• Journal of the Society of Disaster Information
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• v.2 no.1
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• pp.53-64
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• 2006

This study presents the laboratory properties on the frost heave under various moisture contents and compaction efforts in pavement subgrade soil. Many researches were conducted on the frost heave. However, the researches with the domestic soils have not been so active until now. In particular, the evaluation of the frost heave in pavement subgrade soils was not established by many researchers. The problems relating with the frost heave have been serious causes in the distresses of pavements. The study was performed using an appropriate field simulation. The research results revealed that the drainage conditions in earth work should be treated cautiously.

• International journal of advanced smart convergence
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• v.10 no.1
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• pp.89-96
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• 2021

The goal of this study is to develop experiment monitoring system of agriculture fields using ZigBee wireless modules. Soil moisture, ambient temperature, atmospheric pressure and intensity of sunlight are the most important factorsto grow a wheat crop and other vegetables. In orderto monitorthe factorssoil moisture (YL69), air pressure (BMP180), temperature (DS18B20), photoresistor were used for sensing environment data. The TI CC2530 RF SoC chip was used in the system. ZigBee modules were connected to star topology. ZigBee modules send data wirelessly to a data center. This data can be displayed and analyzed on the main monitoring program as needed also sent to the client mobile. Characteristics of the sensors were determined by experiment results.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.331-336
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• 2011

Capacitance soil moisture sensor is extensively used by soil research and irrigation management with its convenience and accuracy. This experiment was conducted to evaluate the acceptability of capacitance soil moisture sensor, named EnviroSCAN made by Sentek Ltd., in Jeju Island where volcanic ash soils are widely distributed, and to calibrate it to various soils with different amount of soil organic matter. For sensor calibration equation of volcanic ash soils, a logarithm function is better than a typical power function of non-volcanic ash soils. So there are possibilities of under evaluated in soil water contents in very wet and very dry conditions by using typical power function with volcanic ash soil areas. We suggested practical coefficients of typical calibration equation for using capacitance sensor in volcanic ash soils, also suggested equations for estimation of them with soil organic matter contents. The measurement of soil water content with a capacitance sensor can be affected by some soil characteristics such as porosity, soil organic matter content, EC, etc. So those factors should be controlled for improving the accuracy of measurement.

• Journal of Wetlands Research
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• v.14 no.2
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• pp.237-242
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• 2012

In order to determine the ecological characteristics of Quercus serrata and Q. aliena, which are potential natural vegetation of riverine in Korea, we cultivated the seedlings of two oak species under light, soil moisture and nutrient gradients from April to October in glasshouse. Then, we measured aboveground, belowground and total plant biomass and analyzed the differences in growth between two oak species. The two oak species showed decreasing growth with lower light intensity, but reduction in growth of Q. aliena was greater than that of Q. serrata. Q. serrata and Q. aliena had a constant growth state under soil moisture gradients, but Q. aliena grew well more than Q. serrata in lower soil moisture gradient. As soil nutrient availability decreased, the growth of Q. aliena was greater than Q. serrata. These results mean that the growth of two oak species is not affected by soil moisture, but the part of growth in Q. serrata may be positively affected in lower soil moisture condition. Also, Q. serrata has strong shade tolerance and the ability to adapt high nutrient condition relative to Q. aliena. Thus, Q. serrata and Q. aliena will be advantageous for the growth in stream ecosystem due to high light availability, but Q. serrata will be distributed near the lowlands by the water environment. Also, because the two oak species need high soil nutrient, it is important to preserve herbaceous vegetation to prevent nutrients that flowed in the streams.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.2
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• pp.29-39
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• 2009

Research was initiated to investigate a vegetation characteristics of the winter season by seeding periods. 3 seeding periods (Mid-December seeding plot, Late January seeding plot and Early March seeding plot) and 3 zones (the top zone, the middle zone and the bottom zone) in each plot were treated with 3 replications on the experimented slope. Data such as vegetation coverage (%), soil hardness (MPa), temperature ($^{\circ}C$) and moisture (%) content were analyzed. The vegetation coverage was high in Early March seeding plot, medium in Mid-December, and low in Late January seeding plot. Early March seeding plot was effective in moisture content, soil hardness, and temperature for the growth of vegetation when compared to Late January seeding plot and Mid-December seeding plot. From the standpoint of coverage ratio of plant species, the coverage of Dianthus sinensis and Albizzia julibrissin were high in the Late January seeding plot whereas the coverage of Lotus corniculatus and Cool-season turfgrass were high in Early March seeding plot. These results indicated that the high vegetation coverage of Dianthus sinensis and Albizzia julibrissin in Early March seeding plot was caused by scarification during winter season. There was no difference observed in plant height regardless of seeding periods except in early surveying time of May and June after seeding. As far as each zone of the plot was concerned, the vegetation coverage was high. in the bottom zone, medium in the middle zone and low in the top zone. The bottom area of the experimented slope was high in moisture content when compared to the middle zone and the top zone.

• Magazine of the Korean Society of Agricultural Engineers
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• v.33 no.2
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• pp.112-119
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• 1991

Some experiments were carried out to investigate the effects of freezing and thawing on the strength and strain characteristics of alluvial silty clay under the different temperatures, loading and moisture conditions. The results were as follows; 1. The soil used was proved to be consisted of silty clay with honey-combed structure, and showed higher dilatancy, frost activity and lower stability in natural state. 2. Soil treated with freezing and thawing cycles showed lower compressive strength compared with the non treated, The strength decreased with incement of freezing and thawing cycles. It's shapes of stress-strain curves were flat and did not formulate a peak while the peak strength of higher moisture content soil decreased with the increment of moisture content. It's decrement ratio was most distinctly shown at the first one cycle of freezing and thawing. 3. The cohesion decreased due to freezing and thawing cycles but internal frcition angle was not changed. 4. The liquid limit decreased with increment of freezing and thawing cycles, and became almost constant after three cycles of freezing and thawing. 5. The strength under simple loading at failure mode was appeared to be higher compared with the cyclic loading after freezing and thawing but initial moisture content effect was not observed. 6. Ice lense was not observed within 50% of ice content ratio but observed over 100%. The higher the ice content ratio, the higher the peak strength. As a matter of fact, it seems that an optimum ice content ratio exists for plastic mode and the least compressive strength.

