• Title/Summary/Keyword: Erosion.Deposition

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A Time-Series Analysis of the Erosion and Deposition around Halmi-island, Baramarae (안면도 바람아래 할미섬 주변의 시계열적 침식·퇴적환경 변화 분석)

  • Yu, Jae Jin;Kim, Jang-soo;JANG, Dong-Ho
    • Journal of The Geomorphological Association of Korea
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    • v.23 no.1
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    • pp.47-60
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    • 2016
  • In this study, datum points measurement have been collected and then weather data have been analyzed to figure out erosion and deposition environmental change around Halmi-island, Baramarae. First of all, it was difficult to analyze geomorphological change which is caused by climate change because of quite short term of collection period of data. However, differences in spatial distribution of erosion and deposition have locally been shown. In all season, the wind is blowing in north and north-west direction mostly except in summer which is shifted to south direction. However, since its ratio which are above 5m/s is much lower than the north and north-west wind, its effect on geomorphological process is very tiny. In order to look at a tendency of erosion and deposition environmental change around Baramarae Halmi-island, the periphery of Halmi-island was classified to east and west part, then accumulated erosion and deposition values have been calculated. As a result, generally, the datum points are located in the west part which are mostly depositional sites. On the other hand, the datum points are located in east part showed the dominant erosion patterns.

Deposition and Erosion Relief of Riverfront by Vegetation (식생에 의한 하안 퇴적과 침식 경감)

  • Kim, Jin-Hong
    • Ecology and Resilient Infrastructure
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    • v.2 no.2
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    • pp.154-160
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    • 2015
  • This paper presents the field investigation of deposition and erosion relief of a riverfront using vegetation. The results obtained were as follows: Phragmites japonica showed 0.2 m of deposition and 0.3 m-0.4 m of erosion relief of river front by the critical velocity of 1.0 m/s-1.2 m/s. P. communis showed 0.1 m-0.4 m of deposition and 0.2 m-0.3 m of erosion relief by the critical velocity of 0.6 m/s-0.7 m/s. Salix gracilistyla showed 0.1 m-0.2 m of deposition and 0.4 m-0.5 m of erosion relief by the critical velocity of 1.2 m/s-1.4 m/s. Miscanthus sacchariflorus showed 0.1 m-0.4 m of deposition and 0.1 m-0.2 m of erosion relief by the critical velocity of 0.6 m/s-0.7 m/s. S. gracilistyla had the greatest role, while M. sacchariflorus had the lowest role for erosion relief. These results showed that aquatic plants had an effective role in sustaining a stable channel.

Assessment of the Effect of Geographic Factors and Rainfall on Erosion and Deposition (지형학적 인자 및 강우량에 따른 침식 및 퇴적의 영향 평가)

  • Yu, Wan-Sik;Lee, Gi-Ha;Jung, Kwan-Sue
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.2
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    • pp.103-112
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    • 2011
  • This study aims to demonstrate the relationship between various factors and soil erosion or deposition, simulated from distributed rainfall-sediment-runoff model applications. We selected area, overland flow length, local slope as catchment representative characteristics among many important geographic factors and also used the grid-based accumulated rainfall as a representative hydro-climatic factor to assess the effect of these two different types of factors on erosion and deposition. The study catchment was divided based on the Strahler's stream order method for analysis of the relationship between area and erosion or deposition. Both erosion and deposition increased linearly as the catchment area became larger. Erosion occurred widely throughout the catchment, whereas deposition was observed at the grid-cells near the channel network with short overland flow lengths and mild slopes. In addition, the relationship results between grid-based accumulated rainfall and soil erosion or deposition showed that erosion increased gradually as rainfall amount increased, whereas deposition responded irregularly to variations in rainfall. Within the context of these results, it can be concluded that deposition is closely related with the geographic factors used in this study while erosion is significantly affected by rainfall.

