• Title/Summary/Keyword: Land Topography

Search Result 395, Processing Time 0.024 seconds

An Analysis of Landslides at Jinhae District Dated 25th of August, 1979 (1979년(年) 8월(月) 집중호우(集中豪雨)에 의한 진해지구(鎭海地区)의 산사태(山沙汰)에 관한 연구(研究))

  • Kang, Wee Pyung
    • Journal of Korean Society of Forest Science
    • /
    • v.52 no.1
    • /
    • pp.72-78
    • /
    • 1981
  • On August 25, 1979 a heavy daily rainfall of 465 mm pured into Jinhae area by the influence of Typhoon Judy. In consequence of the typhoon, 38 persons were killed, houses and arable land were demolished and caused wide ranges of landslides in the area. According to the previous investigation, there had been five cases of such typhoons accompanied a daily precipitation over 300 mm for 27 years, however, there had not occurred any landslides before, even though it is reported that any typhoon accompanied by heavy daily rainfalls over 300 mm is normally known to cause various kinds of landslides. This phonomenon was described to the fact that there has been a qualitative change in the agents of landslides such as precipitation, geology, topography and forest. Thus, in this report, the relations of the agents to the development of landslides were to be analysed and brought forth the following confirmation: 1. In the district, 71 landslides of which area covered 15.3 ha were observed. 2. In terms of geology of the landslided sites. 89 and 11% in numbers were observed in the andesite and the granite respectively, and the areas of those landslide estimated 45 and 55% respectively. 3. In a topographical point of view, 44% of the numbers of landslides(55% in area basis) were occurred within the slopes of $26-35^{\circ}$, while no landslides were observed in either lower (below $9^{\circ}$) or upper (above $41^{\circ}$) slopes. In terms of slope patterns, 39 and 33% in numbers (52 and 46% on the basis of area) were observed in concave slopes and compound slopes respectively. 4. In terms of forest ages, the most landslides were observed in 5-15 year-old forest, of which averages were 2.19 landslides per 100 ha and 0.47 ha per 100 ha. However, no landslides were observed in the forest of over 26 years old. 5. Among the agents, precipitation, geology, topography are considered not to be controlled but the only agent, the forest, to be controlled by human beings. Thus, this firstly observed landslides at Jinhae District are conclusively considered as the result of qualitative changes of one agent, the forest, in the area.

  • PDF

Review of Remote Sensing Studies on Groundwater Resources (원격탐사의 지하수 수자원 적용 사례 고찰)

  • Lee, Jeongho
    • Korean Journal of Remote Sensing
    • /
    • v.33 no.5_3
    • /
    • pp.855-866
    • /
    • 2017
  • Several research cases using remote sensing methods to analyze changes of storage and dynamics of groundwater aquifer were reviewed in this paper. The status of groundwater storage, in an area with regional scale, could be qualitatively inferred from geological feature, surface water altimetry and topography, distribution of vegetation, and difference between precipitation and evapotranspiration. These qualitative indicators could be measured by geological lineament analysis, airborne magnetic survey, DEM analysis, LAI and NDVI calculation, and surface energy balance modeling. It is certain that GRACE and InSAR have received remarkable attentions as direct utilization from satellite data for quantification of groundwater storage and dynamics. GRACE, composed of twin satellites having acceleration sensors, could detect global or regional microgravity changes and transform them into mass changes of water on surface and inside of the Earth. Numerous studies in terms of groundwater storage using GRACE sensor data were performed with several merits such that (1) there is no requirement of sensor data, (2) auxiliary data for quantification of groundwater can be entirely obtained from another satellite sensors, and (3) algorithms for processing measured data have continuously progressed from designated data management center. The limitations of GRACE for groundwater storage measurement could be defined as follows: (1) In an area with small scale, mass change quantification of groundwater might be inaccurate due to detection limit of the acceleration sensor, and (2) the results would be overestimated in case of combination between sensor and field survey data. InSAR can quantify the dynamic characteristics of aquifer by measuring vertical micro displacement, using linear proportional relation between groundwater head and vertical surface movement. However, InSAR data might now constrain their application to arid or semi-arid area whose land cover appear to be simple, and are hard to apply to the area with the anticipation of loss of coherence with surface. Development of GRACE and InSAR sensor data preprocessing algorithms optimized to topography, geology, and natural conditions of Korea should be prioritized to regionally quantify the mass change and dynamics of the groundwater resources of Korea.

