• Korean Journal of Environment and Ecology
• /
• v.26 no.4
• /
• pp.620-628
• /
• 2012

This study addressed the influence of forest harvesting on seasonal water table dynamics in small headwater riparian areas. Four treatments including potential Best Management Practices(BMPs) for ephemeral and intermittent streams were implemented(BMP1, BMP2, clearcut and reference). Water table measurements were obtained at bi-monthly intervals for 3 years including one year of pre- and two years of post-harvest observations. Overall, water table responses affected largely by rainfall amount. In addition, significant increases in water table levels following harvesting occurred throughout the two post-harvest years. Water table levels increased up to 28.2cm in the clearcut treatment during 2008 and up to 54.2cm in BMP2 during 2009. However, increase in water table elevation was not directly related to basal area removal despite considerable differences in basal area removed between BMP2 and clearcut treatments. Water table rises were apparent in that water table were more elevated during dry season(June through November) than during wet season(December through May). These seasonal fluctuations were presumably driven by changes in evapotranspiration caused by differences in leaf area of overstory canopy and understory following harvest.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.18 no.4
• /
• pp.298-306
• /
• 2016

Planting date shift is one of the means of adapting to climate change in Kimchi Cabbage growers in major production areas in Korea. This study suggests a method to estimate the potential yield of Kimchi Cabbage based on daily temperature accumulation during the growth period from planting to maturity which is determined by a plant phenology model tuned to Kimchi Cabbage. The phenology model converts any changes in the thermal condition caused by the planting date shift into the heat unit accumulation during the growth period, which can be calculated from daily temperatures. The physiological maturity is estimated by applying this model to a variable development rate function depending either on growth or heading stage. The cabbage yield prediction model (Ahn et al., 2014) calculates the potential yield of summer cabbage by accumulating daily heat units for the growth period. We combined these two models and applied to the 1km resolution climate scenario (2000-2100) based on RCP8.5 for South Korea. Potential yields in the current normal year (2001-2010) and the future normal year (2011-2040, 2041-2070, and 2071-2100) were estimated for each grid cell with the planting dates of July 1, August 1, September 1, and October 1. Based on the results, we divided the whole South Korea into 810 watersheds, and devised a three - dimensional evaluation chart of the time - space - yield that enables the user to easily find the optimal planting date for a given watershed. This method is expected to be useful not only for exploring future new cultivation sites but also for developing cropping systems capable of adaptation to climate change without changing varieties in existing production areas.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.24 no.1
• /
• pp.89-97
• /
• 2006

Soil erosion has caused serious environmental problems which threaten the foundation of natural resources. In this paper, we chose RUSLE erosion model, which could be connected easily with GSIS and available generally in mid-scale watershed among soil erosion models, and extracted factors entered model by using GSIS spatial analysis method. First, this study used GIS database as soil map, DEM, land cover map and rainfall data of typhoon Memi (2003) to analyze soil loss amount of Dam basin. To analyze the changes of soil loss in considering basin characteristics as up-, mid- and downstream, this study calculated soil erodibility factor (K), topographic factors (LS), and cover management factor (C). As a result of analysis, K and LS factors of upstream showed much higher than those of downstream because of the high ratio of forest. But C factor of downstream showed much higher than that of upstream because of the high ratio of agricultural area. As a result of analysis of soil loss, unit soil loss of upstream is 4.3 times than soil loss of downstream. Therefore, the establishment of countermeasures for upstream is more efficient to reduce soil loss.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.12 no.2
• /
• pp.111-119
• /
• 2009

The purpose of this study is to decide the suitability of the land use on eco-city by analysing ecological elements using GIS. Selected ecological elements for suitability analysis were altitude, slope, watershed, biotope, soil productivity, visual sensitivity, vegetation, and green connection. The category of each element was classified into 5 grades, and was given weight according to each element. The maximum value of each element was extracted from overlay analysis process. The result of analysis was classified into 5 grade finally. As a result, land use was proposed to be development, conservation, and preservation area.

• Journal of Environmental Science International
• /
• v.14 no.11
• /
• pp.1057-1062
• /
• 2005

The present study investigated runoff characteristics of non-point pollutants and discharge load amount according to the land utilization in Yeinam river basin. The land utilization of target basin was divided into paddy field, dry field, forest, residential area and composition area. The study on the runoff characteristics of non-point pollutants by rainfall-runoff process showed that COD, SS and T-P had the first-flushing effect with relatively high concentration in early-stage of the rainfall-runoff process, but the T-P revealed similar runoff characteristics. Event Mean Concentration(EMC) of BOD and COD according to the land utilization revealed the range of $3.11\~15.50mg/L$ and $3.37\~33.42mg/L$, and the highest concentration of EMC corresponding to BOD and COD was detected in the paddy field. The EMC of SS showed $1.7\~305.02mg/L$ and it's highest concentration was found in the dry field. The EMC of T-N and T-P represented the highest concentration in the paddy field and dry field with range of $0.91\~8.76mg/L$ and $0.02\~0.44mg/L$.

