• Title/Summary/Keyword: earth surface processes

Search Result 161, Processing Time 0.023 seconds

Case Study forthe Conceptualization of Location Knowledge (위치 지식의 개념화를 위한 사례 연구)

  • Kee, Keun-Doh
    • Journal of The Geomorphological Association of Korea
    • /
    • v.24 no.3
    • /
    • pp.133-147
    • /
    • 2017
  • This study investigated the cases of relative location, especially focused on the geomorphological situation, for the conceptualization of the location knowledge. In order to perform this study, first of all, I approached meaning of location. In this study I used the terms 'site' and 'situation'. 'Site' as used here means the location of a given place with its local internal features or resources. 'Situation' refers to the location of place as related to other places. As to location, no place exists in isolation. Therefore, it is necessary to look beyond the internal nature of the area itself to perceive its external relations with other areas. The examples of geomorphological situation were focused on the scale linkage of the examples, the interaction between elements of earth surface processes, and the method of comparative region. The regions of examples were the landscape of Mt. Hymalaya to Bengal deep sea fan, the climatical difference of continental east and west, the landscape of Mt. Geum & Sangju beach, the landscape of the south and north face of Mt. Mai., Hamjibaakgol asymmetrical valley, and the landscape of inland sea and outer sea type island.

Analysis of Problem-Solving Processes through Data-based STEAM Education: Focusing on Atmospheric Circulation and Surface Currents (데이터 기반 STEAM 교육을 통한 문제 해결 과정 분석: 대기대순환과 표층 해류 내용을 중심으로)

  • Hong, Seok Young;Han, Shin;Kim, Hyoungbum
    • Journal of the Korean Society of Earth Science Education
    • /
    • v.13 no.3
    • /
    • pp.330-343
    • /
    • 2020
  • In this study, STEAM program on the subject of 'atmospheric circulation and surface current' was produced based on data and applied to 106 first-year high school students to analyze its effect and problem-solving processes. This program was organized to collect, refine, visualize, and analyze data and to allow communication processes to proceed based on these results. Using this, the concept of circulation in daily life was expanded from a global perspective to identify problems about circulation around the world. As a result of the application of the program, significant changes were identified in knowledge information processing competency. Also, significant changes were made in terms of convergence and creativity, which are sub categories among STEAM core competencies. It also sought to obtain suggestions for data-based STEAM education by analyzing students' responses in the form of a Text network.

Oceanic Variables extracted from Along-Track Interferometric SAR Data

  • Kim, Duk-Jin;Moon, Wooil-M.
    • Proceedings of the KSRS Conference
    • /
    • 2002.10a
    • /
    • pp.429-434
    • /
    • 2002
  • The Synthetic Aperture Radar (SAR) data are considered to contain the greatest amount of information among various microwave techniques developed for measuring ocean variables from aircraft or satellites. They have the potential of measuring wavelength, wave direction and wave height of the ocean waves. But, it is difficult to retrieve significant ocean wave heights and surface current from conventional SAR data, since the imaging mechanism of ocean waves by a SAR is determined by the three basic modulation processes arise through the tilt modulation, hydrodynamic modulation and velocity bunching which are poorly known functions. Along-Track Interferometric (ATI) SAR systems can directly detect the Doppler shift associated with each pixel of a SAR image and have been used to estimate wave fields and surface currents. However, the Doppler shift is not simply proportional to the component of the mean surface current. It includes also contributions associated with the phase velocity of the Brags waves and orbital motions of all ocean waves that are longer than Brags waves. In this paper, we have developed a new method for extracting the surface current vector using multiple-frequency (L- & C-band) ATI SAR data, and have generated surface wave height information.

