• Journal of Korean Society of Forest Science
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• v.45 no.1
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• pp.11-25
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• 1979

There was much mass movement at many different mountain side of Peong Chang area in Kwangwon province by the influence of heavy rainfall through August/4 5, 1979. This study have done with the fact observed through the field survey and the information of the former researchers. The results are as follows; 1. Heavy rainfall area with more than 200mm per day and more than 60mm per hour as maximum rainfall during past 6 years, are distributed in the western side of the connecting line through Hoeng Seong, Weonju, Yeongdong, Muju, Namweon and Suncheon, and of the southern sea side of KeongsangNam-do. The heavy rain fan reason in the above area seems to be influenced by the mouktam range and moving direction of depression. 2. Peak point of heavy rainfall distribution always happen during the night time and seems to cause directly mass movement and serious damage. 3. Soil mass movement in Peongchang break out from the course sandy loam soil of granite group and the clay soil of lime stone and shale. Earth have moved along the surface of both bedrock or also the hardpan in case of the lime stone area. 4. Infiltration seems to be rapid on the both bedrock soil, the former is by the soil texture and the latter is by the crumb structure, high humus content and dense root system in surface soil. 5. Topographic pattern of mass movement spot is mostly the concave slope at the valley head or at the upper part of middle slope which run-off can easily come together from the surrounding slope. Soil profile of mass movement spot has wet soil in the lime stone area and loose or deep soil in the granite area. 6. Dominant slope degree of the soil mass movement site has steep slope, mostly, more than 25 degree and slope position that start mass movement is mostly in the range of the middle slope line to ridge line. 7. Vegetation status of soil mass movement area are mostly fire field agriculture area, it's abandoned grass land, young plantation made on the fire field poor forest of the erosion control site and non forest land composed mainly grass and shrubs. Very rare earth sliding can be found in the big tree stands but mostly from the thin soil site on the un-weatherd bed rock. 8. Dangerous condition of soil mass movement and land sliding seems to be estimated by the several environmental factors, namely, vegetation cover, slope degree, slope shape and position, bed rock and soil profile characteristics etc. 9. House break down are mostly happen on the following site, namely, colluvial cone and fan, talus, foot area of concave slope and small terrace or colluvial soil between valley and at the small river side Dangerous house from mass movement could be interpreted by the aerial photo with reference of the surrounding site condition of house and village in the mountain area 10. As a counter plan for the prevention of mass movement damage the technics of it's risk diagnosis and the field survey should be done, and the mass movement control of prevention should be started with the goverment support as soon as possible. The precautionary measures of house and village protection from mass movement damage should be made and executed and considered the protecting forest making around the house and village. 11. Dangerous or safety of house and village from mass movement and flood damage will be indentified and informed to the village people of mountain area through the forest extension work. 12. Clear cutting activity on the steep granite site, fire field making on the steep slope, house or village construction on the dangerous site and fuel collection in the eroded forest or the steep forest land should be surely prohibited When making the management plan the mass movement, soil erosion and flood problem will be concidered and also included the prevention method of disaster.

• Korean Journal of Remote Sensing
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• v.33 no.6_1
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• pp.931-946
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• 2017

