scholarly journals An Improved Method to Estimate Soil Hydrodynamic and Hydraulic Roughness Parameters by Using Easily Measurable Data During Flood Irrigation Experiments and Inverse Modelling

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1581
Author(s):  
Mohamed Alkassem Alosman ◽  
Stéphane Ruy ◽  
Samuel Buis ◽  
Patrice Lecharpentier ◽  
Jean Bader ◽  
...  
Keyword(s):  
Soil Surface ◽  
Surface Flow ◽  
Performance Criteria ◽  
Soil Parameters ◽  
Well Performance ◽  
Estimation Errors ◽  
Hydraulic Roughness ◽  
Infiltration Model ◽  
Estimation Uncertainty ◽  
Using Data

Surface irrigation is known as a highly water-consuming system and needs to be optimized to save water. Models can be used for this purpose but require soil parameters at the field scale. This paper aims to estimate effective soil parameters by combining: (i) a surface flow-infiltration model, namely CALHY; (ii) an automatic fitting algorithm based on the SIMPLEX method; and (iii) easily accessible and measurable data, some of which had never been used in such a process, thus minimizing parameter estimation errors. The validation of the proposed approach was performed through three successive steps: (1) examine the physical meaning of the fitted parameters; (2) verify the accuracy of the proposed approach using data that had not been served in the fitting process; and (3) validate using data obtained from independent irrigation events. Three parameters were estimated with a low uncertainty: the saturated hydraulic conductivity Ks, the hydraulic roughness k, and the soil water depletion ∆θ. The estimation uncertainty of the soil surface depressional storage parameter H0 was of the same order of magnitude of its value. All experimental datasets were simulated very well. Performance criteria were similar during both the fitting and validation stages.

ANALISIS PENANGGULANGAN KELONGSORAN TANAH PADA RUAS JALAN GUNUNG TUGEL PATIKRAJA BANYUMAS

2017 ◽  
Vol 14 (1) ◽  
pp. 53
Author(s):  
Arwan Apriyono ◽  
Sumiyanto Sumiyanto ◽  
Nanang Gunawan Wariyatno
Keyword(s):  
Limit Equilibrium ◽  
Retaining Wall ◽  
Limit Equilibrium Method ◽  
Pile Foundations ◽  
Soil Parameters ◽  
The Road ◽  
Realistic Option ◽  
Stable Conditions ◽  
Using Data ◽  
Wall Slope