A Basic Study on Spatial Configuration of Gang-jin Nongsanbyeoleop (강진 농산별업(農山別業)의 공간구성에 대한 기초 연구)

  • Seo, Dong-Il;Lee, Jae-Keun
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.30 no.2
    • /
    • pp.64-71
    • /
    • 2012
  • This is a basic study for recovering original form of Nongsanbyeoleop(農山別業) in Gangjin, Jeonnam, created in the latter part of Joseon period and the estimation of originla form at the time of creation was conducted by analyzing related literature and inspecting the actual site. "Joseokruki(朝夕樓記)" of Dasan Jung, Yak Yong could estimate spatial structure and using form of Nongsanbyeoleop and the arrangement of spatial structure in literature could be confirm by on-the-site inspection. The results of this study are as follows. The first, Nongsanbyeoleop managed spatial factors applying natural topography. For the spatial characteristics of Nongsanbyeoleop, the location of ancestral ritual space including deceased father's tomb and tomb house far from the main levee of Yun, Kwang Taek, a father of Yun, Seo Yu by 1.9km and housekeeping could be confirmed. The second, spatial estimation by "Joseokruki" could be possible. "Joseokruki" describes Joseokru.Youngmojae.Hanokkwan.Cheokyunjung.Sangam as construction factors, Wundang.Kookdan.Nokwunoh. as plant factors, Sookyunggan.Keumkoji.Nokeumjung.Uijanghae as hydroponic factors and Pyoeunkok.Aengjakang as natural topography factors. However, most of them were disappeared and at present, only Youngmojae, Keumgoji, Kukdan and Wundang show the past trace. The third is for the changed space of Nongsanbyeoleop and its reason. The surrounding space of Nongsanbyeoleop was planated by land arrangement in 1960s and it played a role of topographical damage because it's recognized as the plane factor including Nongsanbyeoleop's surrounding landscape rather than dotted factor. The forth, the actual measurement of Nongsanbyeoleop and digitalization of manual map of numerical value are judged to be sufficient to apply as the basic material for recovering garden in the future. Because of the diatahce changing method applied at that time, the garden recovery of Nongsanbyeoleop intended to be concreted and 3D model established by digitalized basic materials is considered to apply for multilateral studying. Thus, Nongsanbyeoleop which is byeolseo including the tomb of deceased father based on the conceptual hyo thought shows clear differences from the organized factors of Byolseowonrim of precedent studies and the importance of Byolseowonrim is sufficient. But, the constructional factors which cannot know disappeared spatial factors and accurate location became the limitation of this study. In the future, clear verification of original form must be progressed by excavation which can confirm the location of construction factors.

Micro Feeding Site Preference of Wintering Cranes by Topography and Vegetation in Cheorwon Basin, Korea (철원지역에서 월동하는 두루미류의 지형과 식생에 의한 미소 취식지 선호성)

  • Yoo, Seung-Hwa;Kim, In-Kyu;Lee, Han-Soo;Lee, Ki-Sup
    • Korean Journal of Environment and Ecology
    • /
    • v.23 no.5
    • /
    • pp.418-430
    • /
    • 2009
  • The main purpose of this study is to investigate the relationship between the topography of land and vegetation and the preferred habitat of wintering cranes. Investigations were conducted twelve times in Cheorwon basin, South Korea, during two wintering seasons (12/2005 - 2/2006; 1/2007 - 2/2007). The density of rice grain in the middle of rice paddies was higher than that of the areas along the edge of rice paddies. However it was observed that red-naped cranes preferred to feed along the edges of rice paddies rather than to feed in the middle of the paddies. White-naped cranes, on the other hand, Preferred to feed in the middle of paddies. To be more specific, red-crowned cranes preferred feeding sites such as levees of the paddies or the areas where the level of the rice beds was comparatively more elevated. But the preference of the white-naped cranes turned out to be just the opposite. Another finding was that both red-naped cranes and white-naped cranes preferred concealed areas for their feeding site, and the frequency rate of their feeding in concealed areas has little to do with weather factors. This finding contradicts a widely accepted view that cranes prefer open spaces for their feeding site. Besides, red-crowned cranes, compared with white-naped cranes, preferred to feed in more concealed areas. The frequency rate of feeding in both concealed areas and non-concealed areas had little to do with the size of feeding flocks. There was no difference between a flock of fewer than five cranes and a flock of more than five cranes in terms of frequency rate of their feeding. In conclusion, the result of these investigations indicate that red-naped cranes comparatively prefer concealed areas for their feeding site, and white-naped cranes are less prone to them, and there is no direct connection between their preference of feeding site or frequency and the size of their flock. This is presumed to be the characteristics unique to their individual species.

