• 대한공간정보학회지
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• 제16권4호
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• pp.59-64
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• 2008

우리나라의 야생동식물 조사가 시간적, 경제적 이유로 주로 출현지역만을 대상으로 하고 있어 종분포모형을 개발할 때 각 모형의 장점을 최대한 이용하는 것이 필요하다. 본 연구는 위치자료의 종류(출현/비출현자료)에 따라 가장 대표적인 출현/비출현모형(presence-absence model)인 GAM(Generalized Additive Model)과 출현모형(presence-only model)인 Maxent(Maximum Entropy Model)를 이용하여 비교 검토하였다. 본 연구의 대상종으로는 캘리포니아의 보호종인 피셔(Martes pennanti)를 선정하고 대상지를 지역에 따라 나누었으며, 서식지환경을 설명하는 지형, 기후, 식생변수들을 이용하여 모형을 적용하였다. 그 결과 첫째, 실제 출현/비출현자료를 사용한 GAM이 임의 비출현자료를 사용한 GAM과 출현자료만을 사용한 Maxent보다 전체적으로 나은 것을 볼 수 있었다. 둘째, 실제 출현자료만을 이용한 모형을 개발할 경우 임의 비출현자료를 이용한 GAM보다 출현자료만을 이용한 Maxent가 더 나은 것을 알 수 있었다. 마지막으로 세부지역에서 개발된 모형(Klamath/Shasta, Sourthern Sierra)은 서로 서식환경이 다를 경우 다른 지역의 서식지를 잘 예측하지 못함을 알 수 있었고, 대상지 외부지역에 대해 과추정하는 경향을 보였다. 위 결과를 바탕으로 위치자료의 종류, 공간적 분포 등을 감안하여 대상지의 환경에 알맞은 모형을 선택하는 것이 바람직할 것으로 판단된다.

• 한국지형학회지
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• 제24권2호
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• pp.91-101
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• 2017

Quantitative forecasting methods based on spatial data and geographic information system have been used in predicting the landslide location. This study compared the simulated results of logistic, Bayesian, and maximum entropy models to understand the uncertainties of each model and identify the main factors that influence landslide. The study area is Boeun gun where 388 landslides occurred in the year of 1998. The verification results showed that the AUC of the three models was 0.84. However, the landslide susceptibility distribution of Maxent model was different from those of the other two models. With the same landslide occurrence data, the result of high susceptible area in Maxent model is smaller than Logistic or Bayesian. Maxent model, however, proved to be more efficient in predicting landslide than the other two models. In Maxent's simulations, the responsible factors for landslide susceptibility are timber age class, land cover, timber diameter, crown closure, and soil drainage. The results suggest that it is necessary to consider the possibility of overestimation when using Logistic or Bayesian model, and forest management around the study area can be an effective way to minimize landslide possibility.

• 환경영향평가
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• 제25권6호
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• pp.432-441
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• 2016

본 연구에서는 도심 내 단절되어 있는 서식지의 연결성을 고려하여 생태통로를 구축하고자 하는 선행연구로 서울시의 인왕산과 안산의 생물 종 분포를 예측하였다. 연구대상지역인 인왕산과 안산의 생물 종 분포는 출현자료만으로도 결과를 예측할 수 있는 Maxent(Maximum Entropy Approach) 모형을 이용하여 분석하였다. Maxent 모형을 활용하여 종 분포를 예측하기 위해, 출현자료는 포유류 23개 지점과 박새류(Parus major, P. palustris, P. varius) 3종 15개 지점을 활용하였다. Maxent 모형의 환경변수로는 지형인자 4가지, 식생인자 4가지와 거리인자 2가지를 대상으로 구축하였다. 이 변수들을 활용하여 종 분포를 예측한 결과, 포유류의 경우에는 수치표고자료(DEM)가 34%, 산림지역의 경계로부터 산림내부의 거리가 24.8%, 수종이 10% 순으로 종 분포 모형에 기여도가 높았다. 반면 박새류의 경우에는 수치표고자료가 39.6%, 도로로부터의 거리가 35.4%, 나무의 밀도가 8.2% 순으로 모형에 기여도가 높았다. 따라서 조류 및 포유류는 산림 내부지역을 선호하는 것으로 나타났으며, 이 지역 보전이 필요한 것으로 판단된다.

