• Journal of Korea Water Resources Association
• /
• v.53 no.3
• /
• pp.215-223
• /
• 2020

The objective of this study is to develop a prediction model of specific degradation using data mining classification especially for the rivers in South Korea river. A number of critical predictors such as erosion and sediment transport were extracted for the prediction model considering watershed morphometric characteristics, rainfall, land cover, land use, and bed material. The suggested model includes the elevations at the mid relative area of the hypsometric curve of watershed morphomeric characteristics, the urbanization ratio, and the wetland and water ratio of land cover factors as the condition factors. The proposed model describes well the measured specific degradation of the rivers in South Korea. In addition, the development model was compared with the existing models, since the existing models based on different conditions and purposes show low predictability, they have a limit about the application of Korean River. Therefore, this study is focusing on improving the applicability of the existing model

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.25 no.3
• /
• pp.83-95
• /
• 2022

This study aims to present primary data for habitat restoration and artificial breeding conditions of L. unmunsana by identifying the habitat conditions and the larvae's food sources. In order to investigate the habitat characteristics of the adult L. unmunsana and land snails, which are the primary food sources for the larvae, field surveys were conducted on a total of 10 habitats in south-central parts of Korea including Sanseongcheon, Jeonju. The results revealed that the L. unmunsana habitat in the Sanseongcheon area had a broadleaf forest with a multi-layered vegetation structure, adjacent water features, and the north/northeast/northwest slopes with little effect of artificial lighting. The adult L. unmunsana in the Sanseongcheon area appeared from the end of May to the end of June, and was especially intensively observed around the middle of June. The most active time was from 23:30 to 00:30 with a temperature range of 19~22℃ and higher than 80% humidity. The peak count of the observed adults L. unmunsana was a total of 774 on June 11, 2021. In the case of land snails, 11 families and 23 species were observed in 10 habitats of L. unmunsana, and Euphaedusa fusaniana was the most extensive and the most observed in the five survey areas. The land snails of L. unmunsana habitats are mostly found under the organic layers of leaves and a fallen tree branch in broadleaf forests, where a thick organic material layer buffers temperature changes and provides high humidity for various snails. These habitat conditions are suitable for the larva of L. unmunsana and land snails to inhabit, feed, hide and hibernate.

• Ocean and Polar Research
• /
• v.45 no.3
• /
• pp.103-111
• /
• 2023

To evaluate the impact of effluents from land-based fish farms on the coastal ocean of Wando, Korea, we analyzed inorganic nutrients, particulate organic carbon (POC), dissolved organic carbon (DOC), and colored dissolved organic matter (CDOM) in the effluent and influent of land-based fish farms during the summer (July) of 2021. The average concentrations of nutrients (Dissolved inorganic nitrogen, phosphorus, and silicate; DIN, DIP, and DSi, respectively) in the effluents of this study area were 17±3.7 μM, 1.4±0.7 μM, and 14±1.6 μM, respectively. The average concentrations of POC and DOC were 37±22 μM and 81±13 μM, respectively, with POC accounting for about 30% for total organic carbon in effluents. The Reduced Dissolved Inorganic Nitrogen/Total Dissolved Inorganic Nitrogen ratio (0.7), potential short-period index, indicates that the discharge of nutrients excreted by the fish and unconsumed feed into coastal water results in such nutrients being deposited and accumulated in the sediment. Subsequently, this continuous accumulation triggers the release of ammonium ions during organic matter decomposition, and the ammonium-enriched waters that encroach on fish farms as influent seem to be due to the diffusion of high concentrations of ammonium from bottom sediment. Furthermore, we used fluorescence indices to examine the characteristics of organic matter sources, obtaining mean values of 1.54±0.19, 1.06±0.06, and 1.56±0.06 for the humification index, biological index, and fluorescence index, respectively, in the effluent. These results indicate that the organic matters had an autochthonous origin that resulted from microbial decomposition, and such organic matters were rapidly generated and removed by biological activity, likely supplied from the sediment. Our results suggest that the effluent from land-based fish farms could be a potential source of deoxygenation occurrence in coastal areas.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.40 no.3
• /
• pp.295-302
• /
• 2020

Disaster Preventing Zone (DPZ) is one of the zoning for land use regulation. Though the purpose of the designating of DPZs is to improve the area be safer, people has the negative recognition on DPZs. They think DPZs are regulation to restrict the actions and finally causes decrease on the land price. In this context, the aim of this study is to investigate the correlation between the designation of the DPZs and the land price of the DPZs in Seoul Metropolitan City. We applied the Difference in different (DID) which is one of the research methods to verify the cause and effect of specific policy. As a result, it was found statistically significant that land price of parcels designated as DPZs was 420,000 won higher than those not designated. The same results were obtained when the land characteristics were added, and the robustness of the model was indirectly confirmed. Based on the results, the designating of the DPZs was contrary to the expectation. Although it is necessary to analyze the result of the study more microscopically, It will be necessary to change the perception that it will decline.

