• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.161-161
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• 2021

본 연구에서는 금강 상류의 용담댐 유역(930.0 km²)을 대상으로 Sentinel-1 SAR(Synthetic Aperture Radar) 및 Sentinel-2 MultiSpectral Instrument(MSI) 위성영상을 활용한 토양수분 산출연구를 수행하였다. 연구에 사용된 자료는 10 m 해상도의 Sentinel-1 IW(Interferometric Wide swath) mode GRD(Ground Range Detected) product의 VV(Vertical transmit-Vertical receive) 및 VH(Vertical transmit-Horizontal receive) 편파자료와 Sentinel-2 Level-2A Bottom of Atmosphere(BOA) reflectance 자료를 2019년에 대해 각 6일 및 5일 간격으로 구축하였다. 위성영상의 Image processing은 SNAP(SentiNel Application Platform)을 활용하여 Sentinel-1 영상의 편파 별(VV, VH) 후방산란계수와 Sentinel-2의 적색(Band-4) 및 근적외(Band-8) 영상을 생성하였다. 토양수분 산출 모형은 다중선형회귀모형(Multiple Linear Regression Model)을 활용하였으며, 각 지점에 해당하는 토양 속성별로 모형을 생성하였다. 모형의 입력자료는 Sentinel-1 위성의 편파별 후방산란계수, Sentinel-1 위성에서 산출된 식생지수 RVI(Radar Vegetation Index)와 Sentinel-2 위성에서 산출된 NDVI(Normalized Difference Vegetation Index)를 활용하여 식생의 영향을 반영하고자 하였다. 모의 된 토양수분을 검증하기 위해 6개 지점의 TDR(Time Domain Reflectometry) 기반 실측 토양수분 자료를 수집하고, 상관계수(Correlation Coefficient, R), 평균제곱근오차(Root Mean Square Error, RMSE) 및 IOA(Index of Agreement)를 활용하여 전체 기간 및 계절별로 나누어 검증할 예정이다.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.280-288
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• 2009

To identify controlling factors for spatial variation of vegetation in reclaimed tidal flats, plant stands were investigated in a newly reclaimed as well as three matured tidal flats, and a natural tidal flat in the midwest coast of Korea. Electrical conductivity of saturated soil extract (ECe) was measured to assess soil salinity. Soil salinity differed significantly among plant stands. Depending on soil salinity, plant species showed different niches: glycophyte predominated low saline spots, halophyte predominated high saline spots. Soil salinity for each plant habitats was in order of as follow: bare soil or plant wilted > mixed pioneer halophyte > pioneer halophyte > mixed with pioneer halophyte and facultative halophyte > mixed facultative halophyte > facultative halophyte > mixed with facultative halophyte and glycophyte > glycophyte > mixed glycophyte stands. These results suggested that plant distribution might have been influenced by spatial edaphic gradient (soil salinity), and thus it could be utilized as an indicator for field soil salinity gradient. Relationship between soil salinity and plant distribution was not different among the aged reclaimed tidal flats, suggesting that the vegetative population might have changed into a similar direction since the reclamation.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.231-238
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• 2009

This study was carried out to investigate the effect of vegetative buffer to reduce runoff and soil and nutrient loss at highland agricultural area. The soil of experimental field was classified as Ungyo series (Fine, Humic Hapludults). An area of each field with lysimeter was $50m^2(width\;2.5m{\times}length\;20m)$ and was a gradient of 17%. Chinese cabbage (Brassica campestris L.) was cultivated by general management in each field. For establishing vegetative buffer, rye (Secalecereale L.), tall fescue (Festucaarundinacea Schreb) and orchard grass (Dactylis glomerata L.) were planted at the edge of field. Rye buffers were 1m, 2m and 4m wide. Both orchard grass and tall fescue buffers were 2m wide. Vegetative buffers were set up in September 2005 and chinese cabbage was planted in June 2006. Soil loss, runoff and nutrient loss were measured from June to August in 2006. Since the precipitation amount was heavy in July, amounts of runoff, soil erosion and nutrient loss were the highest in July during this study period. In comparison with control, vegetative buffers of rye 2m, orchard grass 2m and tall fescue 2m reduced runoff by 3%, 1% and 2%, respectively. In comparison among width of rye buffer, rye 1m, rye 2m, and rye 4m reduced by 1%, 4% and 13%, respectively. Vegetative buffers of rye 2m, orchard grass 2m and tall fescue 2m showed the reducing of soil loss by 59%, 46% and 28%, respectively. In comparison among width of rye buffer, the highest reducing effect of 88% was observed in 4m treatment. Additionally, vegetative buffer reduced N, P and K losses in runoff and eroded soil which were 10 to 54%, 7 to 24% and 11 to 21%, respectively. In different widths, wider vegetative buffer showed lower loss of N, P and K in runoff and eroded soil. As a result of this study, the vegetative buffer of rye was most effective for reducing runoff and soil loss in comparisons with other plants. In addition, wider range of buffers recommended for reducing runoff and soil loss, if possible.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.114-114
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• 2011

