• Title/Summary/Keyword: maxent

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Environmental features of the distribution areas and climate sensitivity assesment of Korean Fir and Khinghan Fir (구상나무와 분비나무분포지의 환경 특성 및 기후변화 민감성 평가)

  • Park, Hyun-Chul;Lee, Jung-Hwan;Lee, Gwan-Gyu;Um, Gi-Jeung
    • Journal of Environmental Impact Assessment
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    • v.24 no.3
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    • pp.260-277
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    • 2015
  • The object of this study was the climate change sensitivity assessment of Korean Fir and Khinghan Fir as a representative subalpine plant in South Korea. Using species distribution models, we predicted the probability of current and future species distribution. According to this study, potential distribution that have been predicted based on the threshold (MTSS) is, Khinghan Fir was higher loss rate than Korean Fir. And in the climate change sensitivity assessment using the scalar sensitivity weight ($W_{is}$), $W_{is}$ of Korean Fir was higher relatively than the sensitivity of Khinghan Fir. When using the species distribution models as shown in this study may vary depending on the probability of presence data and spatial variables. Therefore should be prior decision studies on the ecological environment of the study species. Based on this study, if it is domestic applicable climate change sensitivity assessment method is developed. it would be important decision-making to climate change and biological diversity of adaptation policy.

A study on the characteristics of inhabitation environment of Hydropotes inermis in Daebudo Island, Ansan-si (안산시 대부도 일대의 고라니 서식환경 특성 연구)

  • Nam, Taek-Woo;Park, Seok-Cheol;Han, Bong-Ho
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.23 no.5
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    • pp.45-58
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    • 2020
  • This study was conducted to comprehend the spatial distribution characteristics, habitats and appearances of Hydropotes inermis by using the biotope mapping in Daebudo Island, Ansan-si. The result is base data to understand status and manage potential inhabitation of Hydropotes inermis in Daebudo Island through the Maximum Entropy model. The study used 105 traces from the primary investigation and 452 traces in the secondary investigation. The biotope types were distinquished Hydropotes inermis habitats largest from the order of natural forest (15.1%), natural coast (13.7%), marshy cultivated land (12.6%), and dry cultivated land (11.7%), and from the inhabitation trace results. Hydropotes inermis appearanced biotope types were the greatest in the order of cultivated land (49.73%) > forest (18.85%) > coast (7.00%) > grassland (6.28%). Since forests in Daebudo Island have low slope and altitude, it was concluded that Hydropotes inermis would live in most of the forests. A high number of Hydropotes inermis was found to appear in areas where the grassland is formed including cultivated lands (include unused paddies and fields) and marshy grasslands, which would result in direct damage of crops. According to the Maxent modeling analysis that used location information of Hydropotes inermis, the AUC value was 0.635 based on the ROC curve. In Daebudo Island, areas with over 0.635 potential inhabitation value are distributed all over the place, and it was concluded that each population would have a different scope of influence and home range. Hydropotes inermis living in Daebudo Island have high habitat suitability mainly around the cultivated lands near the roads, but due to the bare lands and roads, it is expected that their habitats would be fragmented and damaged, which would have a direct and indirect effect in maintaining the Hydropotes inermis population. Also, considering habitat disturbance, diverse methods for reducing damage including capturing some individuals within the limit that does not disperse Hydropotes inermis population in Daebudo Island must be carried out.

Exploring Spatial Distribution of Empty Houses and Vacant Land Due to Population Decrease in Mokpo (인구 감소 현상에 따른 목포시 빈집 및 공지의 공간적 분포 전망)

  • Jo, Young-Woo;Choi, You-Bin;Park, Chan
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.23 no.2
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    • pp.33-47
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    • 2020
  • With population losses and stagnant or depressed economies, the local governments embrace shrinkage and accept having a significantly smaller population. Both the initial and ongoing causes of shrinkage hold dramatic effects on the city and its remaining residents. In this context, vacant land increases as an overabundance of unused infrastructure is demolished and municipalities become burdened with increasing maintenance costs of this land. The result is that vacant land often experiences minimal management relative to social norms and have chance to provide a setting for ecological processes with urban rightsizing strategy. Therefore, urban ecosystems undergo major shifts in structure and function. We need to better understand the possibilities of where and how much of houses and land will be abandoned to assist land planners and policymakers to mitigate conflict between optimal ecological and sociological outcomes. This article, therefore, aims to identify distributional characteristics of vacant houses and lands with case study of Mokpo. The study found and verified affecting factors of vacant houses and lands by type through the use of a Maxent model and spatial data that explained housing choice and preference theory. We can predict the vacancies with the spatial variables such as land price, the population ratio over 65, and the distance from security facility. Based on the analysis, the ways of managing housing and land vacancy for sustainable development and ecological restoration method are discussed.