• Journal of Environmental Impact Assessment
• /
• v.16 no.4
• /
• pp.267-275
• /
• 2007

In this study, relationship between the air pollution of Siheung city and the relative contribution of automobiles to the city's pollution was evaluated for the first time. Then, new air pollution exposure index was developed through simulation. Using the newly developed index, two different urban development scenarios were compared to present a sustainable urban development plan to reduce air pollution from the land utilization point of view. According to the result of this simulation, air quality of the city was found to be affected significantly by human activities. More populated area showed worse level of air quality. Any development in the city resulted in more automobile activity and deterioration of air quality. This simulation result thus explains that a rapid increase of automobiles accompanied by the land development near local roadsides in the city is the major cause of air pollution in Siheung city. In this study, if urban activities are vigorous in an area with high air pollution, people are more likely to be exposed to air pollutant under the bad environmental conditions. On the other hand, if urban activities are less vigorous in an area with high pollution or if urban activities are vigorous in an area with less pollution, the environmental condition was positive. The APEI (Air Pollution Exposure Index) was developed based on these considerations. Scenarios 1 and 2 were compared and analyzed using APEI. In result, scenario 1 is the case in which land is developed and used in an environmentally favorable manner. From this study, it was proved that the impact of air pollution on human health can be minimized with proper land use. The result form the current study can be used as the basic information to solve problems from improper land utilization and air pollution (by road traffic). It also can be utilized to evaluate air pollution level according to land use and road characteristics and to help to choose the best location of land use to comply with the road function and status.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.6 no.1
• /
• pp.61-69
• /
• 2004

A long-term growth simulation was performed at 99 land units in Yeoncheon county to test the potential adaptability of each land unit for growing soybean cultivars. The land units for soybean cultivation(CZU), each represented by a geographically referenced land patch, were selected based on land use, soil characteristics, and minimum arable land area. Monthly climatic normals for daily maximum and minimum temperature, precipitation, number of rain days and solar radiation were extracted for each CZU from digital climate models(DCM). The DCM grid cells falling within a same CZU were aggregated to make spatially explicit climatic normals relevant to the CZU. A daily weather dataset for 30 years was randomly generated from the monthly climatic normals of each CZU. Growth and development parameters of CROPGRO-soybean model suitable for 2 domestic soybean cultivars were derived from long-term field observations. Three foreign cultivars with well established parameters were also added to this study, representing maturity groups 3, 4, and 5. Each treatment was simulated with the randomly generated 30 years' daily weather data(from planting to physiological maturity) for 99 land units in Yeoncheon to simulate the growth and yield responses to the inter-annual climate variation. The same model was run with input data from the Crop Experiment Station in Suwon to obtain a 30 year normal performance of each cultivar, which was used as a "reference" for evaluation. Results were analyzed with respect to spatial and temporal variation in yield and maturity, and used to evaluate the suitability of each land unit for growing a specific cultivar. A computer program(MAPSOY) was written to help utilize the results in a decision-making procedure for agrotechnology transfer. transfer.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.14 no.5
• /
• pp.113-125
• /
• 2011

Since the government of Korea (Ministry of Environment, MOE) introduced the policy applying 'Biotope-Area-Ratio-Indicator (BARI)' to huge residential land developments which Environmental Impact Assessment (EIA) should be performed, MOE has come to have the necessity to apply the indicator concretely at the stage of Prior Environment Review System (PERS) and EIA in various types of large scale land development projects. This study was conducted with the aim of supporting the application of BARI and related decision making in various other types of EIA projects as well as residential development projects through remodeling the system to apply the indicator of the past. Through the analysis of the problems in applying the past BARI and experimental appraisals to 11 types of EIA projects, the results and implications as follows were drawn. First, it's possible to extend the range of applications of BARI, which has been applied to only residential land development project, to all kinds of projects with area-typed land use pattern out of environmental impact assessment target projects. Second, it's also possible to set a target value into which regional characteristics and differences among locational properties are reflected. In addition, it's come to be able to differentially apply the target value of BARI according to the condition of the existing site. Third, it's improved to be able to suggest a macroscopic target value at the stage of PERS and to set detailed target values in each detailed land use at the stage of EIA. The key point underlies inducing methodology to determine target values to secure more permeable land coverage ratio for detailed land use patterns at the stage of EIA by making it possible to calculate BARI of the present land cover condition of the EIA target projects.

