• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.2
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• pp.61-72
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• 2008

Leaf area index (LAI) is a key biophysical variable influencing land surface processes such as photosynthesis, transpiration and energy balance, and is a required input to estimate evapotranspiration in various ecological and hydrological models. The development of more correct and useful LAIs estimation techniques is required by these importance, but LAIs had been assumed in most LAI research through simple relations with the normalized difference vegetation index (NDVI) because the field measurement is difficult on wide area. This paper is to evaluate the MODIS LAI Product's practical use by comparing with LAIs that is derived from NOAA AVHRR NDVIs and the 2 years (2003-2004) measured LAIs of Korea Forest Research Institute in Gyeongancheon watershed (561.12 $Km^2$). As a result, the MODIS LAIs of deciduous forests showed higher values about 14 % and 15~30 % than the measured LAIs and NOAA LAIs. In the year of 2003, the MODIS LAIs in coniferous forests were 5 % higher than the measured LAIs, and showed about 7 % differences comparing with the NOAA LAIs except April. These differences come from the insufficient field data measured in partial points of the target area, and the extracted reference data from MODIS LAIs include the limits of spatial resolution and the error of incorrect land cover classification. Thus, using the MODIS data by the proper correction with the measured data can be useful as an input data for ecological and hydrological models which offers the vegetation information and simulates the water balance of a given watershed.

• Korean Journal of Remote Sensing
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• v.31 no.2
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• pp.77-83
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• 2015

Leaf water content is one of important indicators that shows states of vegetation. It is important to monitor vegetation water content using remote sensing for forest management. In this study, we investigated the degree of water stress in Korean peninsula with Normalized Difference Water Index (NDWI) to study the water content of vegetation canopy. We calculated the NDWI using SPOT/VEGETATION S10 channel data over forest from 1999 to 2013. We calculated Simple Moving Average (SMA) to remove temporal noises of NDWI in time series, and used standardized anomaly to investigate temporal changes. We classified the NDWI anomalies into three scales (low, moderate, and high) in order to monitor intuitively. We also investigated suitability of the NDWI as an evaluation criterion about water stress of vegetation canopy by comparing and verifying forest fires damaged area over 150 ha. Consequently, huge forest fire occurred 24 times during the study period. Also, negative anomalies appeared in every forest fire location and their neighboring areas. In particular, we found huge forest fires where NDWI anomalies were in 'high' scale.

• Journal of Korea Water Resources Association
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• v.40 no.7
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• pp.555-570
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• 2007

The effects of climatic changes owing to urbanization on annual water balance have been studied. In this study, 56 meteorological stations including Seoul metropolis in South Korea have been selected, and the area of study site is $314\;km^2$. The meteorological station is centrally located in the study area with a 10 km radius. Land use status of study area was examined to estimate the urbanization extent, so that annual actual evapotranspiration could be estimated. Annual runoff was estimated by annual water balance approach using the estimated annual actual evapotranspiration and measured annual precipitation. Annual actual evapotranspiration was estimated by applying experimental equation suggested by Zhang et al, (2001) which was evaluated from 250 watersheds all over the world. Study results show that reference evapotranspiration is tending upwards due to urbanization; therefore, it seems that climatic change due to urbanization may increase the amount of annual actual evapotranspiration. However, the increase of residential area due to urbanization in study area may decrease the amount of annual actual evapotranspiration. The study results indicate that urbanization effect on annual trend of precipitation was not significant. In urban area, annual runoff is directly affected by annual precipitation, and compared with annual precipitation, annual variation of actual evapotranspiration was not significant even though it was estimated by using annual precipitation. It seems that the effect of urbanization on annual actual evapotranspiration does not influence on annual runoff significantly, and that urbanization effect on annual runoff Is not significant.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.3
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• pp.107-116
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• 2020

In this data paper, we share the dataset obtained during 2019 from the test-bed to develop soil moisture estimation technology for upland fields, which was built in Seosan and Taean, South Korea on May 3. T his dataset includes various eco-hydro-meteorological variables such as soil moisture, evapotranspiration, precipitation, radiation, temperature, humidity, and vegetation indices from the test-bed nearby the Automated Agricultural Observing System (AAOS) in Seosan operated by the Korea Meteorological Administration. T here are three remarkable points of the dataset: (1) It can be utilized to develop and evaluate spatial scaling technology of soil moisture because the areal measurement with wide spatial representativeness using a COSMIC-ray neutron sensor as well as the point measurement using frequency/time domain reflectometry (FDR/TDR) sensors were conducted simultaneously, (2) it can be used to enhance understanding of how soil moisture and crop growth interact with each other because crop growth was also monitored using the Smart Surface Sensing System (4S), and (3) it is possible to evaluate the surface water balance by measuring evapotranspiration using an eddy covariance system.

• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.18-24
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• 2013

The objective of study was to protect seabird breeding site and vegetation restoration of Chilbal and Sokugul island in Shinan county Jeonnam province, April and December 2011. We analyzed the soil properties according to the dominant communities and environmental gradient. As a result, It was highly analyzed to moisture content, organic matter, salinity, total nitrogen in Commelina communis community and low analyzed in Achyranthes japonica community. Carex boottiana community which mainly used as a seabird habitat has a wide range and Achyranthes japonica and Artemisia princeps community was narrowed to soil properties. Soil pH of Carex boottiana community in Sogugul island was the lowest on 3.14 and Peucedanum japonicum community was the highest. Soil moisture content and organic matter was analyzed by the high value in Peucedanum japonicum community. In contrast, Achyranthes japonica was the low value and Carex boottiana community was analyzed the highest on the salinity and total nitrogen. On the soil environmental characteristics according to the environmental gradient, The higher altitude, moisture content, organic matter, salinity and total nitrogen was the lower in Chilbal island. In the case of Sokugul island, the altitude difference did not show the characteristics of soil environmental factors for small area and low altitude. But moisture content is similar to soil property of Chilbal island. Soil property was strongly acid soil because of seabird dropping. This results will be helpful to manage the invasive plants.

• Journal of the Korean Geographical Society
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• v.42 no.3 s.120
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• pp.344-354
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• 2007

Estuarine wetlands for 33 watersheds in the Han River estuary were delineated on topographic maps from the 1910s, 1970s, and 2000s. Then, these data were used to address the issue of spatial distribution and temporal variation. Watershed characteristics such as drainage density, location, watershed size, slope, and elevation were identified for each watershed to determine the relationship between watershed characteristics and spatial distribution of estuarine wetlands. The analysis of estuarine wetlands indicated that wetlands in the estuary had declined gradually between the 1910s and the 1970s, although most wetlands were lost since the 1970s mainly caused by the large development projects related to urban expansion in metropolitan Seoul. The sediment composition and formation processes of the wetlands differed with watershed location; mud flats dominate in the lower part of the estuary, and relatively more sandy and emergent-plant wetlands occur near the main channel and tributaries of the Han River. Relatively more estuary wetlands occur in large watersheds, which have high slopes and low elevations. Estuarine wetlands have been lost dramatically in the densely populated watershed regions (i.e., Han River Seoul, Han River Goyang, West Han River), while relatively more wetlands have remained in undeveloped regions, including the Lower Imjin River and Lower Han River. In particular, anthropogenic disturbance has played an important role in the loss of wetland through the conversion of wetland into agricultural and developed land.

• Korean Journal of Environment and Ecology
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• v.23 no.1
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• pp.56-65
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• 2009

In Korea, Red pine(Pinus densiflora) stands at a very important place, historically, culturally, and emotionally and it is one of the tree species that can produce domestic timber as forest resources economically. The growing space for Red pine forest in Korea is gradually reducing while the space for deciduous tree forests including oak series is gradually increasing. Thus, it is required that the research work should be done on renewal for pine forest retention and its related forest management practices. This research aims at developing stable, sustainable management forests and inducing nature renewal by grasping growth environment and succession process through the pattern of stand and structure analysis of the red pine(Pinus densiflora) for central region. The pine forests in central region were classified into four communities, such as Acer pseudo-sibolianum, Quercus acutissima, Lindera erythrocarpa, and Pinus densiflora and they are showing different characteristics by pattern according to their growing district. There appeared a lot of red pines in the upper layer, but there existed high weight of broad-leaved forest tree species, such as oak series in the middle layer and the appearance of the red pine was meager in the lower layer. Therefore, it appears that the red pine has a high influential ecological strength in terms of correlativity; however, if the red pine in tree layer is dead by aging in nature state with the lapse of time, it is considered that oak species, such as Quercus mongolica, Quercus variabilis, and Quercus serrata will be dominant below sub-tree layer. In addition, there appear differences in characteristics and growth pattern of the red pine forest depending on stand pattern, so it is considered that a differential application method should be employed in the pine forest management.

• Journal of Wetlands Research
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• v.16 no.2
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• pp.251-259
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• 2014

Recently, wetland and paddy wetland are being highlighted as the international environmental issues. However, research system which can assess paddy wetland is lacking. Thus, the purpose of this study is to assess the value of paddy wetland by applying RAM to paddy wetland. In addition, we would like to use this study as the data to establish assessment method for paddy wetland. 16 sites were selected as research targets based on altitude and soil. As the results of wetland assessment, 16 research target sites had total score of 212~227 and the average of 2.17~2.50. It was similar to those of Lacustrine Wetlands, Palustrine Wetland and Riverine Wetland which were sites in previous studies. The value could be recognized as the wetland. However, there was no difference in assessment results based on altitude and soil. It was found that all conservation values were the same. The factor the most closely affecting conservation value was the area. However, there was limitation to apply existing wetland assessment system to paddy wetland. In order to assess paddy wetland, factors such as rice farming methods, topography, vegetation, growth environment and biodiversity should be added. It was thought to supplement wetland assessment system through various further studies.