Anticipation of the Future Suitable Cultivation Areas for Korean Pines in Korean Peninsula with Climate Change (기후변화를 고려한 잣나무의 미래 적지적수 변화 예측)

  • Choi, Jaeyong;Lee, Peter Sang-Hoon;Lee, Sanghyuk
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.1
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    • pp.103-113
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    • 2015
  • Korean pines(Pinus koraiensis) are one of the major plantation species in the Republic of Korea and their natural habitats range from Japan and China to Siberia. The seed of Korean pines, pine nuts, are well know for good food reserves. Due to the global changes which drive the Korean peninsula into the semi-tropical climate, current plantations and natural habitats of Korean pines are faced with the change in the environmental conditions to some extent. To anticipate suitable sites for Korean pines in the future, the location of Korean pines were extracted from the 'Map of suitable trees on a site' that provides the map of suitable trees on a site considering tree species for timber and special uses, and then MaxEnt modelling was used for generating a prediction map on the basis of statistical analysis. As a result, the order of predicted suitable sites were Kangwon-do, Kyungsangbuk-do and Chungcheongbuk-do provinces and sites with high elevation within those provinces were considered most suitable in common. The prediction map of suitable sites for Korean pines presented that suitable sites in the future decreased by 72.2% by 2050's and almost disappeared with a decrease of 92.1% by 2070's on a nationwide scale. In relation to the major production regions of pine nuts in South Korea - Gapyung gun and Yangpyung gun, Kyunggi province and Hongcheon gun, Kangwon province, suitable sites within their areas were predicted to increase by 2050's but become extinct in South Korea by 2070's. To establish a long-term countermeasures against the improvement on forest productivity quality in terms of managing national food security, the result from this study can be considered as a firm basis of predicting plantation suitability. Also, it can be used to predict the changes in supply of forest products and thereby market values in accordance with climate change scenarios.

Prediction of potential spread areas of African swine fever virus through wild boars using Maxent model

  • Lim, Sang Jin;Namgung, Hun;Kim, Nam Hyung;Oh, Yeonsu;Park, Yung Chul
    • Journal of Ecology and Environment
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    • v.46 no.1
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    • pp.54-61
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    • 2022
  • Background: In South Korea, African swine fever virus (ASFV) has spread among wild boars through Gangwon-do to Dangyang-gun, Chungcheongbuk-do on the southern border of Gangwon-do. To prevent the spread of ASFV to African swine fever (ASF)-free areas, it is necessary to identify areas with a high probability of finding ASFV-infected carcasses and to reduce the density of wild boars in those areas. In this study, we described the propagation trend of ASFV among wild boars, constructed the habitat suitability maps for ASFV-infected carcasses, and suggested areas with a high probability of finding ASFV-infected carcasses and an important route of ASFV transmission. Results: Despite the active quarantine policies in Korea to prevent the spread of ASFV through wild boars, there was no significant difference in the monthly average of number of ASFV-infected carcasses observed between 2020 and 2021. The ASFV-infected carcasses were found more in winter and spring (January to April). Since the first ASF outbreak in wild boars on October 2, 2019, the maximum width of ASFV-infected carcass distribution area was 222.7 km for about 26 months till November 20, 2021. The habitat suitability map, based on GPS coordinates of ASFV-infected wild boar carcasses, shows that highly detectable areas of ASFV-infected carcasses were sporadically dispersed in western and southwestern parts of Gangwon-do, and ranged from north to south of the province along the Baekdudaegan Mountains, whereas poorly detectable areas ranged along the north to the south in the middle parts of the province. Conclusions: Our suitability model, based on the GPS coordinates of ASFV-infected carcasses, identifies potential habitats where ASFV-infected carcasses are likely to be found and ponential routes where ASFV is likely to spread. Among ASF-free areas, the areas with high suitability predicted in this study should be given priority as survey areas to find ASFV-infected carcasses and hunting areas to reduce wild boar populations.

