• Title/Summary/Keyword: VALLEYS

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Relation between Hydraulic Properties and Growth of Rice in Poorly Drained Paddy Soils (습답(濕畓)에서 수리특성(水理特性)과 수도생육(水稻生育)과의 관계(關係))

  • Park, Chang-Seo;Im, Jeong-Nam;Ryu, Kwan-Sik
    • Korean Journal of Soil Science and Fertilizer
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    • v.14 no.4
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    • pp.185-189
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    • 1982
  • Piezometric head, soil temperature, and redox potential were investigated to identify the factors causing the poor growth of rice in poorly drained paddy soils. 1. In local valleys the variegated piezometric head difference was observed place to place and resulted in uneven growth of rice while nearly uniform head difference was observed in alluvial plains. 2. Direction of water flow in paddy soils seemed to develop a significant difference in soil temperature and plant growth. 3. Negative correlation between piezometric head and rice growth and/or yiled was observed, and yield was decreased with the increase of upward flow of water. 4. There was a positive correlation between soil temperature and rice growth and/or yield. Cold temperature below $20^{\circ}C$ retarded significantly the plant growth and rice plant, at $16^{\circ}C$, could not grow.

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Investigation on Agricultural Land Use and Soil Characteristics along Bonghwang-cheon Watershed in Milyang (밀양 봉황천 수계지역의 토지이용현황과 토양특성)

  • Lim, Dong-Kyu;Kang, Hang-Won;Jung, Yeun-Tae;Park, Kyeong-Bae;Park, Moo-Eon
    • Korean Journal of Soil Science and Fertilizer
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    • v.30 no.3
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    • pp.280-287
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    • 1997
  • This study was carried out to investigate agricultural status and soil fertility of Bonghwang-cheon watershed area which is located at Chodong-myeon, Milyang-si. The acreage of arable land was about 1,209ha, and the population was 3,706 people. Out of total arable land, paddy was 64.4%, upland 19.6% and orchard 16.0%. Chicken was the largest in the number of livestock and poultry, but pig seems to contribute most severly to water pollution. The geology in the lower stream was alluvium but andesite and derivated materials from it were occupied most upland areas. Tuff was scattered in the small area near by the alluvium of Nakdong river, and diorite and granodiorite were located at the low hill and mountains respectivately. The principal paddy soils in the area were Geumgog, Jisan and Imgog series etc of fine loamy on sloped valleys and fans. The Pyeongtaeg series, fine silty family of imperfectly drained on plain was irrigated by Chodong reservoir. The clayey Honam series on alluvium was distributed along the low hill while Gyuam series, coarse silty alluvial soil way close to Nakdong river. In chemical properties of soils, the vinyl house soils were higher in EC, and orchard soils in OM, $P_2O_5$, exchangeable canons than other soils.

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Floristic study of Mt. Unbongsan in the basalt areas, Korea (현무암지대 운봉산의 관속식물상)

  • Kim, Jung-Hyun;Park, Hwan-Joon;Lee, Kyeong-Ui;Kim, Jin-Seok
    • Korean Journal of Environmental Biology
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    • v.38 no.3
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    • pp.371-387
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    • 2020
  • This study was conducted to investigate the flora of Mt. Unbongsan in the basalt areas of Korea. From the results of eight field surveys undertaken from March to October 2017, we identified 404 total taxa, representing 364 species, seven subspecies, and 33 varieties, which were placed in 256 genera and 91 families. The plant formation of Mt. Unbongsan is a deciduous broad-leaved and conifer mixed forest, which is common in the middle part of the Korean peninsula. Most of the mountain is covered by a young secondary forest, which is mainly composed of Quercus monglica and Pinus densiflora. Out of these 404 taxa, 193 were the first records for the region, six were endemic to Korea, three were listed on the Korean Red List of threatened species, 34 were floristic target species, and 40 were invasive alien species. The naturalized index(NI) percentage was 9.9%. Mt. Unbongsan has plant diversity, which was associated with the geomorphological landscapes. We considered that the composition and distribution of the species were affected by different environmental factors according to the presence of granite, taluses, block streams, drying ridges, valleys, puddles, wetlands, and streams.

