• Journal of the Korean association of regional geographers
• /
• v.16 no.6
• /
• pp.623-634
• /
• 2010

The elevated water storage tanks highly crowded in the western region in Jeju island is an important landmark of Jeju island. This study examines the reasons that the elevated water storage tanks appeared in a high density. After examination, this study found that the elevated water storage tanks formed under the influences of climate, hydrogeologic structure, soil, topography and land use. In particular, the elevated water storage tanks in Jeju are closely related to the crapping system with which water has to be supplied using sprinkler due to well drained soil and hydrogeological characteristics. The results of this study show that elevated water storage tank landscape in the western region of Jeju island is an agricultural landscape particularly made in the course of farmers' adaptation to the natural environment of Jeju island.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.22 no.4
• /
• pp.339-347
• /
• 2004

This study aims at calculating the exact soil conversion factor of cutting and banking areas of weathering rocks in large-scaled construction sites where land is being developed into home lots. For this, we have excavated the respective 20 sites of the cutting and banking areas in the said site and then calculated the volume after the excavation. As a result, the relative accuracy of the difference was calculated at 0.5% in average. We have calculated the exact soil conversion factor by the use of function ratio as per the wet unit weight and the indoor soil quality test as per volume calculated. And then we have found out minor differences as a result of the comparison and analysis with soil conversion factor determined by the dry unit weight test as per sand replacement method. This may be judged as a rational design method for the calculation of soil conversion factor, as well as high reliability of site test as a precision photogrammetry is adopted for volume measurement of the irregular excavating areas.

• Journal of Korean Society on Water Environment
• /
• v.26 no.1
• /
• pp.168-176
• /
• 2010

This study proposes the improvement of the present Total Maximum Daily Load (TMDL) management system of MOE (Ministry of Environment). The margin of safety (MOS) is calculated by a method using standard error and a method using variability and uncertainty. The allocation of pollutant loads are calculated using three methods, equal load reduction method, equal percent removal method and method using equity standards. This study applied the improved TMDL management system to the Anyangcheon watershed. Since MOS varies from 12% to 44% due to the high variability of measured and simulated data, it must not be ignored in the TMDL. The method using equity standards is the most proper in this application since the others produced unrealistic allocations. Area, runoff, water use quantity, population and budget are considered for equity standards. This study shows that this allocation method can be also applicable for the administrative units as well as the sub-watersheds. Finally, Hydrologic Simulation Program-FORTRAN (HSPF) with the allocated pollutant load was used to confirm whether it satisfy the water quality standard or not. This study will be helpful to improve the MOS and allocation system TMDL in the future.

• Korean Journal of Environment and Ecology
• /
• v.24 no.1
• /
• pp.37-45
• /
• 2010

This study was conducted to provide a database for biotope conservation and restoration of the Jeonju region in North Cheolla Province. To accomplish this task, investigations were made on the characteristics of the distribution pattern of naturalized plants in the region. From May to June 2008, the flora and lists of naturalized plants were investigated and, based on these data the ratio of naturalization was calculated. The results of this investigation areas follows: a total of 113 families and 54 species were found in the flora. The naturalized plants among them amounted to 19 families and 54 species. The ratio of naturalization was most high in the biotope type of rural dried stream(36.4%). The biotype that showed the lowest ratio of naturalization was coniferous natural forest type, which had no naturalized plants in it. The average naturalization ration of the Jeonju region turned out to be 18.9%, which is similar to that of other mid-size cities in Korea.

• Spatial Information Research
• /
• v.19 no.1
• /
• pp.29-40
• /
• 2011

GOCI the world first Ocean Color Imager in Geostationary Orbit, which could obtain total 8 images of the same region a day, however, its spatial resolution(500m) is not enough to use for the accurate land application, Super Resolution(SR), reconstructing the high resolution(HR) image from multiple low resolution(LR) images introduced by computer vision field. could be applied to the time-series remotely sensed images such as GOCI data, and the higher resolution image could be reconstructed from multiple images by the SR, and also the cloud masked area of images could be recovered. As the precedent study for developing the efficient SR method for GOCI images, on this research, it reproduced the simulated data under the acquisition process of the remote sensed data, and then the simulated images arc applied to the proposed algorithm. From the proposed algorithm result of the simulated data, it turned out that low resolution(LR) images could be registered in sub-pixel accuracy, and the reconstructed HR image including RMSE, PSNR, SSIM Index value compared with original HR image were 0.5763, 52.9183 db, 0.9486, could be obtained.

• Journal of Soil and Groundwater Environment
• /
• v.26 no.6
• /
• pp.47-64
• /
• 2021

In this study, the annual and monthly groundwater recharge for the Sapgyo-cheon upstream basin in Chungnam Province was evaluated by water balance analysis utilizing WetSpass-M model. The modeling input data such as topography, climate parameters, LAI (Leaf Area Index), land use, and soil characteristics were established using ArcGIS, QGIS, and Python programs. The results showed that the annual average groundwater recharge in 2001 - 2020 was 251 mm, while the monthly groundwater recharge significantly varied over time, fluctuating between 1 and 47 mm. The variation was high in summer, and relatively low in winter. Variation in groundwater recharge was the largest in July in which precipitation was heavily concentrated, and the variation was closely associated with several factors including the total amount of precipitation, the number of days of the precipitation, and the daily average precipitation. This suggests the extent of groundwater recharge is greatly influenced not only by quantity of precipitation but also the precipitation pattern. Since climate condition has a profound effect on the monthly groundwater recharge, evaluation of monthly groundwater recharge need to be carried out by considering both seasonal and regional variability for better groundwater usage and management. In addition, the mathematical tools for groundwater recharge analysis need to be improved for more accurate prediction of groundwater recharge.

