• Proceedings of the KSEEG Conference
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• 2002.04a
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• pp.40-41
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• 2002

• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.155-161
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• 2018

For the efficient recovering of collapsed sloped soil, using a soil binder that can support the soil strongly and help the growth of plants is very important. The soil binder should also have functions of recovering the soil ecologically as well as be environmental friendly materials. In this research, optimum values of the water content and permeability and direct shear strength were searched by adding the water absorbent and coagulant into the soil binder. The polyacrylamide (PAM) with various anionic strength, super absorbent polymer (SAP) and cellulose ether (CE) were used as a soil binder, water absorbent and coagulant, respectively. Effects of the soil binder on the characteristics of soil were observed by changing the mixing ratio of PAM, SAP and CE. Experimental results showed that the soil binder increased the direct shear strength tens of times and the water content around two times, whereas decreased the water permeability. Also, the addition of CE to increase the coagulation of SAP increased more of the direct shear strength and water content.

• Journal of Korea Water Resources Association
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• v.51 no.5
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• pp.417-424
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• 2018

This study analyzed the effect of irrigation reservoirs, antecedent soil moisture conditions (AMC) and Huff time distribution on peak discharge using Monte Carlo simulation. The peak discharge was estimated for four different cases in combination of irrigation reservoir capacity, AMC, and Huff time distribution. Applying 100% reservoir capacity or AMC-III, the peak discharges corresponding return periods of 50~300 years were overestimated by 25~30% compared to those of cases that considered the probability of occurrence for individual condition. Applying the 3rd quantile huff distribution, the peak discharges were overestimated by 5% over the peak discharge that considered the probability of occurrence. The overall results indicated that the effect on the peak flood of Huff distribution was less than AMC and reservoir storage.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.2
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• pp.129-134
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• 1997

Effect of soil moisture level on the growth of ginger plant was investigated through a pot experiment. The soil used for this study was collected from a newly reclaimed hillside land. The soil was a silty clay loam(19% sand, 57% of silt and 24% of clay), acidic in soil rection(pH 4.7, in $H_2O$) and low in organic matter content(1.2%). Soil moisture levels selected for the experiment were 10, 15, 20, 25, and 30% on weight basis. Under the soil moisture of 20-25%, the emergence ratio was 80-100%, 25 days alter planting. The performance of above ground parts was best under 20-25% of soil moisture. When the soil moisture content was far from 25%, high or low, the die out of above ground parts of ginger tended to increase. Under 20-25% of soil moisture the growth of roots was best and the occurrence of root rot was minimal.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.2
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• pp.175-181
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• 1982

This experiment was carried out to study the influence of the various soil water regimes on photosynthesis and growth and development of ginseng plant (3 years). The results were as follows: optimum soil water content for root dry weight and diameter appeared to be 62% of field capacity (13.9% fresh weight basis). The 62% field capacity showed superiority in leaf area, leaf dry weight and also in number of flower, fruit, seed per plant. Net photosynthesis rates per unit area increased with increasing soil water content but net photosynthesis rates per plant were superior in 62% field capacity. Rates of transpiration increased linearly with increasing soil water content but density of stomata decreased with increasing soil water content.

• 한국방재학회:학술대회논문집
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• 2010.02a
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• pp.89.1-89.1
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• 2010

본 연구는 토양의 함수비를 측정하기 위하여 TDR(Time Domain Reflectometry, 시간영역 광전자파 분석기) 방식의 함수센서(CS616)에 대한 올바른 보정시험을 제안하기 위하여 피복두께, 센서간 간섭 영향, 온도의 영향 및 다짐율 변화에 대한 실내 시험을 수행하였다. 시험 결과 피복두께, 센서간 간섭 영향 및 온도의 영향은 체적함수비의 크기에 미치는 영향은 크지 않은 것으로 나타났으며, 오히려 보정시험시 정확한 체적함수비 조건을 유지하는 것이 중요할 것으로 사료된다. 또한 보정시험을 수행할 때 다짐율까지 고려한 시험을 수행하는 노력에 비하여 얻어지는 체적함수비의 정확도의 크기는 다짐율과 주기를 고려하여 얻어진 회귀식을 살펴보면 주기에 비하여 상대적으로 영향이 작은 것으로 사료된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.343-343
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• 2023

