 m grid (16 points). The unsaturated hydraulic conductivity (K) and the sorptivity (S) were estimated for short or long time analysis of cumulative three-dimensional infiltration. The single tracer technique was used to calculate mobile water fraction (Ф) by measuring the solute concentration underneath the ring infiltrometer at the end of the infiltration. Two solute transfer numerical models based on the mobile-immobile water concept were used. The mobile water fraction (Ф), the dispersion coefficient (D), and the mass transfer coefficient (a) between mobile and immobile were estimated from both the measured infiltration depth and the Cl- concentration profile underneath the infiltrometer. The classical convection-dispersion (CD) and the mobile-immobile (MIM) models showed a good agreement between calculated and experimental values. However, the lowest standard errors to the fitted parameters were obtained by the CD model.

The Influence of Soil Conditioning on Soil Infiltration Rate in Urban Facilities

Several attempts have been made to increase the permeable area in the cities, which include the building of green facilities such as parks and urban forests. Since these areas were built with soil compaction, the potential for infiltrating water differs compared with the natural green area. Therefore, this research aims to analyze the influence of soil conditioning on the constant infiltration rate using variables such as soil compaction, texture, and the presence of vegetation cover in urban facilities. The data used were obtained through field infiltration measurement using a single ring infiltrometer. In this research, the analysis carried out includes soil texture, Horton equation, the difference between conditioned soils and control plots, and USDA hydrologic soil classifications. The results showed that all variables (soil compaction, the presence of vegetation cover, and soil texture) have a significant effect on the constant infiltration rate. Based on the soil conditioning, the infiltration rate is increased on the vegetated plots and decreased on the plots with the combination of vegetation and compaction, as well as the compacted plots. Furthermore, the effect of vegetation cover is more significant in silt loam textured soil, while the influence of compaction is more on clay textured soil. The potential constant infiltration rate on the plots of similar characteristics with green urban areas are on K2 and L2 with 2.698 mm/h and 1.525 mm/h, respectively. Therefore, these plots have a moderate runoff potential based on USDA hydrologic soil classification.&#x0D; Keywords: Compaction; Infiltration; Soil conditioning; Urban facilities&#x0D; &#x0D; Copyright (c) 2021 Geosfera Indonesia and Department of Geography Education, University of Jember&#x0D; This work is licensed under a Creative Commons Attribution-Share A like 4.0 International License

Soil Infiltration Management on Perspective of Sustainable Development Goals (SDGs)

UB Forest is a Forest Area with Special Purpose (KHDTK) located on the slopes of Mount Arjuno. Before being managed by the University of Brawijaya, there was a change in land cover from natural forest to pine and mahogany production forest. This change was a result of the PHBM (Collaborative Forest Management) contract agreement between Perhutani and the community to carry out agricultural management. The input of organic matter with different quality and quantity will affect the organic matter content and in turn will affect the physical properties of the soil such as bulk density, density and soil porosity. Soil porosity is a physical property of soil that affects soil infiltration. The objective of this study is to identify and analyze the management of Forest Areas and to build a green economy model in the management of KHDTK University of Brawijaya Forest in the Perspective of Sustainable Development Goals (SDGs) in Malang Regency. The method used in this research is qualitative research. Implementation of green economy model in the management of KHDTK University of Brawijaya Forest in the concept of forestry sector contribution related to climate change; the concept of sustainable forest resource management; and the concept of environmental service providers. The results of the infiltration measurement using the single ring infiltrometer method can better describe the infiltration that occurs in the soil. The highest soil infiltration is in protected areas with a soil infiltration rate of 131.33 cm/hour (single ring infiltrometer). Meanwhile, the lowest infiltration was found in the pine production forest plot overlaid with seasonal crops with a soil infiltration rate of 12 cm/hour (single ring infiltrometer).

