• Title/Summary/Keyword: Slope land

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Study on the Classification of Gyeonggi-Do's Conservation Areas by Improvement of National Land Environmental Assessment (국토환경성평가 개선을 통한 경기도지역의 보전지역 구분에 관한 연구)

  • Lee, Dong-Kun;Sung, Hyun-Chan;Jeon, Seong-Woo;Lee, Sang-Dae;Kim, Kwi-Gon;Kim, Jae-Uk
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.8 no.4
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    • pp.43-51
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    • 2005
  • Due to rapid and reckless economic development, natural resources of the national land have been damaged and polluted. Accordingly, the necessity for environment-friendly development has been on the rise and many have made efforts to assess the environmental value of the national land. This study divides the conservation areas by means of using relative elevation, slope, and development of housing land based on environmental evaluation of the national land. The relative elevation is obtained by the difference of altitude at the edge of the forest patch extracted from the land cover classification map based on the ridgeline, and the slope is obtained by environment-oriented land suitability analysis. The development of housing land is classified in accordance with the progress of each project. Twenty-six evaluation criteria are divided into five different grades using the minimal indicator approach and then sub-divided into ten grades by means of using the following two scenarios. The first one uses the weight of input materials while the second one relies on the size of patches that are emphasized in landscape ecology. Consequently, such a study demonstrated the following results. The method relying on the weight of input materials revealed the limitation of emphasizing input materials excessively, whereas the method of considering the size of patches resulted in the division of conservation areas that embody regional characteristics. This study is meaningful in that it classifies the conservation areas by reflecting the regional characteristics and the ecological values of animals and plants.

An Analysis of Agricultural Landuse Suitability Using Landuse Limitation Factors - A Case Study of Ibang-myeon, Changnyeong-gun, Kyungsangnam-do - (토지이용 제한인자를 활용한 농업적 토지이용 적합성 분석 - 경상남도 창녕군 이방면을 대상으로 -)

  • Jang, Gab-Sue;Park, In-Hwan
    • Journal of Environmental Impact Assessment
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    • v.15 no.6
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    • pp.357-372
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    • 2006
  • The excessive land activities in farming can cause soil erosion, inundation by a flood, and fallow. So far land evaluation has been analyzed using the land use limitation derived from the excessive land activities. This study was done for evaluating the agricultural fields by using 3 land use limitations, inundation potential, soil erodibility potential, and fallow potential. The study area is Ibang-myeon, Changnyeong-gun, Gyeongnam-province, Korea. A logistic regression model was applied to recognize the inundation potential by a flood in the Nakdong river basin. And potential soil erodibility index (PSEI) was derived from USLE model to analyze the soil erodibility potential. And a probability model from a logistic regression model was applied to detect the fallow potential. Therefore, we found 220.7ha for the 4th grade and 86.1ha for the 5th grade was analyzed as water damage potential. Large area near Nakdong river have problem to grow the rice due to the damage by water inundation. And 213.6ha for the 3rd grade and 103.3ha for 4th grade was detected as a result of the analysis of soil erosion potential. The soil erosion potential was high when within-field integrity of soil was not stable, or the kinetic energy was high or the slope length was long due to a steep slope of a specific land. And 869.1ha for 3rd grade, 174.9ha for 4th grade, and 110.6ha for 5th grade was detected to be distributed having the fallow potential. Especially, a village, having a steep mountain, had 249.5ha for the 3rd grade, which was 28.7% of total area showing the 3rd grade. Finally, Three villages, including An-ri, Geonam-ri, Songgok-ri, showed they had largest area of the suitable land in the study area. These villages had similar topographic condition where they were far from Nakdong river, and they had relatively higher elevation and flat lands.

