• Title/Summary/Keyword: Dry Areas

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Impacts of the Land-sea Distribution around Korean Peninsula on the simulation of East Asia Summer Precipitation (동아시아 여름 강수 모의에 있어 한반도 주변 해륙분포가 미치는 영향)

  • Cha, Yu-Mi;Lee, Hyo-Shin;Kwon, Won-Tae;Boo, Kyung-On
    • Atmosphere
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    • v.17 no.3
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    • pp.241-253
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    • 2007
  • This paper investigates summer precipitation change in East Asia according to switching surface boundary condition over South Korea and Shantung. Simulations are carried out by ECHO-G/S for 20 years (1980-1999). Surface condition over both areas in ECHO-G/S is represented by ocean (OCN experiment). In OCN experiment, the summer precipitation is considerably underestimated around the Korean peninsula (the dry region) and overestimated over the eastern Tibetan Plateau (the wet region). It may be related that the lack of the heat sources from the unrealistically prescribed land-sea mask weakens northward expansion of rainband and the development of convective precipitation. Moreover the simulated rainband retreats before June in connection with the early genesis of summer monsoon circulation. The systematic bias of the summer precipitation over the dry and wet regions are reduced comparing with the OCN experiment when the land-sea masks over South Korea and Shantung are realistically considered as land (LND experiment). These improvements can be explained by the thermodynamical dissimilarity between land and ocean. Enhanced warming by switching the areas from sea to land has led to develop the thermal low over Yellow Sea with the cyclonic circulation. Thus, this cyclonic circulation supports moistures from the south to the dry region and blocks to the wet region. The heat transport from the land surface to atmosphere plays a key role in the developing convective precipitation in local scale and maintaining the precipitation and the rainband. Therefore, this results indicate that the design of the realistic land-sea distribution is required for the accurate simulation of the regional precipitation.

Growth Characteristics and Major Medicinal Components of Endemic Resource Plants, Artemisia sp., Gynostemma pentaphyllum and Humulus japonicus, in Different Areas and Cultural Methods in Korea (자생식물 쑥, 돌외 및 환삼덩굴의 지역별, 재배방법별 생육 특성과 주요 약리 성분)

  • Ryu, Ik-Sang;Hwang, Ju-Kwang
    • Korean Journal of Medicinal Crop Science
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    • v.4 no.1
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    • pp.27-30
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    • 1996
  • This study was conducted to obtain basic information on growth characteristics and major components of three Korean endemic resource plant species, Artemisia sp., Gynostemma pentaphyllum Makino and Humulus japonicus S. et Z. , growing in different areas in Korea. Three geographical types of artemisia, namely Pangssuk, Ongjinssuk and Yakssuk which were collect in Suwon, Ongjin and Eumsong, respectively were compared in yield, and Pangssuk artemisia was higher in yield than the others. However, essential oil content was the highest in Yakssuk artemisia. Dry weight of areal parts of G. pentaphyllum was higher in the cultural method with props for tendril growth than in the conventional cultural method without props. Rutin was detected in areal parts of G. pentaphyllum. Dry weight of areal parts of H. japonicus collected at the Kyeryong mountain in Chungnam province was higher than that collected in Eumsong. A phenolic compound isoquercitrin was detected in areal parts of H. japonicus.

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Analysis of pollutant build-up model applied to various urban landuse