The purpose of this study is to observe and analyze soil moisture conditions with high resolution and to evaluate its application feasibility to agriculture. For this purpose, we used three Landsat-8 OLI (Operational Land Imager)/TIRS (Thermal Infrared Sensor) optical and thermal infrared satellite images taken from May to June 2015, 2016, and 2017, including the rural areas of Jeollabuk-do, where 46% of agricultural areas are located. The soil moisture conditions at each date in the study area can be effectively obtained through the SPI (Standardized Precipitation Index)3 drought index, and each image has near normal, moderately wet, and moderately dry soil moisture conditions. The temperature vegetation dryness index (TVDI) was calculated to observe the soil moisture status from the Landsat-8 OLI/TIRS images with different soil moisture conditions and to compare and analyze the soil moisture conditions obtained from the SPI3 drought index. TVDI is estimated from the relationship between LST (Land Surface Temperature) and NDVI (Normalized Difference Vegetation Index) calculated from Landsat-8 OLI/TIRS satellite images. The maximum/minimum values of LST according to NDVI are extracted from the distribution of pixels in the feature space of LST-NDVI, and the Dry/Wet edges of LST according to NDVI can be determined by linear regression analysis. The TVDI value is obtained by calculating the ratio of the LST value between the two edges. We classified the relative soil moisture conditions from the TVDI values into five stages: very wet, wet, normal, dry, and very dry and compared to the soil moisture conditions obtained from SPI3. Due to the rice-planing season from May to June, 62% of the whole images were classified as wet and very wet due to paddy field areas which are the largest proportions in the image. Also, the pixels classified as normal were analyzed because of the influence of the field area in the image. The TVDI classification results for the whole image roughly corresponded to the SPI3 soil moisture condition, but they did not correspond to the subdivision results which are very dry, wet, and very wet. In addition, after extracting and classifying agricultural areas of paddy field and field, the paddy field area did not correspond to the SPI3 drought index in the very dry, normal and very wet classification results, and the field area did not correspond to the SPI3 drought index in the normal classification. This is considered to be a problem in Dry/Wet edge estimation due to outlier such as extremely dry bare soil and very wet paddy field area, water, cloud and mountain topography effects (shadow). However, in the agricultural area, especially the field area, in May to June, it was possible to effectively observe the soil moisture conditions as a subdivision. It is expected that the application of this method will be possible by observing the temporal and spatial changes of the soil moisture status in the agricultural area using the optical satellite with high spatial resolution and forecasting the agricultural production.

• Korean Journal of Environment and Ecology
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• v.30 no.3
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• pp.335-343
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• 2016

Of the Nak-dong Jeongmaek, five mountains, viz. Mt. Baek-byeong, Mt. Chil-bo, Mt. Baek-am, Mt. Un-ju, Mt. Go-heon, which are considered to well represent the natural environmental characteristics of Nak-dong Jeongmaek as well as its various terrain, were selected for this study. Two fixed plots were selected as sample study areas of each type of bird habitats and surveyed from May to October in 2015. According to the results of the survey conducted in the five mountains of Nak-dong Jeongmaek, a total of 47 species with 1,163 individuals birds was identified. The largest variety of species occupying a particular habitat type was found in the forest road and the ridge with 31 species. Also, the number of individuals was highest in the valley with 471 individuals. According to the results of nesting guild analysis of the vein (Pearson Chi-Square test, ${\chi}^2=13.377$, p = 0.037) by each Nak-dong Jeongmaek habitat type, the communities that belong to the canopy nesting guild showed a high frequency in development land and the valley while the communities that belong to the hole nesting guild showed a high frequency on the forest road and ridge. The results of Pearson Chi-Square test (${\chi}^2=15.555$, p=0.004) showed that the communities that belong to Bush foraging guild were most frequent in the development area and the community that belong to canopy foraging guild were most frequent inthe valley, the forest road and the ridge. These findings show that different habitat types of Nak-dong Jeongmaek support a great variety of birdlife by providing diverse and excellent resources.

• Journal of Korean Society of Forest Science
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• v.105 no.4
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• pp.401-413
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• 2016

Forest resources utilization and variable disturbance history have been affected the rarity and conservation value of forest relict trees, which served as habitat for forest biodiversity, important carbon stock and cultural role include human and natural history in South Korea. This study was conducted to establish the baseline data for forest resources conservation by clarifying species diversity, spatial distribution and ecological characteristics (individual and habitat) of forest relict trees (DBH > 300 cm) based on the data getting from mountain trail, high resolution aerial photos and field professionals and field survey. As results, 54 taxa (18 family 32 genus 48 species 1 subspecies 3 variety and 2 form) as about 22% of tree species in Korea was identified in the field. 837 individuals of forest relict trees were observed and the majority of the trees was in Pinaceae, deciduous Fagaceae and Rosaceae, which families are abundant in population diversity. High elevation area was important to relict trees as mean altitudinal distribution was 1,200 m a.s.l as likely affected by human activity gradients and mid-steep slope and North aspect was important environment for the trees remain. Many individuals exhibited 'damage larger branch' (55.6%) and consequent relatively lower mean canopy coverages (below 80%). Synthetically, present diversity and abundance of relict forest trees in South Korea were the result of complex process among climate variation, local weather and biological factors and the trees of big and old were estimated to important forest biodiversity elements. In the future, clarifying the role and function of relict trees in forest ecosystem, in- and ex- situ programmes for important trees and habitat, and activities for building the background of conservation policy such as "Guideline for identifying and measurement of forest relict trees".