Analysis of the Distribution Characteristics of Abandoned Paddy Wetlands according to Topographical Environments (지형환경에 따른 묵논습지 분포 특성 분석)

  • Park, Miok
    • Journal of Wetlands Research
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    • v.24 no.2
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    • pp.93-101
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    • 2022
  • This study was conducted to analyze the distribution characteristics of abandoned paddy wetlands according to topography and land cover. In Seosan-si, Dangjin-si, Boryeong-si, and Taean-gun, Chungcheongnam-do, abandoned rice wetlands were found through GIS and field surveys, and the distribution status according to slope, elevation and land cover type was analyzed. As a result of the study, a total of 106 abandoned paddy wetlands were identified, and the average elevation of each abandoned paddy wetlands was 38.85m (S.D.32.76), the average slope was 6.27˚ (S.D.5.39), and the total area was 24,200km2. 90 sites (84.9%) of abandoned paddy wetlands were distributed on flat land with less than 5˚ slope, 63 sites (12,121.07km2), and 27 sites(9,524.15km2) at 5-10˚ (9,524.15km2) on flat land with less than 10˚. The area is 21,645.22km2(89.5%) of the total area of abandoned paddy wetlands. 48 sites(12,326km2) in the lowlands with an altitude of less than 25 m, 29 sites(4,909.4km2) below 50m. It accounts for 71.2% of the total area of abandoned paddy wetlands. Among environmental factors of abandoned paddy wetlands, there was no statistically significant correlation between slope and altitude. According to the land cover classification, it was widely distributed in artificial grasslands (38), paddy fields (33), and fields (22).

Study on the Improvement of Land Clearing Methods by Bulldozer & Fertilization of Cleared Soil (불도우저에 의한 개간 공법의 개선과 숙지화에 관한 연구)

  • Hwang, Eun
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.17 no.1
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    • pp.3627-3641
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    • 1975
  • The Government is trying to increase total food grain yield to meet national self sufficiency by means of increasing unit yield as well as extending crop land, and this year he set the target of 321,000 hectare of forest to clear for cropping. This study was carried to investigate the most efficient method of clearing hillock by bulldozer, and successful method to develope yielding potential of newly cleared land in short term. Since the conventional land clearing method is just earth leveling and root removing neglecting top soil treatment, the growth of crop was poor and farmer tends not to care the land. The top-soil-furrowing method is applied through out this study, that is advantageous especially for the land having shallow top soil and low fertility like Korean forest. In this study, various operating method were tried to find out most efficient method separately in connection with the land slope less than 25 percent and over, and several fertilizing methods to develop yielding potential. The results are as follows; 1) For the natural land slope utilization method, applicable to the land having less than 25 percent slope, reverse operating was more efficient than using forward gear of bulldozer. The operating time was 3 hour 32 minutes and 36 seconds using forward gear was 2 hour 32 minutes and 30 seconds for reverse gear operation per 1,000 square meter. 2) Bulldozer having angle blade adjustment needed 7hr 15min. for constructing of terrace per 10a compaire with the one having angle & tilt adjustment needed 6hr 4min for same operations. Specially there is significant difference for operation time of first period (earth cutting) such as bulldozer having angle blade adjustment needed 3hr 56min compaired with the one having angle & tilt adjustment 3hr 59min. In construction of terrace, the bull-dozer having tilting and angle blade adjustment was most suitable and performed efficiently. 3) For the fertilizer application treatment, the grass (Ladino clover) yield in first year was almost same as ordinary field's in the plot applied(N.P.K+lime+manure) while none fertilizer plot showed one tenth of it, and (N.P.K.+lime) applied plot yielded on third. 4) The effect of different land clearing method to yield showed significant difference between each treatment especially in the first year, and the conventional method was the lowest. In the second year, still conventional terracing plot yielded only half of ordinary field while the other plots showed as same as ordinary field's. 5) The downward top soil treatment plot showed most rapid improvement in soil structure during one year physio chemically, it showed increase in pH rate and organic composition, and the soil changed gradually from loam to sand-loam and the moisture content increased against the pF rate, and it gives good condition to grow hay due to the increase of field water capacity with higher available water content. 6) Since the soil of tested area was granite, the rate of soil errosion was increased about 2 to 5 percent influencing in soil structure more sand reducing clay content, and an optimum contour farming method should be prepared as a counter measure of errosion.