GRID-BASED SOIL-WATER EROSION AND DEPOSITION MODELING USING GIS AND RS

  • Kim, Seong-Joon
    • Water Engineering Research
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    • v.2 no.1
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    • pp.49-61
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    • 2001
  • A grid-based KIneMatic wave soil-water EROsion and deposition Model(KIMEROM) that predicts temporal variation and spatial distribution of sediment transport in a watershed was developed. This model uses ASCII-formatted map data supported from the regular gridded map of GRASS (U.S. Army CERL, 1993)-GIS(Geographic Information Systems), and generates the distributed results by ASCII-formatted map data. For hydrologic process, the kinematic wave equation and Darcy equation were used to simulated surface and subsurface flow, respectively (Kim, 1998; Kim et al., 1998). For soil erosion process, the physically-based soil erosion concept by Rose and Hairsine (1988) was used to simulate soil-water erosion and deposition. The model adopts single overland flowpath algorithm and simulates surface and subsurface water depth, and sediment concentration at each grid element for a given time increment. The model was tested to a 162.3 $\textrm{km}^2$ watershed located in the tideland reclaimed ares of South Korea. After the hydrologic calibration for two storm events in 1999, the results of sediment transport were presented for the same storm events. The results of temporal variation and spatial distribution of overland flow and sediment areas are shown using GRASS.

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The Study of erosion characteristics for MgO layer in plasma display panel (플라즈마 디스플레이 패널의 MgO막 부식 특성에 관한 연구)

  • Shin, Jae-Hwa;Jeong, Dong-Hyo
    • Proceedings of the KIEE Conference
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    • 2002.06a
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    • pp.72-74
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    • 2002
  • In this paper, we showed the erosion characteristics of MgO protector layer releated to lifetime of plasma display panel(PDP). We observed MgO erosion characteristic as a functions of deposition conditions. In RIE condition of Xe gas, the lowest erosion rate appears in the conditions of no heating, bias voltage -30V and pressure 5mtorr. In general. as deposition rate increases, erosion rate decreases.

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Comparison of soil erosion simulation between empirical and physics-based models

  • Yeon, Min Ho;Kim, Seong Won;Jung, Sung Ho;Lee, Gi Ha
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.172-172
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    • 2020
  • In recent years, soil erosion has come to be regarded as an essential environmental problem in human life. Soil erosion causes various on- and off-site problems such as ecosystem destruction, decreased agricultural productivity, increased riverbed deposition, and deterioration of water quality in streams. To solve these problems caused by soil erosion, it is necessary to quantify where, when, how much soil erosion occurs. Empirical erosion models such as the Universal Soil Loss Equation (USLE) family models have been widely used to make spatially distributed soil erosion vulnerability maps. Even if the models detect vulnerable sites relatively well by utilizing big data related to climate, geography, geology, land use, etc. within study domains, they do not adequately describe the physical process of soil erosion on the ground surface caused by rainfall or overland flow. In other words, such models remain powerful tools to distinguish erosion-prone areas at the macro scale but physics-based models are necessary to better analyze soil erosion and deposition and eroded particle transport. In this study, the physics-based Surface Soil Erosion Model (SSEM) was upgraded based on field survey information to produce sediment yield at the watershed scale. The modified model (hereafter MoSE) adopted new algorithms on rainfall kinematic energy and surface flow transport capacity to simulate soil erosion more reliably. For model validation, we applied the model to the Doam dam watershed in Gangwon-do and compared the simulation results with the USLE outputs. The results showed that the revised physics-based soil erosion model provided more improved and reliable simulation results than the USLE in terms of the spatial distribution of soil erosion and deposition.

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Impacts of temperature variations on soil organic carbon and respiration at soil erosion and deposition areas

  • Thet Nway Nyein;Dong Kook Woo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.447-447
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    • 2023
  • Soil organic carbon (SOC) is a critical indicator of soil fertility. Its importance in maintaining ecological balance has received widespread attention. However, global temperatures have risen by 0.8℃ since the late 1800s due to human-induced greenhouse gas emissions, resulting in severe disruptions in SOC dynamics. To study the impacts of temperature variations on SOC and soil respiration, we used the Soil Carbon and Landscape co-Evolution (SCALE) model, which was capable of estimating the spatial distribution of soil carbon dynamics. The study site was located at Heshan Farm (125°20'10.5"E, 49°00'23.1"N), Nenjiang County in Heilongjiang Province, Northeast China. We validated the model using observed soil organic carbon and soil respiration in 2015 and achieved excellent agreement between observed and modeled variables. Our results showed considerable influences of temperature increases on SOC and soil respiration rates at both erosion and deposition areas. In particular, changes in SOC and soil respiration at the deposition area were greater than at the erosion area. Our study highlights that the impacts of temperature elevations are considerably dependent on soil erosion and deposition processes. Thus, it is important to implement effective soil conservation strategies to maintain soil fertility under global warming.