A Study on Riparian Habitats for Amphibians Using Habitat Suitability Model (서식지적합성 모형을 이용한 수변지역 양서류 서식지 분석)

  • Jeong, Seunggyu;Seo, Changwan;Yoon, Jaehyun;Lee, Dong Kun;Park, Jonghoon
    • Journal of Environmental Impact Assessment
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    • v.24 no.2
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    • pp.175-189
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    • 2015
  • The objective of this study was to analyze characteristics of distribution of amphibian species and the affecting ecological factors. For the study, habitat environment factors were determined and applied to a habitat suitability model for the data collected from the Seom River in Hoengseong County and Wonju City, Gangwon Province, Korea between March 2013 to October 2013. The analyzed amphibian species were Rana nigromaculata, Hyla japonica, Rana dybowski, and Rana rugosa Temminck and Schlegel, and a logistic regression model was used with the pseudo-absence data. The result of the model analysis suggests that the major factors for Rana nigromaculata are distance to vegetation and rock and that for Hyla japonica is waterway. Rana dybowski and Rana rugosa Temminck and Schlegel have similar habitat characteristics, but the latter is shown to be dominant due to its wider habitat preference. According to the species richness model, the analyzed amphibian species are shown to have tendency to move between valleys or streams. This study quantitatively analyzed habitat environment characteristics using species distribution model, however, there is a limitation in terms of analysis on food factor and connectivity with other species. Combined with additional density or habitat analysis on birds or fish, this study can lead to more comprehensive analysis on biological environment factors.

A Basic Study on the Establishment of Designated Area for Conservation plan of Traditional Landscape - Focus on the Designation Status of Linear Scenic Sites - (전통경관 보존계획을 위한 지정구역 설정에 대한 기초연구 - 선형(線形) 명승의 지정 현황을 중심으로 -)

  • Lee, Chang-Hun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.38 no.1
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    • pp.67-76
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    • 2020
  • This study aims to elicit criteria regarding reassessment and designation of linear scenic sites henceforth. The results are as follows; First, based on the documents from the Cultural Properties Protection Committee of Korea, 23 out of 113 scenic sites in Korea were drawn, and their linear characteristics were categorized into four types including valleys, paths, rivers, and ridges. The linear scenic sites provide certain features in terms of sequence and direction, which results in the similar utilization among the sites which share the linear similarity. Second, the 23 sites mentioned above were intensely examined on the basis of six criteria for linear scenic sites through FGI, focus group interview. The criteria consist of six elements involving core resource(12), lot number(8), unclear(8), management path(5), ridge(4), basin(3). Third, the Cultural Heritage Administration has prioritized core resource since 2010, when designating a scenic site, whereas it tended to consider lot number as priority prior to 2010. It is thought that the authority gave consideration to issues related to private ownership of property in the scenic sites and the purpose of designation. Fourth, scenic sites are generally designated in accordance with the boundary of core resource, and in most cases, there are buffer zones alongside the core resource.

Application of Ventilation Corridor to Mitigate Particulate Matter for the Sejong-Si (미세먼지 저감대책으로서 바람길 적용 방안 : 세종시를 대상으로)