Estimate on the Crustal Thickness from Using Multi-geophysical Data Sets and Its Comparison to Heat Flow Distribution of Korean Peninsula (다양한 지구물리 자료를 통해 얻은 한반도의 지각두께 예측과 지열류량과의 비교)

  • Choi, Soon-Young;Kim, Hyung-Rae;Kim, Chang-Hwan;Park, Chan-Hong;Suh, Man-Chul
    • Economic and Environmental Geology
    • /
    • v.44 no.6
    • /
    • pp.493-502
    • /
    • 2011
  • We study the deep structure of Korean Peninsula by estimating Moho depth and crustal thickness from using land and oceanic topography and free-air gravity anomaly data. Based on Airy-Heiskanen isostatic hypothesis, the correlated components between the terrain gravity effects and free-air gravity anomalies by wavenumber correlation analysis(WCA) are extracted to estimate the gravity effects that will be resulted from isostatic compensation for the area. With the resulting compensated gravity estimates, Moho depth that is a subsurface between the crust and mantle is estimated by the inversion in an iterative method with the constraints of 20 seismic depth estimates by the receiver function analysis, to minimize the uncertainty of non-uniqueness. Consequently, the average of the resulting crustal thickness estimate of Korean Peninsula is 32.15 km and the standard deviation is 3.12 km. Moho depth of South Korea estimated from this study is compared with the ones from the previous studies, showing they are approximately consistent. And the aspects of Moho undulation from the respective study are in common deep along Taebaek Mountains and Sobaek Mountains and low depth in Gyeongsang Basin relatively. Also, it is discussed that the terrain decorrelated free-air gravity anomalies inferring from the intracrustal characteristics of the crust are compared to the heat flow distributions of South Korea. The low-frequency components of terrain decorrelated Free-air gravity anomalies are highly correlated with the heat flow data, especially in the area of Gyeongsang basin where high heat flow causes to decrease the density of the rocks in the lower crust resulting in lowering the Moho depth by compensation. This result confirms that the high heat sources in this area coming from the upper mantle by Kim et al. (2008).

A study on the utilization of drones and aerial photographs for searching ruins with a focus on topographic analysis (유적탐색을 위한 드론과 항공사진의 활용방안 연구)

  • Heo, Ui-Haeng;Lee, Wal-Yeong
    • Korean Journal of Heritage: History & Science
    • /
    • v.51 no.2
    • /
    • pp.22-37
    • /
    • 2018
  • Unmanned aerial vehicles (UAV) have attracted considerable attention both at home and abroad. The UAV is equipped with a camera that shoots images, which is advantageous for access to areas where archaeological investigations are not possible. Moreover, it is possible to acquire three-dimensional spatial image information by modeling the terrain through aerial photographing, and it is possible to specify the interpretation of the terrain of the survey area. In addition, if we understand the change of the terrain through comparison with past aerial photographs, it will be very helpful to grasp the existence of the ruins. The terrain modeling for searching these remains can be divided into two parts. First, we acquire the aerial photographs of the current terrain using the drone. Then, using image registration and post-processing, we complete the image-joining and terrain-modeling using past aerial photographs. The completed modeled terrain can be used to derive several analytical results. In the present terrain modeling, terrain analysis such as DSM, DTM, and altitude analysis can be performed to roughly grasp the characteristics of the change in the form, quality, and micro-topography. Past terrain modeling of aerial photographs allows us to understand the shape of landforms and micro-topography in wetlands. When verified with actual findings and overlapping data on the modelling of each terrain, it is believed that changes in hill shapes and buried Microform can be identified as helpful when used in low-flying applications. Thus, modeling data using aerial photographs is useful for identifying the reasons for the inability to carry out archaeological surveys, the existence of terrain and ruins in a wide area, and to discuss the preservation process of the ruins. Furthermore, it is possible to provide various themes, such as cadastral maps and land use maps, through comparison of past and present topographical data. However, it is certain that it will function as a new investigation methodology for the exploration of ruins in order to discover archaeological cultural properties.

