• Journal of Korean Society of Environmental Engineers
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• v.31 no.8
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• pp.611-618
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• 2009

Road construction has been worked on by focusing on cost effectiveness such as the reduction of construction costs without understanding the natural environment and ecosystems. In addition, since ecosystems have been destroyed and the habitats of animals and plants have been isolated, wild animals have sought other habitats or have moved into isolated habitats. Thus, issues such as roadkills or the extermination of species are increasingly occurring. Based on this background, the development and application of a general assessment method need to be researched in order to verify whether or not spaces or habitats where animals can be inhabited and their species can be maintained exist. The purpose of this study is to develop an ecosystem map where a conservation value evaluation method considering the functions of an ecosystem where animals live as well as the naturalness of ecosystems is used and can be made into a drawing. The items applied to evaluate the habitat conservation values were naturalness, rarity, and functionality, and sub-items for evaluation were created. GIS as well as the evaluation items were used to create a digital map about the level of importance based on the evaluation criteria. The created digital map showed that it was not limited to the adjustment or distribution of the fauna and flora but was applicable for a general ecosystem evaluation method for the conservation of habitats. It is expected that the isolation of habitats would be able to be minimized if the digital map is used for road construction projects. The digital map is deemed to be able to be used for the construction of environmentally friendly roads, which will minimize the destruction of ecosystems and the isolation of habitats for creatures.

• Ecology and Resilient Infrastructure
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• v.7 no.4
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• pp.366-373
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• 2020

This study investigated habitat diversity changes by conducting weir operations at the Sejongbo site in the Geum River basin. High-resolution aerial photographs taken before and after the weir-opening operation were used for habitat analyses. We classified water and bar areas into 17 types, such as lotic habitats, including riffles, runs, and glides, and lentic habitats, including reservoirs, pools, bar-head backwaters, and bar ponds. Then, we estimated each habitat area quantitatively, calculated a habitat diversity index, and established a habitat diversity map. Our results indicated that after the weir-opening operation, lotic habitats and new types of shallow lentic habitats increased in the water area. In addition, for the bar area, bare lands without cultivation increased distinctively. Finally, we observed that the habitat diversity index drastically increased after the weir-opening operation, which could provide a relatively simple channel of diverse habitats.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.7-7
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• 2017

범람파동 개념에 따르면 하도와 홍수터의 횡적 연결성은 하천 생태계의 생물다양성과 생산성 증대에 중요한 역할을 한다. 제방에 의하여 제내지 홍수터가 하도와 차단된 우리나라 하천에서 생태적 서비스를 증대하기 위해서 횡적 연결성을 복원하는 기술 개발이 필요하다. 횡적 연결성의 복원 기술을 개발하기 위해서는 우선 하도와 홍수터 사이에 생태적 연결성의 현황을 파악하고 연결성을 저해하는 요인을 진단하는 평가 기술 개발이 시급히 요청되고 있다. 따라서 본 연구에서는 제방에 의하여 차단된 제내지 하천환경에서 수리적, 생태적 횡적 연결성을 평가하고 진단하는 기술을 개발하고 연결성 회복 방안을 제안하고자 한다. 차단된 제내지 하천환경 평가는 1) 지리정보시스템을 이용하여 차단된 하천공간을 탐색하고, 2) 탐색된 전체 재내지에서 원격평가에 의하여 간편하게 횡적 연결성 평가를 실시하고, 3) 선정된 특정 제내지 대상지에서 현장평가에 의하여 상세하게 연결성을 평가하는 순서로 수행된다. 차단된 하천공간의 획정은 홍수가 범람할 수 있는 제내지 공간을 잠재적 하천공간으로 정의하고 수치표고모델 (DEM)과 하천기본계획의 30년 빈도 홍수위 자료를 이용하여 제내지 홍수터를 탐색하였다. 제내지 홍수터의 원격 연결성평가는 지리정보시스템에서 수치지도와 토지피복도 등 공간자료를 이용하여 수리 및 서식처 환경성, 제방 차단성과 하도 및 육상 연결성을 평가하고 원격평가 결과를 토대로 현장평가 대상지를 선정하였다. 횡적 연결성의 현장평가를 위하여 크게 하도-홍수터 연결성과 제내지 서식처 보존성으로 평가 항목을 선정하였다. 또한 연결성 평가는 수리연결성과 생물연결성으로, 서식처 보존성 평가는 습지유지율, 습지보존성, 육역지보존성을 세부항목으로 구성하였다. 평가 항목별로 5 등급의 평가 기준에 따라서 평가 점수를 부여하고 평가 총점을 산출하여 최종 연결성 평가 등급을 5 단계로 구분하였다. 현장평가를 위한 MS Access 기반 소프트웨어를 개발하여, 데이터 입력과 관리 및 평가 결과 산출과 비교를 편리하게 하였다. 개발된 제내지 하천환경 평가법을 청미천과 만경강에 적용하여 검증하였다. 개발된 평가법을 바탕으로 차단된 제내지 하천환경에서 연결성 회복에 따른 어류와 식생의 분포를 예측하는 수리생태 결합모델을 개발하였다. 먼저 차단된 제내지에서 연결 수로를 복원하여 유속, 수심 분포를 준이차 수리수문 모델로 예측하였다. 예측된 수리 환경에 따라서 지표어종의 서식처 적합도 지수 (HSI)를 이용하여 서식 분포 확률을 모의하였다. 또한 일반화가법모델 (GAM)을 이용하여 환경구배에 의한 우점식생의 분포를 예측하였다. 차단된 제내지 하천환경의 생태적 연계성 평가 기술을 기반으로 제방제거, 제방후퇴, 제방고 하강, 수문 및 연결수로 개선, 생물이동 저해 장벽 제거 등의 다양한 복원기술이 개발되어야 할 것으로 생각된다.