Rapid and accurate measurement methods for determining soil hydraulic properties: A review

Abstract The determination of soil hydraulic properties is important in several environmental sciences but may be expensive and time consuming. Therefore, during the last decades, a great effort has been made in soil sciences to develop relatively easy, robust, and inexpensive methods for soil hydraulic characterization. In this manuscript, we reviewed and discussed different infiltrometer techniques in light of the available experimental applications. More specifically, we considered the simplified falling head (SFH) infiltrometer technique and the single-ring infiltration experiment of the Beerkan type. Concerning this latter method, we considered different algorithms for data analysis: two simplified methods based on the analysis of transient (TSBI) and steady (SSBI) Beerkan infiltration data, and the Beerkan Estimation of Soil pedoTransfer parameters algorithm (BEST), that allows to estimate the soil characteristics curves, i.e., the soil water retention curve and hydraulic conductivity functions. For a given method, after dealing briefly theory and practice, available literature references were reported to account for specific applications in order to provide findings on method validation and application. With the aim to provide practical information on available tools for a simpler application of the reviewed methods, several video tutorials were reported to show i) how to conduct correctly field experiments and ii) how to calculate saturated hydraulic conductivity or soil hydraulic functions using user-friendly tools for data analysis. Finally, details on a new automated single-ring infiltrometer for Beerkan infiltration experiments (i.e., construction, assembly and field use) were presented.

Peculiarities of Infiltration Measurements in Water-Repellent Forest Soil

The paper deals with measurements of water infiltration carried out on a well-developed forest floor formed by needle-leaf litter of Norway spruce. Three field methods (tension disk permeameter, single-ring infiltrometer and Guelph permeameter) were used to determine the soil hydraulic conductivity. The results were strongly influenced by the water repellency at the interface between the O- and A-horizons. This interface was severely water repellent during the hot and dry summer season, regardless of the generally humid mountain climate of the High Tatras foothill. The single-ring method paradoxically provided lower hydraulic conductivity (3.2 × 10−4 ± 1.3 × 10−4) compared to the tension disk permeameter (8.5 × 10−4 ± 3.3 × 10−4) due to the presence of the water-repellent O/A-interface. This effect was also observed with the Guelph permeameter method, which gave the lowest value (5.6 × 10−5 ± 4.3 × 10−5). Abrupt retardation of infiltration on the water-repellent interface may generate shallow subsurface runoff (as was proved by the irrigation experiment) or litter splash during extreme rainfall events and promote water flow to deeper soil horizons through preferential pathways. The observed effects of the forest floor on rainfall infiltration will depend on the seasonal variability of soil water repellency. Although the forest floor is a source of hydrophobic substances that cause water repellency at the O/A-interface and can trigger runoff generation, at the same time its cohesive duff layer protects the forest soil from erosion.

Regional Farmers’ Perception and Societal Issues in Vineyards Affected by High Erosion Rates

We explore the current situation in a viticultural region in Eastern Spain from a holistic and multifaceted research approach, which allowed us to understand the biophysical conditions, economic cost, social impact, and perception of the farmers’ community to the use of catch crops. A survey of the perception of the farmers, and an assessment of the biophysical impact of catch crops (CC) and tillage (C = Control plot) on soil organic matter, bulk density, infiltration capacity (single ring infiltrometer), and runoff generation and soil erosion (rainfall simulation experiments) was carried out. Two representative fields as study sites were selected in Les Alcusses valley, within Els Alforins wine production region. The results show that the use of CC increased soil organic matter, favored higher infiltration rates and runoff generation was delayed. Moreover, runoff rates and soil erosion were lowered. The perception of the farmers was mainly against the use of catch crops due to their view as it being ‘dirty’, their cost, and the loss of their reputation and respect by other farmers. Our survey proves that the farmers would accept the catch crops if a subsidy of 76.56 € ha−1 on average would be paid. Farmers see the use of a catch crop more as a benefit for the health of the Planet than for themselves. To achieve land degradation neutrality, education and dissemination programs should be developed to teach and inform the farmers of their key role in the proper management of vineyards.

