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Evaluation of forest carbon uptake in South Korea using the national flux tower network, remote sensing, and data-driven technology

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AGRICULTURAL AND FOREST METEOROLOGY 2021年 311卷 108653-108653页

作者： Cho, Sungsik Kang, Minseok Ichii, Kazuhito Kim, Joon Lim, Jong-Hwan Chun, Jung-Hwa Park, Chan-Woo Kim, Hyun Seok Choi, Sung-Won Lee, Seung-Hoon Indrawati, Yohana Maria Kim, Jongho Natl Ctr Agro Meteorol Seoul 08826 South Korea Seoul Natl Univ Interdisciplinary Program Agr & Forest Meteorol Seoul 08826 South Korea Chiba Univ Ctr Environm Remote Sensing Chiba 2638522 Japan Natl Inst Environm Studies Ctr Global Environm Res 16-2 Onogawa Tsukuba Ibaraki 3058506 Japan Seoul Natl Univ Dept Landscape Architecture & Rural Syst Engn Seoul 08826 South Korea Seoul Natl Univ Inst Green Bio Sci & Technol Pyeonchang Campus Pyeongchang 25354 South Korea Seoul Natl Univ Res Inst Agr & Life Sci Seoul 08826 South Korea Natl Inst Forest Sci Forest Ecol Div Seoul South Korea Natl Inst Forest Sci Forest ICT Res Ctr Seoul South Korea Seoul Natl Univ Coll Agr & Life Sci Dept Agr Forestry & Bioresources Seoul 08826 South Korea

Forests provide most of the carbon sequestration of atmospheric carbon dioxide (CO2);however, accurately quantifying the uptake amount over a region remains challenging. For reginal or national estimates, the forest productivity model and forest inventories are used which provide information for national greenhouse gas inventories. However, it has some limitations, such as not considering below-ground biomass, its lack of species-specific allometric models, the restrictions it places during fieldwork, and the long period it takes to complete the survey. In contrast to inventory-based biomass estimates, the eddy covariance (EC) method can assess net CO2 exchange of a whole ecosystem continuously and automatically with a high temporal resolution. Since, these measurements only represent a site-level observation scale (similar to 1 km(2)), upscaling via linkages with observation data, remote sensing, and modeling methods has been used to estimate regional or national land-atmosphere carbon fluxes. In this study, we employ a data-driven method to estimate the national-scale gross primary production (GPP) and net ecosystem CO2 exchange (NEE) by combining EC flux data from 10 sites in South Korea with remote sensing data through a machine learning algorithm based on support vector regression (SVR) for the period 2000-2018. Site-level evaluation of estimated GPP and NEE from the SVR-based model shows equivalent performance compared to other continental and global upscaled models. The mean estimated annual GPP and NEE of the South Korea forests region over the period 2000-2018 were 1465 +/- 37 and -243 +/- 32 g C m(2) year(-1) respectively. The SVR-based net primary production (NPP) was consistent with the biometric-based NPP = 0.46, p < 0.05). This study shows that combining data from a national flux network and remote sensing using a data-driven approach can be used to estimate forest CO2 fluxes on a national scale.

关键词： Carbon flux Eddy covariance KoFlux Data-driven approach Support vector regression Remote sensing

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Spatial and temporal variations in soil respiration among different land cover types under wet and dry years in an urban park

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landscape AND URBAN PLANNING 2017年 167卷 378-385页

作者： Bae, Jeehwan Ryu, Youngryel Seoul Natl Univ Dept Landscape Architecture & Rural Syst Engn Seoul 151921 South Korea Seoul Natl Univ Interdisciplinary Program Agr & Forest Meteorol Seoul South Korea Seoul Natl Univ Interdisciplinary Program Landscape Architecture Seoul South Korea Seoul Natl Univ Res Inst Agr & Life Sci Seoul South Korea