1960년대 산업화와 도시화 이전 우리나라 하천은 모래, 자갈 사주가 경관생태의 대부분을 이룬 이른바 'White River'이었으나, '70년대 이후 댐건설, 하천정비 등으로 유황과 유사이송 특성이 변하면서 수변에 식생이 번무하는 이른바 'Green River'가 진행 중이다. 하천에서 식생활착은 생태 측면에서 생물 종의 다양성에 일부 긍정적인 역할을 하는 반면에, 고유종이 감소, 소멸하는 문제가 생긴다. 치수 측면에서는 흐름저항 증가와 하도의 고착화를 촉진시켜 치수 안정성에 문제를 야기할 수 있다. 본 연구는 사주 상 식생활착 현상을 정량적으로 규명하기 위한 연구의 시작으로서, 하천 식생사주역에서 식생활착에 직접적인 영향을 주는 소류력과 토양 수분 등 2대 물리 요소 중에서 후자에 초점을 맞추어 토양수분 요인과 식생 이입, 활착, 천이와의 관계를 규명한다. 이를 위해 모래하천인 낙동강 제1지류 내성천의 국가하천 구간 하류 지점인 회룡포 직상류 약 4km 지점을 시험하천 구간으로 선정하여 하천수위, 지하수위, 토양수분을 연속적으로 측정할 수 있는 시설을 설치하였다. 이러한 관측 시설을 가지고 1차적으로 2010년 8월부터 2011년 4월 초까지 지하수위와 하천수위, 토양수분을 연속적으로 모니터링하고 상호 관계를 분석하였다. 사주 상 식생 활착 특성도 주기적으로 조사하였다. 이번 일차 기초 조사 및 분석 결과, 하안에서 약 140-240m에 위치한 지하수위 관측정에서 측정된 지하수위는 하천수위 변화에 비해 시간적으로 약 20시간 지체되는 것으로 나타났다. 한편 사주 토양수분은 일반적으로 지하 깊이에 따라 커지나, 동시에 토층구조(soil texture)에 영향을 받는 것으로 나타났다.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.352-359
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• 2015

This study was conducted to evaluate how the special protection area designations of degraded trails effect on the soil and vegetation recovery of degraded trails. The study areas were established on an opened trail and a 16-year closed trail, which was prohibited to enter after the designation as a special protection area for recovery, at Bukhansan National Park. Soil core sampling and measurements of vegetation cover were performed to compare soil and vegetation properties of the trails. Soil bulk density increased and soil water total nitrogen decreased on the opened trail, while no significant differences were found on bulk density, soil water, total nitrogen, acidity, and organic matter on the closed trail. On the opened trail, vegetation cover was seemed to be degraded, because vegetation litter cover ratio was low and barren rock cover ratio was high. On the closed trail, litter rock barren cover ratio of the closed trail was recovered, but only limited recovery was found on vegetation cover by applying environmental damage condition rating class. In conclusion, the closed trail was recovered by designation of special protection area, while difference in recovery progress of soil and vegetation was found. Therefore, designation of special protection area of degraded area should be based on scientific basis of recovery characteristics of the area. In order to improve the effectiveness of special protection area system, further specific standards for special protection area designation and management would be needed, considering ecological and social importance of target areas.

• Journal of Korea Water Resources Association
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• v.56 no.11
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• pp.721-728
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• 2023

Agricultural drought is triggered by a depletion of moisture content in the soil, which hinders photosynthesis and thus increases carbon dioxide (CO₂) concentrations in the atmosphere. The aim of this study is to analyze the relationship between soil moisture (SM) and vegetation activity toward quantifying CO₂ concentration in the atmosphere. To this end, the MODerate resolution imaging spectroradiometer (MODIS), an optical multispectral sensor, was used to evaluate two regions in South Korea for validation. Vegetation activity was analyzed through MOD13A1 vegetation indices products, and MODIS gross primary productivity (GPP) product was used to calculate the CO₂ flux based on its relationship with respiration. In the case of SM, it was calculated through the method of applying apparent thermal inertia (ATI) in combination with land surface temperature and albedo. To validate the SM and CO₂ flux, flux tower data was used which are the observed measurement values for the extreme drought period of 2014 and 2015 in South Korea. These two variables were analyzed for temporal variation on flux tower data as daily time scale, and the relationship with vegetation index (VI) was synthesized and analyzed on a monthly scale. The highest correlation between SM and VI (correlation coefficient (r) = 0.82) was observed at a time lag of one month, and that between VI and CO₂ (r = 0.81) at half month. This regional study suggests a potential capability of MODIS-based SM, VI, and CO₂ flux, which can be applied to an assessment of the global view of the agricultural drought by using available satellite remote sensing products.