• Journal of Electrochemical Science and Technology
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• v.14 no.3
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• pp.205-214
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• 2023

Soil salinity is becoming one of the most devastating environmental hazards over the years. Soil investigation involves fast, low cost and non disturbing methods to measure soil characteristics for both construction projects as well as for agricultural use. The electrical resistivity of saline soils is greatly governed by salt concentration and the presence of moisture in soil matrix. Experimental results of this investigation highlight that there is a significant relationship between the electrical resistivity of soil samples mixed with chloride solutions (NaCl, KCl, and MgCl₂) at various concentrations, and soil physical properties. Correlations represented by quadratic functions were obtained between electrical resistivity and soil characteristics, namely, water content, degree of saturation and salt concentration. This research reveals that the obtained correlations between electrical resistivity, salt concentration, water content and degree of saturation are effective for predicting the characteristics of salt affected soils in practice, which constitute a governing element in the assessment of saline lands sustaining infrastructure.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.6
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• pp.77-83
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• 2001

The purpose of this study is to provide the fundamental material and information for the plant maintenance after rooftop planting through physiochemical characteristics. The characteristics of artificial soils after rooftop planting from 1993 to 1999 was investigated. Fourteen investigation areas were selected from 4 cities(2 areas selected by each year). The analysis of the circumstances of the areas, the physical characteristics, and the chemical characteristics of the soil were conducted. The artificial soil pH ranged 5.26∼7.40 showing that after construction the soil pH tended to decrease. The soil bulk density of the site was lowest in 1999, 0.15g/㎤, and used to increase toward 1993. We found the fact that the soil bulk density increased gradually after rooftop application . The coefficients of permeability of the soils range from 0.016 to 0.052 cm/sec, which seemed to be in good permeability level. The artificial soils had relatively high water moisture capacity of 62.69∼71.36%. The soil organic matter content of the artificial soils ranged from 0.43 to 1.34%. The exchangeable caution concentration in the artificial soil ranged, Na, 2.36∼4.71mg·{TEX}$kg^{-1}${/TEX}, Mg 0.88∼2.84mg·{TEX}$kg^{-1}${/TEX},K 2.97∼9.61 mg·{TEX}$kg^{-1}${/TEX}, and Ca 9.39∼28.23 mg·{TEX}$kg^{-1}${/TEX}. The amount of total N ranged from 0.003 to 0.286% in study sites. Soil chemical properties varied year to year and showed little tend. The research results showed that some characteristics of the artificial soil were changed after rooftop planting, i.e., soil pH and soil bulk density. Soil bulk density had a negative relationship with the coefficient of permeability, showing that the drainage condition might be limited after some period. This study suggests that a diversity of the research in the changes of the plant growth basis on the areas after construction.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.6
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• pp.749-758
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• 2004

Nitrous oxide ($N_2$O) has been known as an important trace gas due to the greenhouse gas and the major source of stratospheric oxide of nitrogen (NO). Soil is the major source of $N_2$O in nature. The physicochemical characteristics of soils affect the emission of $N_2$O from soil. These physicochemical parameters are soil moisture, soil temperature, and soil N content. Since these parameters are correlated to the flux of $N_2$O from soil individually and compositely, there still remain many unknowns in the mechanism to produce $N_2$O in soil and the roles of such physicochemical parameters which affect the soil $N_2$O emission. Soil $N_2$O fluxes were measured at different levels in water filled pore space (WFPS), soil temperature and soil N contents from the same amounts of soils which were sampled from agriculturally managed upland field in a depth of ～30 cm at Kunsan. The soil $N_2$O flux measurements were conducted in a laboratory with a closed flux chamber system. The optimum soil moisture and soil temperature were observed at 60% of WFPS and ～13$^{\circ}C$. The soil $N_2$O flux increased as soil N contents increases during the whole experimental hours (up to 48 hours). However, average $N_2$O flux decreased after ～30 hours when organic carbon was mixed with nitrogen in the sample soils. It is suggested that organic carbon could be important for the emission of $N_2$O, and that the ratio of N to C needs to be identified in the process of $N_2$O soil emission.

• Advances in environmental research
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• v.8 no.1
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• pp.39-54
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• 2019

This paper presents comprehensive scientific details about mangrove soil in Gulf of Kachchh, Gujarat. A total of ten sites were studied during November, 2011 to December, 2014 in order to know the physico-chemical characteristics of mangrove soil. The results indicated that the soil in GoK had silty loam texture. Other physico-chemical parameters ranged as; pH: 7.39-7.61, Bulk Density: 0.30 g/㎤-0.54 g/㎤, Particle Density: 1.26 g/㎤-1.76 g/㎤, Organic Carbon: 0.70%-1.13%, Organic Matter: 1.01%-1.74% and Moisture Content: 33.45%-56.38%. The paper would be useful to the stakeholders, coastal managers and scientific communities to know the mangrove soil conditions of Gulf of Kachchh for management and planning for conservation of mangrove ecosystem.