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Topography and Soil Characteristics Related to Land Creep in 37 Areas in South Korea (우리나라 37개 땅밀림지의 지질 및 토양 특성)

  • Park, Jae-Hyeon;Seo, Jung Il;Ma, Ho-Seop;Kim, Dongyeob;Kang, Minjeng;Kim, Kidae
    • Journal of Korean Society of Forest Science
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    • v.108 no.4
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    • pp.540-551
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    • 2019
  • This study was conducted to provide basic data for classifying patterns of land creep in 37 areas in South Korea using geological and soil property analyses. Geological time, as it relates to land creep areas in South Korea, had been most impactful for the Gyeongsang Supergroup and its sedimentary bedrock during the Cretaceous period. In this area, perfect ridge cliffs in land creeping areas included 20 plots (approximately 54.0%), while tension cracking areas with ambiguous ridge cliff characteristics included 17 plots (approximately 46.0%). Hesitant slide slope types included 20 plots (approximately 54.0%) within theslide slope of an incident pattern (slide slope figure) in land creeping areas. Colluvial debris types among land creep patterns were the most frequent and included 25 plots (approximately 68.0%). The direct causes of land creep were cutting of foothills, quarrying, land-clearing in mountains, mining exploration, and the creation of burial grounds, all of which added to geological impacts. Among land creeping areas, 27 plots (approximately 73.0%) were the result of man-made activities, and 10 plots (approximately 27.0%) were derived via natural causes such as earthquakes, heavy rainfall, and caving.

Two-dimensional Coupled Moisture and Heat Flow Model and Sensitivity Analysis (이차원 복합적 습기와 열흐름의 분석모델과 민감도 분석)

  • Kim, Suk-Nam
    • Journal of the Korean Geotechnical Society
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    • v.19 no.5
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    • pp.99-107
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    • 2003
  • Moisture flow and heat flow within pavement systems have been recognized as coupled processes with complex interactions between them. The distribution of moisture and temperature within pavement due to the moisture flow and heat flow varies not only seasonally but also vertically and horizontally. This paper presents an analysis model by the finite element method for the two-dimensional coupled moisture and heat flow in unsaturated soils. To test the model the analysis result by the model is compared with the analysis result by the software, GEO-SLOPE developed by GEO-SLOPE International Ltd. in Alberta, Canada. And a sensitivity analysis using ASTM method is performed to identify how model inputs affect the modeling analysis.

Optimum Geomorphological Environment of Location of Dwelling Site in Bronze Age in Asan Area Using GIS Analysis -Paying Attention to the Gradient of Each of Micro-Landforms of Hillslope - (GIS 분석과 사면 미지형별 경사도를 이용한 충남 아산지역에 있어서 청동기시대 주거지 입지의 최적 지형환경)

  • PARK, Jong-Chul;PARK, Ji-Hoon
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.2
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    • pp.65-80
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    • 2011
  • This is to find out geomorphological environment of optimum location for the object of dwelling site of Bronze Age (hereinafter called dwelling site) of total 177 unit confirmed in Yongducheon basin and Onyangcheon basin (hereinafter called investigation-object basin) in Asan-si Chungnam. To do this, hill of investigation-object basin where dwelling sites were confirmed was divided into 11 units of hillslope geomorphological and this was combined with the grade of 5 units of gradient and again subdivided into total 55 units of micro-landforms of Hillslope. Based on this, in the viewpoint of 'gradient of each of micro-landforms' analyzed 'number of dwelling sites' and 'dwelling site distribution density (unit: number of dwelling sites/1000m2)'. As the result, the optimum geomorphological environment where dwelling sites were located was largely confirmed be 5 units(① semi-gentle slope land of crest slope ②gentle slope land of crest slope ③ slope of upper sideslope ④ flat land of crest slope ⑤ flat land of crest flat). It is thought that this analysis data will be used in the future as basic data for the study of predicting distribution of dwelling sites in Bronze Age which might have been buried in the investigation-object basin.

