• Title/Summary/Keyword: aquatic habitat

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An Analysis of Ecological Habitat Characteristics in Medium-scale Stream -A Case of the Bokha Stream- (중규모 하천 생물 서식처의 특성 분석 -복하천을 중심으로-)

  • 안홍규;우효섭
    • Journal of the Korean Institute of Landscape Architecture
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    • v.32 no.2
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    • pp.102-119
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    • 2004
  • This study investigates the relation between the location of a habitat and the ecological connections according to the habitat type in the riparian zone at the Bokha stream. Stream habitat is classified into nine types for the aquatic insects and fish. For vegetation and birds, habitat is classified into five types of medium-scale streams, including both physical and chemical streams are analyzed accordingly. The major results of this study are as follows: 1) A pool connected to the main stream has a certain water depth (about 80 cm) and is disturbed at least 5 to 6 times a year. Although the pool has a somewhat bad water quality, it provides a habitat for various types of young fish. 2) A meander riffle is about 15 cm deep, the flow velocity in the region is about 75 cm/s. This region does not have large structures to which aquatic insects can attach, so it cannot be used as a spawning ground. 3) A rock type pool is about 60 cm deep, the flow velocity in the meander riffle is about 25 cm/s. In this region, many aquatic insects attached to large structures appear. Due to various riparian vegetation, the rock type pool is used as a habitat for aquatic insects. 4) A pool which is only connected to the main stream during floods has a bad water quality. Despite of its relatively small size, it has a high population density of aquatic insects. faculty.

A study on historical changes of landforms and habitat structures in the mid-stream of the Mangyeong River by weirs (보 설치로 인한 만경강 중류의 하천지형과 서식처 구조 변화에 관한 연구)

  • Choi, Mikyoung;Kim, Ji-sung;Ock, Giyoung;Jung, Kwansue
    • Journal of Korea Water Resources Association
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    • v.52 no.spc2
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    • pp.791-799
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    • 2019
  • This study explained the historical changes in the habitat structures based on the aerial photographs (1948, 1967, 1973, 1989 and 2010) of the mid-stream reach of the Mangyeong River. The habitat structure was divided into landforms and aquatic habitats. The landform was classified into bare land, vegetated land, water surface, farmland and artificial land. The aquatic habitat was classified into natural riffle, artificial riffle, run, head wando, tail wando, mid wando, pond and chute channel. The ratio of bareland decreased, and water surface and vegetated land increased after the excavation in 1970s and since the construction of weir in 1980s. As historical changes of aquatic habitat, ratio of run decreased sharply while mid wando increased sharply. aquatic habitats such as head wando, tail wando, and pond located on bars decreased dramatically.

A Study on the Habitat Restoration Model for Chinemys reevesii (남생이 서식처 복원을 위한 서식처 모형 연구)

  • Kim, Su-Ryeon;Lee, Ji-Hyun;Song, Jae-Young;Chang, Min-Ho;Sung, Hyun-Chan;Cho, Dong-Gil
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.16 no.2
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    • pp.115-125
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    • 2013
  • In this research, a habitat model for Chinemys reevesii is suggested based on the components and variables of the Habitat Suitability Index which was determined through a series of literature researches, site surveys, and behavioral analysis. After reviewing the general habitat requirements, the site surveys(9 reservoirs) from July to December 2010, and the behavioral analysis of five Chinemys reevesii, the relationship between the behavioral and habitat use pattern was evaluated. According to the site surveys and behavioral analysis, the ecological core area(FK 50%) was about 0.96ha on average, the influence area(FK 90%) 4.22ha, and the home range was about $37.75{\pm}17.26m$ on average. As for the habitat use pattern of Chinemys reevesii, it travels through canals, and is influenced by the surrounding land uses. Also when there is a lack of food, the home range increases, and during hibernation, Chinemys reevesii prefers to be in an area within 1~2m range of water shores of fine textured soil and aquatic plants. After analyzing the information, the HSI standard was set and its components were determined as food, sunbathing and cover, aquatic environment, and spatial relationships. And the variables and the ranges of the components was determined as aquatic plant cover(0~49.81%), sandy area($3{\sim}13m^2$) and water velocity(0~60cm/s) etc. Lastly, plans and sections of the habitat model is provided designed according to the information from the researches, and problems to consider during habitat restoration was suggested in order to help understand about Chinemys reevesii habitat.