  • Nam, Seongwoo;Sung, Sunyong;Park, Jong-Soon
    • The Journal of the Korea Contents Association
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    • v.20 no.3
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    • pp.1-9
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    • 2020
  • The purpose of this study is to verify the effects of ventilation corridor and derive adequate policy alternatives to its application for the city of Sejong, which is located in an inland of Korean Peninsula. In order to introduce the ventilation corridor in the city, it is necessary both to understand change on fresh air flow affected by the construction of new cities and to show its effects which are able to circulate air flow of the city. The study identified ventilation effects using computational fluid dynamics models. In particular, it analyzed change on wind speed and direction after constructing of a new town and cool air flow along the lowlands generated after sunset. In addition, it identified those of reducing particulate matter when arranging buildings conforming to the ventilation corridor at block level. The policy implications derived from simulation can be summarized as follows. First, it is desirable to plan ventilation corridors so that fresh air from mountains, forests, and valleys can flow into cities and mitigate the concentration of particulate matter. Furthermore, public facilities covering parks, plazas, and playgrounds should be installed preferentially to attract safe outdoor activities near to areas with low levels of particulate matter. Finally, it is adequate to prepare for a number of alternative plans by analyzing ventilation corridors when setting out district unit plan.

Analysis on the Characteristics of the Landslide - With a Special Reference on Geo-Topographical Characteristics - (땅밀림 산사태의 발생특성에 관한 분석 - 지형 및 지질특성을 중심으로 -)

  • Park, Jae-Hyeon
    • Journal of Korean Society of Forest Science
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    • v.104 no.4
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    • pp.588-597
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    • 2015
  • This study was carried out to identify the reasons of the landslide by land creeping in South Korea in order to provide basic information for establishing the management plan for prevention. Total 29 sites of landslide areas caused by land creeping were observed in South Korea. Among them, the soil-composition of most frequent landslide areas occurred by land creeping was colluvium landslide as 75.9% (22 sites), followed by clay soil landslide as 10.3% (3 sites), bedrock landslide as 6.9% (2 sites), and weathered rock landslide as 6.9% (2 sites). According to the types of parental rocks, the investigated landslide areas were divided into 3 types: 1) metamorphic rocks including schist, phylite, migmatitic gneiss, quartz schist, pophyroblastic gneiss, leucocratic granite, mica schst, banded gneiss and granitic gneiss, 2) sedimentary rocks including limestone, sandstone or shale and mudstone, 3) igneous rocks such as granite, andesite, rhyolite and masanite. As a result, it was noticed that the landslides occurred mostly at the metamorphic rocks areas (13 sites; 44.8%), followed by sedimentary rock areas (12 sites; 41.4%), and igneous rock areas (4 sites; 13.8%). Looking at the direct causes of the landslide, the anthropological activities (71%) such as cut slopes for quarrying, construction of country house, plant, and road, farming of mountain top, and reservoir construction were the biggest causes of the landslides, followed by the land creeping landslides (22%) caused by geological or naturally occurred (22%), and cliff erosions (7%) by caving of rivers and valleys.

Syntaxonomical and Synecological Description on the Forest Vegetation of Juwangsan National Park, South Korea (주왕산국립공원 삼림식생의 군락분류와 군락생태)

  • Oh, Hae-Sung;Lee, Gyeong-Yeon;Kim, Jong-Won
    • Korean Journal of Environment and Ecology
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    • v.32 no.1
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    • pp.118-131
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    • 2018
  • The forest vegetation of Juwangsan National Park, which is famous for its towering scenic valleys, was syntaxonomically described. The study adopted the $Z{\ddot{u}}rich$-Montpellier School's method emphasizing a matching between species composition and habitat conditions. A combined cover degree and the r-NCD (relative net contribution degree) were used to determine a performance of 265 plant species listed-up in a total of 52 phytosociological $relev{\acute{e}}s$. Nine plant communities were classified through a series of table manipulations, and their distribution and actual homotoneity($H_{act}$) were analyzed. Syntaxa described were Carex gifuensis-Quercus mongolica community, Athyrium yokoscense-Quercus mongolica communiy, Arisaema amurense-Quercus serrata community, Lespedeza maximowiczii var. tomentella-Quercus variabilis community, Tilia rufa-Quercus dentata community, Carex ciliatomarginata-Carpinus laxiflora community, Aristolochia manshuriensis-Zelkova serrata community, Onoclea orientalis-Fraxinus mandshurica community, and Carex humilis var. nana-Pinus densiflora community. A zonal distribution was reviewed and the altitude of about 700 m was the transition zone between the cool-temperate central montane zone (Lindero-Quercenion mongolicae region) and southern submontane zone (Callicarpo-Quercenion serratae region). Only 19 taxa were associated with r-NCD 10% or more, most of which were tree species occurring in the Lindero-Quercenion and some of which was a member of open forests. Species composition of forest vegetation was much less homogeneous, showing the lowest $H_{act}$. Nearly natural forests and/or secondary forests in the Juwangsan National Park were defined as a regional vegetation type, which reflects much stronger continental climate in the Daegu regional bioclimatic subdistrict, rhyolitic tuff predominant, and wildfire interference.