Predicting change of suitable plantation of Schisandra chinensis with ensemble of climate change scenario (기후변화 시나리오 앙상블을 통한 오미자의 재배적지 변화 예측)

  • Lee, Sol Ae;Lee, Sang-Hyuk;Ji, Seung-Yong;Choi, Jaeyong
    • Journal of Environmental Impact Assessment
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    • v.25 no.1
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    • pp.77-87
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    • 2016
  • Predicting possible distributed area of Schisandra chinensis which has long term cultivation period among non-timber forest products is needed to be studied to deal with climate change. Hence, distribution of Schisandra chinensis in the 2050s and 2070s was predicted under two scenario, RCP 4.5 and RCP 8.5, with ensemble of 5 climate models used in IPCC AR5. According to estimation using RCP 4.5, distribution of Schisandra chinensis in 2050s appeared to decrease 43% of current area and appeared to decrease 57% in 2070s respectively. Moreover, According to estimation using RCP 8.5, distribution of Schisandra chinensis in 2050s appeared to decrease 55% of current area and appeared to decrease 85% in 2070s. As a final outcome, Schisandra chinensis was estimated to extinct in the future except Gangwon-do and Gyeongsangbuk-do when analyzing change between current distributed area and future distributed area. As a result, those areas were classified as vulnerable areas to climate change. Therefore, Gangwon-do and Gyeongsangbuk-do were thought to be ideal for growing Schisandra chinensis. The result from this study can be used to provide basic information for selecting proper area of Schisandra chinensis considering climate change effect.

Predicting the Potential Habitat and Risk Assessment of Amaranthus patulus using MaxEnt (Maxent를 활용한 가는털비름(Amaranthus patulus)의 잠재서식지 예측 및 위험도 평가)

  • Lee, Yong Ho;Na, Chea Sun;Hong, Sun Hea;Sohn, Soo In;Kim, Chang Suk;Lee, In Yong;Oh, Young Ju
    • Korean Journal of Environmental Biology
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    • v.36 no.4
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    • pp.672-679
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    • 2018
  • This study was conducted to predict the potential distribution and risk of invasive alien plant, Amaranthus patulus, in an agricultural area of South Korea. We collected 254 presence localities of A. patulus using field survey and literature search and stimulated the potential distribution area of A. patulus using maximum entropy modeling (MaxEnt) with six climatic variables. Two different kinds of agricultural risk index, raster risk index and regional risk index, were estimated. The 'raster risk index' was calculated by multiplying the potential distribution by the field area in $1{\times}1km$ and 'regional risk index' was calculated by multiplying the potential distribution by field area proportion in the total field of South Korea. The predicted potential distribution of A. patulus was almost matched with actual presence data. The annual mean temperature had the highest contribution for distribution modeling of A. patulus. Area under curve (AUC) value of the model was 0.711. The highest regions were Gwangju for potential distribution, Jeju for 'raster risk index' and Gyeongbuk for 'regional risk index'. This different ranks among the index showed the importance about the development of various risk index for evaluating invasive plant risk.

Prediction of Potential Habitat and Damage Amount of Rare·Endemic Plants (Sophora Koreensis Nakai) Using NBR and MaxEnt Model Analysis - For the Forest Fire Area of Bibongsan (Mt.) in Yanggu - (NBR과 MaxEnt 모델 분석을 활용한 희귀특산식물(개느삼) 분포 및 피해량 예측 - 양구 비봉산 산불피해지를 대상으로-)

  • Yun, Ho-Geun;Lee, Jong-Won;An, Jong-Bin;Yu, Seung-Bong;Bak, Gi-Ppeum;Shin, Hyun-Tak;Park, Wan-Geun;Kim, Sang-Jun
    • Korean Journal of Plant Resources
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    • v.35 no.2
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    • pp.169-182
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    • 2022
  • This study was conducted to predict the distribution of rare·endemic plants (Sophora koreensis Nakai) in the border forests where wildfire damage occurred and to quantify the damage. For this purpose, we tried to derive more accurate results through forest area damage (NBR) according to the Burn severity of wildfires, damage by tree species type (Vegetation map), and MaxEnt model. For Burn severity analysis, satellite imagery (Landsat-8) was used to analyze Burn severity (ΔNBR2016-2015) and to derive the extent of damage. To prepare the Vegetation map, the land cover map prepared by the Ministry of Environment, the Vegetation map prepared by the Korea Forest Service, and the vegetation survey conducted by itself were conducted to prepare the clinical map before and after the forest fire. Lastly, for MaxEnt model analysis, the AUC value was derived by using the habitat coordinates of Sophora koreensis Nakai based on the related literature and self-report data. As a result of combining the Maxent model analysis data with the Burn severity data, it was confirmed that 45.9% of the 44,760 m2 of habitat (predicted) area of Sophora koreensis Nakai in the wildfire damaged area or 20,552 m2, was damaged.

