• Economic and Environmental Geology
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• v.51 no.1
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• pp.15-26
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• 2018

The spatio-temporal variations of nitrate concentrations in groundwater of Jeju Island were evaluated by an analysis of time series groundwater quality data (N = 21,568) that were collected from regional groundwater monitoring (number of wells = 4,835) for up to 20 years between 1993 and 2015. The median concentration of $NO_3-N$ is 2.5 mg/L, which is slightly higher than those reported from regional surveys in other countries. Nitrate concentrations of groundwater in wells tend to significantly vary according to different water usage (of the well), administrative districts, and topographic elevations: nitrate level is higher in low-lying agricultural and residential areas than those in high mountainous areas. The Mann-Kendall trend test and Sen's slope analysis show that nitrate concentration in mid-mountainous areas tends to increase, possibly due to the expansion of agricultural areas toward highland. On the other hand, nitrate concentrations in the Specially Designated Groundwater Quality Protection Zones show the temporally decreasing trend, which implies the efficiency of groundwater management actions in Jeju. Proper measures for sustainable groundwater quality management are suggested in this study.

• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.481-493
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• 2023

In high-density urban areas, the urban heat island effect increases urban temperatures, leading to negative impacts such as worsened air pollution, increased cooling energy consumption, and increased greenhouse gas emissions. In urban environments where it is difficult to secure additional green spaces, rooftop greening is an efficient greenhouse gas reduction strategy. In this study, we not only analyzed the current status of the urban heat island effect but also utilized high-resolution satellite data and spatial information to estimate the available rooftop greening area within the study area. We evaluated the mitigation effect of the urban heat island phenomenon and carbon sequestration capacity through temperature predictions resulting from rooftop greening. To achieve this, we utilized WorldView-2 satellite data to classify land cover in the urban heat island areas of Busan city. We developed a prediction model for temperature changes before and after rooftop greening using machine learning techniques. To assess the degree of urban heat island mitigation due to changes in rooftop greening areas, we constructed a temperature change prediction model with temperature as the dependent variable using the random forest technique. In this process, we built a multiple regression model to derive high-resolution land surface temperatures for training data using Google Earth Engine, combining Landsat-8 and Sentinel-2 satellite data. Additionally, we evaluated carbon sequestration based on rooftop greening areas using a carbon absorption capacity per plant. The results of this study suggest that the developed satellite-based urban heat island assessment and temperature change prediction technology using Random Forest models can be applied to urban heat island-vulnerable areas with potential for expansion.

• Land and Housing Review
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• v.2 no.4
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• pp.429-437
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• 2011

The purpose of this research is to seek the suggestions applicable to Korean green-growth(development) policy and the realization of low carbon society by looking around the promotion policy and the process, the promotion system, main environmental policy in each city about the business for environmental model city in Japan which has been promoted in a city in order to realize low-carbon society. Japan had selected 13 local governments as an environmental model city as a part of a policy to build low-carbon society in 2008~2009, and Japan has formed information sharing between cities and provinces, the spread of information sharing and the free competition among local governments for an environmental model city through Zero Carbon City Promotion Council consisting of local governments and specialists. When examining these cases in Japan, the green-growth policy promoting currently in Korea needs to be converted from the central government-dominated policy to the local government-dominated policy and Koreaneeds to make more effort to develop software programs in order to realize green-growth social system.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.540-547
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• 2011

This study was conducted to compare classification accuracy by tree species using QuickBird imagery for pixel- and segment-based classifications that have been mostly applied to classify land covers. A total of 398 points was used as training and reference data. Based on this points, the points were classified into fourteen land cover classes: four coniferous and seven deciduous tree species in forest classes, and three non-forested classes. In pixel-based classification, three images obtained by using raw spectral values, three tasseled indices, and three components from principal component analysis were produced. For the both classification processes, the maximum likelihood method was applied. In the pixel-based classification, it was resulted that the classification accuracy with raw spectral values was better than those by the other band combinations. As resulted that, the segment-based classification with a scale factor of 50% provided the most accurate classification (overall accuracy:76% and ${\hat{k}}$ value:0.74) compared to the other scale factors and pixel-based classification.

• Ecology and Resilient Infrastructure
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• v.5 no.1
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• pp.45-53
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• 2018

Ecological networks can be generally classified into core areas, buffer zones, and corridors. Particularly, buffer zones connect core areas or ecological corridors, and preserve ecological network by reducing the impact from outside. We examined related laws and researches about buffer zone establishment associated with the resources of high ecological and conservation value to find out more researches are needed. In this study, we investigated various examples of the criteria for establishing buffer zones at domestic and overseas. Based on the results of railway environmental impact assessment and railway construction guidelines, we analyzed the application methods applicable to the railway development area and proposed the criteria to evaluate land cover status, species diversity, rarity, and connectivity. Through this study, the environmental and ecological value around the development area of the railroad was examined to reduce the environmental damage from railroad construction.

