• Water Engineering Research
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• v.4 no.1
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• pp.31-43
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• 2003

The impacts of climate change on soil moisture in sub - Arctic watershed simulated by using the hydrologic model. A range of arbitrary changes in temperature and precipitation are applied to the runoff model to study the sensitivity of soil moisture due to potential changes in precipitation and temperature. The sensitivity analysis indicates that changes in precipitation are always amplified in soil moisture with the amplification factor for flow. The change in precipitation has effect on the soil moisture in the catchment. The percentage change in soil moisture levels can be greater than the percentage change in precipitation. Compared to precipitation, temperature increases or decreases alone have impacts on the soil moisture. These results show the potential for climate change to bring about soil moisture that may require a significant planning response. They are also indicative of the fact that hydrological impacts affecting water supply may be important in consider-ing the cost and benefits of potential climate change.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.3
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• pp.266-269
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• 1995

Methane emission was measured every two hours for a whole day at heading stage of rice plantsby using a closed static chamber installed in NPK(11-70-80 kg/ha) plot and NPK+rice straw(5 ton/ha) plots. The effect of air and soil temperature on methane emission was studied. In NPK plot the diel change of methane emission was synchronized better with soil temperature than air temperature because of abrupt rise of air temperature from 11 : 00 to 17 : 00 hours. In NPK+rice straw plot diel methane emission showed proportionally increased with increase of soil temperature except for times from 11 : 00~17 : 00 hours when air temperature was very high, but showed a closer relation with change of air temperature. It was suggested that the diel change of methane emission was closely related to that of air temperature where organic matter was abundant, while to that of soil temperature where organic matter was limited.

• Journal of the Korean Data and Information Science Society
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• v.20 no.4
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• pp.649-654
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• 2009

Soil temperature is an important tool in predicting a change of climate and agricultural environment together with the change of atmospheric temperature. In this paper, we examine changing patterns of soil temperature measured in 0.5m under ground from 1932 to 1990 and atmospheric temperature from 1961 to 2008, and derive a relationship between atmospheric temperature and soil temperature. Using this model, we predict unmeasured soil temperature in Daegu area and soil temperature is found to be increasing about $0.028^{\circ}C$per a year. Prediction of soil temperature is an important indicator for climate change in Daegu and will be useful information to help us take precautions for global warming, etc.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.3
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• pp.105-113
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• 2007

This study was conducted to analyze the effects of environmental factors such as soil moisture, light intensity, temperature and humidity on changes in cambial electrical resistance. To improve data quality, cambial electrical resistance was continuously measured at fixed points by using a data logger isolated from alternating current. The relationship between environmental factors and changes in cambial electrical resistance was also analyzed. The results are as follows: 1. Cambial electrical resistance is highly correlated to the temperature of the measured area(r=-0.934). Therefore, temperature compensation is needed to analyze the effects of other environmental factors on cambial electrical resistance changes. 2. If temperature is compensated for, the change of cambial electrical resistance is highly correlated to water vapor pressure(r=-0.836). 3. If temperature and humidity are compensated for, the change of cambial electrical resistance is highly correlated to intensity of light(r=-0.738). 4. Diurnal deviation of soil water potential is not more significantly related than the change of cambial electrical resistance. However, in the long-term, soil water potential and cambial electrical resistance are highly correlated(r=-0.831). This indicates that soil moisture significantly influences the long-term change of cambial electrical resistance.

• The Korean Journal of Ecology
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• v.23 no.2
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• pp.117-123
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• 2000

Changing patterns and the possibility of climate change in the area of Cheiudo island, the southernmost Island in Korea, were analyzed using daily temperature and Precipitation data observed at the Cheiu Regional Meteorological Office from May 1923 to December 1998. A hydrologic simulation model "BROOK" was used to simulate and analyze the dynamics of daily soil moisture content and soil moisture deficit by applying the daily weather data. During the period, significantly increasing pattern was observed in temperature data of both annual and monthly basis, while no significantly changing pattern was observed in precipitation data. During the last 76 years. mean annual temperature was observed to have risen about 1.4$^{\circ}C$, which may show the Possibility of the initiation of climate change on the island whose validity should be tested in future studies after long-term studies on temperature. Based on the simulation, due to increased temperature, significant increase was predicted in evapotranspiration. while no significant decrease was detected in simulated soil moisture content during the period. Changing pattern of annual soil moisture content was markedly different from those of precipitation. In some dominant trees, negative effects of the drought of the late season for the previous year were shown to be statistically significant to radial growth of the tree for the current year. As annual variation of radial growth of trees is mainly affected by the soil moisture content. the information on the dynamics of soil moisture deficit possibly provides us with useful information for the interpretation of tree growth decline on the mountain. mountain.

• Journal of the Korean GEO-environmental Society
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• v.10 no.7
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• pp.93-101
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• 2009

Standing column well (SCW) heat pump system produces geothermal energy by the heat exchange of the groundwater. If SCW system changed the temperature of soil and groundwater, it could also change species or population of microorganisms. Therefore it is needed to research about the effect of temperature change on microorganisms to use eco-friendly geothermal energy. We produced the simulative heat pump system (SHPS) and observed the change of the soil temperature in SHPS. Characteristic analysis of microorganisms isolated from soil was performed and groundwater temperature variation was evaluated. Also the bleeding effect in SHPS was investigated and the results are included. As the results, the population of microorganisms was increased about 90%, as the groundwater temperature increased 2-3 celsius degree. However the species of microorganism was little influenced by the temperature change of the soil.

