scholarly journals Research on Influence of Soil Moisture Content of Farmland on Infiltration Model Parameters

2020 ◽  
Vol 189 ◽  
pp. 01011
Author(s):  
Zhiwei Zheng ◽  
Zhuozhuo Gao
Keyword(s):  
Moisture Content ◽  
Soil Column ◽  
Initial Moisture Content ◽  
Test Method ◽  
Model Parameters ◽  
Initial Water Content ◽  
Initial Water ◽  
Infiltration Process ◽  
Infiltration Model ◽  
Kostiakov Model

In order to study the influence of the initial moisture content on the parameters of the infiltration model using an indoor soil column test method, and the relationship between the initial moisture content and each model parameter was analyzed by using the Green-Ampt model, the Kostiakov model, and the Horton model. The results show that there is a certain relationship between the initial water content and the parameters of the infiltration model. Based on comprehensive considerations, the Kostiakov model is the best surface irrigation infiltration model, and the Kostiakov model has the best effect when the observation time is not less than 80 minutes to simulate the soil infiltration process.

scholarly journals Initial Moisture Content of Corncobs Plays an Important Role in Maintaining its Quality during Storage

2018 ◽  
Vol 38 (2) ◽  
pp. 167
Author(s):  
Lince Mukkun ◽  
Herianus J.D. Lalel ◽  
Yuliana Tandirubak
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
Insect Pests ◽  
Initial Moisture Content ◽  
High Water ◽  
High Water Content ◽  
Initial Water Content ◽  
Initial Water ◽  
Plant Materials ◽  
Randomized Design

Maize is one of the important staple foods for people in Timor, East Nusa Tenggara Province, Indonesia. Subsistent farmers store the maize for their own consumption until the next harvest season, for seed and feed.  However, high initial water content of the kernel due to improper drying prior storage initiate serious damage and losses during the maize storage.  High water content promotes the growth of fungi and insects, and increase respiration rate, resulting in rapid deterioration of maize. The purpose of this study was to determine the initial moisture content that might minimize damage and losses of maize in the farmers’ storage, and to study the effects of some plant materials that are used to smoke corns before storage. The experiment was initiated by sun-drying the harvested corncobs for 0, 2, 4, 6, 8, and 10 days (6 hours a day). This experiment was designed using Completely Randomized Design with 6 treatments and 3 replications. Dried corncobs were stored in the farmer’s storage for 4 months. The effects of maize kernels’ initial water content on the development of water content in kernels; the percentage of damaged kernels; and the species of pathogen and insects were investigated during storage with 2-week intervals.  The results demonstrated that drying the corncobs prior storage for 10 days, resulting in 12.96% of water content, significantly decreased the percentage of seed damage to 6.5%, as compared to without drying process which resulted  in 63%.  Aspergillus flavus, Fusarium sp., and Penicillium sp were found to be the main pathogen during storage.  There are no insect pests found during the storage. 

Prediction Study of Capillary Rise Height on Unsaturated Soil

2013 ◽  
Vol 860-863 ◽  
pp. 1260-1264 ◽  
Author(s):  
Nian Qin Wang ◽  
Qing Tao Wang ◽  
Xiao Ling Liu ◽  
Qi Pang
Keyword(s):  
Moisture Content ◽  
Unsaturated Soil ◽  
Vertical Section ◽  
Capillary Rise ◽  
Initial Moisture Content ◽  
Absorption Capacity ◽  
Initial Water Content ◽  
Initial Water ◽  
The Difference ◽  
Rise Height