A Study on Hydrologic Clustering for Standard Watersheds of Korea Water Resources Unit Map Using Multivariate Statistical Analysis (다변량 통계분석기법을 이용한 전국 표준유역 대상 수문학적 군집화 연구)

  • Ahn, So-Ra;Kim, Sang-Ho;Kim, Seong-Joon
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.17 no.1
    • /
    • pp.91-106
    • /
    • 2014
  • This study tries to cluster the 795 standard watersheds of Korea Water Resources Unit Map using multivariate statistical analysis technique. The 30 factors of watershed characteristics related to topography, stream, meteorology, soil, land cover and hydrology were selected for comprehensive analysis. From the factor analysis, 16 representative factors were selected. The significant factors in order were the pedological feature, scale and geological location and meteorological and hydrological features of the watershed. As a next step, the 73 gauged watersheds were selected for cluster analysis. They are scattered properly to the whole country and the discharge data were within a confidential level. Based on the 73 watersheds, the other ungaged watersheds were clustered by applying the 16 factors and calculating Euclidian distances. The clustering results showed that the similarity between standard watersheds within the same river basin were 87%, 69%, 41%, 52%, and 27% for Han, Nakdong, Geum, Seomjin, and Yeongsan river basins respectively.

Soil Organic Matter and Nutrient Accumulation at the Abandoned Fields

  • Park, Byung Bae;Shin, Joon Hwan
    • Journal of Korean Society of Forest Science
    • /
    • v.97 no.5
    • /
    • pp.492-500
    • /
    • 2008
  • Since vegetation significantly influences on soil carbon and nutrient storage, vegetation change has been focused on terrestrial carbon and nutrient cycling studies. In this study we investigated soil carbon and major nutrient capitals at the abandoned fields, which had different vegetation composition: a three year abandoned field ($AGR_3$), two ten years abandoned fields ($PD_{10}$ dominant with Pinus densiflora and Fraxinus rhynchophylla and $PM_{10}$ dominant with Populus maximowiczii), and an over sixty years forest ($FOR_{60}$). which were located at Hongcheon-gun, Kangwon-do, South Korea. Both main effects for organic matter (%) were significant: shallow soil > deep soil and $FOR_{60}=PM_{10}$ > $AGR_3=PD_{10}$. Nitrogen concentrations at $PM_{10}$ were the highest, while the lowest at $PD_{10}$. Available phosphorus concentrations were the highest at $PD_{10}$, which were over 10 times of site $FOR_{60}$ and $AGR_3$ at 0-10 cm soil depth. The average organic matter ($173Mg\;ha^{-1}$) and nitrogen contents ($10Mg\;ha^{-1}$) of $PM_{10}$ and $FOR_{60}$ were higher than those of $AGR_3$ and $PD_{10}$ by 57% and 42%, respectively. The available phosphorus contents above 30 cm mineral soil at $PD_{10}$ ($3.8Mg\;ha^{-1}$) and $PM_{10}$ ($1.3Mg\;ha^{-1}$) were over 120 times and 40 times more than at $FOR_{60}$. Calcium ($3.7Mg\;ha^{-1}$) and magnesium contents ($2.8Mg\;ha^{-1}$) at $FOR_{60}$ were twice or three times higher than at other sites. Organic matter amounts in 0-10 cm and 10-30 em soil had significant positive relationships with nitrogen, calcium, and magnesium contents, but not available phosphorus and potassium contents. This study could not identify the effect of chronological factor and vegetation composition on soil carbon and nutrient capital owing to diverse topography as well as limited study sites. However, this study suggests the accuracy of investigation for regional carbon and nutrient sequestration can be achieved by considering the period of abandoned time on the fields and the land use types. These results may suggest the benefits of forest restoration for soil carbon and nutrient accumulation in marginal agricultural lands in South Korea.