  • Choi, Jiyeon;Na, Eunhye;Ryu, Jichul;Kim, Jinsun;Kim, Hongtae;Shin, Dongsuk
    • Membrane and Water Treatment
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    • v.10 no.1
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    • pp.13-17
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    • 2019
  • This study was conducted to analyse the application of pollutant build-up model on various urban landuses and to characterize pollutant build-up on urban areas as a source of stormwater runoff pollution. The monitored data from impervious surfaces in urban areas such as commercial (8 sites), industrial (10 sites), road (8 sites), residential (10 sites), recreational (5 sites) from 2008 to 2016 were used for the analysis of pollutant build-up model. Based on the results, the average runoff coefficients vary from 0.35 to 0.61. In all landuses except recreational landuse, the runoff coefficient is 0.5 or more, which is the highest in the commercial area. Commercial landuse where pollutants occur at the highest EMC in all landuse, and it is considered that NPS management is necessary compared with other landuses. The maximum build-up load for organic matter (BOD) was highest in the commercial area ($4.59g/m^2$), and for particular matter (TSS) in the road area ($5.90g/m^2$) while for nutrient (TN and TP) in the residential area ($0.40g/m^2$, $0.14g/m^2$). The rate constants ranged from 0.1 to 1.3 1/day depending on landuse and pollutant parameters, which means that pollutant accumulation occurs between 1 and 10 days during dry day. It is clear that these build-up curves can generally be classified based on landuse. Antecedent dry day (ADD) is a suitable and reasonable variable for developing pollutant build-up functions. The pollutant build-up curves for different landuse shows that these build-up curves can be generally categorized based on landuse.

Users' Satisfaction from the Use of Park and Greens based on their Utilization in Gwangju-si (광주시 공원녹지 이용자의 이용 행태에 따른 만족도)

  • Jung, Su-Dong;Yeom, Sung-Jin;Seo, Joung-Young
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.24 no.2
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    • pp.1-17
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    • 2021
  • As population concentration, high-rise, and high-density progresses amid rapid industrialization and urbanization in Korea, green areas in the city have decreased significantly and the natural environment has deteriorated day by day due to various development projects. In order to cope with these social changes, many studies related to park and green areas have been conducted, but in the case of Gwangju-si, only studies on green areas such as vegetation structures, street facilities, and recreation forests have been conducted on park green areas. The situation is not losing. Therefore, in this study, a survey was conducted on Gwangju citizens to understand the usage behavior and satisfaction of park green areas, and to provide basic data for future park development and reorganization. As a result, first, to induce a variety of static and dynamic activities in order to increase the park satisfaction of Gwangju citizens, it is possible to create a park that has not been formed as soon as possible, and by planning programs with various themes. Second, it is necessary to expand green space services in marginalized areas by creating water streams, flower pots, and rooftop greening around the lives of Gwangju citizens, and create park green spaces with themes using cultural and historical resources for each administrative district. Third, in order to solve the dry landscape in some urban areas, it is necessary to establish a three-dimensional landscape plan by creating a variety of green areas such as potted plants, green areas, and street trees, and by giving functions of park green areas such as expanding leisure and convenience facilities.

The Study on the Selection of Revegetation Methods on Weathered Granite Cut-soil Slopes (화강풍화토 흙깎기 비탈면 녹화공법 선정 방안 연구)

  • Kim, Nam-Choon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.2
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    • pp.121-135
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    • 2016
  • The present study is an analysis of the monitoring results of the four areas that underwent the experimental construction of Straw-net+seedspray, Vegetation media spray method(t=2cm), and Vegetation media spray method(t=3cm), with the purpose of selecting the adequate revegetation of cutting slopes in weathered granite soil. Cutting slopes are mostly designed in the Straw-net+seedspray method, but since weathered granite soil slopes tend to have an infertile soil quality that runs down, it is difficult for seed germination and growth. It is difficult to apply Straw-net+seedspray to weathered granite soil slopes considering the germination rate and coverage rate of the Straw-net+seedspray method, which accompanies erosion and scouring. The final conclusions are summarized as follows. First, Straw-net+seedspray has difficulty recruiting plants to infertile weathered granite soil, which results in a lower coverage rate and fewer species, so it is not adequate construction method. Second, Vegetation spraying methods with wet media are more advantageous in early revegetation. The wet construction methods are faster than the dry construction methods in terms of early germination and its early growth are more excellent. Third, when constructing Vegetation spray methods with dry media, it were more advantageous if the thickness was thicker. When the soil-media is thicker, the soil is resilient to droughts, so the thickness must be flexibly applied according to the soil quality and slant of the weathered granite soil slope. The present study is a monitoring result for some areas of Gangwon-do, so its results may differ from other areas.