Gunung Tugel is an area that located Patikraja Region, Southern Banyumas. Thetopography of the area is mostly mountainous with a slope that varies from flat to steep. Thiscondition makes to many areas of this region potentially landslide. In 2015, a landslideoccurred in Jalan Gunung Tugel. The Landslide occurred along 70 meters on the half of theroad and causing traffic Patikraja-Purwokerto disturbed. To repair the damage of the road andavoid further landslides, necessary to analyze slope stability. This study is to analyze landslidereinforcement that occurred at Gunung Tugel and divides into 3 step. The first step is fieldinvestigation to determine the condition of the location and dimensions of landslides. Thesecond step is to know the soil parameters and analyzes data were obtained from the field. Andthe final step is analyzed of the landslide reinforcement by using data obtained from thepreceding step. In this research, will be applied three variations of reinforcement i.e. retainingwall, pile foundation and combine both of pile foundations and retaining wall. Slope stabilityanalysis was conducted using limit equilibrium method. Based on the analysis conducted onthe three variations reinforcement, combine both of pile foundations and retaining wall morerecommended. Application of and combine both of pile foundations and retaining wall is themost realistic option in consideration of ease of implementation at the field. From thecalculations have been done, in order to achieve stable conditions need retaining wall withdimensions of 2 meters high with 2,5 meters of width. DPT is supported by two piles of eachcross-section with 0.3 meters of diameter along 10 meters with 1-meter in space. Abstrak: Gunung Tugel adalah salah satu daerah yang terletak di Kecamatan PatikrajaKabupaten Banyumas bagian selatan. Kondisi topografi daerah tersebut sebagian besar berupapegunungan dengan kemiringan yang bervariasi dari landai sampai curam. Hal inimenyebabkan banyak daerah di wilayah Gunung Tugel yang berpotensi terjadi bencana tanahlongsor. Pada tahun 2015, peristiwa longsor kembali terjadi di ruas Jalan Gunung Tugel.Kelongsoran yang terjadi sepanjang 70 meter pada separuh badan jalan tersebut menyebabkanarus lalu lintas patikraja-purwokerto menjadi terganggu. Untuk memperbaiki kerusakan jalandan mencegah kelongsoran kembali, diperlukan analisis perkuatan tanah terhadap lerengtersebut. Studi analisis penanggulangan kelongsoran jalan yang terjadi di Gunung Tugel inidilakukan dengan tiga tahapan. Tahapan pertama adalah investigasi lapangan untukmengetahui kondisi lokasi dan dimensi longsor serta mengambil sampel tanah di lapangan.Tahap kedua adalah melakukan pengujian parameter tanah dan analisis data yang diperolehdari lapangan. Tahapan yang terakhir adalah analisis penanggulangan longsor denganmenggunakan data yang diperoleh dari tahapan sebelumnya. Pada penelitan ini, akanditerapkan tiga variasi perkuatan lereng yaitu dinding penahan tanah (DPT), turap dan DPTyang dikombinasikan dengan pondasi tiang. Analisis stabilitas lereng dilakukan dengan metodekeseimbangan batas. Berdasarkan hasil analisis yang dilakukan terhadap ketiga variasiperkuatan, DPT dengan kombinasi tiang pancang lebih direkomendasikan. Penerapan DPTyang dikombinasikan dengan minipile merupakan pilihan yang paling realistis denganpertimbangan tingkat kemudahan pelaksanaan di lapangan. Dari perhitungan yang telahdilakukan, untuk mencapai kondisi stabil diperlukan DPT dengan dimensi tinggi 2 meterdengan lebar bawah 2,5 meter. DPT tersebut ditopang oleh dua tiang tiap penampangmelintang dengan diameter 0,3 meter sepanjang 10 meter dengan jarak antar tiang 1 meter.kata kunci: tanah longsor, perkuatan tanah, metode keseimbangan batas

Evaluating the Efficiency of Crushed Gravel Filters around Field Drains

2021 ◽  
Author(s):  
Amer Al-Haddad ◽  
◽  
Dhuha Mahdi ◽  
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Surface ◽  
Filter Material ◽  
Head Loss ◽  
Surface Flow ◽  
Laboratory Work ◽  
Drain Pipe ◽  
Drainage Systems ◽  
Total Head ◽  
Irrigation Condition

Engineers have employed various ways to protect drain openings from the entry of sediment with varying degrees of success. This study aims to compare and evaluate the hydraulic performance and efficiency of using natural graded gravel filter and crushed gravel filter in drainage systems. An aquifer tank (sand tank) 70 cm long, 50 cm wide and 80 cm high, a perforated drain pipe of 50 mm diameter was used in the laboratory work. The laboratory study was performed with two types of soil: loam and loamy sand. These two soils were used with the two types of gravel filters after taking the particle size distribution test for the two soils. For each case, the inflow was applied to the model from the soil surface (to represent irrigation condition) and from the sides of the tank (to represent sub –surface flow condition and effluence of the groundwater). Each case involved ten runs; for each run, discharge, total head loss, and amount of sediment were recorded. It was found that crushed gravel filter would work similarly to natural graded gravel filter after a certain time from the beginning of runs. It was also found that the discharge and sediment when using crushed gravel filter were close to or equal to that with natural graded gravel filter. The hydraulic conductivity and the exit gradient values were calculated in this research. It was found that their values were so different between the two types of filters, but at the end of the laboratory work, the hydraulic conductivity would be approximately the same. The exit gradient of crushed gravel filter was lower than that of natural graded gravel filter due to the large pores between the filter particles. Finally, the results showed that, it is possible to use crushed gravel filter material in drainage systems, which is less costly and easier to place than natural graded gravel filter.

scholarly journals Examination of soil parameters based on the evaluation of the spectroradiometric reflectance characteristics of the topsoil