Construction and Testing of A Single and Double Ring Infiltrometers in Auchi Polytechnic, Edo State

This paper presents the results of the construction of an improvised double and single ring infiltrometers. The study was carried in Auchi Polytechnic campus, after the construction, the double ring and single ring infiltrometer were used to carryout infiltration tests at four different locations. The t-test was used to test check the performance of the double and single ring infiltrometers. The results of the soil properties showed that the soil texture was predominantly sandy loam and loam respectively. The result presented herein showed a high significant difference between the performance of the single and double ring infiltrometer at Plot A and no significant other plots. The total cumulative infiltration depth of the single-ring infiltrometer for the A, B, and C and D fields were 188.30 cm, 59.70 cm, 77.00 cm and 97.00 cm, respectively. The total cumulative infiltration depth of the Double-ring infiltrometer for the A, B, and C and D fields were 123.30 cm, 75.60 cm, 70.50 cm and 95.20 cm, respectively. Generally, Philip’s model performed better than Kostiakov’s model Keywords : Single and Double ring infiltrometer, infiltration models DOI: 10.7176/JNSR/12-3-04 Publication date: February 28 th 2021

USE OF DIFFERENT INFILTROMETERS TO ASSESS ENVIRONMENTAL DAMAGE CAUSED BY DIFFERENT LAND USES

The present work had an objective to compare the stable infiltration rate obtained by infiltrometers with reduced dimensions and varied forms in different land uses. The infiltration tests were carried out in areas planted with cowpea, crotalaria, pigeon pea and millet, as crops previous corn planting, and managed with no-tillage, minimum tillage and conventional tillage and native forest area. In order to compare and analyze the results of the stable infiltration rates obtained between the alternative infiltrometers and the considered standard, the criteria involving the standard error of estimation (EPE), the standard error of estimation adjusted (EPEa), the standard error of estimation adjusted by origin (EPEao) and coefficients of adjustments of the linear equations with their respective determination coefficients (R2) were used. It was verified that the double-ring reduced, single-ring and double square infiltrometers provided a water saving of 57.06%, 66.19% and 38.54% respectively, relative to the standard. The alternative infiltrometers overestimated the stable infiltration rate in relation to the standard. The single-ring infiltrometer obtained a stable infiltration rate correction equation that showed results very close to the standard and the best statistical indices of stable infiltration rate results were obtained by the reduced double-ring infiltrometer.

Field monitoring of preferential infiltration in loess using time-lapse electrical resistivity tomography

The effect of preferential flow (PF) in loess is of direct interest as flood irrigation is commonly found in loess regions where precipitation is scarce. This study was to assess the applicability of time-lapse electrical resistivity tomography (ERT) data on monitoring infiltration in loess and to analyze the effects of preexisting preferential path on infiltration process at a localized scale. An in situ single-ring infiltrometer (SRI) test was conducted above a preexisting near-surface crack under a constant influx (10 cm water head for 8h), and the test was monitored by the means of 2-D time-lapse ERT and validated by an exploratory trench. The ERT results observed some increasing uncertainties in the electrical resistivity in part due to daily temperature variation; however, they showed that the infiltration process under the presence of preferential path can be effectively monitored by time-lapse ERT with a combination of unit electrode spacing (UES). The test results showed a high relative reduction of electrical resistivity (>80%) due to matrix flow (MF) and PF within 0–0.5h of the test, and followed by a transformation of preferential flow to a more matrix-dominated unsaturated flow, i.e. preferential-to-matrix flow (PMF), with continuous downward progression into the deeper subsurface (greater than 1.2 m) while MF stagnated at the near-surface (about 0.4 m). The results suggested that the presence of even a near-surface preferential path significantly accelerate the infiltration into the deeper loess by the means of PMF, as compared to observed slow infiltration of pure matrix flow in previous studies.

A field performance evaluation of the periodic maintenance for pervious concrete pavement

The pores of pervious concrete pavement will be clogged by sediment carried by rainwater runoff and atmospheric deposition on the pavement in the course of using, thus reducing the permeability of pavement. It is necessary to adopt effective maintenance measures to keep the permeability of the pavement. In this study, an improved single ring infiltrometer is used to measure the permeability of a newly constructed pervious pavement. In order to study the deterioration process of the pavement permeability under periodic clogging maintenance conditions, four different gradations of clogging materials and eight different maintenance methods were used for 32 test cases. Different maintenance methods are designed to find the best combination, including different pressure wash, sweep + vacuum and pressure wash + vacuum. The study shows when the pressure wash is between 5 and 20Mpa, the maintenance effect has little difference, and the combination of pressure wash and vacuum suction has the best maintenance effect.