Sterols as Indicators of Fecal Pollution in Sediments from Shellfish Farming Areas (Yeoja Bay and Gangjin Bay) of Korea (분변계 스테롤을 이용한 남해안 패류양식어장(여자만과 강진만)의 퇴적물내 분변오염도 평가)

  • Choi, Minkyu;Lee, In-Seok;Hwang, Dong-Woon;Kim, Hyung Chul;Kim, Ye-Jung;Kim, Sook-Yang
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.4
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    • pp.437-444
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    • 2013
  • Eight fecal sterols were analyzed in surface sediments collected from shellfish farming areas in Yeoja Bay and Gangjin Bay, Korea, to evaluate sewage-derived fecal pollution. The concentrations of coprostanol, a good marker of sewage-derived organic contamination, in sediments were in the range of 10-530 ng/g-dry in Yeoja Bay, and 10-190 ng/g-dry in Gangjin Bay. Coprostanol levels were markedly higher in the inner bay than in the outer bay. These levels were lower than those reported in urbanized bays in Korea, however, they were comparable to levels in other shellfish farming areas including Gamak Bay. A multivariate analysis of the ratios of other sterols suggested that the sterols originated from sewage and plankton/benthos. Sewage was the dominant source at stations located close to the river mouth and wastewater treatment plant (WWTP) outfalls, and plankton/benthos was the primary source in the outer bay. These results suggest that management of point sources, e.g., WWTP as well as non-point sources, e.g., riverine inputs is important for improving the water quality in Yeoja Bay and Gangjin Bay.

Estimating Soil Loss in Alpine Farmland with RUSLE and SEDD (RUSLE와 SEDD를 이용한 고랭지 경작지로부터의 토양유실 평가)

  • Cho Hong-Lae;Jeoung Jong-Chul
    • Spatial Information Research
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    • v.13 no.1 s.32
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    • pp.79-90
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    • 2005
  • The purpose of this study is to estimate quantitatively soil loss and sediment yield in alpine farmland. For this purpose, Naerinchon watershed in Gangwon province was selected as our study area and total annual soil loss and sediment yield was estimated respectively by the Revised Universal Soil Loss Equation (RUSLE) model and the Sediment Delivery Distributed (SEDD) model. The results of this study clearly show that dry field areas have significant impact on the total soil erosion and sediment yield compared with other land use. Dry field areas represent only $2.6\%$ of the total area of the watershed but soil loss and sediment yield account for $10.9\%$ and $33.12\%$ of the total amount respectively Especially as with alpine farmland, this result is more clearly shown. These areas account for $1.8\%$ of the entire watershed but contribute to $7.7\%$ and $15\%$ of the total soil loss and sediment yield respectively. From the above results, we can know that alpine farmland is important source of soil loss and sediment yield and it is need to prevent and control. soil erosion from alpine filmland urgently.

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Effects of Mowing and TIBA(Triiodobenzoic acid) on Dry Matter Production of Cultivated Zoysia japonica Community (잔디깍기와 TIBA 처리가 잔디 인공군락의 물질생산에 미치는 영향)

  • 진희성
    • Journal of Plant Biology
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    • v.30 no.2
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    • pp.135-149
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    • 1987
  • An experiment was made in order to analyze the growth characteristics and productivity of Zoysia japonica under control, mowing and TIBA treatment conditions at the experimental farm of Kyung Hee University. The field was planned by the split plot design method and each treatment was given to two plots (40$\times$40 and 100$\times$100 mm) and was replicated three times. Each plot was 9$m^2$ for Zoysia japonica. The sampling of each plot was taken once a week after sowing. In order to know the dry matter of total standing crops, each organ of plants was kept at 9$0^{\circ}C$ and weighed. Total leaf area of a plant was measured by drawing method. The author adopted the growth analysis of English School. Holocellulose analysis by sodium chlorite method was made. The increasing rate of LAI was high in all plots between 10th and 12th week after sowing and high growth rate of assimilatory organ was observed in low density area of TIBA plot. Between 10th and 12th week after sowing all the experimental plots showed high increasing rate of standing crop and in the process of growth each density area of TIBA plot recorded high increasing rate. In all the plots F/C ratio and RGR were high when the growth rate of assimilatory organ was increasing cosiderably, and the higher the planting density was, the higher F/C ratio was recorded. In all the plots NAR recorded maximum rate before the growth period to show a high increase of RGR. In the process of the growth TIBA plot showed high icnreasing rate of NAR. CGR showed high value in high density areas of all the plots and reached its maximum in the 13th week after sowing. Compared to the other experimental areas the low planting density areas of control plot and TIBA plot showed considerable earlier lignification indicating low Holocellulose content in the growth process.