Soil respiration (R-s) determines land surface carbon balance;however, there have been few studies that measured R-s in heterogeneous urban landscapes. Here, we investigated the spatial and temporal variations in R-s in six land cover types (mixed forest, deciduous broadleaf forest, evergreen needleleaf forest, lawn, wetland, and bare land) in Seoul Forest Park, Republic of Korea, between March 2013 and September 2014, which included a wet (2013) and an extremely dry (2014) summer. Spatially, there was a three-fold difference (0.48-1.45 kgC m(-2)) in annual R-s among the six land cover types. The soil organic carbon stock at a dept. of 0.1 m explained 72% of the spatial variation in the annual R-s across the land cover types. During the entire study period, the soil temperature explained 82-97% of the temporal variation in R-s among different land cover types. Comparing the two summers, the 2014 drought only resulted in a decrease in R-s in the lawn plots (25%), which was driven by a reduction in the leaf area index and the fine root density. The temperature sensitivity of R-s in 2014 (dry summer) compared to 2013 (wet summer) was significantly lower in mixed forest, deciduous broadleaf forest, and lawn, and did not change in evergreen needleleaf forest, wetland, or bare land. The differences in R-s in these drought responses highlight the importance of the careful selection of land cover type during park planning to better manage carbon cycles.

关键词： Soil respiration Land cover type Urban drought Urban park

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Spatial and temporal patterns of microclimates at an urban forest edge and their management implications

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ENVIRONMENTAL MONITORING AND ASSESSMENT 2018年第2期190卷 93-93页

作者： Li, Yingnan Kang, Wanmo Han, Yiwen Song, Youngkeun Seoul Natl Univ Interdisciplinary Program Landscape Architecture Seoul 08826 South Korea Seoul Natl Univ Res Inst Agr & Life Sci Seoul 08826 South Korea Seoul Natl Univ Grad Sch Environm Studies Dept Landscape Architecture Seoul 08826 South Korea

Fragmented forests generate a variety of forest edges, leading to microclimates in the edge zones that differ from those in the forest interior. Understanding microclimatic variation is an important consideration for managers because it helps when making decisions about how to restrict the extent of edge effects. Thus, our study attempted to characterize the changing microclimate features at an urban forest edge located on Mt. Gwanak, Seoul, South Korea. We examined edge effects on air temperature, relative humidity, soil temperature, soil moisture, and photosynthetically active radiation (PAR) during the hottest three consecutive days in August 2016. Results showed that each variable responded differently to the edge effects. This urban forest edge had an effect on temporal changes at a diurnal scale in all microclimate variables, except soil moisture. In addition, all variables except relative humidity were significantly influenced by the edge effect up to 15 m inward from the forest boundary. The relative humidity fluctuated the most and showed the deepest extent of the edge effect. Moreover, the edge widths calculated from the relative humidity and air temperature both peaked in the late afternoon (16:00 h). Our findings provide a reference for forest managers in designing urban forest zones and will contribute to the conservation of fragmented forests in urban areas.

关键词： Edge effect Edge width Microclimate Urban forest Forest management

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BESS-Rice: A remote sensing derived and biophysical process-based rice productivity simulation model

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AGRICULTURAL AND FOREST METEOROLOGY 2018年 256卷 253-269页

作者： Huang, Yan Ryu, Youngryel Jiang, Chongya Kimm, Hyungsuk Kim, Soyoun Kang, Minseok Shim, Kyomoon Seoul Natl Univ Res Inst Agr & Life Sci Seoul South Korea Seoul Natl Univ Dept Landscape Architecture & Rural Syst Engn Seoul South Korea Seoul Natl Univ Interdisciplinary Program Agr & Forest Meteorol & Seoul South Korea Seoul Natl Univ Brain Korea Plus Team 21 Seoul South Korea Natl Ctr Agro Meteorol Seoul South Korea Rural Dev Adm Natl Inst Agr Sci Jeonju Si Jeollabuk Do South Korea