A Case Study of the Aquatic Habitat Changes due to Weir Gate Operation (보 수문 운영에 따른 수생 서식처 변화 연구)

  • Choi, Byungwoong;Lee, Namjoo
    • Ecology and Resilient Infrastructure
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    • v.7 no.4
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    • pp.300-307
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    • 2020
  • This study was conducted to evaluate the impact of weir gate operation in aquatic fish habitats through a physical habitat simulation of Geum River, Korea. The target species was Zacco platypus, which is a dominant species in the study area. The River2D model was used to compute the flow, and the habitat suitability index model was used to estimate the quality and quantity of the habitat using a habitat suitability curve. An unopened case and a partially opened case were investigated to assess the impact of weir gate operation on the aquatic fish habitat. The simulation results showed that the aquatic habitats of the target species in the partially opened case improved significantly, compared to the case without a gate opening. Furthermore, the weighted usable area increased by a factor of approximately 13, owing to weir gate operation in the study area.

Impacts of Aquatic and Riparian Environmental Factors on Eurasian Otter (Lutra lutra) Presence Characteristics in the Nakdong River Basin (낙동강 권역의 하천 수면공간 및 수변환경이 수달의 출현에 미치는 영향분석)

  • Shin, Geehoon;Rho, Paikho
    • Journal of Environmental Science International
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    • v.26 no.12
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    • pp.1341-1353
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    • 2017
  • This study aimed to identify the aquatic and riparian factors associated with the presence/absence of the Eurasian otter in the Nakdong river basin, where the species is relatively more abundant than other otter species. Environmental factors and presence records were collected. Geographical Information System technology and chi-square test were used to compare environmental gradients in aquatic and riparian factors between presence and absence sites. Aquatic habitat attributes were evaluated with natural riverside sandbars and channel crossing artificial structures, the ratio of channel width to alluvial plain width, riverbed substrate, and flow diversity. Riverbank characteristics, bank materials, man-made embankment types, and land use/land cover of inland and riverside areas were selected as riparian habitat attributes. Compared to the aquatic attributes, riparian attributes were highly significant when assessing otter presence and absence sites, suggesting that conservation of suitable riparian areas to provide maternity and resting areas for otter species is essential in the Nakdong river basin. None of the aquatic attributes examined were statistically significant when evaluating otter presence or absence. These results indicate that the presence of suitable riparian area for resting and reproduction habitats is more critical to the presence of Eurasian otter than food availability in aquatic areas. To inform implementation of effective conservation actions, broad-scale factors, such as watershed attributes, would be needed to further assess habitat conditions of the Eurasian otter.

CLASSIFICATION OF AQUATIC AREAS FOR NATURAL AND MODIFIED RIVERS

  • Cheong, Tae-Sung;Seo, Il-Won
    • Water Engineering Research
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    • v.2 no.1
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    • pp.33-48
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    • 2001
  • For the design of suitable aquatic habitats and habitat management purposes, sensitive descriptors for aquatic areas were identified and analyzed. The classification system of the aquatic areas were developed for natural streams and modified streams in Korea. Relationships among the descriptors of an aquatic area such as channel width, meander wave length, and arc angle have been defined. The analysis indicates that the total mean sinuosity is 1.25 for the main channels of natural streams, whereas the mean value of the sinuosity of modified streams is 1.14. The mean values of the total area, the width, and the length for the sandbars of natural streams are larger than those of modified streams.

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Site Assessment Using Habitat Suitability Index for Manila Clam Ruditapes philippinarum in Geunso Bay Tidal Flats (서식지 적합지수를 이용한 근소만 갯벌 바지락(Ruditapes philippinarum)의 어장적지평가)

  • Choi, Yong-Hyeon;Hong, SokJin;Jeon, Seung-Ryul;Cho, Yoon-Sik
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.52 no.5
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    • pp.511-518
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    • 2019
  • Evaluating the habitat suitability of potential aquaculture sites for cultured species is critical to the sustainable use of tidal flats. This study evaluated the habitat suitability index (HSI) of 12 sites in a tidal flat aquaculture farm at Geunso Bay, Taean, in June 2016. The parameters used to model the suitability index were Growth (water temperature, chlorophyll ${\alpha}$, hydrodynamics), Survival (sediment-sand, mean size, air exposure), and Environment (DO, salinity). The HSI was calculated using weighted and No weighted geometric means. The results showed high habitat suitability at the bay's entrance (HIS; No weighted, 0.60-0.70; weighted, 0.60). Hydrodynamics, air exposure, sediment-sand and mean size are thought to have a significant impact on habitat selection by Manila clams Ruditapes philippinarum. This study explored the optimum habitat for Manila clams by calculating the HSI, providing basic data for tidal flat management.