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Review of earthquake-induced landslide modeling and scenario-based application

  • Lee, Giha;An, Hyunuk;Yeon, Minho;Seo, Jun Pyo;Lee, Chang Woo
    • Korean Journal of Agricultural Science
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    • v.47 no.4
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    • pp.963-978
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    • 2020
  • Earthquakes can induce a large number of landslides and cause very serious property damage and human casualties. There are two issues in study on earthquake-induced landslides: (1) slope stability analysis under seismic loading and (2) debris flow run-out analysis. This study aims to review technical studies related to the development and application of earthquake-induced landslide models (seismic slope stability analysis). Moreover, a pilot application of a physics-based slope stability model to Mt. Umyeon, in Seoul, with several earthquake scenarios was conducted to test regional scale seismic landslide mapping. The earthquake-induced landslide simulation model can be categorized into 1) Pseudo-static model, 2) Newmark's dynamic displacement model and 3) stress-strain model. The Pseudo-static model is preferred for producing seismic landslide hazard maps because it is impossible to verify the dynamic model-based simulation results due to lack of earthquake-induced landslide inventory in Korea. Earthquake scenario-based simulation results show that given dry conditions, unstable slopes begin to occur in parts of upper areas due to the 50-year earthquake magnitude; most of the study area becomes unstable when the earthquake frequency is 200 years. On the other hand, when the soil is in a wet state due to heavy rainfall, many areas are unstable even if no earthquake occurs, and when rainfall and 50-year earthquakes occur simultaneously, most areas appear unstable, as in simulation results based on 100-year earthquakes in dry condition.

Estimation of Runoff Characteristics of Non-point Pollutant Source by Land Cover Characteristics (토지피복 특성에 따른 비점오염원 유출특성 평가)

  • Lee, Jae-Woon;Yi, Youn-Jeong;Kwon, Hun-Gak;Yoon, Jong-Su;Lee, Chun-Sik;Cheon, Se-Uk
    • Journal of Environmental Science International
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    • v.21 no.8
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    • pp.977-988
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    • 2012
  • This study analyzed the characteristics of stormwater runoff by rainfall type in orchard areas and transportation areas for 2 years(2010~2011year). Effluents were monitored to calculate the Event Mean Concentrations(EMCs) and runoff loads of each pollutant. The pollutant EMCs by volume of stormwater runoff showed the ranges of BOD 0.9~13.6 mg/L, COD 13.7~45.2 mg/L, SS 4.1~236.4 mg/L, T-N 2.123~21.111 mg/L, T-P 0.495~2.214 mg/L in the orchard areas, and was calculated as BOD 2.3~22.5mg/L, COD 4.4~91.1 mg/L, SS 4.3~138.3 mg/L, T-N 0.700~13.500 mg/L, T-P 0.082~1.345 mg/L in the transportation areas. The correlation coefficient of determination in the orchard area was investigated in the order of Total Rainfall(0.81) > Total Runoff(0.76) > Rainfall Intensity(0.56) > Rainfall Duration(0.46) > Antecedent Dry Days(0.27). Also, in the case of the transportation area was investigated in the order of Total Rainfall (0.55) > Total Runoff(0.54) > Rainfall Intensity(0.53) > Rainfall Duration(0.24) > Antecedent Dry Days(0.14). As the result, comparing valuables relating to runoff of non-pollutant source between orchard areas and transportation areas, orchard area($R^2{\geq}0.5$ : X3, X4, X5) was investigated to have more influence of diverse independent valuables compared to the transportation area($R^2{\geq}0.5$ : X3, X4) and the difference of discharge influence factor by the land characteristics appeared apparently.