Conventional process-based crop simulation models and agro-land surface models require numerous forcing variables and input parameters. The regional application of these crop simulation models is complicated by factors concerning input data requirements and parameter uncertainty. In addition, the empirical remotely sensed regional scale crop yield estimation method does not enable growth process modeling. In this study, we developed a process-based rice yield estimation model by integrating an assimilate allocation module into the satellite remote sensing-derived and biophysical process-based Breathing Earth System Simulator (BESS). Normalized accumulated gross primary productivity (GPP(norm-accu)) was used as a scaler for growth development, and the relationships between GPP(norm-accu) and dry matter partitioning coefficients were determined from the eddy covariance and biometric measurements at the Cheorwon Rice paddy KoFlux site. Over 95% of the variation in the dry matter allocation coefficients of rice grain could be explained by GPP(norm-accu) . The dynamics of dry matter distribution among different rice components were simulated, and the annual grain yields were estimated. BESS-Rice simulated GPP and dry matter partitioning dynamics, and rice yields were evaluated against in-situ measurements at three paddy rice sites registered in KoFlux. The results showed that BESS-Rice performed well in terms of rice productivity estimation, with average root mean square error (RMSE) value of 2.2 g C m(-2)d(-1) (29.5%) and bias of-0.5 g Cm-2 d(-1) (-7.1%) for daily GPP, and an average RMSE value of 534.8 kg ha(-1) (7.7%) and bias of 242.1 kg ha(-1) (3.5%) for the annual yield, respectively. BESS-Rice is much simpler than conventional crop models and this helps to reduce the uncertainty related to the forcing variables and input parameters and can result in improved regional yield estimation. The process-based mechanism of BESS-Rice also enables an agronomic diagnosis to

关键词： Crop modeling Carbon allocation Gross primary productivity Yield Rice BESS

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Parametric Method Using Grasshopper for Bulbous Bow Generation

Parametric Method Using Grasshopper for Bulbous Bow Generati...

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International Conference on Computing, Electronics & Communications Engineering (iCCECE)

作者： Yongxing Zhang Dong-Joon Kim Aldias Bahatmaka Interdisciplinary program of Marine Pukyong National University Busan Republic of Korea Dept. of Naval Architecture and Marine Systems Engineering Pukyong National University Busan Republic of Korea

ISBN: (纸本)9781538649053;9781538649046

Green ship technology is increasingly important in different areas of ship design. Hydrodynamic optimization shape design is an integral part of the overall fuel economy design. To get the optimal design, the geometry modification of ship takes extremely important place in an optimization loop. A conventional non-parametric approach has numerous disadvantages because the geometry is typically generated by low-level entities. In this study, a new bulbous bow modification method was developed for automatic generation and modification of a bulbous bow. A bulbous bow represented by the Non-Uniform Rational B-Spline (NURBS) surfaces. The generated bulbous bow can be automatically modified. In this study, Grasshopper is applied to generate and reconstruct a parametric bulbous bow. And attach the generated bulbous bow to a fixed hull automatically.

关键词： Optimization Marine vehicles Shape Surface reconstruction Surface treatment Geometry Computational fluid dynamics

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Verification of CFD Method for Meshing Analysis on the Propeller Performance with OpenFOAM

Verification of CFD Method for Meshing Analysis on the Prope...

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International Conference on Computing, Electronics & Communications Engineering (iCCECE)

作者： Aldias Bahatmaka Dong-Joon Kim Yongxing Zhang Interdisciplinary program of Marine Convergence Design Pukyong National University Busan Republic of Korea Dept. of Naval Architecture and Marine Systems Engineering Pukyong National University Busan Republic of Korea

ISBN: (纸本)9781538649053;9781538649046

This paper inspects the capability if using the Computational Fluid Dynamics (CFD) tools to investigate the effect of free surface with marine propeller. We conducted the numerical simulation for propeller performance on the open-water test. The numerical simulations were compared the meshing strategies for the propeller. The simulations show that effect on the thrust and torque. The OpenFOAM was applied to solve the propeller problem, where open water performances of propeller (KP505) is estimated by a Reynold-average Navier-Stokes equations (RANS) solver which is using the three-dimensional unsteady incompressible viscous flow and using the turbulence of k-Omega SST. For the mesh generation, unstructure meshes used in the numerical simulation with hexahedral meshing. The Arbitrary mesh strategy (AMI) and Multiple Rotating Frame (MRF) were compared to define the best meshing. The meshing strategies were selected in 3 categories, e.g coarse, medium, and fine mesh. Thus, the propeller can be performed in the best mesh. The numerical results were validated with the experimental data. The KT, KQ, and Efficiency of the propeller were compared to an experimental result and for all of the meshing strategies. Thus, the simulations show the influence of meshing in order to perform the propeller performance.