Plant Community Structure for Five Major Valleys in Bukhansan National Park (북한산 국립공원 주요 5개 계곡의 식물군집구조)

  • Lee, Kyung-Jae;Cho, Woo;Hwang, Seo-Hyun
    • Korean Journal of Environment and Ecology
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    • v.9 no.1
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    • pp.15-29
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    • 1995
  • To investigate plant community structure of Uiryung valley, Harujae valley, Kugi valley, Songchu valley, Tobongsan valley in Bukhansan National Park, each thirty eight, forty, twenty six. twenty eight, thirty six plots (plot size 100$m^2$) were set up and surveyed. The surveyed data were integrated and classification by TWINSPAN and DCA ordination techniques were applied to the study area. The plant community were divided into nine groups in seventy nine plots by TWINBPAN and the dividing groups were Carpinus laxiflora community(I), Quercus mongolica community(II), Pinus densiflora community(III), Q. mongolica-P. densiflora community(IV) Q. mongolica-Q. serrata- Prunus sargentii community(V), Q. mongolica Q. variabilis community(Ⅵ), Robinia pseudoacacia-Q. serrata community(Ⅶ). P. rigida-Q. serrata community(Ⅷ), Q. mongolica- Q. variabilis- Styrax obassia community(Ⅸ). So the successional trends of tree species at the natural forest seem to be from P. densiflora to Q. mongolica and at the artificial forest seem to be from R. pseudoacacia, P. rigida to Q. acutissima, Fraxinus rhynchophylla in canopy layer And in the subtree and shrub layer, it wag supposed that from Deotzia prunifolia, Rhus trichocarpa. Rhododendron yedoense var. poukhasleilse, Euonymus oxyphyllous to Magnolia sieboldii, Acer psuedo-sieboldianum, Lindera obtusiloba. In comparing successional trends with past study, it was postulated that successtion is not progressed by human disturbance and soil acidification by the air pollution.

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Distribution Pattern of Ageratina altissima Along Trails at Mt. Umyeon in Seoul, Korea (우면산 등산로 주변 서양등골나물의 분포 경향)

  • Kim, Hyonook;Jang, Yoo Lim;Park, Pil Sun
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.3
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    • pp.227-232
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    • 2014
  • Ageratina altissima is an invasive plant species known to threaten native plant communities in Korea. A. altissima is thought to invade shady forests from disturbed open areas; however, uncertainty remains as to how shade and litter depth might affect establishment. A study of A. altissima distribution characteristics in areas adjacent to trails was undertaken at Mt. Umyeon in Seoul, Korea. Increasing densities of A. altissima were found to correlate with greater light availability and decreasing litter depth (p < 0.001) within 10 m distance from trail locations and on ridges rather than further within forests and valleys. The effects of soil moisture content, soil gravel content and soil pH on distribution were not found to be significant, suggesting that A. altissima is adaptable to a broad range of soil conditions. Results indicate that forest areas close to trails may be particularly susceptible place to A. altissima invasion, demonstrating the need to carefully consider implications for A. altissima expansion in trail management.