• Journal of The Korean Society of Grassland and Forage Science
• /
• v.36 no.2
• /
• pp.109-114
• /
• 2016

This study was conducted to determine grazing intensity of growing Korean native goats (Capra hircus coreanae) on mountainous pasture. It was carried out to obtain basic information for improvement of mountainous pasture management and establishing feeding system of Korean native goats. Castrated, male goats (n=10) with average initial body weight (BW) of $23.33{\pm}2.15kg$ and an average age of 4 months were used in this study. Grazing goats were supplemented by concentrates with 1.0% of BW. The crude protein content of forage was the highest in October ($22.71{\pm}0.25%$) and there were significantly differences (p<0.05) in monthly comparison. The forage productivity of pasture was the highest from May to June ($1718.7{\pm}207.5{\sim}1672.0{\pm}422.8kg/ha$ but it was decreased in July ($1356.0{\pm}103.8kg/ha$) because of drought and summer depression. Average daily gains (ADG) of goats were the highest in June ($99.5{\pm}6.4d/g$). Grazing intensity was calculated by forage productivity and dry matter intake (DMI) and was the highest in May (65 head/ha). As shown in the results of this research, grazing intensity was suggested to average 39 head/ha from May to October. It is desirable that adequate grazing intensity was maintained by adjusting supplemental feed.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.18 no.3
• /
• pp.4184-4194
• /
• 1976

Located in the southwestern part of Korea, the Yong San Gang river flows generally northeast to southwest, and because of the specific location, topography and climate, the basin area is subject to recurrent drought and flood damages. To eliminate the cause of such damages and ensure an increase in the farm income by means of effective irrigation supply and increased cropping intensity, efforts are being made to speed up implementation of an integrated agricultural development project which would include construction. of an estuary dam and irrigation facilities as well as land development and tidal reclarnation. In formulating a basin development project plan, it is necessary to study a series of long-term runoff data. The catchment area at the proposed estuary damsite is 3,471$\textrm{km}^2$ with the total length of the river channel up to this point reaching 138km. An analysis of runoff in this area was carried out. Rainfall was estimated by the Thiessen Network based on records available from 15 of the rainfall observation stations within the area. Out of the 15 stations, Kwang Ju and Mok Po stations were keeping long-term precipitation records exceeding some 60 years while the others were in possession of only 5-10 years records. The long-term records kept by those stations located in the center of the basin were used as base records and records kept by the remaining stations were supplemented using the coefficient of correlation between the records kept by the base stations and the remainder. The analyses indicate that the average annual rainfall measured at Kwang Ju during 1940-1972 (33 years) amounts to 1,262mm and the areal rainfall amounts to 1,236mm. For the purpose of runoff analysis, 7 observatories, were set up in the middle and lower reaches of the river and periodic measurements made by these stations permitted analysis of water levels and river flows. In particular, the long-term data available from Na Ju station significantly contributed to the analysis. The analysis, made by 4-stage Tank method, shows that the average annual runoff during 1940-1972 amounts to 2,189 million ㎥ at the runoff rate of 51%. As for the amount of monthly runoff, the maximum is 484.2 million ㎥ in July while the minimum is 48.3 million ㎥ in January.

• Journal of Soil and Groundwater Environment
• /
• v.16 no.6
• /
• pp.66-78
• /
• 2011

It is getting difficult to manage water resources in South Korea because more than half of annual precipitation is concentrated in the summer season and its intensity is increasing due to global warming and climate change. Artificial recharge schemes such as well recharge of surface water and roof-top rainwater harvesting can be a useful method to manage water resources in Korea. In this study, potential artificial recharge site is evaluated using geographic information system with hydrogeological and social factors. The hydrogeological factors include annual precipitation, geological classification based on geological map, specific capacity and depth to water level of national groundwater monitoring wells. These factors were selected to evaluate potential artificial recharge site because annual precipitation is closely related to source water availability for artificial recharge, geological features and specific capacity are related to injection capacity and depth to water is related to storage capacity of the subsurface medium. In addition to those hydrogeological factors, social aspect was taken into consideration by selecting the areas that is not serviced by national water works and have been suffered from drought. These factors are graded into five rates and integrated together in the GIS system resulting in spatial distribution of artificial recharge potential. Cheongsong, Yeongdeok in Gyeongsangbuk-do and Hadong in Gyeongsangnam-do, and Suncheon in Jeollanam-do were proven as favorable areas for applying artificial recharge schemes. Although the potential map for artificial recharge in South Korea developed in this study need to be improved by using other scientific factors such as evaporation and topographical features, and other social factors such as water-curtain cultivation area, hot spring resorts and industrial area where groundwater level is severely lowered, it can be used in a rough site-selection, preliminary and/or feasibility study for artificial recharge.