  • PDF

A DFT Study on Alkali and Alkaline Earth Metal Encapsulated Fullerene-Like BeO Cluster

  • Ravaei, Isa;Beheshtian, Javad
    • Journal of the Korean Chemical Society
    • /
    • v.61 no.6
    • /
    • pp.311-319
    • /
    • 2017
  • By using Density Functional Theory (DFT), we have performed alkali metal and alkaline earth metal inside fullerene-like BeO cluster (FLBeOC) in terms of energetic, geometric, charge transfer, work function and electronic properties. It has been found that encapsulated processes of the alkali metal are exothermic and thermodynamically more favorable than alkaline earth metal encapsulation, so that interaction energy ($E_{int}$) of the alkali metal encapsulation FLBeOC is in the range of -0.02 to -1.15 eV at level of theory. It is found that, the electronic properties of the pristine fullerene-like BeO cluster are much more sensitive to the alkali metal encapsulation in comparison to alkaline earth metal encapsulation. The alkali and alkaline earth metal encapsulated fullerene-like BeO cluster systems exhibit good sensitivity, promising electronic properties which may be useful for a wide variety of next-generation nano-sensor device components. The encapsulation of alkali and alkali earth metal may increase the electron emission current from the FLBeOC surface by reducing of the work function.

Geomorphological Processes of Yuga Alluvial Fan in Korea (유가 선상지의 지형 형성과정)

  • Lee, Gwang-Ryul;Cho, Young Dong
    • Journal of the Korean Geographical Society
    • /
    • v.48 no.2
    • /
    • pp.204-217
    • /
    • 2013
  • This study shows the geomorphological processes of Yuga alluvial fan at Dalseong-gun, Daegu in Korea, based on characteristics of geomorphological surfaces, analysis of geomorphological deposits and OSL age dating. Alluvial fans of this area are classified into three surfaces(YG-F1, YG-F2, YG-F3) and were formed by the depositional processes resulting from the changes in hydraulic geometry of flowing water which was a stream flowing out of mountains debouched on to a plain, not by a sudden decrease in surface gradient of river bed. YG-F3 surface, about 110,000 yr B.P.(MIS 5.4), was formed as Yongri river deposited a lot of debris. This result was due to the process that the deposition took place actively with the upward of base level as the last interglacial period began. Later, the denudation of the river valley and geomorphological surface constantly occurred and the local and seasonal changes were found in precipitation and stream discharge with the beginning of the interstadial of the last glacial stages(MIS 3), leading to YG-F2 formed by debris flow, earth flow, mud flow and stream flow. Then, short-term climate changes and temporal climate events repeatedly caused aggradation and denudation over time and going through these processes, YG-F1 is believed to have been made by earth flow or mudflow during the last glacial maximum(MIS 2).

  • PDF

A Review on Atmospheric Correction Technique Using Satellite Remote Sensing (인공위성 원격탐사를 이용한 대기보정 기술 고찰)

  • Lee, Kwon-Ho;Yum, Jong-Min
    • Korean Journal of Remote Sensing
    • /
    • v.35 no.6_1
    • /
    • pp.1011-1030
    • /
    • 2019
  • Remote sensing sensors used in satellites or aircrafts measure electromagnetic waves passing through the earth's atmosphere, and thus the information on the surface of the earth is affected as it is absorbed or scattered by the earth's atmosphere. Although satellites have different wavelength ranges and resolutions depending on the purpose of onboard sensors, in general, atmospheric correction must be made to remove the influence of the atmosphere in order to accurately measure the spectral signal of an object on the earth's surface. The purpose of atmospheric correction is to remove the atmospheric effect from remote sensing images to determine surface reflectivity values and to derive physical parameters of the surface. Until recently, atmospheric correction algorithms have evolved from image-based empirical methods or indirect methods using in-situ observation data to direct methods that numerically interpret more complex radiative transfer processes. This study analyzes the research records of atmospheric correction algorithms developed over the past 40 years, systematically establishes the current state of atmospheric correction technology and the results of major atmospheric correction algorithms and presents the current status and research trends of related technologies.

Temporal Variation of Air Temperature in Ice-Valley at Milyang in Association with Ice Formation

  • Lee, Soon-Hwan;Hwang, Soo-Jin
    • Journal of the Korean earth science society
    • /
    • v.28 no.5
    • /
    • pp.598-602
    • /
    • 2007
  • A long-term in situ observation was carried out in the Ice-valley at Milyang in order to explain the factors and processes associated with the summertime ice formation. The variation of temperature inside Ice-valley in relation with ice formation in summer time was found to depend on precipitation rate in spring and cold air sinking in autumn and winter. The rate of temperature rising tends to correspond to sensible heat release depending on the precipitation amount at the freezing location. The reason of the cold air accumulation in a talus in the Ice-valley is the cold air sinking over the surface of talus due to the occurrence of outside clod air mass and the accumulated cold air from autumn to spring flow outside at the bottom of talus. The out-flowing cold air can result in the ice formation in the hot summer.

