• Title/Summary/Keyword: 공간적인 분포

Search Result 1,635, Processing Time 0.024 seconds

Spatial Upscaling of Aboveground Biomass Estimation using National Forest Inventory Data and Forest Type Map (국가산림자원조사 자료와 임상도를 이용한 지상부 바이오매스의 공간규모 확장)

  • Kim, Eun-Sook;Kim, Kyoung-Min;Lee, Jung-Bin;Lee, Seung-Ho;Kim, Chong-Chan
    • Journal of Korean Society of Forest Science
    • /
    • v.100 no.3
    • /
    • pp.455-465
    • /
    • 2011
  • In order to assess and mitigate climate change, the role of forest biomass as carbon sink has to be understood spatially and quantitatively. Since existing forest statistics can not provide spatial information about forest resources, it is needed to predict spatial distribution of forest biomass under an alternative scheme. This study focuses on developing an upscaling method that expands forest variables from plot to landscape scale to estimate spatially explicit aboveground biomass(AGB). For this, forest stand variables were extracted from National Forest Inventory(NFI) data and used to develop AGB regression models by tree species. Dominant/codominant height and crown density were used as explanatory variables of AGB regression models. Spatial distribution of AGB could be estimated using AGB models, forest type map and the stand height map that was developed by forest type map and height regression models. Finally, it was estimated that total amount of forest AGB in Danyang was 6,606,324 ton. This estimate was within standard error of AGB statistics calculated by sample-based estimator, which was 6,518,178 ton. This AGB upscaling method can provide the means that can easily estimate biomass in large area. But because forest type map used as base map was produced using categorical data, this method has limits to improve a precision of AGB map.

Spatial Distribution of Extremely Low Sea-Surface Temperature in the Global Ocean and Analysis of Data Visualization in Earth Science Textbooks (전구 대양의 극저 해수면온도 공간 분포와 지구과학교과서 데이터 시각화 분석)

  • Park, Kyung-Ae;Son, Yu-Mi
    • Journal of the Korean earth science society
    • /
    • v.41 no.6
    • /
    • pp.599-616
    • /
    • 2020
  • Sea-surface temperature (SST) is one of the most important oceanic variables for understanding air-sea interactions, heat flux variations, and oceanic circulation in the global ocean. Extremely low SSTs from 0℃ down to -2℃ should be more important than other normal temperatures because of their notable roles in inducing and regulating global climate and environmental changes. To understand the temporal and spatial variability of such extremely low SSTs in the global ocean, the long-term SST climatology was calculated using the daily SST database of satellites observed for the period from 1982 to 2018. In addition, the locations of regions with extremely low surface temperatures of less than 0℃ and monthly variations of isothermal lines of 0℃ were investigated using World Ocean Atlas (WOA) climatology based on in-situ oceanic measurements. As a result, extremely low temperatures occupied considerable areas in polar regions such as the Arctic Ocean and Antarctic Ocean, and marginal seas at high latitudes. Six earth science textbooks were analyzed to investigate how these extremely low temperatures were visualized. In most textbooks, illustrations of SSTs began not from extremely low temperatures below 0℃ but from a relatively high temperature of 0℃ or higher, which prevented students from understanding of concepts and roles of the low SSTs. As data visualization is one of the key elements of data literacy, illustrations of the textbooks should be improved to ensure that SST data are adequately visualized in the textbooks. This study emphasized that oceanic literacy and data literacy could be cultivated and strengthened simultaneously through visualizations of oceanic big data by using satellite SST data and oceanic in-situ measurements.

Estimation of Significant Wave Heights from X-Band Radar Using Artificial Neural Network (인공신경망을 이용한 X-Band 레이다 유의파고 추정)

  • Park, Jaeseong;Ahn, Kyungmo;Oh, Chanyeong;Chang, Yeon S.
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.32 no.6
    • /
    • pp.561-568
    • /
    • 2020
  • Wave measurements using X-band radar have many advantages compared to other wave gauges including wave-rider buoy, P-u-v gauge and Acoustic Doppler Current Profiler (ADCP), etc.. For example, radar system has no risk of loss/damage in bad weather conditions, low maintenance cost, and provides spatial distribution of waves from deep to shallow water. This paper presents new methods for estimating significant wave heights of X-band marine radar images using Artificial Neural Network (ANN). We compared the time series of estimated significant wave heights (Hs) using various estimation methods, such as signal-to-noise ratio (${\sqrt{SNR}}$), both and ${\sqrt{SNR}}$ the peak period (TP), and ANN with 3 parameters (${\sqrt{SNR}}$, TP, and Rval > k). The estimated significant wave heights of the X-band images were compared with wave measurement using ADCP(AWC: Acoustic Wave and Current Profiler) at Hujeong Beach, Uljin, Korea. Estimation of Hs using ANN with 3 parameters (${\sqrt{SNR}}$, TP, and Rval > k) yields best result.