• Ecology and Resilient Infrastructure
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• 제3권3호
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• pp.189-200
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• 2016

종분포 모델은 어떤 지역에서 침입외래종이 어떻게 확장되고 어떤 환경 요인이 이들의 분포에 영향을 미치는지를 이해하는데 매우 유용한 도구이다. 본 연구에서는 한반도에서 두 침입외래종인 돼지풀 (Ambrosia artemisiifolia)과 물참새피 (Paspalum distichum)의 분포에 대하여 연구하였다. 이 두 종의 현재의 분포지에서 기후환경 요인을 분석하고 이 두 종의 분포를 예측하기 위하여 Maxent (the maximum entropy) 모델을 이용하였다. 이 두 종의 출현 자료는 Global Biodiversity Information Facility와 우리나라의 식물종 데이터베이스에서, 생물기후 자료는 WorldClim 자료로부터 얻었다. 모델을 수행한 결과, 자생지 위치자료를 이용한 예측 결과보다 전지구 위치자료를 이용한 예측이 연구 대상종의 잠재적 분포지를 잘 설명하였다. 이들 종의 분포에 기여한 기후환경 요인으로서 돼지풀에서는 최건월의 강수량과 연평균온도가, 물참새피에서는 연평균온도와 최한사분기의 평균온도가 선정되었다. Maxent 종분포 모델은 외래종의 침입을 예측하고 이들의 확산을 관리하는데 유용한 도구가 될 것으로 생각된다.

• 환경영향평가
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• 제21권4호
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• pp.593-607
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• 2012

The Ministry of Environment have started the 'National Ecosystem Survey' since 1986. It has been carried out nationwide every ten years as the largest survey project in Korea. The second one and the third one produced the GIS-based inventory of species. Three survey methods were different from each other. There were few studies for species distribution using national survey data in Korea. The purposes of this study are to test species distribution models for finding the most suitable modeling methods for the National Ecosystem Survey data and to investigate the modeling results according to survey methods and taxonominal group. Occurrence data of nine species were extracted from the National Ecosystem Survey by taxonomical group (plant, mammal, and bird). Plants are Korean winter hazel (Corylopsis coreana), Iris odaesanensis (Iris odaesanensis), and Berchemia (Berchemia berchemiaefolia). Mammals are Korean Goral (Nemorhaedus goral), Marten (Martes flavigula koreana), and Leopard cat (Felis bengalensis). Birds are Black Woodpecker (Dryocopus martius), Eagle Owl (Bubo Bubo), and Common Buzzard (Buteo buteo). Environmental variables consisted of climate, topography, soil and vegetation structure. Two modeling methods (GAM, Maxent) were tested across nine species, and predictive species maps of target species were produced. The results of this study were as follows. Firstly, Maxent showed similar 5 cross-validated AUC with GAM. Maxent is more useful model to develop than GAM because National Ecosystem Survey data has presence-only data. Therefore, Maxent is more useful species distribution model for National Ecosystem Survey data. Secondly, the modeling results between the second and third survey methods showed sometimes different because of each different surveying methods. Therefore, we need to combine two data for producing a reasonable result. Lastly, modeling result showed different predicted distribution pattern by taxonominal group. These results should be considered if we want to develop a species distribution model using the National Ecosystem Survey and apply it to a nationwide biodiversity research.

• 한국환경복원기술학회지
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• 제13권6호
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• pp.161-172
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• 2010

As the interest on biodiversity has increased around the world, researches about evaluating potential for habitat are also increasing to find and comprehend the valuable habitats. This study focus on comprehending the significance of stream in evaluating habitat's potential. The purpose of this study is to evaluate habitat potential with applying stream as a main variable, and to comprehend the relationship between the variables and habitat potential. Basin is a unit that has hydrological properties and dynamic interaction with ecosystem. Especially, biodiversity and suitability of habitat in basin area has direct correlation with stream. Existing studies also are proposing for habitat potential evaluation in basin unit, they applied forest, slope and road as main variables. Despite stream is considered the most important factor in basin area, researchers haven't applied stream as a main variable. Therefore, in this study, three variables that can demonstrate hydrological properties are selected, which are, riparian distance, stream order and land use disturbance, and evaluate habitat potential. Habitat potential is analyzed by using Maxent (Maximum entropy model), and vertebrate's presence data is used as dependent variables and stream order map and land cover map is used as base data of independent variables. As a result of analysis, habitat potential is higher at riparian and upstream area, and lower at frequently disturbed area. Result indicates that adjacent to stream, upstream, and less disturbed area is the habitat that vertebrate prefer. In particular, mammals prefer adjacent area of stream and forest and reptiles prefer upriver area. Birds prefer adjacent area of stream and midstream and amphibians prefer adjacent area of stream and upriver. The result of this research could help to establish habitat conservation strategy around basin unit in the future.