• Journal of Environmental Science International
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• v.5 no.6
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• pp.727-738
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• 1996

An one dimensional atmosphere-canopy-soil interaction model is developed to estimate of the heat budget parameter in the atmospheric boundary layer. The canopy model is composed of the three balance equations of energy, temperature, moisture at ground surface and canopy layer with three independent variables of Tf(foliage temperature), Tg(ground temperature), and qg(ground specific humidity). The model was verilied by comparative study with OSUID(Oregon State University One Dimensional Model) proved in HAPEX-MOBILHY experiment. Also we applied this model in two dimensional land-sea breeze circulation. According to the results of this study, surface characteristics considering canopy acted importantly upon the simulation of meso-scale circulation. The factors which used in the numerical experiment are as follows ; the change for a sort of soil(sand and peat), the change for shielding factor, and the change for a kind of vegetation.

• Journal of Ecology and Environment
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• v.42 no.2
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• pp.77-84
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• 2018

Background: For understanding and evaluating a more realistic and accurate assessment of ecosystem carbon balance related with environmental change or difference, it is necessary to analyze the various interrelationships between soil respiration and environmental factors. However, the soil temperature is mainly used for gap filling and estimation of soil respiration (Rs) under environmental change. Under the fact that changes in precipitation patterns due to climate change are expected, the effects of soil moisture content (SMC) on soil respiration have not been well studied relative to soil temperature. In this study, we attempt to analyze relationship between precipitation and soil respiration in temperate deciduous broad-leaved forest for 2 years in Gwangneung. Results: The average soil temperature (Ts) measured at a depth of 5 cm during the full study period was $12.0^{\circ}C$. The minimum value for monthly Ts was $-0.4^{\circ}C$ in February 2015 and $2.0^{\circ}C$ in January 2016. The maximum monthly Ts was $23.6^{\circ}C$ in August in both years. In 2015, annual precipitation was 823.4 mm and it was 1003.8 mm in 2016. The amount of precipitation increased by 21.9% in 2016 compared to 2015, but in 2015, it rained for 8 days more than in 2016. In 2015, the pattern of low precipitation was continuously shown, and there was a long dry period as well as a period of concentrated precipitation in 2016. 473.7 mm of precipitation, which accounted for about 51.8% of the precipitation during study period, was concentrated during summer (June to August) in 2016. The maximum values of daily Rs in both years were observed on the day when precipitation of 20 mm or more. From this, the maximum Rs value in 2015 was $784.3mg\;CO_2\;m^{-2}\;h^{-1}$ in July when 26.8 mm of daily precipitation was measured. The maximum was $913.6mg\;CO_2\;m^{-2}\;h^{-1}$ in August in 2016, when 23.8 mm of daily precipitation was measured. Rs on a rainy day was 1.5~1.6 times higher than it without precipitation. Consequently, the annual Rs in 2016 was about 12% higher than it was in 2015. It was shown a result of a 14% increase in summer precipitation from 2015. Conclusions: In this study, it was concluded that the precipitation pattern has a great effect on soil respiration. We confirmed that short-term but intense precipitation suppressed soil respiration due to a rapid increase in soil moisture, while sustained and adequate precipitation activated Rs. In especially, it is very important role on Rs in potential activating period such as summer high temperature season. Therefore, the accuracy of the calculated values by functional equation can be improved by considering the precipitation in addition to the soil temperature applied as the main factor for long-term prediction of soil respiration. In addition to this, we believe that the accuracy can be further improved by introducing an estimation equation based on seasonal temperature and soil moisture.

• Korean Journal of Ecology and Environment
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• v.46 no.3
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• pp.409-418
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• 2013

Global warming due to climate change is a problem facing the entire world. Several factors, such as $CO_2O$ concentration, level of warming, soil temperature, precipitation, water content of soil and denitrification by denitrifying bacteria influence the emission of nitrous oxide ($N_2O$) from soil. In this study, we investigated nitrous oxide emissions from the soil of two wetlands, Jilmoineup in Mt. Odae and Moojechineup in Mt. Jungjok, according to temperature change. Soil collected in Jilmoineup in July showed increasing $N_2O$ emissions as temperature increases, but did not show any significant differences at $10^{\circ}C$ (p<0.05). Soil of $15^{\circ}C$ and $20^{\circ}C$ showed increasing pattern of $N_2O$ emissions until 24 h. After that, however, there was no difference in temperature. Overall, $N_2O$ emissions showed significant differences according to temperature (p<0.05). Soil collected from Moojechineup in July showed increasing $N_2O$ emissions according to temperature increase, but did not show any significant differences at $10^{\circ}C$ (p<0.05) as was the case for Jilmoineup soil. On the other hand, two wetland soils showed a slight increase of $N_2O$ emissions by additional nitrogen supply, but did not show any significant differences in the presence of nitrogen or between nitrogen sources. In conclusion, increasing temperature the wetland soil increased the emission of $N_2O$, which is a known greenhouse gas. In order to more clearly identify $N_2O$ emissions, various subsequent studies such as the influence and correlation of several factors are required.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.440-448
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• 2023

This study measured soil respiration in pine forests dominated by Pinus densiflora in Mt. Jeombong, Mt. Namsan, Mt. Jirisan in Republic of Korea from 2009 to 2010. The seasonal variations, along with temperature and soil moisture content, were measured to understand the characteristics at each site. Soil respiration was highest in summer and autumn, closely influenced by the increase in soil temperature. Throughout the measurement period, soil respiration ranged from 205.6 to 312.2 mg CO₂ m^-2 h^-1, with Mt. Namsan showing the highest values and Mt. Jirisan the lowest. A strong correlation was observed between soil respiration and soil temperature, with Q₁₀ values ranging from 2.5 to 3.0. Precipitation significantly affected soil moisture content, and although it appeared to influence soil respiration, no significant correlation was found.