• Title/Summary/Keyword: Land slope

Search Result 675, Processing Time 0.029 seconds

Study on Applicability of Slope Types to Permission Standard for Forestland Use Conversion (산지의 사면유형을 고려한 산지전용허가기준에 관한 연구)

  • CHOI, Jung-Sun;KWAK, Doo-Ahn;KWON, Soon-Duck;BAEK, Seung-A
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.21 no.4
    • /
    • pp.145-157
    • /
    • 2018
  • Mountainous areas are 64% in Korea and are allowed to be used by the permission standards of the "Mountainous Districts Management Act". In the act, slope and elevation criteria are defined to regulate the use of vulnerable land parcels to disaster. However, the standards cannot represent topographical variation in a land parcel such as terrain relief. Therefore, the applicability of slope type standard as a permission standard was tested using Catena in this study. Based on the theoretical grounds, two slope types were analyzed as 'risky slope' with disaster risk. The slope types of landslides in Namwon City were analyzed that 'risky slope' types were distributed about 57%. This study analyzed the forestland parcels that could be used when applying the current permission standards and the parcels that were already used in Namwon City. The ratio of the 'risky slope' in the parcels was more than 50%. Therefore, it is necessary to prevent the mountain development in 'risky slope' by establishing permission standard related to slope types. In addition, this study suggested the ratio of 'risky slope' in the parcel for the permission standard for forestland use conversion.

Delineation of the Slip Weak Zone of Land Creeping with Integrated Geophysical Methods and Slope Stability Analysis (복합 지구물리탐사와 사면 안정해석 자료를 이용한 땅밀림 지역의 활동연약대 파악)

  • Lee, Sun-Joong;Kim, Ji-Soo;Kim, Kwan-Soo;Kwon, Il-Ryong
    • The Journal of Engineering Geology
    • /
    • v.30 no.3
    • /
    • pp.289-302
    • /
    • 2020
  • To determine the shallow subsurface structure and sliding surface of land creeping in 2016 at Hadong-gun, Gyeongsangnam-do, geophysical surveys (electric resistivity, and refraction seismic methods, borehole televiewer) and slope stability analysis were conducted. The subsurface structure delineated with borehole lithologies and seismic velocity structures provided the information that the sediment layer on the top of the slope was rather as thick as 20 m and the underlying weathered rock (anorthosite) was thinner than 1 m. Based on the tension cracks observed during the geological mapping, televiewer scanning was performed at the borehole BH-2 and detected the intensive fracture zones at the ground-water level, associated with the slip weak zones mapped in dipole-dipole electrical resistivity section. Downslope sliding and slightly upward pushing at the apex of high resistive bedrock explains the curved slip plane of the land creeping. Such a convex structure might play a role of natural toe abutment for preventing the downward development of slip weak zones. In slope stability analysis, the safety factors of the slip weak zone are calculated with varying the groundwater levels for dry and rainy seasons and the downslope is founded to be unstable with safety factor of 0.89 due to fully saturated material in rainy season.

Developing slope hazard map system with mobile PPT (모바일 PPT를 이용한 사면 붕괴 위험도 산출 시스템 구축)

  • Yang, Seung-Tae;Seong, Eun-Yeong;Kang, Young-Shin;Kang, In-Joon
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
    • /
    • 2007.04a
    • /
    • pp.367-370
    • /
    • 2007
  • Recently, With explosive national land developments construction fields ate increasing, and slope failures are disastrous when they occur in mountainous area adjoining highways. but public institutions and supervisors, to manage slope need GIS for managing it more quickly and correctly. For manage slope, it is nesessary to use new IT, especially wireless internet. The current domestic population using cell phones exceeded 30 million and the domestic wireless Internet environment has matured, but implementation of mobile technology for government services isnot matured enough. In this paper the author proposed a new system of mobile PPT monitoring for managing slope inspection for Ubiquitous Environment. This new system manages data in real time and reduces human power when applied to current working environments. This research was supported by a grant(NEMA-06-NH-05) from the Natural Hazard Mitigation Research Group, National Emergency Management Agency.