2014 ◽  
pp. 75-80
Author(s):  
Károly Bakos ◽  
Attila Dobos ◽  
János Nagy
Keyword(s):  
Measurement Techniques ◽  
Soil Surface ◽  
Soil Parameters ◽  
Surface Reflectance ◽  
Imaging Spectrometer ◽  
Top Soil ◽  
Multiple Samples ◽  
Physical And Chemical ◽  
Landscape Formation

In this article we are presenting the methodology applied to analyse and interpret the topsoil surface reflectance parameters of multiple samples collected in the Mugello valley area in northern Italy in October 2012. The main aim of the whole project was to discover geomorphological behaviour and situation of the area ino order to improve potential for correct dating of certain archaeological artefacts found in the nearby areas. One of the crucial problem researchers are facing in the area is the lack of understanding of the underlying geological and geomorphological processes that were describing and characterizing the area and that played important role not only in the current geography and landscape formation but also in the transportation of various sediments and artefacts. In this particular research the main aim is to examine the possibility of developing a quick way to assess low level properties of the soil using hand held spectrometer and rapid analysis of cross-section using in situ measurement techniques. In this work we collected over 2000 individual samples of topsoil surface reflectance properties that we organized into a spectral library. This library is then to be used to describe physical and chemical processes in the soil. To support the analysis results were compared to analysis results from different kind of assessments in the same area. Our results show a great potential of application of hand held imaging spectrometer in soil property analysis based on the top soil surface reflectance parameters.

scholarly journals The Research on a Confined Modeling Method of the Effect of Deformable Ground Soil and Crawler Board

2018 ◽  
Vol 237 ◽  
pp. 02011
Author(s):  
LV Wei ◽  
Zhong-xin LI ◽  
LOU Peng
Keyword(s):  
Maximum Stress ◽  
Ground Deformation ◽  
Soil Mechanics ◽  
Soil Surface ◽  
Physical Significance ◽  
Soil Parameters ◽  
Soil Test ◽  
Analysis Model ◽  
Soil Pressure ◽  
Vehicle Mobility

There is a great relationship between the passing capacity of vehicles on the ground deformation road and the properties of confined and shear of ground soil, so it is necessary to establish a model that can reflect the soil pressure of the deformation. Physical significance of classic soil pressure experience parameters model is indeterminate, it was generally obtained by a lot of specific soil test. In this paper a new analysis model was built though introducing the maximum stress value of the crawler board and soil surface on basis of a kind of existing analysis model. This model reveals the relations among the confined characteristics of soil, soil parameters and the geometry of confined crawler board. These soil parameters can be obtained through the conventional soil mechanics test without a large number of specific soil test. Through the contrast experiment and predictions results, this model can effectively predict the sinkage of ground soil under the load, and provide a theory basis for the prediction of vehicle mobility.

scholarly journals Predicted Infiltration for Sodic/Saline Soils from Reclaimed Coastal Areas: Sensitivity to Model Parameters

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
Dongdong Liu ◽  
Dongli She ◽  
Shuang’en Yu ◽  
Guangcheng Shao ◽  
Dan Chen
Keyword(s):  
Water Movement ◽  
Soil Surface ◽  
Coastal Areas ◽  
Model Parameters ◽  
Wetting Front ◽  
Sodic Soils ◽  
Infiltration Process ◽  
Infiltration Model ◽  
Soil Physical Quality ◽  
Cumulative Infiltration

This study was conducted to assess the influences of soil surface conditions and initial soil water content on water movement in unsaturated sodic soils of reclaimed coastal areas. Data was collected from column experiments in which two soils from a Chinese coastal area reclaimed in 2007 (Soil A, saline) and 1960 (Soil B, nonsaline) were used, with bulk densities of 1.4 or 1.5 g/cm3. A 1D-infiltration model was created using a finite difference method and its sensitivity to hydraulic related parameters was tested. The model well simulated the measured data. The results revealed that soil compaction notably affected the water retention of both soils. Model simulations showed that increasing the ponded water depth had little effect on the infiltration process, since the increases in cumulative infiltration and wetting front advancement rate were small. However, the wetting front advancement rate increased and the cumulative infiltration decreased to a greater extent whenθ0was increased. Soil physical quality was described better by theSparameter than by the saturated hydraulic conductivity since the latter was also affected by the physical chemical effects on clay swelling occurring in the presence of different levels of electrolytes in the soil solutions of the two soils.