• Journal of Wetlands Research
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• v.22 no.4
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• pp.286-294
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• 2020

This study aims to economically evaluate rice production and various ecological services provided by organic rice paddy carrying out rice-fish mixed farming. It was also conducted to find a stable structure for increasing the income of rice-producing farmers and promoting ecological services by evaluating the economic feasibility of organic rice paddy for rice-fish mixed farming. As a result of the analysis of expected effects by ecological service functions according to the types of agriculture in the rice-fish mixed farming, general conventional paddy fields were evaluated to have an effect of continuously decreasing biodiversity such as amphibian reptiles, aquatic insects, bird habitats, experience and ecological education, and vegetation diversity, while the biodiversity of organic and rice-fish mixed paddy fields was assessed to increase. As a result of evaluating the economic value, as the area for fish production increases compared to the common practice and organic paddy fields, rice production decreases, but fish production increases and total income was analyzed to increase. In addition, if the value of ecosystem service functions is assessed in the future, it will increase further. It is hoped that these findings will be used as basic data for solving oversupply problems in the rice industry, preserving safe farm income, and improving sustainable farming and ecosystem service functions.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2010.10a
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• pp.5-5
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• 2010

제주지역에 분포하는 특산식물의 현황을 알아보기 위해 지난 2007년부터 2010년까지 현지조사를 실시하여 44과 75속 63종 17변종 13품종으로 총 93분류군에 대한 자생지 환경, 개체군 동태, 생육특성 및 위협요인 등에 대한 자료를 구축하였다. 이중 세계적으로 제주지역에만 분포하는 제주특산식물은 긴다람쥐꼬리(Huperzi integrifolium) 등 27과 46속 36종 12변종 8품종으로 총 56분류군으로 분석되었으며, 제주도를 포함하여 우리나라에만 분포하는 한국특산식물은 구상나무(Abies koreana) 등 20과 28속 24종 4변종 4품종으로 총 32분류군인 것으로 파악되었다. 그리고 조사대상 특산식물 중 바위좀고사리(Asplenium sarelii var. anogrammoides) 등 5분류군은 분류학적 검토와 함께 특산식물여부에 대한 검토가 필요한 것으로 판단되었다. 그리고 개나리(Forsythia koreana)는 조경용으로 식재된 종이므로 제주지역에 자생지가 확인된 특산식물은 39과 70속 59종 16변종 12품종으로 총 87분류군으로 볼 수 있다. 제주지역의 특산식물은 해안지대에서 확인된 갯겨이삭(Puccinellia coreensis)부터 한라산 정상에서 자라는 한라솜다리(Leontopodium hallaisanense)까지 제주도 전역 분포하고 있으나 종에 따라 서로 다른 분포특성을 보였다. 특히, 한라산 해발 1,400m 이상 아고산대에 집중 분포하는 특성을 보였다. 특산식물의 자생지내 개체군의 동태를 보면 대부분의 식물이 개체수 및 분포범위가 한정되어 있는 것으로 나타났다. 더욱이 지리산오갈피(Eleutherococcus divaricatus var. chiisanensis)는 2개체만이 확인되어 종보전이 시급한 것으로 조사되었고, 한라솜다리, 모데미풀(Megaleranthis saniculifolia), 한라각시둥굴레(Polygonatum humile var. humillimum) 등 상당수의 식물 종이 수십 개체 이내로 매우 적은 개체수를 유지하고 있었다. 제주지역에 분포하는 특산식물은 인위적 또는 자연적 요인으로 인해 많은 자생지 면적감소나 개체수 감소 등의 위협요인을 갖고 있는 것으로 나타났다. 특히, 중산간 이하에 자라는 특산식물은 접근성 등이 용이하여 도채 등의 위험성이 높은 것으로 판단된다. 그리고 한라산국립공원 내에 분포하는 특산식물은 인위적 훼손 위험성은 상대적으로 낮은 편이나 자연적 요인 즉, 식생변화 등으로 인해 자생지 및 개체수 감소가 이루어질 것으로 보여 체계적인 종 보존전략이 마련되어야 할 것으로 판단된다. 한편, 제주지역 특산식물 중 자생지가 확인된 식물 종을 대상으로 근연종 분석 등을 통해 유용성을 분석하면 식물체 일부가 약용으로 가능한 식물 종이 개족도리(Asarum maculatum) 등 전체의 67.1%를 차지하였고, 관상용으로 활용가치가 높은 식물 종은 구상나무(Abies koreana) 등 전체의 60.2%인 것으로 분석되었으나 대부분의 종이 희소성의 가치가 있어 모든 특산식물이 관상용으로 이용가치가 있는 것으로 판단되었다. 제주지역에서 확인된 특산식물 중 전체적으로 90.9%가 유용성이 있는 것으로 나타나고 있으며 아직까지 유용성에 대한 정보가 미흡한 종도 자원적인 연구접근에 따라 다양한 자원으로 활용가치가 있는 것으로 판단된다.