Stability Analysis of Rock Slope (암반절취사면의 안정해석)

  • Cho, Seong Seop;Kim, Yong Seong;Chee, In Taeg;Lee, Dal Won
    • Korean Journal of Agricultural Science
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    • v.23 no.1
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    • pp.1-12
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    • 1996
  • To design the safe and rational rock slope, several rock slopes of roads in Kang-won area were analyzed, and the following results were obtained ; 1. The results were analyzed by stereographic projection at the rock slope that the joint was developed. All of the sloped which were designed by standard slope of rock was not considered that the joints were unstable. 2. The relation of rainfall and slope failure, as well as the danger of failure, was very high when the maximum hourly rainfall was larger than 20mm and when there was a 2-day cumulative rainfall that was larger than 200mm. 3. In the design of rock slope, operated by the stereographic projection considering discontinuity. If turn out unstable, it should be analyzed carefully using the limit equilibrium method. 4. In the design of rock slope, it is desirable to consider the discontinuity of rock(joint, bedding, fault).

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A Study on Soil Suitability Criteria for Liriopis Platyphylla

  • Cho, Hyun-Jun;Hyun, Byung-Keun;Sonn, Yeon-Kyu;Park, Chan-Won;Chun, Hyen-Chung;Song, Kwan-Cheol;Noh, Dae-Cheol;Yun, Kwan-Hee
    • Korean Journal of Soil Science and Fertilizer
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    • v.46 no.6
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    • pp.542-548
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    • 2013
  • Soil properties and yields of liriopis platyphylla were investigated to establish soil suitability of Korean liriopis platyphylla at 116 farms in Korea. Morphological and physical properties of the soils were investigated along with the average yield of 2~3 years. The impact factors of soil properties to the yield of liriopis platyphylla were selected based on standard error of each factor. The yields of liriopis platyphylla showed the greatest values when the morphology was alluvial plains, when the drainage was well or moderately well, when the slope was 0-2%, the texture was coarse loamy, when the gravel content was less than 15% and when the available soil depth was more than 100 cm. Contribution factors of soil properties to the yields were 0.15 by morphology, 0.15 by drainage level, 0.13 by slope, 0.18 by texture, 0.16 by gravel content and 0.23 by available soil depth, respectively. Soil suitability classes were set as follows; the best suitable land if score was greater than 92, suitable land if score ranged from 91 to 86, the possible land if the score ranged from 85 to 83, and low productive land if score was less than 82. According to the criteria, 17.8% of the production area was the best suitable land, 43.1% was suitable land, 17.3% was possible land, and 21.8% was low productive land. The sum of both the best and suitable lands were 60.9% of the farm area of Miryang in Gyeongsangnam-do.

A Study on Soil Suitability Criteria for Adzuki Bean

  • Cho, Hyun-Jun;Hyun, Byung-Keun;Sonn, Yeon-Kyu;Hur, Seung-Oh;Shin, Kook-Sik
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.6
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    • pp.412-417
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    • 2014
  • Soil properties and yields of red been were investigated to establish soil suitability of Korean adzuki bean at 166 farms in Korea. The soil morphological and physical properties were investigated by 1:5,000 scale average yield of 2~3 years. The impact factors to the adzuki bean yields and soil properties were selected based on standard error of each factor. The yields of adzuki bean showed the greatest values when the morphology was alluvial plains, the drainage was well or moderately well, the slope was 2~7%, the texture was fine loamy, the gravel content was less than 15% and the available soil depth was more than 100 cm. Contribution factors of soil properties to the yields were 0.18 of morphology, 0.18 of drainage level, 0.23 of slope, 0.20 of texture, 0.11 of gravel content and 0.10 of available soil depth, respectively. Soil suitability levels were set as the best suitable land if score was greater than 90, suitable land if score ranged from 89 to 85, the possible land if the score ranged from 79 to 84 and low productive land if score was less than 78. According to the criteria 37.5% of the production area was the best suitable land, 29.4% was suitable land, 22.3% was possible land and 10.8% was low productive land. The best and suitable lands were total of 66.9% in Gyeongju, Gyeosangbuk-do.