scholarly journals Laboratory development of a vertically oriented penetrometer for shallow seabed characterization

2016 ◽  
Vol 53 (1) ◽  
pp. 93-102 ◽  
Author(s):  
Fauzan Sahdi ◽  
David J. White ◽  
Christophe Gaudin ◽  
Mark F. Randolph ◽  
Noel Boylan
Keyword(s):  
Soil Surface ◽  
Site Investigation ◽  
Soil Strength ◽  
Small Scale ◽  
Soil Parameters ◽  
Embedment Depth ◽  
Fine Grained ◽  
Centrifuge Models ◽  
Measured Resistance ◽  
And Performance

Current site investigation practice for offshore pipeline design relies on soil parameters gathered from boreholes or in situ test soundings to depths of 1–2 m below the mudline. At these depths, the fine-grained seabed is very soft and possesses low undrained strength, which can be difficult to measure. This paper describes a centrifuge test programme undertaken to evaluate the feasibility and performance of a novel penetrometer designed to assess the shallow strength of soft seabed over continuous horizontal profiles. This device is termed the vertically oriented penetrometer (VOP). Tests were performed on a normally consolidated kaolin sample, with the VOP translated horizontally at velocities ranging from 1 to 30 mm/s, after embedding the VOP at 30 and 45 mm depths. All tests involved many cycles of VOP forward and backward movement to assess its potential to derive the ratio of intact to fully remoulded strength. Strength determination is achieved by dragging the VOP at a specified embedment depth along the soil surface, and deriving the soil strength from the measured resistance as if the VOP were a laterally loaded pile. The VOP is shown to yield comparable strength measurements to that of a T-bar penetrometer. The VOP is a potentially valuable addition to the range of tools used to characterize soil strength, both in small-scale centrifuge models and, following practical development, potentially also in the field.

Some investigations into soil and vegetation relationships associated with alkaline-saline soil surfaces in the Walcha area, Northern Tablelands, New South Wales

1995 ◽  
Vol 46 (1) ◽  
pp. 209 ◽  
Author(s):  
KH Kreeb ◽  
RDB Whalley ◽  
JL Charley
Keyword(s):  
Cynodon Dactylon ◽  
New South ◽  
New South Wales ◽  
Soil Surface ◽  
Tree Planting ◽  
Soil Parameters ◽  
Alkali Cations ◽  
Grazing Land ◽  
South Wales ◽  
Wide Range

The characteristics of the soil, vegetation and groundwater at a dryland salinity site on Miramoona, a property near Walcha on the Northern Tablelands of New South Wales, were investigated. Soil parameters measured at 23 points along a 200 m transect were highly correlated with the pattern of vegetation. Of overriding significance was soil pH, which varied from a high of over 10 on bare areas delineated by Critesion marinum and Cynodon dactylon to a low of less than 5 on grazing land supporting the growth of a wide range of pasture species. The bare areas were characterized by alkalinity. While they were sodic at all depths measured, they were only marginally saline and then only at the soil surface. The chemical composition of the groundwater collected from three piezometer tubes varied quite markedly over the site. It is hypothesized that the presence of alkaline bare areas on the Northern Tablelands is not a new problem, but rather the natural result of alternating wet and dry periods which have induced accumulation of carbonates and bicarbonates of the alkali cations, notably sodium. Drainage of the original perched swamps by the early landholders, tree clearing and the grazing of domestic livestock would have accelerated the process since European settlement. However, tree planting would appear unlikely to have any impact on the reclamation process in the short term. A more viable option would be the recreation of the original swamps in suitable situations, although this solution would create problems for grazing management.