A study on the range of native seed habitat analysis using Seedzones and MaxEnt (잠정종자이동구역과 종분포모형을 이용한 자생 종자 분포 범위 연구)

  • Kim, Chae-Young;Kim, Whee-Moon;Song, Won-Kyong;Choi, Jaeyong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.25 no.1
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    • pp.57-74
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    • 2022
  • Seed zones were constructed using temperature and precipitation data for the Korean Peninsula and were described as 65 zones. Seed zones for South Korea were reclassified, and they were classified into 34 districts. This study was conducted to define the spread of 5 native seed species (Pinus densiflora, Quercus acutissima, Quercus variabilis, Acer pictum, Carpinus tschonoskii) by linking the seed zones with MaxEnt. The emergence point of native seeds was acquired through the 1:5,000 Forest Type Map and the 4th national natural environment survey data. Based on the MaxEnt result, regions with a habitat probability of 0.5 or more were extracted and overlapped with seed zones to identify the native seed habitat. After analyzing the climate regions with high habitat density, regions with high habitat density of native seeds for each administrative district were identified. In the case of Pinus densiflora, Quercus acutissima, and Quercus variabilis, the Winter minimum temperature(WMT) -9.4~-6.6℃, Annual Heat:Moisture(AH:M) 19~24℃/m was 37%, 43%, and 34%, respectively. occupied the largest area. In Acer pictum, WMT -6.6~-3.8℃ and AH:M 16~19℃/m accounted for 42% of the area, and Carpinus tschonoskii had WMT -3.8~-1.1℃, AH:M <16℃/m Districts accounted for the largest area at 33%. The regions with high density of Pinus densiflora, Quercus acutissima, and Quercus variabilis by administrative district were distributed in high density in Seoul, Southern Gyeonggi-do, Chungcheong-do, and Gyeongsangbuk-do. Acer pictum was distributed in high density in Jeolla-do and Gyeongsang-do, and Carpinus tschonoskii in Jeju, Jeollanam-do and Gyeongsangnam-do. Through this study, seed zones for each of the 5 native seeds were established, and it is expected to provide basic data for the management of native seeds.

Spatial Distribution Patterns and Prediction of Hotspot Area for Endangered Herpetofauna Species in Korea (국내 멸종위기양서·파충류의 공간적 분포형태와 주요 분포지역 예측에 대한 연구)

  • Do, Min Seock;Lee, Jin-Won;Jang, Hoan-Jin;Kim, Dae-In;Park, Jinwoo;Yoo, Jeong-Chil
    • Korean Journal of Environment and Ecology
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    • v.31 no.4
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    • pp.381-396
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    • 2017
  • Understanding species distribution plays an important role in conservation as well as evolutionary biology. In this study, we applied a species distribution model to predict hotspot areas and habitat characteristics for endangered herpetofauna species in South Korea: the Korean Crevice Salamander (Karsenia koreana), Suweon-tree frog (Hyla suweonensis), Gold-spotted pond frog (Pelophylax chosenicus), Narrow-mouthed toad (Kaloula borealis), Korean ratsnake (Elaphe schrenckii), Mongolian racerunner (Eremias argus), Reeve's turtle (Mauremys reevesii) and Soft-shelled turtle (Pelodiscus sinensis). The Kori salamander (Hynobius yangi) and Black-headed snake (Sibynophis chinensis) were excluded from the analysis due to insufficient sample size. The results showed that the altitude was the most important environmental variable for their distribution, and the altitude at which these species were distributed correlated with the climate of that region. The predicted distribution area derived from the species distribution modelling adequately reflected the observation site used in this study as well as those reported in preceding studies. The average AUC value of the eigh species was relatively high ($0.845{\pm}0.08$), while the average omission rate value was relatively low ($0.087{\pm}0.01$). Therefore, the species overlaying model created for the endangered species is considered successful. When merging the distribution models, it was shown that five species shared their habitats in the coastal areas of Gyeonggi-do and Chungcheongnam-do, which are the western regions of the Korean Peninsula. Therefore, we suggest that protection should be a high priority in these area, and our overall results may serve as essential and fundamental data for the conservation of endangered amphibian and reptiles in Korea.