HYDRODYNAMIC AND HYDRODISPERSIVE CHARACTERIZATION OF A FLUVIC CAMBISOL IN THE NORTHEAST REGION OF BRAZIL1

ABSTRACT The determination of the hydraulic and hydrodispersive properties of soil is necessary for the understanding of water dynamics and soil solute transport, and they are used as input data in several models. Determinations of soil hydraulic and hydrodispersive parameters are usually obtained by separate methodologies. Axisymmetric infiltration tests using a single ring infiltrometer with a conservative tracer (KBr) in the field (Beerkan-Solute) lead to the determination of the most realistic hydraulic and hydrodispersive properties of the study area. The objective of this work was the hydrodynamic and hydrodispersive characterization of an irrigated soil, classified as Fluvic Cambisol, from the lowland areas of the northeastern semi-arid region, located in the backwoods of the state of Pernambuco, in the municipality of Serra Talhada-PE. The hydrodispersive parameters were determined with the CXTFIT 2.0 program, using the CDE and MIM models. The studied soil presented hydrodynamic characteristics with high values of sorptivity (S) that were associated with high values of saturated hydraulic conductivity (Ks), indicating that the soil has good permeability and resistance to surface crumbling caused by rain drops or soil management. It was observed the predominance of the convective process, being the CDE model the one that presented the best performance in the transport of the KBr tracer under field conditions, indicating the absence of two water regions mobile and immobile in the studied soil.

Field determination of the hydraulic conductivity of a compacted sand layer controlling water flow on an experimental mine waste rock pile

Small-scale infiltration tests were performed on a flow control layer made of compacted sand, installed at the surface of an experimental waste rock pile. The hydraulic conductivity of the sand layer was evaluated from a field investigation using three different testing methods: single-ring infiltrometer, double-ring infiltrometer and Guelph permeameter. The objective was to evaluate and compare the use of these techniques to assess the in-situ hydraulic conductivity of the sand layer. Results from analytical solutions and inverse numerical modelling were also compared. The field approaches gave fairly similar results when the measurements were interpreted with existing approximate solutions, although tests with the Guelph permeameter and single-ring infiltrometer led to slightly higher values of the hydraulic conductivity. The numerical interpretation generally gave lower values for the saturated hydraulic conductivity compared with those obtained analytically, but the differences remain within a factor of 3 or less. The predictive models used in this study, and validated with laboratory measurements, also gave comparable values for the saturated hydraulic conductivity. Any of the three testing methods applied here could, therefore, be used to evaluate the field hydraulic conductivity of the sand layer. Numerical simulations have the advantage of not relying on empirical parameters but require more work with a good estimate of the water retention curve. The investigation also showed that the predictive models used here gave reliable values for hydraulic conductivity when the void ratio was properly determined; such models should however be validated with controlled tests, as was the case here.

FABRICATION AND PERFORMANCE EVALUATION OF A SINGLE AND DOUBLE RING INFILTROMETERS

This paper presents the results of the construction of an improvised double and single ring infiltrometers. The study was carried in Auchi Polytechnic campus, after the construction, the double ring and single ring infiltrometer were used to carryout infiltration tests at four different locations. The t-test was used to test check the performance of the double and single ring infiltrometers. The results of the soil properties showed that the soil texture was predominantly sandy loam and loam respectively. The result presented herein showed a high significant difference between the performance of the single and double ring infiltrometer at Plot A and no significant other plots. The total cumulative infiltration depth of the single-ring infiltrometer for the A, B, and C and D fields were 188.30 cm, 59.70 cm, 77.00 cm and 97.00 cm, respectively. The total cumulative infiltration depth of the Double-ring infiltrometer for the A, B, and C and D fields were 123.30 cm, 75.60 cm, 70.50 cm and 95.20 cm, respectively. Generally, Philip’s model performed better than Kostiakov’s model Key Words : Single and Double ring infiltrometer, infiltration models DOI : 10.7176/JNSR/9-22-06 Publication date: November 30 th 2019