• Ecology and Resilient Infrastructure
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• v.10 no.4
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• pp.135-142
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• 2023

A various technology of remote sensing and image analysis are applied to study landscape changes and their influencing factors in stream corridors. We developed a method to detect landscape changes over time by calculating the optical index using multispectral images taken from satellites at various time points, calculating the threshold to delineate the boundaries of water bodies, and creating binarized maps into land and water areas. This method was applied to the upstream reach of the weirs in the Geumgang River to track changes in the sandbar formed by the opening of the weir gate. First, we collected multispectral images with a resolution of 10 m × 10 m taken from the Sentinel-2 satellite at various times before and after the opening of the dam in the Geumgang River. The normalized difference water index (NDWI) was calculated using the green light and near-infrared bands from the collected images. The Otsu's threshold of NDWI calculated to delineate the boundary of the water body ranged from -0.0573 to 0.1367. The boundary of the water area determined by remote sensing matched the boundary in the actual image. A map binarized into water and land areas was created using NDWI and the Otsu's threshold. According to these results of the developed method, it was estimated that a total of 379.7 ha of new sandbar was formed by opening the three weir floodgates from 2017 to 2021 in the longitudinal range from Baekje Weir to Daecheong Dam on the Geumgang River. The landscape detection method developed in this study is evaluated as a useful method that can obtain objective results with few resources over a wide spatial and temporal range.

• Korean Journal of Environment and Ecology
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• v.30 no.3
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• pp.353-368
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• 2016

This study surveyed the diversity and distributional characteristics of benthic macroinvertebrates and freshwater fish during the period from April to October, 2015 in Seonun Mountain Provincial Park. As a result, a total of 78 species of benthic macroinvertebrates belonging to 50 families, 16 orders, and four phyla were observed in Seonun stream; additionally, 25 species of freshwater fish belonging to six families were identified in all the investigated sites. Among benthic macroinvertebrates, Ephemeroptera(13 spp.: 22.81%) was the largest group in terms of species richness. In the FFGs, gathering-collectors(30 spp.: 36.14%) were relatively larger as represented by Ephemeroptera that usually inhabit fast flowing streams. In the HOGs, clingers(23 spp.: 29.49%) and burrowers(17 spp.: 21.79%) were the dominant groups. For both EPT ratio and ESB index, site 8 appeared to be the highest with 44.44% and 72 marks respectively, while the sites 4 and 9 showed relatively lower rates and indices. According to the results of evaluation, site 8 needs to be designated as the highest protection area while the sites 4 and 9 may be designated as target areas for preferential improvement. According to the analysis of fish community, the dominant species was Zacco teminchkii(333 inds.: 36.80%), and the dominant index was the lowest(0.24) and diversity index was the highest(1.81) at site 8, which therefore represents a stable freshwater fish community. In this survey, six Korean endemic species were identified: Ephemera separigata, Neoperla coreensis, Rhodeus uyekii, Squalidus gracilis majimae, Microphysogobio yaluensis, and Iksookimia koreensis. Also, three species belonging to the management of exportable group(Davidius lunatus, E. separigara, N. coreenis) were observed. Two habitat specific species: Thraulus grandis and Anguilla marmorata, were found for the first time in Gochang area and marked on the Korean distribution map through discussion.

• Korean Journal of Ecology and Environment
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• v.46 no.2
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• pp.215-224
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• 2013

We clarified the background for establishment of vegetation by comparing the spatial distribution maps of vegetation and substrate on a gravel bar in the Bangtae stream located on Inje-gun of Gangwon-do, the central eastern Korea. The total vegetation coverage was higher in the interior and lower in the marginal parts of the gravel bar. Spatial distribution of vegetation on the longitudinal section of the gravel bar tended to be arranged in the order of shrub, subtree, and tree dominated vegetation types from the front (upstream) toward the rear (downstream) parts. Coverage of the herbaceous plants was higher in the central and rear parts and lower in the front and right parts of the gravel bar. Vegetation height was higher in the rear part and became lowered as move toward the front part. Substrate was distributed in the order of boulder, gravel, sand, and boulder from the front toward the rear parts. Ordination of stands based on vegetation data was arranged in the order of annual plant, perennial herb, shrub, and tree dominated vegetation as move from the right to the left parts on the axis I. Species richness was higher in the order of Pinus densiflora community, Phragmites japonica community, Salix gracilistyla community, Fraxinus rhynchophylla community, annual plant dominated vegetation, and Prunus padus for. padus community based on the species rank-abundance curve. The order based on the Shannon's index was some different; diversity of Phragmites japonica community and Salix gracilistyla community, which showed higher dominance degree, were low differently from species richness. In conclusion, it was evaluated that the gravel bar newly established toward the upstream and vegetation dynamics of the gravel bar seemed to follow ecosystem mechanisms of succession. As were shown in the above results, the Bangtae stream corresponded to the upstream and thereby particle size of substrate was big. Therefore, they move by rolling and are accumulated for the upstream. Vegetation types were arranged in the order of woodland, shrub-land and grassland from the rear toward the front parts of the gravel bar and thereby reflected the formation process of the bar. However, the gravel bar is disturbed frequently by not only the running water but also the suspended sand as the dynamic space. Such disturbances cause habitat diversity and consequently led to high biodiversity.