Based on the understanding of diseases of building’s foundation and manmade slope caused by water capillary rise, this thesis carried out a large number of laboratory tests by selfdeveloped absorption permeameter for unsaturated soil, in order to explore the capillary transport law of unsaturated soil. The thesis obtains some valuable results and conclusions: The moisture content shows minishing trend as the seepage fronts increasing, and reflects the gravitational potential of normal relations with the capillary action; (2) the water seepage frontal Hω% relation curve has no obvious inflection point, but the initial water content has an certain influence on the capillary moisture content distribution, the moisture content uses the initial moisture content of 12.5%, 9.8%, 8.0% and5.3% for testing showed an increasing trend at 4 cm and 16 cm sections, and the moisture content at the same section increased with the initial moisture content increasing, this reflects the rule that the smaller the moisture content is, the greater the matric potential, the water absorption capacity becomes stronger. (3)The moisture content difference between 4 cm and 16 cm of the initial moisture content is 12.5%, 9.8%, 8.0% and 9.8% is 1.48 %, 1.5 %, 1.7 % and 2.2 %, indicating that the smaller the initial moisture content is, the difference at the vertical section is greater. Finally, based on the relationship of Hω% curve, the thesis establishes the grey correlation prediction model, and forecasts the maximum capillary height of Lishi loess is 182cm.

scholarly journals Factors Affecting the Swelling-Compression Characteristics of Clays in Yichang, China

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Changxi Huang ◽  
Xinghua Wang ◽  
Hao Zhou ◽  
Yan Liang
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Stress Path ◽  
Dry Density ◽  
Initial Water Content ◽  
Initial Water ◽  
Swelling Properties ◽  
Vertical Loading

Expansive soil has been studied for eighty decades because it is prone to cause geotechnical engineering accidents. The results of the moisture content effects on the expansive pressure were not consistent in the literatures. In this paper, swelling deformation and pressure tests were conducted to clarify the effects of the initial water content on the swelling properties. The relation of expansive stress and initial moisture content was accurately described with a Gaussian distribution, unlike in the previously published studies. These results could be explained by the change in the microstructure with diverse moisture contents. In addition, dry density and vertical stress influences on expansive properties were analysed. With an increase in the vertical loading, the soil samples first expanded, and then the samples with a lower dry density collapsed; however, the samples with a higher dry density did not collapse, even under a considerable vertical loading. Furthermore, the relation between stress path and expansive pressure was examined. It was observed that the swelling pressures obtained from the constant volume tests were greater than the results from the swell under load tests. The relationship between the swelling pressure and swelling strain was also analysed.

scholarly journals Adjustment of mathematical models and quality of soybean grains in the drying with high temperatures

2016 ◽  
Vol 20 (4) ◽  
pp. 385-392 ◽  
Author(s):  
Paulo C. Coradi ◽  
Carlos H. P. Fernandes ◽  
Jean C. Helmich
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
Initial Moisture Content ◽  
Effective Diffusivity ◽  
Isosteric Heat ◽  
Initial Water Content ◽  
Initial Water ◽  
Drying Time ◽  
Moisture Contents

ABSTRACT The aim of this study was to evaluate the influence of the initial moisture content of soybeans and the drying air temperatures on drying kinetics and grain quality, and find the best mathematical model that fit the experimental data of drying, effective diffusivity and isosteric heat of desorption. The experimental design was completely randomized (CRD), with a factorial scheme (4 x 2), four drying temperatures (75, 90, 105 and 120 ºC) and two initial moisture contents (25 and 19% d.b.), with three replicates. The initial moisture content of the product interferes with the drying time. The model of Wang and Singh proved to be more suitable to describe the drying of soybeans to temperature ranges of the drying air of 75, 90, 105 and 120 °C and initial moisture contents of 19 and 25% (d.b.). The effective diffusivity obtained from the drying of soybeans was higher (2.5 x 10-11 m2 s-1) for a temperature of 120 °C and water content of 25% (d.b.). Drying of soybeans at higher temperatures (above 105 °C) and higher initial water content (25% d.b.) also increases the amount of energy (3894.57 kJ kg-1), i.e., the isosteric heat of desorption necessary to perform the process. Drying air temperature and different initial moisture contents affected the quality of soybean along the drying time (electrical conductivity of 540.35 µS cm-1g-1); however, not affect the final yield of the oil extracted from soybean grains (15.69%).

scholarly journals Experimental Study on Relationship between Free Load Swelling Rate and Water Content of Medium Expansive Soil