식생피복(Vegetation cover)은 대기 중의 강우와 토양 사이에서 침식으로부터 표토를 보호하는 역할을 한다. 자유 낙하하는 강우의 물방울은 식생을 통과하면서 차단(interception), 수관통과(throughfall), 수간유하(stemflow)의 형태로 변화한다. 식생은 강우입자의 운동에너지와 수량을 감소시키고, 지표면에 도달하는 시간을 지연시킴에 따라 지표유출(overland flow) 저감에 기여한다. 유출수의 흐름과정에서 식물의 줄기, 낙엽, 뿌리 등은 유속을 감소시키는 장애물로 작용하여 궁극적으로 토양침식은 감소한다. 토양침식은 식생피복이 증가함에 따라 일반적으로 감소하며, 지수함수의 관계를 갖는다. 식생의 종류와 구조 그리고 잎의 모양 등에 따라 수문물리적인 반응이 달라진다. 캐노피를 갖는 지상식물(canopy cover plant)은 물방울의 운동에너지를 갖는 반면, 지피식물(ground cover plant)은 낙하고가 작기 때문에 운동에너지는 적으며, 특히 낙엽층은 지표면을 보호하여 토양침식의 저감효과가 더욱 크다. 산불지역의 식생피복에 따른 토양침식 측정 자료에 따르면, 강우운동에너지는 식생피복이 증가함에 따라 지상피복(canopy cover)에 의한 감소보다는 지면피복(ground cover)과 낙엽피복(litter cover)에 의한 감소효과가 상대적으로 컸다. 식생피복에 의해 차단되는 강우의 손실량보다 침투량 증가에 의한 손실량이 상대적으로 많았다. 낙엽피복에 대한 강우모의 실험 결과에 따르면, 낙엽의 피복율이 증가함에 따라 지수적으로 토양침식량은 감소하였다. 낙엽 피복율의 40% 이상은 토양침식량을 현격이 감소시킨 반면, 피복율의 70% 이상은 지표유출량을 현저히 감소시켰다. 낙엽 피복율이 70%이상이면, 유출계수가 33%가 감소하였으나, 토양침식민감도는 94%로 크게 감소하였다.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.478-485
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• 2019

As environmentally sound agriculture emphasize gradually as well as the importance of environment, many studies on weed and soil nematode control of new concept which does not affect adversely environment are in progress. For this purpose, plant seeds which are representative weed species in field were selected and treated with microwave having generating capacity of $17.73kw/m^3$, and investigated germination rates of weed seeds and the number of soil nematode according to soil moisture contents, soil depth and irradiation times. The microwave effect on the germination rates was extremely high in soil moisture content of 40% and irradiation time over 40 seconds for irradiation time, while soil depth did not affect germination rate. In view of the results so far achieved, it seems that universal dispersed microwave system is effective for the control of weed seeds.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.496-503
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• 2005

This study was conducted to investigate the influences of sapflow flux on soil water tensions and soil moisture content at the Abies holophylla plots in Gwangneung, Gyeonggido, from September to October 2004. The Abies holophylla had been planted in 1976 and thinning and pruning were carried out in 1996 and 2004. Sapflow flux was measured by the heat pulse method, and soil water tension was measured by tensiometer at hillslope and streamside. Time domain reflectometry probes (TDR) were positioned horizontally at the depth of 10, 30 and 50 cm to measure soil moisture content. All of data were recorded every 30 minutes with the dataloggers. The sapflow flux responded sensitively to rainfall, so little sapflow was detected in rainy days. The average daily sapflow flux of sample trees was 10.16l, a maximum was 15.09l, and a minimum was 0.0l. The sapflow flux's diurnal changes showed that sapflow flux increased from 9 am and up to 0.74 l/30 min. The highest sapflow flux maintained by 3 pm and decreased almost 0.0 l/30 mm after 7 pm. The average soil water tensions were low ($-141.3cmH_2O$, $-52.9cmH_2O$ and $-134.2cmH_2O$) at hillslope and high ($-6.1cmH_2O$, $-18.0cmH_2O$ and $-3.7cmH_2O$) at streamside. When the soil moisture content decreased after rainfall, the soil water tension at hillslope responded sensitively to the sapflow flux. The soil water tension decreased as the sapflow flux increased during the day time, whereas increased during the night time when the sapflow flux was not detected. On the other hand, there was no significant relationship between soil water tension and sapflow flux at streamside. Soil moisture content at hillslope decreased continuously after rain, and showed a negative correlation to sapflow flux like a soil water tension at hillslope. As considered results above, it was confirmed that the response of soil moisture tension to sapflow flux at hillslope and streamside were different.

• Proceedings of the KSEEG Conference
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• 2000.04a
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• pp.57-58
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• 2000