• The Journal of the Korea Contents Association
• /
• v.18 no.1
• /
• pp.154-163
• /
• 2018

Not only South Korea but also Global world show that the frequency and damages of large-scale natural disaster due to the rise of heavy rain event and typhoon or hurricane intensity are increasing. Natural disasters such as typhoon, flood, heavy rain, strong wind, wind wave, tidal wave, tide, heavy snow, drought, earthquake, yellow dust and so on, are difficult to estimate the scale of damage and spot. Also, there are many difficulties to take action because natural disasters don't appear precursor phenomena However, if scale of damage can be estimated, damages would be mitigated through the initial damage action. In the present study, therefore, wind wave damage estimation functions for the western coastal zone are developed based on annual disaster reports which were published by the Ministry of Public Safety and Security. The wind wave damage estimation functions were distinguished by regional groups and facilities and NRMSE (Normalized Root Mean Square Error) was analyzed from 1.94% to 26.07%. The damage could be mitigated if scale of damage can be estimated through developed functions and the proper response is taken.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.26 no.3
• /
• pp.258-266
• /
• 1998

The purpose of this study is to investigate the actual conditions, to find problems, and to present an improvement plan of interior landscape in the subway stationis. Moreoiver, it will presume the possibilties to develop the subway and ways to utilie underground space effectively. The results are summarized as follows A light intensity was recorded 0-100 Lux as the lowest light and 500 Lux below as the highest in 61 subway stations. An average temperature of 12 $^{\circ}C$and an air humidity of 38% were recorded over a 4 month period from January to April, but includes a drastic variaton between -8.5$^{\circ}C$ and 21.5$^{\circ}C$. Soil acidity of pH 7 below and soil moisture of 1-2 wet degree were apeared in subway stations mostly. Plant forms consisted of artificial flower & flower. Plant species were recorded at a total of 54 species and appeared in the order of Araucaria heteropylla, Ophiophogon jaburan, Aspidistra elatior cv. 'Asahi' and Hedera helix. Plant height was, for the most part, below 0.5m. Plant species that was fined of conditions were Palm, Camellia japonica, Araucaria heterophylla as a high plant, dracaena fragrans, dracaena deremensis cv. Wakneckii as a middle plant, and Ophiopogon jaburan, Hedra helix, ytomium falcatum, Aspidistra elatior cv. Asahi as a low plant. It used to water materials such as small pool, small cascade, water cycles and natural materials such as natural rock, small rock, sand, bark and animal materials such as squirrels, birds, goldfish as an object for plants in the subway stations. From these actual conditions, First of all, It must make up physical environments such as light, temperature humidity, soil for plant growth, and is important to chooce suitable indoor plants and draw up systematic management in the subway environments. Also, it change plants frequently and uses variable objects for subway stationi individuatism, Moreover, indoor plants with strong environmental adaptation abities such as shade tolerance, drought tolerance and cold tolerance need to develope variable species possibly. If these improvements occur, utilization and amenity of subway stationis will increase, according to the use of interior landscape.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.12 no.4
• /
• pp.84-94
• /
• 2009

Moisture Index time series derived from NOAA/AVHRR data have showed to be useful for humid and arid states. The humid/arid states of the Geum river basin are classified by means of the moisture index estimated from the climatic water budget model. Validations showed that the moisture index has excellent ability to detect humid/arid conditions and to measure time of its onset, intensity and duration. In this study, a simple method to classify the moisture index is proposed by statistical distribution condition. Also, the moisture index is compared with the regional actual state to detect drought area.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.157-157
• /
• 2022

Recent decades have seen all over the world increasing drought in some regions and increasing flood in others. Climate change has been alarming in many regions resulting in degradation and diminution of available freshwater. The effect of global warming and overpopulation associated with increasing irrigated farming and valuable agricultural lands could be particularly disastrous for coastal areas like the one of Benin. The coastal region of Benin is under a heavy demographic pressure and was in the last decades the object of important urban developments. The present study aims to roughly study the general effect of climate change (Sea Level Rise: SLR) and groundwater pumping on Seawater intrusion (SWI) in Benin's coastal region. To reach the main goal of our study, the region aquifer system was built in numerical model using SEAWAT engine from Visual MODFLOW. The model is built and calibrated from 2016 to 2020 in SEAWAT, and using WinPEST the model parameters were optimized for a better performance. The optimized parameters are used for seawater intrusion intensity evaluation in the coastal region of Benin The simulation of the hydraulic head in the calibration period, showed groundwater head drawdown across the area with an average of 1.92m which is observed on the field by groundwater level depletion in hand dug wells mainly in the south of the study area. SWI area increased with a difference of 2.59km² between the start and end time of the modeling period. By considering SLR due to global warming, the model was stimulated to predict SWI area in 2050. IPCC scenario IS92a simulated SLR in the coastal region of Benin and the average rise is estimated at 20cm by 2050. Using the average rise, the model is run for SWI area estimation in 2050. SWI area in 2050 increased by an average of 10.34% (21.04 km²); this is expected to keep increasing as population grows and SLR.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.309-309
• /
• 2022