• 한국환경복원기술학회지
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• 제18권1호
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• pp.71-82
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• 2015

Hyla suweonensis is an endemic species and is designated as the only endangered species I among amphibians in 2012 by the Ministry of Environment, however studies about its habitat are lacking. This study was carried out to analyze habitat of H. suweonensis based on the spatial information using Maxent (Maximum entropy model as a species distribution model. We detected 45 present points until 2013 and 10 environmental variables by literature review for the model. The results showed that $429km^2$ (0.95%) of the study area, which was about 7.75% of the total agricultural area, was high possible habitats of H. suweonensis. The habitat of H. suweonensis was analyzed by over $1km^2$ rice paddy fields that were lower elevations, flat slopes, and not fragmented. The distance from forests and rivers was identified as a factor that affects its habitat possibilities. In order to conserve H. suweonensis, a large area of rice paddy fields should be preserved, and especially the area around forests and rivers would be required more intensive management. In addition, to compensate for degraded habitats of H. suweonensis in urban areas like as Suwon city, considering integrated watershed management strategy could be effective in the perspective of ecological habitat network of H. suweonensis.

• 한국임상수의학회지
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• 제36권1호
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• pp.23-29
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• 2019

While research findings suggest that the highly pathogenic avian influenza (HPAI) is the leading cause of economic loss in Korean poultry industry with an estimated cumulative impact of $909 million since 2003, identifying the environmental and anthropogenic risk factors involved remains a challenge. The objective of this study was to identify areas at high risk for potential HPAI outbreaks according to the likelihood of HPAI virus detection in wild birds. This study integrates spatial information regarding HPAI surveillance with relevant demographic and environmental factors collected between 2003 and 2018. The Maximum Entropy (Maxent) species distribution modeling with presence-only data was used to model the spatial risk of HPAI virus. We used historical data on HPAI occurrence in wild birds during the period 2003-2018, collected by the National Quarantine Inspection Agency of Korea. The database contains a total of 1,065 HPAI cases (farms) tied to 168 unique locations for wild birds. Among the environmental variables, the most effective predictors of the potential distribution of HPAI in wild birds were (in order of importance) altitude, number of HPAI outbreaks at farm-level, daily amount of manure processed and number of wild birds migrated into Korea. The area under the receiver operating characteristic curve for the 10 Maxent replicate runs of the model with twelve variables was 0.855 with a standard deviation of 0.012 which indicates that the model performance was excellent. Results revealed that geographic area at risk of HPAI is heterogeneously distributed throughout the country with higher likelihood in the west and coastal areas. The results may help biosecurity authority to design risk-based surveillance and implementation of control interventions optimized for the areas at highest risk of HPAI outbreak potentials.

• 한국환경복원기술학회지
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• 제20권3호
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• pp.55-64
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• 2017

The problem of the population number of honeybees that is decreasing not only domestically but also globally, has a great influence on human beings and the entire ecosystem. The habitat of honeybees is recognized to be superior in urban environment rather than rural environment, and predicting for habitat assessment and conservation is necessary. Based on this, we targeted Cheonan City and neighboring administrative areas where the distribution of agricultural areas, urban areas, and forest areas is displayed equally. In order to predict the habitat preferred by honeybees, we apply the Maxent model what based on the presence information of the species. We also selected 10 environmental variables expected to influence honeybees habitat environment through literature survey. As a result of constructing the species distribution model using the Maxent model, 71.7% of the training data were shown on the AUC(Area Under Cover) basis, and it was be confirmed with an area of 20.73% in the whole target area, based on the 50% probability of presence of honeybees. It was confirmed that the contribution of the variable has influence on land covering, distance from the forest, altitude, aspect. Based on this, the possibility of honeybee's habitat characteristics were confirmed to be higher in wetland environment, in agricultural land, close to forest and lower elevation, southeast and west. The prediction of these habitat environments has significance as a lead research that presents the habitat of honeybees with high conservation value of ecosystems in terms of urban space, and it will be useful for future urban park planning and conservation area selection.

• Journal of Species Research
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• 제12권1호
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• pp.109-113
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• 2023

To build a distribution model for Haemadipsa rjukjuana, we collected current occurrences of the species on Heuksando with adjacent islands. Based on current locations and 19 climate variables with DEM (digital elevation model), we built the MaxEnt (maximum entropy) species distribution model for H. rjukjuana in the islands. Then, we applied the MaxEnt model to the mainland of Korea with the current climate condition and topology. In addition to the current distribution scenario, we predicted the future distribution scenarios in Korea by Coupled Model Intercomparison Project Phase 6 (CMIP6) global climate models. Shared Socioeconomic Pathway (SSP) 585 of two CMIP6 models(GISS-E2-1 and INM-CM4-8) from 2040 to 2100 were used for the future projection.