MLP-based 3D Geotechnical Layer Mapping Using Borehole Database in Seoul, South Korea (MLP 기반의 서울시 3차원 지반공간모델링 연구)

  • Ji, Yoonsoo;Kim, Han-Saem;Lee, Moon-Gyo;Cho, Hyung-Ik;Sun, Chang-Guk
    • Journal of the Korean Geotechnical Society
    • /
    • v.37 no.5
    • /
    • pp.47-63
    • /
    • 2021
  • Recently, the demand for three-dimensional (3D) underground maps from the perspective of digital twins and the demand for linkage utilization are increasing. However, the vastness of national geotechnical survey data and the uncertainty in applying geostatistical techniques pose challenges in modeling underground regional geotechnical characteristics. In this study, an optimal learning model based on multi-layer perceptron (MLP) was constructed for 3D subsurface lithological and geotechnical classification in Seoul, South Korea. First, the geotechnical layer and 3D spatial coordinates of each borehole dataset in the Seoul area were constructed as a geotechnical database according to a standardized format, and data pre-processing such as correction and normalization of missing values for machine learning was performed. An optimal fitting model was designed through hyperparameter optimization of the MLP model and model performance evaluation, such as precision and accuracy tests. Then, a 3D grid network locally assigning geotechnical layer classification was constructed by applying an MLP-based bet-fitting model for each unit lattice. The constructed 3D geotechnical layer map was evaluated by comparing the results of a geostatistical interpolation technique and the topsoil properties of the geological map.

Spatial Analysis of Wind Trajectory Prediction According to the Input Settings of HYSPLIT Model (HYSPLIT 모형 입력설정에 따른 바람 이동경로 예측 결과 공간 분석)

  • Kim, Kwang Soo;Lee, Seung-Jae;Park, Jin Yu
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.23 no.4
    • /
    • pp.222-234
    • /
    • 2021
  • Airborne-pests can be introduced into Korea from overseas areas by wind, which can cause considerable damage to major crops. Meteorological models have been used to estimate the wind trajectories of airborne insects. The objective of this study is to analyze the effect of input settings on the prediction of areas where airborne pests arrive by wind. The wind trajectories were predicted using the HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. The HYSPLIT model was used to track the wind dispersal path of particles under the assumption that brown plant hopper (Nilaparvata lugens) was introduced into Korea from sites where the pest was reported in China. Meteorological input data including instantaneous and average wind speed were generated using meso-scale numerical weather model outputs for the domain where China, Korea, and Japan were included. In addition, the calculation time intervals were set to 1, 30, and 60 minutes for the wind trajectory calculation during early June in 2019 and 2020. It was found that the use of instantaneous and average wind speed data resulted in a considerably large difference between the arrival areas of airborne pests. In contrast, the spatial distribution of arrival areas had a relatively high degree of similarity when the time intervals were set to be 1 minute. Furthermore, these dispersal patterns predicted using the instantaneous wind speed were similar to the regions where the given pest was observed in Korea. These results suggest that the impact assessment of input settings on wind trajectory prediction would be needed to improve the reliability of an approach to predict regions where airborne-pest could be introduced.

Controlling Factors on the Development and Connectivity of Fracture Network: An Example from the Baekildo Fault in the Goheung Area (단열계의 발달 및 연결성 제어요소: 고흥지역 백일도단층의 예)

  • Park, Chae-Eun;Park, Seung-Ik
    • Economic and Environmental Geology
    • /
    • v.54 no.6
    • /
    • pp.615-627
    • /
    • 2021
  • The Baekildo fault, a dextral strike-slip fault developed in Baekil Island, Goheung-gun, controls the distribution of tuffaceous sandstone and lapilli tuff and shows a complex fracture system around it. In this study, we examined the spatial variation in the geometry and connectivity of the fracture system by using circular sampling and topological analysis based on a detailed fracture trace map. As a result, both intensity and connectivity of the fracture system are higher in tuffaceous sandstone than in lapilli tuff. Furthermore, the degree of the orientation dispersion, intensity, and average length of fracture sets vary depending on the along-strike variation in structural position in the tuffaceous sandstone. Notably, curved fractures abutting the fault at a high angle occur at a fault bend. Based on the detailed observation and analyses of the fracture system, we conclude as follows: (1) the high intensity of the fracture system in the tuffaceous sandstone is caused by the higher content of brittle minerals such as quartz and feldspar. (2) the connectivity of the fracture system gets higher with the increase in the diversity and average length of the fracture sets. Finally, (3) the fault bend with geometric irregularity is interpreted to concentrate and disturb the local stress leading to the curved fractures abutting the fault at a high angle. This contribution will provide important insight into various geologic and structural factors that control the development of fracture systems around faults.