• Journal of Environmental Impact Assessment
• /
• v.14 no.6
• /
• pp.403-413
• /
• 2005

The environmental conservation-targeted zoning in urban planning process has been functioned as securing a ecological core in urban green spaces management. Hence, the designation of conservation zones in land use planning is considered as a key task to achieve the sustainability of urban planning. The recently introduced pre-environmental review system for the proposed urban plan, by which the conservative measures for urban ecosystem and landscape are suggested in aspect of environmental impact mitigation, has played an active role in enhancing the environmental performance degraded by wide range of development pressure. This study is aimed at drawing out of objective criteria for designation of environmental conservation zones, which can be applied to urban planning establishment and also to environmental assessment process. To achieve this goal, the study adopted the following methods; pre-study review, analysis of existing official opinion statements released by the Ministry of Environment, contents analysis of related laws, and experts' panel discussions on the finally arranged criteria. The results of this research can be summarized as follows: First, the total criteria of 48 are drown out with categorizing into environment-ecological and socio-cultural sectosr. Second, the environment-ecological part is composed of 33 criteria such as vegetation, animal, geomorphology, watershed, environmental land suitability, and etc. Here, the Degree of Ecological Function, Degree of Environmental Land Suitability, and Vegetation Map are mainly utilized. Third, the 15 socio-cultural criteria relating to the history, social ecology and landscape have such components as forest around relics, Seo-won(school), castle, tomb, landmark, skyline, natural landscape, and etc. Forth, these individual criteria can be applied to designation of each conservation zones among total of 11 conservation areas(or districts).

• Journal of Environmental Impact Assessment
• /
• v.17 no.4
• /
• pp.243-253
• /
• 2008

The purpose of this study was to simulate the reduction effect of soil loss in the Yongdam reservoir watershed using SWAT model. To evaluate accuracy for flow and sediment yield of SWAT model, calibration was performed for the period from Jan. 2002 to Dec. 2003, and the verification for Jan. 2005 to Dec. 2005. The calibration and the verification were carried out using data observed at the Cheoncheon gaging station. The $R^2$ and EI values in terms of a flow were 0.8 and 0.78 respectively for calibration, whereas they for verification were 0.88 and 0.86 respectively. In terms of a sediment yield, they were 0.7 and 0.48 respectively for calibration, whereas for verification were 0.64 and 0.54 respectively. As a results from model simulation, annual mean soil loss rates in terms of forest, paddy and upland were 0.02 ton/ha/yr, 0.15 ton/ha/yr and 7.58 ton/ha/yr, respectively. The results show that the land use type of a upland has more significant impact on a total soil loss as well as a sediment yield than other types of land use. The sediment delivery ratio was determined to be about 0.35. In this study 2 land cover change scenarios for upland area were considered. These scenarios were used an input to SWAT model in order to evaluate their impact on soil loss and sediment delivery. The results show that a reduction of the upland area would reduce the soil loss and sediment yield.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.2 no.1
• /
• pp.29-37
• /
• 1999

Land cover classification is an essential basic information in natural environment management; however, land cover classification studies in Korea have not yet been proceeded to a sufficient level. At the present, only a limited number of the precedent studies that only cover definite city area has been conducted. Furthermore, there is almost no research conducted on the land cover classification schemes that could accurately classify the Korea's land cover conditions. This study primarily focuses on the land cover classification scheme which carries the most urgent priority in order to classify and to map out the Korean land cover conditions. In order to develop the most suitable land cover classification scheme, many foreign land cover classification cases and projects that are being carried out were reviewed in depth. The land cover classification scheme this study proposes comprises 3 levels : The first level consists of 7 different classes; the second level consists of 22 different classes; and the third level is made up of 50 classes. The land cover classification map will serve many important roles in natural environment management, such as the conjecture of natural habitats and estimation of oxygen production or carbon dioxide absorption capability of a forest. In water pollution modelling, the land cover classification data can be used to estimate and locate non-point sources of water pollution. If applied to a watershed, modelling it will allow to estimate the total amount of pollution from non-point sources of pollution in the water shed. The land cover classification data will also be good as a barometer data that determines defusion of air pollutants in air pollution modelling.

• Journal of Korean Society on Water Environment
• /
• v.28 no.1
• /
• pp.1-9
• /
• 2012

It has been known that Golf course could impose negative impacts on water-ecosystem if pollutant-laden runoff is not treated well. It is important to control non-point source and re-use treated wastewater from the golf course to secure water quality of receiving waterbodies. At golf courses, the rainfall-runoff is affected by various practices to manage grasses. In many hydrological modelings, especially in simple rainfall-runoff modeling, effects on runoff of plant growth and cutting are not considered. In the study, the water erosion prediction project (WEPP), capable of simulating plant growth and various management, was evaluated for its runoff prediction from golf course under grass cutting and irrigation. The %Difference, $R^2$ and the NSE for runoff comparisons were 1.15%, 0.93 and 0.92 for calibration, and 18.12%, 0.82 and 0.88 for validation period, respectively. In grass cutting scenario, grass height was managed to be 18~25 mm. The estimated runoff was decreased by 27%. The difference in estimated total runoff was 11.8% depending on irrigation. As shown in this study, if grass management and irrigation are well-controlled, water quality of downstream areas could be obtained.

• Journal of Korean Society on Water Environment
• /
• v.29 no.2
• /
• pp.184-195
• /
• 2013

Urbanization from agricultural/forest areas has been causing increased runoff and pollutant loads from it. Thus, numerous models have been developed to estimate NPS loading from urban area and Long-Term Hydrologic Impact Analysis (L-THIA) model has been used to evaluate effects of landuse changes on runoff and pollutant loads. However, the L-THIA model could not consider rainfall intensity in runoff evaluation. Therefore, the L-THIA model, capable of simulating runoff using 10-minute rainfall data, was applied to the study areas for evaluation of estimated runoff and NPS. The estimated Nash-Sutcliffe coefficient (NSE) values were over 0.6 for runoff, BOD, TN, and TP for most sites and watershed. The calibrated model was further extended to other counties for pollutant load potential evaluation. Pollutant load potential maps were developed and target areas were identified. As shown in this study, the L-THIA 2012 can be used for evaluation runoff and pollutant loads with limited data sets and its estimation could be used in identifying pollutant load hot spot areas for implementation of site-specific Best Management Practices.