• Research in Plant Disease
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• v.18 no.3
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• pp.201-209
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• 2012

The multi-function of 18 Bacillus subtilis isolates collected from agricultural extension centers of local government and National Academy of Agricultural Science was investigated by measuring their antifungal activities against five plant pathogens, such as Rhizoctonia solani, Colletotrichum acutatum, Fusarium oxysporum, Magnaporthe oryzae and Phytophthora capsici, phosphorus solubilization ability, production of indole acetic acid (IAA) and siderophore, and nitrogen fixation. The B. subtilis isolates showed antifungal activity against several plant pathogens and nitrogen fixation activity, and produced siderophore and IAA. They could control pepper powdery mildew (Leveillula taurica), but there was no difference in control efficacy among the B. subtilis isolates. In fields, the control efficacy of B. subtilis R2-1 ($10^8$ cells/ml) was compared with two microbial fungicides, Q-pect and Topsid. In 2009, the control efficacy of B. subtilis R2-1 (37.7%) was lower than that of Topsid (47.6%), but higher than that of Q-pect (25.7%). In 2010, the control efficacy of B. subtilis R2-1 (83.3%) was higher than that of Topsid (67.9%). In order to elucidate mode of action of B. subtilis R2-1 for controlling pepper powdery mildew, spore germination rates of pepper powdery mildew pathogen collected on treated leaves was investigated when suspensions of B. subtilis R2-1 and two microbial fungicides (Q-pect and Topsid) were foliar-sprayed. They highly suppressed spore germination of the pathogen with inhibition values of 84.2% for B. subtilis R2-1, 97.9% for Q-pect and 94.7% for Topsid. Further study on the mass-culturing method and formulation is needed for development of a microbial fungicide.

• Journal of the Korean Society of Hazard Mitigation
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• v.3 no.3 s.10
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• pp.151-163
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• 2003

In this study, the algorithm of groundwater flow process was established for koreanized groundwater program development dealing with the geographic and geologic conditions of the aquifer have dynamic behaviour in groundwater flow system. All the input data settings of the 3-DFM model which is developed in this study are organized in Korean, and the model contains help function for each input data. Thus, it is designed to get detailed information about each input parameter when the mouse pointer is placed on the corresponding input parameter. This model also is designed to easily specify the geologic boundary condition for each stratum or initial head data in the work sheet. In addition, this model is designed to display boxes for input parameter writing for each analysis condition so that the setting for each parameter is not so complicated as existing MODFLOW is when steady and unsteady flow analysis are performed as well as the analysis for the characteristics of each stratum. Descriptions for input data are displayed on the right side of the window while the analysis results are displayed on the left side as well as the TXT file for this results is available to see. The model developed in this study is a numerical model using finite differential method, and the applicability of the model was examined by comparing and analyzing observed and simulated groundwater heads computed by the application of real recharge amount and the estimation of parameters. The 3-DFM model is applied in this study to Sehwa-ri, and Songdang-ri area, Jeju, Korea for analysis of groundwater flow system according to pumping, and obtained the results that the observed and computed groundwater head were almost in accordance with each other showing the range of 0.03 - 0.07 error percent. It is analyzed that the groundwater flow distributed evenly from Nopen-orum and Munseogi-orum to Wolang-bong, Yongnuni-orum, and Songja-bong through the computation of equipotentials and velocity vector using the analysis result of simulation which was performed before the pumping started in the study area. These analysis results show the accordance with MODFLOW's.