Analysis of the Regional Disparity and Optimal Location of Living SOC - Focused on Core Living Facilities (생활SOC의 지역 간 격차와 최적입지 분석 - 생활거점시설을 중심으로)

  • Lee, Se Young;Kim, Hyun Joong;Yeo, Kwan Hyun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.40 no.3
    • /
    • pp.159-168
    • /
    • 2022
  • Local governments should try to resolve the inequality of living SOC (Social Overhead Capital) and construct spatial information on the location of living SOCs and optimal locations. This study analyzed the accessibility, equity, and optimal location of the living SOC, considering the research needs related to the living SOC. The target facility is core living facilities(a public library, a park, a culture center, and a public daycare center). The analysis area is Suwon city in Gyeonggi province, and the base year of the analysis is 2020. The study calculated accessibility per population in a microscopic neighborhood living area(200m×200m). The Gini coefficient was used to identify the regional disparity in accessibility among Dong regions. The optimal location was explored with the Maximal Covering Location Problem theory. As a result, spatial accessibility of facilities except for public daycare centers revealed a large gap between regions. Areas with excellent accessibility also showed significant variations in the facilities. The regional disparity in living SOC was the largest in culture centers, followed by parks, public daycare centers, and public libraries. The optimal locations for public libraries, parks, and culture centers are concentrated in the old downtown, while those of public daycare centers are found throughout Suwon city. The results of this study are the crucial contents of spatial planning for SOC supply in local governments. Therefore, follow-up studies will be able to refer to the analysis structure and results of the study.

Spatial Composition Affecting Bird Collision in Suwon-city, South Korea (수원시의 조류 충돌에 영향을 미치는 공간 구성)

  • Kim, Suryeon;Choi, Jaeyeon;Seo, Jayoo;Kim, Sukyoung;Baek, Jiwon;Song, Wonkyong;Park, Chan
    • Journal of Environmental Impact Assessment
    • /
    • v.31 no.4
    • /
    • pp.241-249
    • /
    • 2022
  • Humans and wild birds coexist in cities, where habitat fragmentation due to urbanization threatens the habitat and movement of birds. In this study, in order to identify landscape features associated with wild bird collide, we characterized landscape composition within a 500 m radius and points of wild bird carcasses in Suwon-city, South Korea. Dead birds were identified as having a Normalized Difference Vegetation Index (NDVI) of 0.3, Normalized Difference Built-up Index (NDBI) of -0.05, and Normalized Difference Water Index (NDWI) of -0.16 at the points of collide. And there were NDVI of 0.34, NDBI of -0.01, NDWI of -0.18, building height of 13.8 m, and soundproof wall length of 227.3 m within a radius of 500 m. Land cover type was dominated by grassland, used area, and bare land. In particular, the edges of urbanized areas, where apartments bordered forests, reservoirs, and golf courses, were identified as high-risk spaces. In order to minimize bird mortality risk in urban environments, the impact of changes to a vertical landscape should be reviewed from an environmental impact assessment approach. In addition, a preventive management plan that considers the temporal and spatial features that wild animals can safely avoid and adapt to in urbanized spaces should be prepared.

A Study on the Relevancy of Application of Land Suitability Assessment in Developed Urban Areas: the case of Seoul (도시지역 토지적성평가의 적정성에 관한 연구 - 서울시를 중심으로 -)

  • Lee, Sekwang;Park, joon
    • Journal of the Korean Regional Science Association
    • /
    • v.38 no.2
    • /
    • pp.43-57
    • /
    • 2022
  • The Land Suitability Assessment is mandatory by National Land Planning and Utilization Act and the results are considered in the establishment of urban master plan and urban management plan. The study aims to examine whether the application of Land Suitability Assessment in developed urban areas is appropriate. A simulation analysis based on the Seoul's data of environmental ecological, physical, and spatial characteristics was conducted on urban green, the only applicable land for the assessment in Seoul. The results of the assessment shows that all pieces of lands in urban green is suitable for 'development'. This conflicts to the purpose of land use of urban green which needs to be conserved to protect the natural environment and landscape, animals and plants, environmental pollution, and urban sprawl. In the analysis applying optional indicators such as the distance from the area of Biotope Class 1 to prevent this conflict, the results shows little difference. This supports the necessity to review this regulation including an option to exclude developed urban areas such as Seoul in the assessment.

A study on the selection of evapotranspiration observatory representative location in Chuncheon Dam basin (증발산량 관측 대표위치 선정에 관한 연구: 춘천댐 유역을 중심으로)

  • Park, Jaegon;Kim, Kiyoung;Lee, Yongjun;Hwag-Bo, Jong Gu
    • Journal of Korea Water Resources Association
    • /
    • v.55 no.11
    • /
    • pp.979-989
    • /
    • 2022
  • In hydrological surveys, observation through representative location is essential due to temporal and spatial limitations and constraints. Regarding the use of hydrological data and the accuracy of the data, there are still insufficient observatories to be used in a specific watershed. In addition, since there is virtually no standard for the location of the current evapotranspiration, this study proposes a method for determining the location of the evapotranspiration. To determining the location of evapotranspiration, a grid is selected in consideration of the operating range of the Flux Tower using the eddy covariance measurement method, which is mainly used to measure evapotranspiration. The grid of representative location was calculated using the factors affecting evapotranspiration and satellite data of evapotranspiration. The grid of representative location was classified as good, fair, and poor. As a result, the number of good grids calculated was 54. It is judged that the classification of the grid has been achieved regarding topography and land use as a characteristic that appeared in the classification of the grid. In particular, in the case of elevation or city area, there was a large deviation, and the calculated good grid was judged to be a group between the two distributions.