• Korean Journal of Agricultural and Forest Meteorology
• /
• v.12 no.3
• /
• pp.197-206
• /
• 2010

To provide baseline information essential for assessing environmental impacts of monsoon rainfalls in a mountainous watershed under mixed land use, we investigated spatiotemporal variations in water quality using a combined approach of seasonal water quality survey and intensive storm samplings. Biannual water sampling at nine locations encompassing major land use types showed generally lower electrical conductivity and Cl- concentrations during the typical wet period compared to the dry period, indicating rainfall-induced dilution of dissolved ions. Total metal concentrations, however, were significantly higher during the monsoon period, probably associated with rainfall-induced increases in suspended sediments. Intensive storm sampling during a small monsoon rainfall event (18 mm) and an extreme event (452 mm) showed rapid changes in both suspended sediments and dissolved solutes in an agricultural stream draining the Haean Basin where arable lands have expanded rapidly over the recent decades. By contrast, a nearby forest stream derived from North Korea showed little responses to the small event compared to larges changes during the extreme event. In the agricultural stream total Pb concentrations showed significant positive relationships with suspended sediments. Although limited sampling frequency and locations require a cautious interpretation, the overall results suggest that expansion of agricultural fields in steep mountainous watersheds can increase the susceptibility of soil erosion and its off-site environmental impacts under increasing rainfall variability and extremes.

• Korean Journal of Environmental Agriculture
• /
• v.24 no.1
• /
• pp.1-5
• /
• 2005

Continuous monocropping of Chinese cabbage in Gangwon highland increased gravel and sand contents due to surface soil erosion. Nutrient leaching and Chinese cabbage growth were investigated with different treatments of gravel contents and nitrogen application levels by using $0.5m^2$ Wagner pots. Gravel contents were 0, 10, 30, 50, 70, and 90%(w/w), nitrogen application levels were 60, 120, and 240 kg/ha, and manure compost application rate was 15 ton per hectare, respectively. Wagner pots were filled with loamy sand soil mixed with 5 cm-sized gravels. Fresh weight of Chinese cabbage was decreased as gravel contents in soil increased, and particularly severely decreased at 240 kg-N/ha. Yields of Chinese cabbage were remarkably decreased at the rate of 60 kg-N/ha with 30% gravel content and 120 kg-N/ha with 50% gravel content. Most of Chinese cabbages were severely wilted by heavy N application at the rate of 240 kg-N/ha in the middle of growth stages regardless of gravel contents, while about 50% of Chinese cabbage showed wilting symptom in the treatment of more than 50% of gravel contents and 120 kg-N/ha. N content in leachate increased as gravel content and N application increased. The relationship between gravel content and N contents showed linear regression: N in leachate = 0.014(gravel content) -0.039 (r = 0.961). Particularly, $NH_4-N$ contents in leachates with more than 30% gravel content and 240 kg-N/ha ranged from $139{\sim}339mg/L$. Chinese cabbage growth in loamy sand soil containing 30%, and 50% gravel contents could be adversely affected by N application at the rate of 240, and 120 kg-N/ha, respectively.

• Journal of Wetlands Research
• /
• v.10 no.1
• /
• pp.59-68
• /
• 2008

Three phases of development in construction projects (i.e. pre-development, construction and post construction) diversely effect the environment, hydraulics and ecosystem. Currently, the domestic environmental policy is in control of the various environmental hazards produced after completion of development operations. Nevertheless, with the enforcement of water pollution total amount management system, improving the water quality; also the water and ecosystem preservation law recommends enforcing the sediment management for development operations in order to lessen the negative impacts to the environment. Recently, the country is experiencing difficulties in various development project locations due to insufficiency of interpreting the fundamental data for sediment loss and miscalculation of soil loss unit loads of sediment. This research utilizes data from 2000 to 2005 discussing a total of 1,036 environment impact assessment projects gathered from various ministries and offices namely Ministry of Environment (MOE), Ministry of Agriculture, the Office of Forestry, and Ministry of Construction and Transportation. Moreover, quantity of sediment from high land agriculture reports involving contaminant discharge characteristic investigation previously did concerning old land agriculture and So-Yang lake non-point pollution source management area as well as management measured data from MOE. The findings of this study reveal that the highest soil loss rate occurred from mountain district for pre-development and post construction and sports facility during construction.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.4 no.3
• /
• pp.1-9
• /
• 2001