• Journal of Korean Society of Forest Science
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• v.111 no.2
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• pp.234-241
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• 2022

We performed this study to determine the foliar nutrient concentration and the nutrient stocks of restoration areas and adjacent Pinus densiflora S. et. Z. (red pine) stands in opencast kaolinite mines in Sancheong-gun, Gyeongsangnam-do, southern Korea. We chose six sites to determine foliage nutrient concentrations and the nutrient stocks of soils (0-10 cm depth). The dominant vegetation planted in restoration areas comprised Quercus acutissima Carruth., P. koraiensis S. et. Z., Festuca arundinacea Schreb., and Lespedeza cuneata G. Don. Invading vegetation in the restoration areas comprised Alnus incana (L.) Medik., Robinia pseudoacacia L., and Lespedeza spp., among others. The carbon and nitrogen stocks at 10 cm soil depth were significantly higher in the red pine stands than those in the restoration areas, whereas those of phosphorus, potassium, and magnesium were not significantly different between the two areas. However, calcium stocks were significantly higher in the restoration areas than in the red pine stands. Nitrogen concentration in foliage was higher in L. cuneata (20.28 mg N g^-1) than that in F. arundinacea (5.67 mg N g^-1), whereas potassium concentration was twice as high in F. arundinacea (18.8 mg K g^-1) as that in L. cuneata (9.07 mg K g^-1). Foliar nitrogen concentrations in invasive vegetation such as A. incana, R. pseudoacacia, and Lespedeza spp. were twice or four times higher than those of Q. acutissima and P. koraiensis. Our results indicate the development of suitable vegetation and soil amendment treatments to improve poor soil environmental conditions in restoration areas are necessary following opencast kaolinite mining.

• The Korean Journal of Ecology
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• v.25 no.5
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• pp.321-328
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• 2002

In order to provide the basic information for restoration of vegetation, conservation of rare species and maintenance of biodiversity, changes of site factors and vegetation by human trampling disturbance were investigated at the subalpine zone near the peak of Mt. Sorak in Korea. The destructed vegetation was found mainly in the southern parts with gentle slope in this study area. Height and coverage of vegetation and the species diversity decreased, and the community structure depended on trampling strength. Soil moisture, organic matter contents and litter thickness in the site with destructed vegetation by human trampling showed lower values than in the undisturbed site. Soil depth decreased, and gravel exposure on the ground surface increased by soil erosion responded to trampling strength.

• Korean Journal of Environment and Ecology
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• v.7 no.1
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• pp.49-57
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• 1993

This study was executed to investgate the impacts of vegetation and soil characteristics on the user's impact in Children's Park and Kumkang Park, Pusan. In survey sites, twenty plots of 100$m^2$ size were set up. The degree of soil hardness was showed above 90kg/$\textrm{cm}^2$ in using area, which was prevented to the plants growth. The user's control was effective to the soil surface softening, while that effects of the other soil characteristics were not cleared. In the analysis of Plant community structure, especially, shrub vegetation was severely damaged. And the user's impact was due to the lowering of species and maximum species diversity. The recreation area protection of the two years was positively operated to the natural vegetation restoration and species diversity enhancement.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.208-208
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• 2011

하구는 하천의 담수와 염수가 교차되고 혼합되는 기 수역으로서 수생 생태계의 중요한 서식처이며 바다와 하천의 중요한 생태통로가 되고 있다. 국내에서는 4대 하천 중에서 한강하구가 유일하게 하구 둑이 없는 자연하구이며 나머지 대하천은 둑으로 인해 담수와 해수의 자연스러운 흐름이 제한되고 생태적인 연결이 단절된 형태이다. 한강하구에는 대규모 습지가 분포하고 있으며 특히 장항습지는 종단길이 약 7.5km, 폭 최대 500m에 달하는 대규모 습지로서 고라니를 비롯한 동물과 줄, 선버들을 비롯한 식물의 대규모 군락이 분포하는 등 생태적 가치가 높은 지역이다. 본 연구에서는 한강하구의 장항습지와 산남습지를 대상으로 특정구간의 물리적 특성, 식생의 분포특성을 파악하고 연관성을 분석하고자 하였다. 이를 위해 1차적으로 포괄적인 현장조사를 통해 전체 식생군락과 분포를 파악하고 특징적인 식생군락을 선정하였다. 2차적으로는 선정된 줄 및 선버들 군락지를 대상으로 토양단면, 토양입경을 분석하고, 새섬매자기 군락지를 대상으로 측량을 실시하였다. 3차적으로는 대상 군락의 지하수위를 측정하여 상호관계를 분석하였다. 이 결과는 우선 한강하구의 지역적 특징에 국한되지만 향후 타 지역과의 비교연구가 수행된다면 대상 식생과 물리적 생장조건과의 정량적인 관계가 도출될 것으로 판단된다.