关键词： Propellers Mathematical model Numerical models Blades Oceans Convergence Computational fluid dynamics

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The impacts of weather on tourist satisfaction and revisit intention: a study of South Korean domestic tourism

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ASIA PACIFIC JOURNAL OF TOURISM RESEARCH 2017年第9期22卷 895-908页

作者： Kim, Songyi Park, Jin Han Lee, Dong Kun Son, Yong-hoon Yoon, Heeyeun Kim, Sungjin Yun, Hee Jeong Korea Culture & Tourism Inst Tourism Policy Res Div Seoul South Korea Seoul Natl Univ Interdisciplinary Program Landscape Architecture Seoul South Korea Seoul Natl Univ Dept Landscape Architecture Coll Agr & Life Sci Gwanakro1 Seoul South Korea Seoul Natl Univ Grad Sch Environm Studies Dept Landscape Architecture Seoul South Korea Kangwon Natl Univ Dept Tourism Adm Coll Business Adm Chunchon South Korea

This study explores the impacts of weather on tourist satisfaction and intention to revisit sites utilizing a survey of 1736 domestic tourists in South Korea. This study adds tourists' perceived quality of weather to a path model that anticipates revisit intention and was originally based on the perceived quality of physical attributes and service, as well as tourist satisfaction. The results of this study show that the perceived quality of weather affects tourist satisfaction and revisit intention directly and indirectly, and that it correlates with the perceived quality of physical attributes and service. It was determined that the impact of weather perception on tourist satisfaction and revisit intention is higher in rainy weather conditions. The results of the study show that to sustain tourist satisfaction and revisit intention, efforts to moderate the negative impacts of uncomfortable weather conditions are required, especially in rainy weather.

关键词： Weather condition perceived quality of weather tourist satisfaction intention to revisit South Korea

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Measuring urban diversity of Songjiang New Town: A re-configuration of a Chinese suburb

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HABITAT INTERNATIONAL 2017年 66卷 32-41页

作者： Cho, Sea Eun Kim, Saehoon Seoul Natl Univ Grad Sch Environm Studies Interdisciplinary Program Landscape Architecture 82-4211 Gwanak Ro Seoul 151742 South Korea Seoul Natl Univ Grad Sch Environm Studies Urban Design Concentrat Dept Landscape Architecture 82-4101 Gwanak Ro Seoul 151742 South Korea

Large-scale New Town projects being built in the developing world, including China, are often criticized for its lack of urban diversity. This is because these areas do not display the characteristics where urban diversity is normally found such as areas that are developed over longer periods of time, places of incremental change, and areas with small urban blocks. However, two aspects challenge the simplistic conclusion that New Towns are physically and socially monotonous: the diversification of the housing provision system in China;and rapid internal migration. Against this background, this study measures the housing and social diversity of four study areas in Songjiang, an outer suburb of Shanghai, using the entropy index to illustrate a more complicated understanding of where and how diversity occurs. The results showed that older, incrementally developed areas were diverse, but more interestingly, new comprehensively developed areas were also diverse through variations in building types and a wide housing price range. The study found disparate tendencies between housing and social diversity in other areas. In conclusion, the study highlighted the different contexts of urban diversity and its importance in drawing appropriate urban design measures which encourage the positive aspects of diversity such as urban vitality and equity. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Housing diversity Social diversity New town Large-scale development Place vitality Migrants

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New Gap-Filling Strategies for Long-Period Flux Data Gaps Using a Data-Driven Approach

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ATMOSPHERE 2019年第10期10卷 568-568页