The purpose of this study was to evaluate the burning impacts of the surface and crown fire occured in yongsan-ri meongsok-myun of chinju-city, Gyeongnam. Environmental influences like surface runoff and soil erosion changes were investigated by comparisons analysis between burned and unburned area about some initial effects after fire. The results obtained from this study were as followed; 1. The average amount of surface runoff in burned area was more 1.7 times than in unburned area. But it was gradually tend to decrease in burned area as times passed. 2. Factors significantly correlated to amount of surface runoff in burned area shown in order to unit rainfall, accumulated rainfall and sand content, as 0.9466 of multiple correlation coefficient, where as the factors in unburned area were unit rainfall, soil erosion, bulk density and soil hardness, as 0.9738 of multiple correlation coefficient. 3. The average amount of soil erosion in burned area was more 11.2 times than in unburned area. But it was gradually tend to decrease in burned area as times passed. 4. Factors significantly correlated to amount of soil erosion in burned area were surface runoff and unit rainfall, as 0.6305 of multiple correlation coefficient. The factors in unburned area shown in order to surface runoff, sand content, bulk density and unit rainfall, as 0.7879 of multiple correlation coefficient.

• Korean Journal of Soil Science and Fertilizer
• /
• v.18 no.3
• /
• pp.289-296
• /
• 1985

To clarify the soil characteristics and genesis of the clayey terrace soils distributed in Yeongcheon (inland region) and Yeongil (coastal region), 9 typifying pedons including a recent local deposits were studied. The physico-chemical properties found were summarized as follows; 1. The contents of available water of the terrace soils were ranged from 12.0 to 20.3%. They were increased with increaseing clay content up to 35%, and then decreased at clay content of 35 to 55%, but were maintained about 12 to 13% when the clay content exceeds 55%. 2. The amount of water stable aggregates in the surface soils were ranged from 55.0 to 81.1%, and were low in cultivated upland where water erosion were accelerated while high in the paddy where the double cropping were practiced. The index of aggregate in cultivated upland were higher in the surface soils but the paddy soils were higher in subsoils. 3. The colloidal reactions checked by the differences between pH in $0.01N-Na_2SO_4$ and $H_2O$ indicate exchangeable acidity to exchangeable neutrality, which means a sort of Red-yellow soil forming process had been prevailed during genesis of the terrace soils. 4. Cation exchange capacity of the clayey terrace soils were averaged about 15.8-20.2me/100g of fine earth and 35.6-52.6me/100g of clay. The rates of base saturation were 32.7 to 57.6% and the rates decreased with increasing the elevations of terraces. 5. The activities of free iron oxides were 0.061 to 0.739 and the values decreased with increasing elevation while the crystallinity index of iron oxides positively correlated with elevations the values ranged from 0.067 to 0.537.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.12 no.2
• /
• pp.82-98
• /
• 2009

This study applied SWAT model to analyze suspended sediment load that is influence on the high density turbid water in Donghyang and Cheoncheon basin, which are located in the upstream of Yongdam Dam. GIS data such as DEM, land cover map and soil map, and meteorological data were used as the input data of SWAT model. And the rating curve equation and Q-SS equation of Donghyang and Cheoncheon gauge station were applied as the measured values of them. As the result of flowout, the coefficient of determination ($R^2$) and the Nash-Sutcliffe coefficient of efficiency (EI) of model calibration showed high as 0.87 and 0.87 at Donghyang gauge station, and the $R^2$ and EI of model validation were high as 0.95 at Cheoncheon gauge station. Also, as the result of suspended sediment load, the $R^2$ and EI of model calibration were high as 0.77 and 0.76 at Donghyang gauge station, and the $R^2$ and EI of model validation marked high as 0.867 and 0.80 at Cheoncheon gauge station. It is considered that the suspended sediment load of 2003 showed the highest due to rainfall amounts and rainfall intensity in using SWAT model. The results of suspended sediment modeled in this study can be applied to the decision-making support data for the evaluation of soil erosion possibility and turbid water potential in the management of reservoir.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.27 no.4
• /
• pp.297-312
• /
• 2007

This study is conducted to evaluate economical value of Jeju grassland and validity of its preservation, and draw up several measures to support. To measure its economical value, this study examined its environmental value and social and cultural value. For environmental value, this study used replacement method while it applied CVM method, a widely used method, to assess social and cultural value and two-level two-best choice selection method, which ask questions by assuming virtual circumstances to avoid reflecting some biased opinions. Jeju grassland has multiple functions-environmental functions such as preventing soil corrosion and flood, handling animal excrement, and purifying air, and social and cultural functions such as promoting physical and mental health and providing recreation places. From the results of the feasibility study, Jeju grassland's annual multiple functions are assessed to have a total $397,115{\sim}418,995$ million won worth. In addition, it is found that Jeju visitors recognize Jeju grassland for its functions to contribute to public interests. That is, they think it can provide attractive views and educational and recreational places and promote emotional development. Especially, many people presented their ideas that it be continuously preserved since it is worthwhile for us and our next generations. To preserve grassland's cultural resource, which create a huge economic value like this, the Government has to support a certain amount of financial aid for turning to a better grassland environment and its maintenance to realize environment-friendly livestock farming on Jeju Island and promote its tourism industry and consequently, add more value to Jeju.