The Analysis on Causes of Areas with Public Appeals to the Ecosystem and Nature Map (생태·자연도 이의신청지역의 원인 분석)

  • Jung, Tae-Jun;Song, Il-Bae;Lee, Ji-Seon;Lee, Sung-Je;Cho, Kwang-Jin;Song, Kyo-Hong;Kim, Ki-Dong;Cha, Jin-Yeol;Cho, Jang-Sam;Leem, Hyosun;Joung, Hae-Joung
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.20 no.1
    • /
    • pp.25-34
    • /
    • 2017
  • The objective of this study is to seek for improvement measures to make the Ecosystem and Nature Map by analyzing causes for grade changes and distributional characteristics of areas with public objections to the Ecosystem and Nature Map notified by e-official gazette from 2014 to June 2016. The receipt of public appeals has been recently increased from average 23 cases a year(2007-2013) to average 33 cases a year(2014-June 2016) while there were 42 areas with public appeals for less than the minimum area($62,500m^2$) for the evaluation of grade of the Ecosystem and Nature Map. Most of the public appeals focused on the 1st grade zone of the Ecosystem and Nature Map. Before grade changes by public appeals, the 1st grade zone of the Ecosystem and Nature Map were 76.0% of the whole areas with public appeals. However, after grade changes by public appeals, it was rapidly decreased to 25.2%, which means that a lot of the 1st grade zone with public appeals were lowered. In the results of analyzing the distributional characteristics of areas with public appeals, they were mostly distributed in lowland(less than 250m altitude), section with $10{\sim}20^{\circ}$ slope, and areas close to or within 100m from built-up area. Regarding areas with public appeals, the biggest time difference between the period of the existing research by National Ecosystem Survey and the period of notice after completing the treatment of public appeals was 18 years while areas showing 6-15 years of time difference were about 70%. Thus, there were huge differences in time of research and notice. Also, the biggest causes for grade changes were boundary errors caused by small-scale survey, and then followed by changes in evaluation of endangered species and occurrence of built-up area and damaged land. Analyzing areas with public appeals in each evaluation item of the Ecosystem and Nature Map, vegetation part was 73.0%, and endangered species area was 23.1% while topography and wetland was less.

The Application of Geospatial Information Acquisition Technique and Civil-BIM for Site Selection (지형공간정보취득기술과 토목BIM을 활용한 부지선정 연구)

  • Moon, Su-Jung;Pyeon, Mu-Wook;Park, Hong-Gi;Ji, Jang-Hun;Jo, Jun-Ho
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.28 no.6
    • /
    • pp.579-586
    • /
    • 2010
  • Due to the recent development of measuring technology and 3D programs, it has become possible to obtain various spatial data. This study utilizes the 2-dimensional data and 3-dimensional data extraction technology based on the existing empirical and statistical DB. The data obtained from geospatial data technology are integrated with civil engineering BIM to conduct the modeling of the topography of the target region and select the optimum location condition by using the cut and fill balance of the volume of earth. The target area is the land around Tamjin River, Jangheong-gun, Jeolla-do. The 3-dimensional topology linked with 3-dimensional mapping technology by using the orth-image and aerial LiDAR that uses aerial photo of the target area is visualized with Civil3D of AutoDesk. By using Civil3D program, the Thanks to the recent development of measuring technology and 3D programs, target area is analyzed through visualization and related data can be obtained for analysis. The method of using civil engineering BIM enables to obtain various and accurate information about the target area which is helpful for addressing the issues risen from the existing methodology. In this regard, it aims at searching for the alternatives and provides suggestions to utilize the information.