作者： Kang, Minseok Ichii, Kazuhito Kim, Joon Indrawati, Yohana M. Park, Juhan Moon, Minkyu Lim, Jong-Hwan Chun, Jung-Hwa Natl Ctr Agro Meteorol Seoul 08826 South Korea Chiba Univ Ctr Environm Remote Sensing Chiba 2638522 Japan Seoul Natl Univ Dept Landscape Architecture & Rural Syst Engn Seoul 08826 South Korea Seoul Natl Univ Interdisciplinary Program Agr & Forest Meteorol Seoul 08826 South Korea Seoul Natl Univ Res Inst Agr & Life Seoul 08826 South Korea Seoul Natl Univ Asia Ctr Future Earth Program Seoul 08826 South Korea Seoul Natl Univ Inst Green Bio Sci & Technol Pyeongchang Campus Pyeongchang 25354 South Korea Boston Univ Dept Earth & Environm Boston MA 02215 USA Natl Inst Forest Sci Forest Ecol & Climate Change Div Seoul 02455 South Korea Natl Inst Forest Sci Res Planning & Coordinat Div Seoul 02455 South Korea

In the Korea Flux Monitoring Network, Haenam Farmland has the longest record of carbon/water/energy flux measurements produced using the eddy covariance (EC) technique. Unfortunately, there are long gaps (i.e., gaps longer than 30 days), particularly in 2007 and 2014, which hinder attempts to analyze these decade-long time-series data. The open source and standardized gap-filling methods are impractical for such long gaps. The data-driven approach using machine learning and remote-sensing or reanalysis data (i.e., interpolating/extrapolating EC measurements via available networks temporally/spatially) for estimating terrestrial CO2/H2O fluxes at the regional/global scale is applicable after appropriate modifications. In this study, we evaluated the applicability of the data-driven approach for filling long gaps in flux data (i.e., gross primary production, ecosystem respiration, net ecosystem exchange, and evapotranspiration). We found that using a longer training dataset in the machine learning generally produced better model performance, although there was a greater possibility of missing interannual variations caused by ecosystem state changes (e.g., changes in crop variety). Based on the results, we proposed gap-filling strategies for long-period flux data gaps and used them to quantify the annual sums with uncertainties in 2007 and 2014. The results from this study have broad implications for long-period gap-filling at other sites, and for the estimation of regional/global CO2/H2O fluxes using a data-driven approach.

关键词： eddy covariance long-term database gap-filling long gap data-driven approach uncertainty

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Corrigendum to 'Evaluating the effect of expert elicitation techniques on population status assessment in the face of large uncertainty' [J. Environ. Manag. 306 (2022) /114453]

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Journal of environmental management 2024年 369卷 122321页

作者： Jennifer F Moore Julien Martin Hardin Waddle Evan H Campbell Grant Jill Fleming Eve Bohnett Thomas S B Akre Donald J Brown Michael T Jones Jessica R Meck Kevin Oxenrider Anthony Tur Lisabeth L Willey Fred Johnson Moore Ecological Analysis and Management LLC Gainesville FL USA. Electronic address: jenn.f.moore@***. U.S. Geological Survey Wetland and Aquatic Research Center Gainesville FL USA. U.S. Geological Survey Eastern Ecological Research Center (formerly the Patuxent Wildlife Research Center) S.O. Conte Anadromous Fish Research Lab 1 Migratory Way Turners Falls MA 01376 USA. University of Florida Department of Landscape Architecture Gainesville FL USA. Conservation Ecology Center Smithsonian Conservation Biology Institute 1500 Remount Rd Front Royal VA 22630 USA. School of Natural Resources West Virginia University Morgantown WV 26506 USA Northern Research Station U.S.D.A. Forest Service Parsons WV 26287 USA. Natural Heritage and Endangered Species Program Massachusetts Division of Fisheries and Wildlife 1 Rabbit Hill Road Westborough MA 01581 USA. Conservation Ecology Center Smithsonian Conservation Biology Institute 1500 Remount Road Front Royal VA 22630 USA. West Virginia Division of Natural Resources 1 Depot St Romney WV 26757 USA. U.S. Fish and Wildlife Service 300 Westgate Center Hadley MA 01035 USA. Antioch University New England Dept. of Environmental Studies 40 Avon St Keene NH 03431 USA. University of Florida Dept of Wildlife Ecology and Conservation Gainesville FL USA.

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