• Journal of Environmental Science International
• /
• v.22 no.5
• /
• pp.599-608
• /
• 2013

Jeju island, which is located along the moving path of typhoon, suffers from flooding and overflow by torrential rain. So abrupt runoff occurring, damages of downstream farm field and shore culturing farms are increasing. In this study, Oaedo stream, one of the mountainous streams on Jeju island, was selected as the basin of study subject and was classified into 3 sub-basins, and after the characteristics of subject basin, the soil erosion amount and the sediment delivery of the stream by land usage distribution were estimated with the use of SATEEC ArcView GIS, the sediment yield amount of 2000 and 2005 was analyzed comparatively. As a result of estimating the sediment yield amount of 2000, the three sub-basins were respectively 12,572.7, 14,080 and 157,761 tons/year. and sediment yield amounts were estimated as 35,172.9, 5,266 and 258,535 tons/year respectively in 2005. The soil erosion and sediment yield amount of 2005 using single storm rainfall were estimated high compared with 2000, but for sub-basin 2, the values rather decreased due to changes in land use, and the land coverage of 2005, since there are many classifications of land usage compared with 2000, enabling to reflect more accurate land usage condition, could deduce appropriate results. It is anticipated that such study results can be utilized as basic data to propose a direction to predict the amount of sediment yield that causes secondary flooding damage and deteriorates water quality within detention pond and grit chamber, and take action against damages in the downstream farm field and shore culturing farms.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2007.05a
• /
• pp.987-992
• /
• 2007

충청북도 내의 농업용 저수지중 26개소를 선정하여 관개초기, 홍수기 및 비관개기의 연 3회에 걸쳐 저수율을 파악하고 채수를 실시하였다. 또한, 현장(수온, pH, DO, EC)과 실내 수질분석(Cd, As, Cn, Hg, 유기인, Pb, $Cr^{+6}$ PCB, ABS, COD, SS, TP, TN)을 실시하여 저수지의 오염도를 평가하였다. 저수율 측정결과, 홍수기(97%)가 관개초기(72%)나 비관개기(66%)보다 높게 나타났다. pH 값의 측정결과, 수질기준$(6.0{\sim}8.5)$을 만족하고 있는 저수지의 비율은 35%(9개소)의 낮은 값을 보였다. EC와 DO 및 SS농도의 측정결과, 거의 모든 저수지에서 수질기준을 만족하고 있었으며, COD, TN, TP농도 측정결과, 수질기준 만족도는 관개초기 100%, 홍수기 81%, 비관개기 65%로 나타나, 저수량이 많은 관개초기보다 저수량이 적은 비관개기에 질소와 인의 관리가 필요한 것으로 판단된다. 또한, 사람의 건강항목(CN, Hg, 유기인, PCB, Cd, 비소As, Pb, $Cr^{6+}$, ABS)은 모든 저수지에서 관개 초기, 홍수기 및 비관개기에 모두 수질기준을 만족하였다. 점오염원을 관리하기 위해서는 저수지 상류유역에 있는 마을하수도를 정비하고, 축산분뇨처리시설 등을 설치하여 저수지로의 유입부하량을 저감할 필요가 있다. 또한, 비점원오염을 관리하기 위한 대책으로서, 질소농도를 저감시키기 위해서는 용존성 성분을 제공하는 비료의 시용량을 줄여야하며, TP농도를 저감시키기 위해서는 강우시 입자성 인의 유출을 제어할 필요가 있으며, 이를 위해서는 비가 많이 오는 여름철에 나지(裸地)나 밭에 식생이나 멀칭(mulching) 등으로 토양침식을 방지할 필요가 있다.가용한 장 단기간의 관측자료와 물수지 분석 연산식의 추정치를 바탕으로 관측자료에 의한 물수지 분석을 수행하였다. 분석 결과로 산지 소하천 유역인 설마천 시험유역의 각 수문요소의 물이동간의 정량적인 값을 알 수가 있었으며, 앞으로 추가적이고 지속적인 수문모니터링이 운영되고 물순환 해석 모형에 의한 검증이 수행된다면 정량적인 물순환 관계를 규명할 수 있을 뿐만 아니라 이와 관련된 수문요소기술을 확보할 수 있을 것이다.절한 타협과 조정을 필요로 한다. 그러나 절제의 한계를 넘어선다고 생각되거나, 조정의 노력이 불가능하거나, 실패했을 때 폭력적인 행동으로 나타나게 된다. 리차즈(I.A Richards)는 분노와 공포는 일단 겉잡을 수 없는 경향이 있다고 하면서 오늘날 폭력에 대한 요구가 일상의 정서 생활에 있어, 억압을 통한, 빈곤함을 반영하고 있지 않은지 생각해봐야 할 것이라고 충고한다. 조성 가이드라인(안)을 제시하였다.EX>$\ulcorner$세종실록$\lrcorner$(世宗實錄) $\ulcorner$지리지$\lrcorner$(地理志)와의 비교를 해보면 상 중 하품의 통합 9개소가 삭제되어 있고, $\ulcorner$동국여지승람$\lrcorner$(東國與地勝覽) 에서는 자기소와 도기소의 위치가 완전히 삭제되어 있다. 이러한 현상은 첫째, 15세기 중엽 경제적 태평과 함께 백자의 수요 생산이 증가하자 군신의 변별(辨別)과 사치를 이유로 강력하게 규제하여 백자의 확대와 발전에 걸림돌이 되었다. 둘째, 동기(銅器)의 대체품으로 자기를 만들어 충당해야할 강제성 당위성 상실로 인한 자기수요 감소를 초래하였을 것으로 사료된다. 셋째, 경기도 광주에서 백자관요가 운영되었으므로 지방인 상주지역에도 더 이