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Cheng Song ◽  
Ligong Yang ◽  
Wei Xia ◽  
Wendong Ji ◽  
Yuting Zhang
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
Moisture Absorption ◽  
Initial Moisture Content ◽  
Expansive Soil ◽  
Experimental Tests ◽  
Expansion Rate ◽  
Dry Density ◽  
Initial Water Content ◽  
Initial Water

Expansive soil has the property of water swelling, which is related not only to the hydrophilic mineral composition of soil particles and the microstructure of soil, but also to the initial moisture content, dry density, and overburden condition of soil. Based on the typical expansive soil in a certain area, the samples were sampled and remodeled at the site. Extensive experimental tests were conducted to investigate the relationship between the hygroscopic expansion rate and the water content of the expansive soil under different initial moisture content, dry density, and free load. The results showed that, under the condition of natural initial water content and dry density, although the hygroscopic expansion rate of the medium expansive soil was nonlinear with the subsequent water content, in the range of large water content (within about 50%), the expansive soil swelled linearly. There was a linear relationship between the rate and the water content. With the increase of the initial water content, the hygroscopic expansion rate and expansion rate of the expansive soil decreased. With the increase of the dry density, the hygroscopic expansion rate and the expansion rate of the expansive soil increased. The water absorption performance did not decrease, and the soil continued to maintain the previous moisture absorption rate and expansion rate after the soil reached saturation, while after the water content reached 1.5∼2.0 times the saturated water content, the soil moisture absorption expansion rate gradually decreased until it finally stabilized. The slope k of the expansion rate increased with the initial dry density and decreased with the initial moisture content. As dry density was increased, the slope k was increased at an increased rate. Moreover, as the initial moisture content was decreased, the slope k was increased at an increased rate.

scholarly journals Temperature and seed moisture content affect electrical conductivity test in pea seeds

2017 ◽  
Vol 39 (4) ◽  
pp. 410-416 ◽  
Author(s):  
Lara Bernardes da Silva Ferreira ◽  
Nayara Alves Fernandes ◽  
Luan Costa de Aquino ◽  
Anderson Rodrigo da Silva ◽  
Warley Marcos Nascimento ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Moisture Content ◽  
Water Content ◽  
Initial Water Content ◽  
Seed Moisture Content ◽  
Initial Water ◽  
Test Efficiency ◽  
Seed Moisture ◽  
Pea Seeds ◽  
Initial Seed

Abstract: Several factors affect the electrical conductivity test efficiency, with emphasis given to the initial water content and the temperature during imbibition. This study aimed to evaluate the effect of the initial water content of pea seeds and the temperature on the electrical conductivity test efficiency. Six lots of ‘Mikado’ pea were used, which were previously tested for initial characterization. In the first trial, based on the initial value of the samples, the seed moisture content was adjusted to 9, 11, 13 and 15% and then the seeds were submitted to the electrical conductivity test. In the second trial, the water for seed imbibition was kept for 24 hours at 10, 15, 20, 25 and 30 ºC, and after that time the seeds were added and soaked for other 24 hours at the temperatures already mentioned. It was observed that initial seed moisture content and water temperature during imbibition influenced the results of the electrical conductivity test. This test should be carried out with distilled water, previously maintained for 24 hours at 25 °C for temperature stabilization. Then, the seeds with seed moisture content between 11 and 15% should be put to soak at 25 °C, and maintained at this temperature for 24 hours.

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.

A Forecasting Method of Kostiakov Infiltration Model Parameters Based on Back-Propagation Model

2012 ◽  
Vol 610-613 ◽  
pp. 2899-2903
Author(s):  
Chong Wen Cao ◽  
Gui Sheng Fan
Keyword(s):  
Back Propagation ◽  
Influence Factors ◽  
Propagation Model ◽  
Water Infiltration ◽  
Physical Parameters ◽  
Model Parameters ◽  
Soil Infiltration ◽  
Infiltration Process ◽  
Infiltration Model ◽  
Bp Model