Coefficients for Quantifying Subsurface Drainage Rates

2017 ◽  
Vol 33 (6) ◽  
pp. 793-799 ◽  
Author(s):  
R. Wayne Skaggs
Keyword(s):  
Meta Analysis ◽  
Soil Surface ◽  
Subsurface Drainage ◽  
Rainfall Events ◽  
Drainage Systems ◽  
Hydraulic Roughness ◽  
Drainage Rate ◽  
Design Projects ◽  
Research And Design ◽  
Different Soils

Abstract. It is proposed that technical papers on drainage research studies and engineered design projects should report standard coefficients or parameters that characterize the hydraulics of the system. The following coefficients define key subsurface drainage rates that can be used to quantify and compare the hydraulics of drainage systems across sites, soils and geographic locations. (1) The steady subsurface drainage rate (cm/d) corresponding to a saturated profile with a ponded surface. This subsurface drainage rate defines the length of time that water remains ponded on the soil surface following large rainfall events. It is proposed that this rate be called the Kirkham Coefficient (KC) in honor of Professor Don Kirkham who derived analytical solutions for saturated drained profiles for most soil and boundary conditions of interest. (2) Drainage intensity (DI), which represents the drainage rate (cm/d) when the water table midway between parallel drains is coincident with the surface. The DI can be estimated by the Hooghoudt equation and is dependent on the effective saturated hydraulic conductivity of the profile, drain depth, spacing, and depth of the soil profile or restrictive layer. (3) The drainage coefficient (DC), which quantifies the hydraulic capacity of the system. This value is the rate (cm/d) that the outlet works can remove water from the site. It is dependent on the size, slope, and hydraulic roughness of the laterals, submains, mains, and, in cases where pumped outlets are used, the pumping capacity. Routine inclusion of these three coefficients in the documentation of research and design projects would facilitate comparison of results from different soils and drainage systems, and generally, the meta-analysis of data pertaining to drainage studies. Keywords: Drainage, Drainage intensity, Drainage coefficient, Drainage nomenclature, Kirkham Coefficient.

scholarly journals Racial and Ethnic Disparities in Years of Potential Life Lost Attributable to COVID-19 in the United States: An Analysis of 45 States and the District of Columbia

2021 ◽  
Author(s):  
Jay J. Xu ◽  
Jarvis T. Chen ◽  
Thomas R. Belin ◽  
Ronald S. Brookmeyer ◽  
Marc A. Suchard ◽  
...  
Keyword(s):  
United States ◽  
District Of Columbia ◽  
Ethnic Disparities ◽  
The United States ◽  
Attributable Mortality ◽  
Estimation Uncertainty ◽  
Race Ethnicity ◽  
Using Data ◽  
Rate Ratios ◽  
Racial Ethnic

AbstractThe coronavirus disease 2019 (COVID-19) epidemic in the United States has disproportionately impacted communities of color across the country. Focusing on COVID-19-attributable mortality, we expand upon a national comparative analysis of years of potential life lost (YPLL) attributable to COVID-19 by race/ethnicity (Bassett et al., 2020), estimating percentages of total YPLL for non-Hispanic Whites, non-Hispanic Blacks, Hispanics, non-Hispanic Asians, and non-Hispanic American Indian or Alaska Natives, contrasting them with their respective percent population shares, as well as age-adjusted YPLL rate ratios – anchoring comparisons to non-Hispanic Whites – in each of 45 states and the District of Columbia using data from the National Center for Health Statistics as of December 30, 2020. Using a novel Monte Carlo simulation procedure to quantify estimation uncertainty, our results reveal substantial racial/ethnic disparities in COVID-19-attributable YPLL across states, with a prevailing pattern of non-Hispanic Blacks and Hispanics experiencing disproportionately high and non-Hispanic Whites experiencing disproportionately low COVID-19-attributable YPLL. Furthermore, observed disparities are generally more pronounced when measuring mortality in terms of YPLL compared to death counts, reflecting the greater intensity of the disparities at younger ages. We also find substantial state-to-state variability in the magnitudes of the estimated racial/ethnic disparities, suggesting that they are driven in large part by social determinants of health whose degree of association with race/ethnicity varies by state.

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