Analysis of Relationship between Vegetation Cover Rates and Surface Temperature Using Landsat TM Data (Landsat TM 데이터에 의한 식생피복율과 지표면온도와의 관계 해석)

  • Park, Jong-Hwa;Na, Sang-Il;Kim, Jin-Su
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2005.10a
    • /
    • pp.569-573
    • /
    • 2005
  • Land surface temperature(LST) is one of the key parameters in physics and meteorology of land-surface processes on regional and global scales. Urban Heat Island(UHI), a meteorological phenomenon by which the air temperature in an urban area increases beyond that in the suburbs, grows with the progress of urbanization. Satellite remote sensing has been expected to be effective for obtaining thermal information of the earth's surface with a high resolution. The main purpose of this study is to produce LST map of Cheongju and to analyze the spatial distributions of surface heat fluxes in urban areas. This study, taking Cheongju as the study area, aims to examine relationship between vegetation cover rates and surface temperature, and to clarify a method for calculation surface temperature with Landsat TM thermal images.

  • PDF

Sedimentologic Characteristics of Tidal Flat Sediments after the Construction of Sea Dyke in Kwangyang Bay, South Coast of Korea (호안 건설 후 광양만 조간대 퇴적물의 퇴적학적 특성)

  • Ryu, Sang-Ock;Sin, Yong-Sik
    • Journal of the Korean earth science society
    • /
    • v.27 no.6
    • /
    • pp.659-669
    • /
    • 2006
  • In Kwangyang Bay, the south coast of Korea, surface sediments and sedimentation rates have been investigated to understand the distribution and variation of tidal flat sediments after the construction of sea dyke. The mean grain size of the surface sediments during autumn is coarser, and decrease from winter to summer except for temporarily coarsening in the early summer. The depositional processes are prevalent in spring, while erosional processes are dominant in summer and autumn. This seasonal variation of sedimentary processes show similar results monitored from 2001 to 2003 before the construction of sea dyke. In the northern area of the bay, net annual sedimentation rates show similar results monitored from 2001 to 2003 before the construction of sea dyke. However, in the western area of the bay, net annual sedimentation rates change from erosion-dominated to deposition-dominated environments. It is considered that the western area of the bay is changed to erosion-dominated environments, as a result of the changes of hydrodynamic conditions, caused by sea dyke construction.

Distribution of Surface Sediments and Sedimentation Rates on the Tidal Flat of Muan Bay, Southwestern Coast, Korea (서해남부 무안만의 표층퇴적물의 분포와 조간대 퇴적률)

  • Ryu, Sang-Ock;Kim, Joo-Young;Chang, Jin-Ho
    • Journal of the Korean earth science society
    • /
    • v.22 no.1
    • /
    • pp.30-39
    • /
    • 2001
  • To consider the distribution of the surface sediments and sedimentary processes in tidal flat after the construction of sea-walls in the semiclosed Muan Bay, the southwest coast of Korea, studies on the sediments and sedimentation rates along two transect lines from February 1999 to March 2000 were carried out. The surface sediments in the bay are classified into 5 facies on the basis of textural parameters. The gravelly sediments including the cobbles and pebbles deposited in the bay-mouth are relic sediments which are formed in nearshore and fluvial environments at the low stand of sea level. In addition, it is considered that the muddy sediments widely distributed on the tidal flat might be originated from suspended matter transported from several rivers and/or offshore. Although the sedimentation rates on the tidal flat vary with season, their estimation rates are -8.9 mm/yr on Line-GR and -48.9 mm/yr on Line-YH, respectively. The erosion-dominated processes in the tidal flat would be caused by strengthened ebb tides due to the decrease of tidal choking at Mokpogu and the migration of tidal currents at the bay-mouth. The hydrodynamical changes mentioned above are interpreted to be occurred after/before the construction of sea-dike/sea-walls in coastal zone of Mokpo.

  • PDF