특정 극치사상 자료에 대한 특성 분석 시 수문자료에 대한 빈도해석은 일반적으로 단일 확률 변수를 기준으로 이루어지는 단변량 해석 방법이 활용된다. 그러나 두 가지 이상의 변량이 서로 상관성을 가지는 경우 다변량 빈도해석이 요구되며, 이를 단변량으로 해석하는 경우 재현기간의 과소추정 등의 문제점이 발생할 수 있다. 최근 이러한 점을 개선하기 위하여 다변량 빈도해석에 관한 연구가 지속적으로 진행되고 있다(Kwon and Lall, 2016; Vaziri et al., 2018). 특히, 가뭄의 경우, 강도(intensity)뿐만 아니라 지속기간, 심도도 매우 중요한 인자로 고려되고 있다. 특히, 가뭄지속기간과 심도의 경우 두 인자 간의 상관성이 매우 크기 때문에 단변량(univariate) 가뭄빈도해석 보다 다변량으로(multivariate) 가뭄빈도해석을 수행하는 것이 가뭄위험도 평가 측면에서 유리하다고 알려져 있다(Shiau and Shen, 2001; Kim et al., 2017). 따라서 이 둘을 결합한 빈도 해석을 위해 Copula Function을 이용한 다변량 빈도 해석에 관한 연구들이 활발히 진행되고 있다. 홍수의 경우 지속시간별 연최대강수량 계열을 이용한 빈도해석 과정이 지침으로 정립되어 수자원 설계 실무에서 활용되고 있으나, 가뭄은 실무에서 활용할 수 있는 지침 및 분석 도구가 없는 실정이다. 이에 환경부와 국가가뭄정보분석센터에서는 '20년도에 단변량 가뭄빈도 해석을 위한 프로그램을 제작·배포하였다. 본 연구에서는 가뭄의 특성을 대변하는 상관도 높은 두 인자인 가뭄 심도(severity)와 가뭄 지속기간(duration)이라는 두 가지 특성을 함께 고려해 이변량(bivariate) 가뭄 빈도를 해석할 수 있는 도구를 개발하는 것을 목표로, 다양한 확률분포형을 이용한 최적 주변 확률분포형 선정과 최신 Copula Function들을 이용한 최적 결합확률분포 추정을 통해 신뢰도 높은 2변량 가뭄빈도 해석을 수행할 수 있는 프로그램을 제작하였으며, 테스트 버전 배포 등을 거쳐 누구나 사용할 수 있도록 공개할 예정이다.

• Journal of Bio-Environment Control
• /
• v.27 no.1
• /
• pp.94-101
• /
• 2018

Mugwort (Artemisia princeps) is a medicinal plant that has a substance called euphatilin, which is effective for cell damage and gastritis recovery. The objectives of this study were to investigate the annual growth characteristics of Artemisia princeps in greenhouse and to increase the eupatiline content by environmental stresses. Growth and eupatilin content of the plants were compared after 6 weeks of seedling and subsequent 8 weeks of greenhouse cultivation. Photosynthesis of mugwort plants did not saturate even at a relatively high light intensity of $1,200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Growth rate of the plants reached its highest at two weeks after transplanting and began to decrease since 8 weeks after transplanting. The plants showed typical characteristics of a perennial herbaceous plant as they were sensitive to seasonal changes. In particular, the plants showed high growth and eupatilin content in spring and summer as vegetative growth periods, but flowering and wintering caused considerable decreases in growth and eupatilin content in fall and winter. Therefore, application of night interruption is essential for year-round cultivationof the plant. Two stresses and a elicitor were treated: drought stresses by stopping irrigation at 5, 6, 7, and 8 days before harvest; salt stresses with nutrient solution concentrations of 2, 4, 6, 8, and $10dS{\cdot}m^{-1}$ by adding sodium chloride at 3 days before harvest; and foliar applications of methyl jasmonates of 12.5, 25, 50, and $100{\mu}M$ at 3 days before harvest. Significant increase in eupatilin content was observed at drought stresses of 7- and 8-days of irrigation stop and foliar application of $25{\mu}M$ methyl jasmonate, while no significant increase observed at salt stresses. From the results, it was confirmed that the environmental treatments can improve the productivity and quality of Artemisia princeps as a phamaceutical raw material.

• Korean Journal of Soil Science and Fertilizer
• /
• v.26 no.3
• /
• pp.143-150
• /
• 1993

To gain the basic informations on soil management practices by determination of the differences of soil genetic characteristics and the contents of soil moisture due to slope aspects of hilly land, this study was conducted at 1992 on sweet persimmon orchard soils derived from porphyry in southern of Korea. The results obtained were summarized as follows. The soils studied were belong to fine loamy family. The degree of soil development was greater in the north than other slope aspects and the solum thickness also the same. The soil chemical properties such as pH and exchangeable cations except for potassium were low generally in the orchards studied but the content of organic matter was lack in the summit and south aspect. The contents of Fe oxide and extractable Al were higher in the subsurface than surface. Fe, Al and clay indexes which indicate relative intensity of B horizon development were higher in the side slope than summit and the highest in the north slope. The rate of solum to B horizon was higher as about 1.5 for summit and west aspect which had thiner B horizon thickness compared to other aspect. North and west aspect had certainly more amount of soil water at drought season than other slope aspects and was lower the difference of soil water between the drought and wet seasons. Therfore, the soil management such as erosion control and irrigation at drought season should be practices differently due to slope aspect and soil chararteristics in the sloped land.