• Industry Promotion Research
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• v.9 no.1
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• pp.259-273
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• 2024

In this study, 31 provincial-level administrative regions in China from 2011 to 2021 were taken as the research objects, and the super-SBM model was used to measure the regional eco-efficiency with capital, labor, land and resource input as input variables, GDP and green coverage as the desirable outputs, and wastewater, waste gas and solid waste emissions as the undesired outputs. Tobit regression was used to analyze the effects of external environmental factors on eco-efficiency. The results showed that the average level of eco-efficiency in China was low, and the eco-efficiency in the eastern region was higher than that in other regions, and there were great differences in the western, northeast and central regions.

• Korean Journal of Ecology and Environment
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• v.51 no.1
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• pp.105-123
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• 2018

Currently, satellite images act as essential and important data in water resources, environment, and ecology as well as information of geographic information system. In this paper, we will investigate basic characteristics of satellite images, especially application examples in water resources. In recent years, researches on spatial and temporal characteristics of large-scale regions utilizing the advantages of satellite imagery have been actively conducted for fundamental hydrological components such as evapotranspiration, soil moisture and natural disasters such as drought, flood, and heavy snow. Furthermore, it is possible to analyze temporal and spatial characteristics such as vegetation characteristics, plant production, net primary production, turbidity of water bodies, chlorophyll concentration, and water quality by using various image information utilizing various sensor information of satellites. Korea is planning to launch a satellite for water resources and environment in the near future, so various researches are expected to be activated on this field.

• Journal of Environmental Impact Assessment
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• v.28 no.3
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• pp.201-214
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• 2019

The concept of ecosystem services is important for the effective management of regional ecological resources. Multiple ecosystem services provided by regional ecosystems are represented as ecosystem service bundles, which define the co-occurrent ecosystem services in a specific region. Bundles provide useful information to identify regional characteristics of ecosystem services and categorize sub-regions with similar patterns of ecosystem service provision. We assessed eleven ecosystem services using modeling approaches and statistical data and produced bundles of cities in Gyeonggi-do.We also conducted principal component analysis and cluster analysis to categorize these cities according to the characteristics of ecosystem services. The results indicated that the cities in Gyeonggi-do were categorized into three groups depending on the types of provision,regulation, and cultural services, and were designated as urbanized, urban-forest, agriculture, or forest cities. These groups were influenced by land use patterns reflecting regional social-environmental features. The results provide useful information for identifying regional ecosystem services and facilitate decision-making in regional ecosystem service management.

• Journal of Environmental Impact Assessment
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• v.29 no.6
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• pp.430-440
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• 2020

The application contents, process, and its limitations are discussed for the setting of Korean legal guides & criteria for water cycle and ecological condition in development project of land use by thorough comparison and examination of prerequisites and credits of water cycle and soil+vegetation by USA's SITES (Sustainable Sites Initiative). In the case of SITES, due to the implementation procedure operated as a non-governmental independent assessment system by Green Business Certification, Inc, the natural condition of water cycle and soil-vegetation items-the key element of ecosystem services can be quantitatively assessed, well along with its legal and institutional guidelines and regulations. On the other hand, in the case of Korea, as a part of the national certification procedure for green building, the ecological area ratio system still have very limited role as an only amenity resource in the creation of artificial green spaces and insufficiency of management system for rain water. In conclusion, it was understood as an urgent situation in necessary for prompt establishment of site's sustainability certification system at the national level, based on management of water circulation and natural soil & vegetation in developed area with consideration of various land uses and types of development projects.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.3
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• pp.11-18
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• 2012

Increasing concern about biodiversity has lead to a rise in demand on the spatial assessment of biological resources such as biodiversity assessment, protected area selection, habitat management and restoration in Korea. The purpose of this study is to create species richness map through data collection and modeling techniques for wildlife habitat assessment. The GAM (Generalized Additive Model) is easy to interpret and shows better relationship between environmental variables and a response variable than an existing overlap analysis and GLM (Generalized Linear Model). The study area delineated by a large watershed contains Jirisan national park, Mt. Baekun and Sumjin river with three kinds of protected areas (a national park, a landscape ecology protected area and an otter protected area). We collected the presence-absence data for wildlife (mammals and birds) using a stratified random sampling based on a land cover in the study area and implemented natural and socio-environmental data affecting wildlife habitats. After doing a habitat use analysis and specifying significant factors for each species, we built habitat suitability models using a presence-absence model and created habitat suitability maps for each species. Biodiversity maps were generated by taxa and all species using habitat suitability maps. Significant factors affecting each species habitat were different according to their habitat selection. Although some species like a water deer or a great tit were distributed at the low elevation, most potential habitats for mammals and birds were found at the edge of a national park boundary or near a forest around the medium elevation of a mountain range. This study will be used for a basis on biodiversity assessment and proected area selection carried out by Ministry of Environment.