• Korean Journal of Remote Sensing
• /
• v.39 no.5_1
• /
• pp.507-519
• /
• 2023

Multi-temporal optical images have been utilized for time-series monitoring of croplands. However, the presence of clouds imposes limitations on image availability, often requiring a cloud removal procedure. This study assesses the applicability of various machine learning algorithms for effective cloud removal in optical imagery. We conducted comparative experiments by focusing on two key variables that significantly influence the predictive performance of machine learning algorithms: (1) land-cover types of training data and (2) temporal variability of land-cover types. Three machine learning algorithms, including Gaussian process regression (GPR), support vector machine (SVM), and random forest (RF), were employed for the experiments using simulated cloudy images in paddy fields of Gunsan. GPR and SVM exhibited superior prediction accuracy when the training data had the same land-cover types as the cloud region, and GPR showed the best stability with respect to sampling fluctuations. In addition, RF was the least affected by the land-cover types and temporal variations of training data. These results indicate that GPR is recommended when the land-cover type and spectral characteristics of the training data are the same as those of the cloud region. On the other hand, RF should be applied when it is difficult to obtain training data with the same land-cover types as the cloud region. Therefore, the land-cover types in cloud areas should be taken into account for extracting informative training data along with selecting the optimal machine learning algorithm.

• Journal of Cadastre & Land InformatiX
• /
• v.49 no.2
• /
• pp.5-21
• /
• 2019

The purpose of this study is to investigate and analyze the cadastral transformation process of Dokdo-ri based on the institutional concept of the cadastre, while presenting the cadastral characteristics of Dokdo-ri therefrom. For this purpose, both the literature search method and the Internet search method were used. As for the analysis method, descriptive analysis method and comparative analysis method were used. The findings support that the cadastral characteristics of Dokdo-ri is drawn as follows: First, from the physical point of view, the cadastral characteristics of Dokdo-ri shows that the territory is given by the smallest lot numbers in the country and that the territory is also given by the land lot number consisting of small size lots without continuing the ground for which the cadastral resurvey project was carried out for the first time. Second, in terms of the rights, the cadastral characteristics of Dokdo-ri shows that the entire area given by the lots is owned by a single owner and no ownership has been changed. Third, in terms of its value, the cadastral characteristics of Dokdo-ri shows that it is the only area given by the lots of which the officially assessed individual land price has never been decreased in the entire lots. Fourth, when it comes to presenting the cadastral characteristics of Dokdo-ri in terms of the use control/restriction, the consciousness of preserving Dokdo-ri and the consciousness of enhancing real territory are confronted but due to the Cultural Heritage Protection Act etc, the cadastre turned out to be a very passive cadastral work.

• Journal of Soil and Groundwater Environment
• /
• v.29 no.4
• /
• pp.21-31
• /
• 2024

Sumgol in Jeju Island plays a significant role in groundwater recharge due to its permeable hydrogeological characteristics. However, a quantitative assessment of the interrelationship between rainfall characteristics and rainwater inflows into Sumgols has not yet been conducted. Therefore, this study examined the characteristics of rainwater inflow into three Sumgols located in the eastern and western regions of Jeju Island and assessed hydrogeologic factors influencing these inflows. During two rainfall events, the studied locations in Sumgol exhibited different characteristics of rainwater inflows, despite experiencing similar rainfall events. Additionally, the delay time for rainwater to reach the Sumgol locations after the rainfall was influenced more by rainfall intensity than by cumulative amount of rainfall. In Sumgols located in non-volcanic ash soil with low hydraulic conductivity, such as those in agricultural areas, rainwater inflows were observed even with small rainfall and low rainfall intensity. This study suggests that rainfall intensity, soil characteristics, permeability of lava flows, and land use are key factors influencing rainwater inflow into Sumgols, revealing that soil characteristics and the permeability of lava flows have a greater impact on surface runoff than land use.