• Korean Journal of Agricultural Science
• /
• v.48 no.3
• /
• pp.589-596
• /
• 2021

Nitrogen applied to soil is highly prone to leaching and volatilization leading to gaseous emissions of nitrous oxide (N₂O) and ammonia (NH₃) which are of great environmental concern. Usage of biochar to reduce the discharge of nitrogen to the environment has attracted much interest in the recent past. Biochar is produced by pyrolyzing various biomasses under oxygen-limited conditions. Biochar is a carbonized material with high adsorptive powers for not only plant nutrients but also heavy metals. The objective of this study was to investigate the adsorption characteristics of NH₄-N onto biochar made from pine needles. The biochar was produced at various pyrolysis temperatures including 300, 400 and 500℃ and holding times of 30 and 120 minutes. The Langmuir isotherm was used to evaluate the adsorption test results. The chemical properties of the biochar varied with the pyrolysis conditions. In particular, the pH, EC and total carbon content increased with the increasing pyrolysis conditions. The rate of adsorption of NH₄-N by the biochar decreased with the increasing pyrolysis conditions. Of these conditions, biochar that was pyrolyzed at 300℃ for 30 minutes showed the highest adsorption rate of approximately 0.071 mg·g^-1. Thus, the use of biochar pyrolyzed at low temperatures with a short holding time can most efficiently reduce ammonia emissions from agricultural land.

• Journal of Korean Society on Water Environment
• /
• v.37 no.6
• /
• pp.531-538
• /
• 2021

In this study, the TOC in six estuarine reservoirs in the West Sea (Ganwol, Namyang, Daeho, Bunam, Sapkyo, and Asan) was estimated using optically-active water quality factors by the water environment monitoring network. First, specification data and land use maps of each estuarine reservoir were collected. Subsequently, water quality data from 2013 to 2020 were collected. The data comprised of 11 parameters: pH, dissolved oxygen, BOD, COD, suspended solids (SS), total nitrogen, total phosphorus, water temperature, electrical conductivity, total coliforms, and chlorophyll-a (Chl-a). The TOC in the estuarine reservoirs was 4.9~7.0 mg/L, with the highest TOC of 7.0 mg/L observed at the Namyang reservoir, which has a low shape coefficient and high drainage density. The correlation of TOC with water quality factors was also analyzed, and the correlation coefficients of Chl-a and SS were 0.28 and 0.19, respectively, while the correlation coefficients of these factors in the Namyang reservoir were 0.42 and 0.27, respectively. To improve the estimation of TOC using Chl-a and SS, the TOC was averaged in 5 mg/L units, and Chl-a and SS were averaged. Correlation analysis was then performed and the R² of Chl-a-TOC was 0.73. The R² of SS-TOC was 0.73 with a non-linear relationship. TOC had a significant non-linear relationship with Chl-a and SS. However, the relationship should be assessed in terms of the spatial and temporal variations to construct a reliable remote sensing system.

• Journal of Environmental Science International
• /
• v.17 no.2
• /
• pp.149-162
• /
• 2008

Aquatic and riparian vegetation of river ecosystems are very important both in ecological and management perspectives. Vegetation surveys were conducted to understand the characteristics of riparian vegetation in the mid and lower reaches of the Nakdong River, Korea. A total of 68 families and 260 species were identified at eleven survey sites. The numbers of taxa were similar to those reported in a previous survey in 1996,but the percentage of naturalized plants increased more than two times compared to that in the previous survey. Survey sites near Yangsan Bridge and Nambu Park in Yangsan showed the highest percentage of naturalized plant species. Urbanization indices of the survey sites were high at 18.8% on average. Therophytes were the most dominant plant life form at the survey sites with 39.2% of total plants identified, followed by phanerophytes (19.2%), hemicryptophytes (18.9%), aquatic plants (13.9%), cryptophytes (5.8%), and chamaephytes (3.1%). The relative composition of hemicryptophytes decreased whereas those of therophytes and chamaephytes increased compared to those in the survey in 1996. This may be due to increase in dryness of riparian soils or degradation of riparian areas. Plant compositions at sites near Jeokpo Bridge and Hwoicheon suggest that the composition and distribution of riparian vegetation are affected by land use pattern surrounding riparian areas or human accessibility to the areas.

• Journal of Korean Society for Atmospheric Environment
• /
• v.26 no.4
• /
• pp.367-379
• /
• 2010

Future climate changes over the Seoul metropolitan area (SMA) were predicted by the Weather Research and Forecasting (WRF) model using future land-use data from the urban growth model (SLEUTH) and forecast fields from ECHAM5/MPI-OM1 GCM (IPCC scenario A1B). Simulations from the SLEUTH model with GIS information (slope, urban, hill-shade, etc.) derived from the water management information system (WAMIS) and the intelligent transportation systems-standard nodes link (ITS-SNL) showed that considerable increase by 17.1% in the fraction of urban areas (FUA) was found within the SMA in 2020. To identify the effects of the urban growth on the temperature and wind variations in the future, WRF simulations by considering urban growth were performed for two seasons (summer and winter) in 2020s (2018~2022) and they were compared with those in the present (2003~2007). Comparisons of model results showed that significant changes in surface temperature (2-meter) were found in an area with high urban growth. On average in model domain, positive increases of $0.31^{\circ}C$ and $0.10^{\circ}C$ were predicted during summer and winter, respectively. These were higher than contributions forced by climate changes. The changes in surface temperature, however, were very small expect for some areas. This results suggested that surface temperature in metropolitan areas like the SMA can be significantly increased only by the urban growth during several decades.