Health Assessment of Aquatic Ecosystem for Wonju Stream Using the Composition of Aquatic Insects (수서곤충을 이용한 원주천 수서생태계 건강도 평가)

  • Choi, Jun-Kil;Shin, Hyun-Seon;Mitamura, Osamu;Kim, Sook-Jung
    • Korean Journal of Environment and Ecology
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    • v.22 no.5
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    • pp.544-550
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    • 2008
  • This study conducted a survey on the ecosystem of Wonju stream from May until November in 2004 and made an health assessment of Wonju stream using family biotic indices(FBI) and physical habitat assessment(PHA) of the aquatic insects. Through this survey, aquatic insects covering 8 orders, 37 families, 62 genuses, and 92 species were observed at 9 stations along Wonju stream. In terms of family biotic indices, it was confirmed that station 1,2 and 3 were maintaining the healthiest stream ecosystem with the value ranging from 4.55 to 4.82. In addition, station 2 was found to have the best habitat environment in the correlation between physical habitat assessment and family biotic indices with its value of 100 and 4.82, respectively. However, station 7 and 9 showed the lowest habitat environment with the value of 45, 6.17 and 45, 6.97, respectively. posing the need for improvement in PHA; further, station 7 and 9 showed inverted correlationship between PHA and FBI.

Application of Habitat Suitability Models for Assessing Climate Change Effects on Fish Distribution (어류 분포에 미치는 기후변화 영향 평가를 위한 서식적합성 모형 적용)

  • Shim, Taeyong;Bae, Eunhye;Jung, Jinho
    • Ecology and Resilient Infrastructure
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    • v.3 no.2
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    • pp.134-142
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    • 2016
  • Temperature increase and precipitation changes caused by change alter aquatic environments including water quantity and quality that eventually affects the habitat of aquatic organisms. Such changes in habitat lead to changes in habitat suitability of the organisms, which eventually determines species distribution. Therefore, conventional habitat suitability models were investigated to evaluate habitat suitability changes of freshwater fish cause by change. Habitat suitability models can be divided into habitat-hydraulic (PHABSIM, CCHE2D, CASiMiR, RHABSIM, RHYHABSIM, and River2D) and habitat-physiologic (CLIMEX) models. Habitat-hydraulic models use hydraulic variables (velocity, depth, substrate) to assess habitat suitability, but lack the ability to evaluate the effect of water quality, including temperature. On the contrary, CLIMEX evaluates the physiological response against climatic variables, but lacks the ability to interpret the effects of physical habitat (hydraulic variables). A new concept of ecological habitat suitability modeling (EHSM) is proposed to overcome such limitations by combining the habitat-hydraulic model (PHABSIM) and the habitat-physiologic model (CLIMEX), which is able to evaluate the effect of more environmental variables than each conventional model. This model is expected to predict fish habitat suitability according to climate change more accurately.

Macroinvertebrate Community Structure along Environmental Conditions in Ponds of Urban Parks, Korea

  • Kim, Myoung-Chul;Chun, Dong-Jun;Ro, Tae-Ho
    • Korean Journal of Ecology and Environment
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    • v.41 no.2
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    • pp.198-205
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    • 2008
  • Benthic macroinvertebrates were examined to elucidate community structures of a set of 9 shallow ponds from a total of 6 parks located in Seoul metropolitan area, Korea. The result showed that macroinvertebrates were diverse and abundant, and aquatic macrophyte provide habitat diversities in ponds. The differences among benthic macroinvertebrate community compositions seemed to be attributed to local biotic and abiotic interactions. We surveyed benthic macroinvertebrate, biotic (macrophyte), abiotic (turbidity, nutrient concentrations, conductivity, heavy metal concentration) and morphometric (area, depth) of the lentic systems. Generally, the benthic macroinvertebrates were dominated by Cloeon dipterum or Coenagrion sp.. Distribution of the aquatic macrophyte community was correlated with the species composition of macroinvertebrates. The result demonstrated a significant and positive relationship between habitat quality and macroinvertebrate composition.