• Journal of Korean Society of Forest Science
• /
• v.58 no.1
• /
• pp.125-131
• /
• 1982

산지개간(山地開墾)에 의한 인공초지(人工草地) 조성(造成)은 급경사지(急傾斜地)이고 복잡(複雜)한 지형(地形)의 한국(韓國) 산악지(山岳地) 조건(條件)과 계절간(季節間)에 기후차(氣候差)가 심한 한국(韓國)의 기후상태(氣候狀態)로 보아 많은 문제점(問題點)이 있을 것이고, 이와 같은 지형(地形)과 기후조건(氣候條件)들 때문에 토지이용시(土地利用時) 신중(愼重)한 배려(配慮)가 요구(要求)된다. 산지황폐(山地荒廢)와 홍수피해(洪水被害) 등(等)이 국토관리상(國土管理上) 큰 문제점(問題點)으로 되어 왔고 금후(今後)에도 이 문제(問題) 해결(解決)은 토지경영(土地經營)에 있어 커다란 과제(課題)로 남아 있다. 또한 식량증산(食糧增産)을 위한 토지(土地)의 경제적(經濟的) 이용(利用)도 큰 과제(課題)의 하나임에는 틀림 없다. 이와 같이 토지이용상(土地利用上)에 서로 상충(相衝)되는 이들 과제(課題)를 해결하기 위하여 인공토지(人工土地) 조성(造成) 대책(對策)을 검토(檢討)한 바 임축인(林畜人)들이 상호(相互) 협동(協同)하여 이 과제(課題)의 기술(技術)을 개발(開發)시켜야 될 것으로 판단(判斷)이 된다. 국토보존(國土保存) 문제(問題)를 해결하고 동시에 인공초지(人工草地)의 문제점인 하고현상 식피밀도(植被密度)와 연년생장(年年生長)의 감소현상을 해결하기 위하여 상호보완적(相互補完的)인 생태적(生態的)인 방법(方法)이 도입(導入)되어야 할 것 같다. 이를 위해 삼림(森林)이 갖고 있는 토양침식방지(土壤浸蝕防止), 토양수분보지기능(土壤水分保持機能), 온도변화기능(温度變化機能), 공중온도(空中温度) 보지기능(保持機能), 방풍기능(防風機能)과 풍치기능(風致機能)을 잘 활용(活用)하여 국토(國土)를 보존(保存)시키고 동시(同時)에 초지생산성(草地生産性)도 높이는 방안(方案)이 인공초지조성(人工草地造成)에 있어 기대될 수 있는 방법(方法)으로 사료(思料)된다. 이의 대책(對策)의 일환으로 유실수(有實樹)와 초(草)와의 혼농림조성(混農林造成), 임간초지(林間草地)와 방목(放牧), 활엽수림하(闊葉樹林下)의 혼림초지(混林草地) 경사지(傾斜地)에 있어 대상식(帶狀式)과 세포식(細胞式)의 방풍(方風) 및 황폐방비림(荒廢防備林)에 의한 초지조성(草地造成) 또한 산능선부와 계곡부의 삼림(森林)을 보존(保存)시키는 초지조성법(草地造成法)을 제시(提示)하였다. 수광량(受光量)이 문제(問題)가 될 경우에는 간벌(間伐)과 가지치기 들(等)으로 조절할 수 있게 되고 예취작업(刈取作業)의 기계화상(機械化上)의 문제(問題)는 상하(上下) 수대(樹大)의 배열(配列) 또는 배식방법(配植方法)에 의해 조절할 수 있으므로 혼림초지조성(混林草地造成)이 초지생산성(草地生産性)에 하등의 영향을 주지 않을 것으로 사료(思料)되며 오히려 초생산량(草生産量)을 증대(增大)시키는 방법(方法)이 될 것이다.