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Bathymetric Changes in the Nakdong River Estuary owing to Discharge from the Nakdong River Barrier and Environmental Factors (하구둑 방류와 환경적 인자에 따른 낙동강 하구 지역 해저 지형변화 연구)

  • Kim, Ki-cheol;Kim, Sung-Bo
    • Journal of Environmental Science International
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    • v.30 no.7
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    • pp.507-517
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    • 2021
  • In this study, the bathymetric data acquired from 2018 to 2020 and the precipitation and suspended sediment data were analyzed for changes in bathymetry owing to the discharge from the Nakdong River barrier and environmental factors, especially the torrential rain in 2020. Sediment erosion and deposition processes are repeated because of complex environmental factors such as discharge from the Nakdong River barrier and the influence of waves generated from the external sea. In the first half of the year after the dry season, bathymetric data showed relative erosion trends, whereas in the second half after the flood season, deposition trends were identified owing to the increase in sediment transport. However, the data from the second half of 2020 showed a large amount of erosion, resulting in tendencies different to those of erosion in the first half and deposition in the second half of the year. This result is judged to be influenced by the weather in the summer of 2020. The torrential rain in the summer of 2020 resulted in a higher force of erosion than that of deposition. In summary, the tendency for erosion is more significant than that of sedimentation, especially in the main channel area of the Nakdong River.

Estimation of Soil Erosion using SATEEC and USPED and Determination of Soil Erosion Hot Spot Watershed (SATEEC과 USPED를 이용한 토양 유실량 산정 및 우선관리 유역 선정 평가)

  • Seo, Il Kyu;Park, Youn Sik;Kim, Nam Won;Moon, Jong Pil;Ryu, Ji Chul;Ok, Yong Sik;Kim, Ki-Sung;Lim, Kyoung Jae
    • Journal of Korean Society on Water Environment
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    • v.26 no.3
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    • pp.497-506
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    • 2010
  • Severe muddy water problem has been the hot issue in Korea. Because of increased nonpoint source pollutions at Kangwon province, best soil erosion management system is required to reduce inflow of nonpoint source pollutions into the waterbodies. The USLE-based SATEEC system have been developed and enhanced for soil erosion and sediment yield estimation. However, the SATEEC cannot estimate soil depositions depending on topography in the watershed, while the USPED estimates soil erosion and deposition using sediment transport capacity of the surface runoff. In this study, the SATEEC and USPED were used to determine soil erosion hot spot subbasins. For this, 54 subbasins were delineated. In general, soil erosion hot spot subbasins were identified similarly with SATEEC and USPED. However, depending on erosion and deposition patterns in each subbasin. USPED estimated soil erosion hot spot subbasins didn't match those estimated with SATEEC. For some subbasins, much deposition was expected than erosion. This indicates that SATEEC estimated soil erosion values may be overestimated for these subbasins. Thus, care should be taken when understanding soil erosion status in the watershed based on USLE-based SATEEC results. In addition, the USPED results could be used to identify the site-specific soil erosion best management practices. If the USPED and USLE-based SATEEC are combined, it would help determining soil erosion hot spot subwatersheds in economic and environmental perspectives.

Thematic Map Construction of Erosion and Deposition in Rivers Using GIS-based DEM Comparison Technique

  • Han, Seung Hee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.34 no.2
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    • pp.153-159
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    • 2016
  • Rivers refer to either natural or artificial structures whose primary functions are flood control and water conservation. Due to recent localized torrential downpours led by climate change, large amounts of eroded soil have been carried away, forming deposits downstream, which in turn degrades the capacity to fulfill these functions. To manage rivers more effectively, we need data on riverbed erosion and deposition. However, environmental factors make it challenging to take measurements in rivers, and data errors tend to prevent researchers from grasping the current state of erosions and deposits. In this context, the aim of the present study is to provide basic data required for river management. To this end, the author made annual measurements with a Real-time Kinematic-Global Positioning System (RTK-GPS) and a total station in Pats Cabin Canyon, Oregon, United States, and also prepared thematic maps of erosion and deposition thickness as well as water depth profiles based on a GIS spatial analysis. Furthermore, the author statistically analyzed the accuracy of three dimensional (3D) measurement points and only used the data that falls within two standard deviations (i.e. ±2σ). In addition, the author determined a threshold for a DEM of Difference (DoD) by installing measurement points in the rivers and taking measurements, and then estimated erosion and deposition thickness within a confidence interval of ±0.1m. Based on the results, the author established reliable data on river depth profiles and thematic maps of erosion and deposition thickness using pre-determined work flows. It is anticipated that the riverbed data can be utilized for effective river management.