• Journal of the Korean Geographical Society
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• v.42 no.4
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• pp.582-600
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• 2007

In a long history of geography, a variety of regional concepts have been suggested to represent the particular situations in each period. Today, post-modem situations, characterized by the development of capitalism and globalization, demand a new variety of regional concepts. The regional characteristics, such as social relations, institutional systems, ideologies and symbolism, are now perceived basically on the level of subjectivity. Currently, it is the most urgent task to integrate many conflicting opinions among a variety of subjects into the one that would seek a voluntary consent from the majority of regional residents. In this paper, it is suggested that the concept of identity is the most efficient in examining and explaining the post-modem trend of a region: variability, subjectivity, mobility, changeability, Finally, it is suggested that a special attention should be paid to the role of institutions, that is institutionalization, in the construction of regional identity, to understand and interpret the cultural-historical aspect of a regional change.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.333-343
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• 2012

In-stream large wood (LW) has a critical impact on the geomorphic characteristics relevant to ecosystem management and disaster prevention, yet relatively little is known about variations in its dynamics and subsequent export on the watershed-scale perspective in Korea. Here we review variations in the dynamics and subsequent export of LW as a function of stream size, which is appropriate for Korean mountain streams. In upstream channels with narrow bankfull widths and low stream discharges, a massive amount of LW, resulting from forest dynamics and hillslope processes, may persist for several decades on valley floor. These pieces, however, are eventually transported during infrequent debris flows from small tributaries, as well as peak hydrology in main-stem channels. During the transport, these pieces suffer fragmentation caused by frictions with boulders, and stream bank and bed. Although infrequent, these events can be dominant processes in the export of significant amounts of LW from upstream channel networks. In downstream channels with wide bankfull widths and high stream discharges, LW is dominantly recruited by forest dynamics and bank erosion only at locations where the channel is adjacent to mature riparian forests. With the LW pieces that are supplied from the upstream, these pieces are continuously transported downstream during rainfall events. This leads to further fragmentation of the LW pieces, which increases their transportability. With decreasing stream-bed slope, these floated LW pieces, however, can be stored and form logjams at various depositional sites, which were developed by interaction between channel forms and floodplains. These pieces may decay for decades and be subsequently transported as particulate or dissolved organic materials, resulting in the limitation of LW fluvial export from the systems. However, in Korea, such depositional sites were developed in the extremely limited streams with a large dimension and no flood history for decades, and thus it does not be expected that the reduction of LW export amount, which can be caused by the long-term storage. Our review presents a generalized view of LW processing and is relevant to ecosystem management and disaster prevention for Korean mountain streams.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.297-297
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• 2009