Based on test data of field soil water infiltration, Back-propagation (BP) model of predicting Kostiakov infiltration model parameters was established after analyzing the primary influence factors of water infiltration model parameters. The results indicate that BP model can reflect the non-linear relationship between the model parameters and the physical parameters of the soil; BP model is high accuracy for prediction soil infiltration model parameters. It can be referred as a new method to predict soil infiltration process using soil physical parameters.

scholarly journals Characterization of the High Swelling Green Clay in the Vicinity of Amman Area

2021 ◽  
Vol 15 (1) ◽  
pp. 360-369
Author(s):  
Monther Abdel Hadi ◽  
Ibrahim Khliefat ◽  
Nafeth Abdelhadi ◽  
Nidhal Saada
Keyword(s):  
Moisture Content ◽  
Clay Mineral ◽  
Initial Moisture Content ◽  
Swelling Pressure ◽  
Liquid Limit ◽  
Engineering Properties ◽  
Dry Density ◽  
Initial Water Content ◽  
Foundation Design ◽  
Green Clay

Introduction: Jordan is awarded huge areas in the north and western part of the country in which brown and green clay is dominant. This research focuses on the problems and behaviour of the green clay only. The main problem of the green clay is its high swelling pressure which is the main cause of excessive settlement and wall cracks in buildings, especially during the wet season. Methods: This study aims to investigate the engineering properties and behaviour of the green clay deposits in the Amman area, which will serve as a guide for both geotechnical and structural engineers when preparing the foundation design. Results: Based on the consolidation test, the investigated green clay showed high swelling pressure of 3.11 kg/cm2, liquid limit (LL) of 73%, plasticity index (PI) of 40%, the shrinkage limit (SL) of 12%, and liquidity index (LI) of 0.125. The moisture content at saturation is 35.14%, while the natural moisture content is 28%, dry density is 1407 kg/m3, cohesion (C) is 0.20 kg/cm2 and unconfined compressive strength is 1.05 kg/cm2. The XRD results of the clay size fraction have confirmed the presence of the expansive clay mineral smectite as the essential clay mineral together with kaolinite. Results provide a general understanding of the behaviour and properties of the green clay, and the regression analysis showed good correlations between the liquid limit and initial moisture content with the compression index and also between the initial void ratios with the swelling index. Conclusion: Changes in the volume are due to the unsaturation level of clay when provided with initial water content.

scholarly journals Rainfall threshold for hillslope outflow: an emergent property of flow pathway connectivity

2006 ◽  
Vol 3 (5) ◽  
pp. 2923-2961 ◽  
Author(s):  
P. Lehmann ◽  
C. Hinz ◽  
G. McGrath ◽  
H.-J. Tromp-van Meerveld ◽  
J. J. McDonnell
Keyword(s):  
Percolation Theory ◽  
Water Saturation ◽  
Soil Depth ◽  
Free Water ◽  
Rainfall Threshold ◽  
Rainfall Amount ◽  
Model Parameters ◽  
Initial Water Content ◽  
Linear Processes ◽  
Initial Water

Abstract. Nonlinear relations between rain input and hillslope outflow are common observations in hillslope hydrology field studies. In this paper we use percolation theory to model the threshold relationship between rainfall amount and outflow and show that this nonlinear relationship arises from simple linear processes at the smaller scale. When the rainfall amount exceeds a threshold value, the underlying elements become connected and water flows out of the base of the hillslope. The percolation approach shows how random variations in storage capacity and connectivity at the small spatial scale cause a threshold relationship between rainstorm amount and hillslope outflow. As a test case, we applied percolation theory to the well characterized experimental hillslope at the Panola Mountain Research Watershed. Analyzing the measured rainstorm events and the subsurface stormflow with percolation theory, we could determine the effect of bedrock permeability, spatial distribution of soil properties and initial water content within the hillslope. Our results indicate that the measured variation in the relationship between rainstorm amount and subsurface flow is dominated by the initial moisture deficit, the loss of free water to the bedrock, the limited size of the system and by the connectivity due to macropores. The values of the model parameters were in agreement with measured values of soil depth distribution and water saturation.

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