  • PDF

An Uncertainty Analysis of Topographical Factors in Paddy Field Classification Using a Time-series MODIS (시계열 MODIS 영상을 이용한 논 분류와 지형학적 인자에 따른 불확실성 분석)

  • Yoon, Sung-Han;Choi, Jin-Yong;Yoo, Seung-Hwan;Jang, Min-Won
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.49 no.5
    • /
    • pp.67-77
    • /
    • 2007
  • The images of MODerate resolution Imaging Spectroradiometer (MODIS) that provide wider swath and shorter revisit frequency than Land Satellite (Landsat) and Satellite Pour I' Observation de la Terre (SPOT) has been used fer land cover classification with better spatial resolution than National Oceanic and Atmosphere Administration/Advanced Very High Resolution Radiometer (NOAA/AVHRR)'s images. Due to the advantages of MODIS, several researches have conducted, however the results for the land cover classification using MODIS images have less accuracy of classification in small areas because of low spatial resolution. In this study, uncertainty of paddy fields classification using MODIS images was conducted in the region of Gyeonggi-do and the relation between this uncertainty of estimating paddy fields and topographical factors was also explained. The accuracy of classified paddy fields was compared with the land cover map of Environmental Geographic Information System (EGIS) in 2001 classified using Landsat images. Uncertainty of paddy fields classification was analyzed about the elevation and slope from the 30m resolution Digital Elevation Model (DEM) provided in EGIS. As a result of paddy classification, user's accuracy was about 41.5% and producer's accuracy was 57.6%. About 59% extracted paddy fields represented over 50 uncertainty in one hundred scale and about 18% extracted paddy fields showed 100 uncertainty. It is considered that several land covers mixed in a MODIS pixel influenced on extracted results and most classified paddy fields were distributed through elevation I, II and slope A region.

An Importance Analysis of Planning Factors for Constructing Environmental-Friendly Industrial Estate (환경친화적 산업단지 조성을 위한 계획요소의 중요도 분석)

  • Lee, Eun Yeob;Kim, Jung Kon;Lee, Hyun Ju
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.15 no.4
    • /
    • pp.1-11
    • /
    • 2012
  • This study prepared the list of planning components required for constructing environment-friendly industrial complex and grasped major environment-friendly planning components by measuring the importance per each planning component via the survey for specialists. As a result of measuring the importance of planning component according to each field for constructing environment-friendly industrial complex, it is indicated that important planning components in natural environment field are establishing complex location plan considering its configuration and slope, excluding projects for steep slope-land, establishing countermeasures for reducing contaminants per its source, and separated location of contamination industry around living space. In living environment field, proposed planning components having relatively high importance are separated location of pollution causing industry, establishing energy saving land use plan, linking with green way, circulation network plan, lowering noise level at roadside, plan for separating between pedestrian and vehicle, securing parking space, extending green park and proper location, installing green buffer zone, conserving and forming landscapes, land use for raising energy efficiency, and expansion of energy source. In case of ecological environment, core planning components such as conserving upper class of ecological naturality degree, conserving main habitat, and biotope forming plan are suggested. This study is limited to find out planning components for constructing environment-friendly physical environment of industrial complex which is a part of non-production process. The approach to solve environmental problem by linking spatially production process and non-production process. There is a need to conduct follow-up study to constructing technique for environment-friendly industrial complex considering production & nonproduction process afterward.

A Study of Limit State Design Method in Soil Slope (토사면의 한계상태 설계법에 관한 연구)

  • Joung, Gi-Hun;Kim, Jong-Min;Jang, Bum-Su
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2005.03a
    • /
    • pp.129-136
    • /
    • 2005
  • The deterministic analysis method has generally used to evaluate the slope stability and it evaluates the slope stability with decision value that is a representative value of design variables. However, one of disadvantages in the deterministic approach is there is not able to consider the uncertainty of soil strength properties, even though it is the biggest influential parameter of the slope stability. On the other hand, the limit state design(LSD) can take a consideration of uncertainties and computes both the reliability index and the probability of failure. LSD method is capable of overcoming the disadvantages of deterministic method and evaluating the slope stability more reliably. In this study, both the mean value and standard deviation of the internal land's representative soil strength properties applied to process the LSD method. The major purpose of this study is to gauge the general applicability of the limit state design in soil slope and to weigh the comparative validity of the proposed partial safety factor. In order to reach the aim of this study, the partial safety factor and resistance factor which totally satisfied the slope's overall safety factor were calculated by the load and resistance safety factor design (LRFD).

  • PDF

Simulation of generable muddy water quantity and pollutant loads in sloping field using artificial rainfall simulator (실내인공강우기를 이용한 경사지 밭의 토양유실량과 오염부하 모의)

  • Shin, Min-Hwan;Choi, Yong-Hun;Seo, Ji-Yeon;Lee, Jae-Woon;Choi, Joong-Dae
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2009.05a
    • /
    • pp.986-990
    • /
    • 2009
  • Using artificial rainfall simulator, the soil loss, which is deemed as most cause of muddy water problem among Non-point source(NPS) pollutant, was studied by the analysis of direct runoff flow, groundwater runoff, and groundwater storage properties concerned with rainfall intensity, slope of area, and land cover. The direct runoff showed increasing tendency in both straw covered and bared boxes which are 5%, 10%, and 20% sloped respectively. Also the direct runoff volume from straw covered surface boxes were much lower than bared surface boxes. It's deemed as that the infiltration capacity of straw covered surface boxes were increased, because the surface sealing by fine material of soil surface didn't occurred due to the straw covering. Under the same rainfall intensity and slope condition, 2.4 ${\sim}$ 8.2 times of sediment yield were occurred from bared surface boxes more than straw covered surface boxes. The volume of infiltrated were increased due to straw cover, the direct runoff flow were decreased with decreasing of tractive force in surface. To understand of relationship the rate of direct runoff flow, groundwater runoff, and groundwater storage by the rainfall intensity, slope, and land cover, the statistical test was performed. It shows good relationship between most of factors, expect between the rate of groundwater storage and rainfall intensity.