최근 유기농산물에 대한 관심과 요구가 급증하면서 소비자들은 고품질 유기농산물을 선호하고 있어 국내 대부분 유기농가들은 무처리 일반종자를 이용하고 있는 실정이다. 앞으로 국제 기준에 부합하는 채소류 유기재배를 위해서는 유기종자의 이용이 필수적이므로 유기종자 채종체계 확립이 필요한 실정이다. 따라서 본 연구에서는 당근 종자(재래종 heimloom)를 사용하여 유기종자의 채종체계를 확립하고자 하였다. 일반적으로 당근종자 생산은 적어도 2년을 요구한다. Seed to seed 방법과 Root to seed 방법이 이용되고 있는데 본 연구에서는 Root to seed 방법을 사용하였다. Root to seed 방법은 6월에 당근종자를 파종하여 가을에 뿌리를 수확하여 지상부를 5cm 정도 남기고 정지하여 일시 저온저장 하였다가 이듬해 뿌리를 이식하여 새순에서 추대시켜 종자를 수확하는 방법으로 종자 생산성이 높아 종자회사에서 많이 사용하고 있다. 본 연구에서도 Root to seed 방법으로 채종 시험하였다. 2008년도에 파종 및 수확한 뿌리를 저온저장고에 일시 저장 후 1차 이식은 2008년 11월 하순에 노지포장에서 실시하고 이때 월동 중 동해를 막기 위하여 보온덮개로 멀칭 처리하였다. 이듬해 3월 중순에 주간거리 75${\times}$40cm 간격으로 솎음하여 처리당 10주씩 배치하였다. 이식후 뿌리에서 새순 1대를 유도하였고 추대 및 개화 6주후부터 종자가 갈색으로 변하기 시작할 때 채종을 시작하였다. 수확부위는 1차 측지 중 1번째 화지를 대상으로 하였고 화경절단은 화총으로부터 20cm 정도 남겨서 잘랐고 실내에서 1개월 이상 충분히 후숙시킨 후 종자를 정선하여 종자생산성을 조사하였다. 결실율과 발아율 조사는 채종된 종자를 이용하여 종자 충실도와 발아력을 조사하였다. 각 품종별 추대율은 15번 품종과 16번, 24번 품종이 5% 미만으로 매우 부진하였고 그밖에 추대된 묘의 생육 및 발육상은 매우 양호하여 개화에는 커다란 문제가 없었다. 종자 결실율은 23번 품종을 제외한 모든 품종에서 높았고 각 품종별 화총구조를 고려해 볼 때 주간 화총, 1차측지, 2차측지 순으로 결실율이 떨어졌다. 각 품종의 천립중은 1, 11, 12, 14, 20번 품종이 2.02g 이상으로 대립종으로 판단되며 각 품종별 화총의 크기는 비슷하여 대립종은 각 화총당 종자수가 적은 것으로 나타났다. 대분분의 대립종은 만생종으로 생육기간이 소립종 보다 10-20일상 길며 종자 성숙기간도 장기간 소요되며 특히 장마기간을 넘겨야 할 경우에는 비가림 시설 채종재배가 필수적인 것으로 나타났다. 발아율은 10, 11, 14, 18, 19, 26번 품종이 80% 이상으로 가장 높았고 다른 품종에서는 다소 떨어져 품종별 차이가 많았다. 종자 생산성은 장근종과 단근종간에 약간의 차이가 있지만 주간 화총을 포함하여 1차 측지 4-5개에서 채종하는 것이 가장 효율적인 것으로 사료된다. 또한 당근의 개화 기간을 보면 1화륜은 8~10일, 1개체는 40~50일, 채종포장에서는 1화륜에서 측지 6개구까지 채종은 60~70일 소요되어 미숙종자와 과숙종자가 혼재되어 적정 수확시기를 결정하기가 매우 어려운 점이 발생하였다. 본 연구 결과에서 생육특성, 수량성, 품질특성, 종자 생산성, 발아율을 고려해 볼 때 1, 7, 8, 9, 10, 14, 19, 26번 품종이 유기농 재배 및 유기채종에 적합한 것으로 사료되었다.

• Korean Journal of Ecology and Environment
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• v.50 no.1
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• pp.29-45
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• 2017

This study explored spatiotemporal variability of water quality in correspondence with hydro-meteorological factors in the four stations of Euiam Reservoir located in the upstream region of the North-Han River from May 2012 to December 2015. Seasonal effect was apparent in the variation of water temperature, DO, electric conductivity and TSS during the study period. Stratification in the water column was observed in the near dam site every year and vanished between August and October. Increase of nitrogen nutrients was observed when inflowing discharge was low, while phosphorus increase was distinct both during the early season with increase of inflowing discharge and the period of severe draught persistent. Duration persisting high concentration of Chl-a (>$25mg\;m^{-3}$: the eutrophic status criterion, OECD, 1982) was 1~2 months of the whole year in 2014~2015, while it was almost 4 months in 2013. Water quality of Euiam Reservoir appeared to be affected basically by geomorphology and source of pollutants, such as longitudinally linked instream islands and Aggregate Island, inflowing urban stream, and wastewater treatment plant discharge. While inflowing discharge from the dams upstream and outflow pattern causing water level change seem to largely govern the variability of water quality in this particular system. In the process of spatiotemporal water quality change, factors related to climate (e.g. flood, typhoon, abruptly high rainfall, scorching heat of summer), hydrology (amount of flow and water level) might be attributed to water pulse, dilution, backflow, uptake, and sedimentation. This study showed that change of water quality in Euiam Reservoir was very dynamic and suggested that its effect could be delivered to downstream (Cheongpyeong and Paldang Reservoirs) through year-round discharge for hydropower generation.