  • PDF

Distribution and Vertical Structures of Water Masses around the Antarctic Continental Margin

  • Kim, Seong-Joong;Lee, Bang-Yong
    • Ocean and Polar Research
    • /
    • v.27 no.3
    • /
    • pp.277-288
    • /
    • 2005
  • Spatial distribution and vertical structures of water masses around the Antarctic continental margin are described using synthesized hydrographic data. Antarctic Surface Water (AASW) over the shelf regime is distinguished from underlying other water masses by the cut-off salinity, varying from approximately 34.35 to 34.45 around Antarctica. Shelf water, characterized by salinity greater than the cut-off salinity and potential temperature less than $-17^{\circ}C$, is observed on the Ross Sea, off George V Land, off Wilkes Land, the Amery Basin, and the Weddell Sea, but in some shelves AASW occupies the entire shelf. Lower Circumpolar Deep Water is present everywhere around the Antarctic oceanic regime and in some places it mixes with Shelf Water, producing Antarctic Slope Front Water (ASFW). ASFW, characterized by potential temperature less than about $0^{\circ}C$ and greater than $-17^{\circ}C$, and salinity greater than the cut-off salinity, is found everywhere around Antarctica except in the Bellingshausen-Amundsen sector. The presence of different water masses over the Antarctic shelves and shelf edges produces mainly three types of water mass stratifications: no significant meridional property gradient in the Bellingshausen and Amundsen Seas, single property gradient where ASFW presents, and a V-shaped front where Shelf Water exists.

Landslide characteristics for Hoengseong area in 2006 (2006년 횡성지역 산사태 발생특성)

  • Yoo, Nam-Jae;Choi, Joon-Sik
    • Land and Housing Review
    • /
    • v.2 no.2
    • /
    • pp.157-162
    • /
    • 2011
  • This paper presents the landslide characteristics occurred in Hoengseong, Gangwondo and around July 16 in 2006, caused by heavy rainfall and antecedent precipitation by two typhoons of Ewiniar and Bilis. The main causes of landslides were antecedent precipitation between July 12 to 13, resulting in weakening grounds by increasing the degree of saturation previously, and the additional heavy rainfall between July 15 to 16. Most of landslides at natural slopes were transitional failures occurred along the boundary between residual weathered soil in shallow depth and hard mother rock. From the results of conclusive analyses for 100 sites in Hoengseong region where landslides occurred, the slope length of landslide and slope width were less than 100m with 87% of frequency and 30m with 74% of frequency, respectively. The average value of slope angles was $24^{\circ}$.

Simulation of Field Soil Loss by Artificial Rainfall Simulator - By Varing Rainfall Intensity, Surface Condition and Slope - (인공강우기에 의한 시험포장 토양유실량 모의 - 강우강도, 지표면 및 경사조건 변화 -)

  • Shin, Minhwan;Won, Chul-hee;Choi, Yong-hun;Seo, Jiyeon;Lee, Jaewoon;Lim, KyoungJae;Choi, Joong-dae
    • Journal of Korean Society on Water Environment
    • /
    • v.25 no.5
    • /
    • pp.785-791
    • /
    • 2009
  • Using artificial rainfall simulator, the soil loss, which is deemed as the most cause of muddy water problem among Non-point source (NPS) pollutant, was studied by the analysis of direct runoff, groundwater discharge, and soil water storage properties concerned with rainfall intensity, slope of area, and land cover. The direct runoff showed increasing tendency in both straw covered and bared soil as slope increases from 5% to 20%. The direct runoff volume from straw covered surface were much lower than bared surface. The infiltration capacity of straw covered surface increased, because the surface sealing by fine material of soil surface didn't occur due to the straw covering. Under the same rainfall intensity and slope condition, 2.4~8.2 times of sediment yield were occurred from bared surface more than straw covered surface. The volume of infiltration increased due to straw cover and the direct runoff flow decreased with decrease of tractive force in surface. To understand the relationship of the rate of direct runoff, groundwater discharge, and soil water storage by the rainfall intensity, slope, and land cover, the statistical test was performed. It shows good relationship between most of factors, except between the rate of groundwater storage and rainfall intensity.