• Journal of Korea Water Resources Association
• /
• v.53 no.10
• /
• pp.833-843
• /
• 2020

Ecohydraulics is a newly born discipline in the early 1990s by the interdisciplinary approach combined with aquatic ecology in one discipline and geomorphology, hydrology, and fluid hydrodynamics in another. Major areas of ecohydraulics can be delineated as habitat hydraulics (including environmental flow), vegetation hydraulics, eco-corridor hydraulics, eutrophication hydraulics, and ecological restoration hydraulics. Reviews of relevant international journals and literature reveal that ecohydraulics has remained in the limited areas of fish response, hydraulic modeling, and physical habitat response. It has not reached a truly interdisciplinary stage. Literature reviews in Korea reveal that only 3% of the total number of the papers listed in the Journal of KWRA during the last 24 years is related to ecohydraulics. It is about 20% of the total listed in the Journal of Ecology and Resilient Infrastructure. Most of those related to ecohydraulics in Korea concern vegetation hydraulics, habitat hydraulics, and ecological restoration hydraulics. In contrast, dynamic flow modeling areas, including turbulence, fauna motion simulation, and eutrophication hydraulics, are not found. Areas of further research in ecohydraulics in Korea may be specified as follows: 1) environmental flows adapted to the traits of the rivers in Korea, 2) development of the dynamic floodplain vegetation models (DFVM) to assess the changes from the white river to green river, 3) development of the eutrophication hydraulic model to predict the freshwater algal blooms, and 4) development of the models to evaluate the physical, chemical, and biological impacts of the stream restoration, decommissioning and removal of old weirs or small dams.

• Journal of Environmental Impact Assessment
• /
• v.21 no.5
• /
• pp.683-693
• /
• 2012

The urban waterfront well created, could provide mental stability and comfort and also foster personality. In addition it could provide the calmness and rest of mind. Especially, recently the urban waterfronts are restored here and there and are created whenever developing a new town The purpose of this study is to develop a method of calculating the weight of each evaluation criterion for deciding the priority of restoration among for deciding the priority of restoration among the urban waterfronts. The method includes the analytic hierarchy process that can calculate the reasonable weight of each evaluation criterion, because the importance (weights) of evaluation criteria appears to be different among the evaluators; the results of this study can be summarized as that this method can be useful for calculating the weights of evaluation criteria, and also that the superiority of ecological resources is the most important factor (highest weight) in selecting the best waterfront, followed by accessibility, tourism vacation, and proximity to parks. And then the lowest factor in importance is the scale of reservoir.

• Journal of People, Plants, and Environment
• /
• v.23 no.3
• /
• pp.293-304
• /
• 2020

Background and objective: This study was carried out to assess the relationship between the internal and external environments and the ecological items in five sites with a high level of artificial use intensity prior to the establishment of Geumgang River riparian ecological belts. Methods: The sites were classified into forest type, cultivated land type and urbanized type in accordance with their respective locational types. Ecological items including plant ecology such as proportion, naturalization index and urbanization index of native species were analyzed and animal ecology such as the number of species and population of wild birds, amphibians and reptiles, mammals, and butterflies and dragonflies, which are indicator insects, were investigated. In addition, species diversity indices of wild birds, butterflies and dragonflies found in all the subject lands were computed. Results: Among the plant ecological items, the ratio of native species in the forest type was higher than 90%, which was a satisfactory level, while the naturalization and urbanization indices were less than 10%. The number of species in the animal ecological characteristics was reduced in the order of forest type, cultivated land type and urbanized type. As the results of correlation analysis, the internal area of the planted area showed a negative correlation with the total of individuals. The area of grasslands showed a positive correlation with the number of dragonfly species and the total number of individuals, thereby illustrating that wet grasslands have positive effects. The area of surrounding forests, as an external environment, had a negative correlation with the urbanization index (UI) but a positive correlation with the inhabitation of butterflies and the total number of species. Conclusion: The results confirmed the need for more diversified special compositions including planted land, grassland, wetland, bodies of water and waterways within the subject land in the wetland ecological belt along with the need for surrounding forest location and preservation from the perspective of purchase and restoration of land for enhancement of wider biodiversity in the future.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.15 no.4
• /
• pp.61-80
• /
• 2012

This study is to offer the basic data for restoration and conservation of wetland ecosystem by surveying and analysing the flora distributed in the Binae marsh, Namhan River, Chungju-si. The flora in the Binae marsh were verified 204 taxa including 48 families, 152 genera, 179 species, 23 varieties and 2 forms. In flora, pteridophyta were 2 taxa including 1 family, 1 genus and 2 species, among angiospermae, dicotyledonae were 153 taxa including 37 families, 110 genera, 138 species, 13 varieties and 2 forms and monocotyledonae were 49 taxa including 10 families, 41 genera, 39 species and 10 varieties. In the result of classifying the life form of flora, megaphanerophytes (M), nanophanerophytes (N) and chamaiphytes (Ch) were each 9 taxa (4.4%), 37 taxa (18.1%) of hemicryptophytes (H), 19 taxa (9.3%) of geophytes (G), 97 taxa (47.6%) of therophytes (Th) and 24 taxa (11.8%) of hydrophytes (HH). The rare plant designated by Korea Forest Service was 1 taxa (Aristolochia contorta), and the endemic plant was 1 taxa (Salix koriyanagi) too. The specific plants by floristic region were 6 taxa. From among these, the species of degree I were 5 taxa including Salix chaenomeloides, Aristolochia contorta, Artemisia selengensis, Cirsium pendulum and Vallisneria natans, and degree III was 1 taxa including Alisma orientale. The naturalized plants were 45 taxa and the invasive alien plants were 3 taxa including Sicyos angulatus, Ambrosia artemisiifolia and Ambrosia trifida. The naturalized index (NI) was about 22.1%, 16.1% of urbanized index (UI) and 27.3% of disturbed index (DI). The extinct species by construction were 17 taxa including Persicaria sagittata, Typha orientalis, Zizania latifolia and so forth. The new-occured species were 14 taxa including Brassica juncea, Thlaspi arvense, Carduus crispus and so forth. The important species among the extinct species were Aristolochia contorta, Alisma orientale and Vallisneria natans.

• Korean Journal of Ecology and Environment
• /
• v.53 no.1
• /
• pp.1-10
• /
• 2020

The Stream/River Ecosystem Survey and Health Assessment has been carried out regarding the ecological health of the streams by the Ministry of Environment (MOE), South Korea. However, the sources of impairment of the stream ecosystem and the interactions between the sources, stressors, and the responses of impaired streams have not been taken into consideration. The purpose of this study is to propose the establishment of diagnosis systems for the impaired stream ecosystem because of the need to incorporate the same in the making of the policy to enable the recovery and improvement of the health of the impaired streams or river ecosystem. First, we define the concept of a diagnosis of the impaired stream or river ecosystem through a literature review. Second, through case studies [e.g., US CADDIS (Causal Analysis/Diagnosis Decision Information System), AUS. Eco Evidence, EU WFD (Water Framework Directive)], we try to develop the diagnosis system for the making of policy. In this study, the diagnosis system that is proposed consists of eight steps including the basic data collection, detecting or suspecting impairment, defining the impaired stream reach, identifying the biological impaired cases and listing the candidate causes, illustrating the interactive conceptual diagrams between stressors and responses, investigating the stressors-responses in the field, verifying causes and identifying the probable causes of the impaired cases, and summarizing and proposing the restoration of the streams. The results of this study will support and enable efficient decision-making for sustainable stream restoration and management based on the diagnosis of the probable causes for the impaired complex and the diverse stream ecosystem.

• Journal of Environmental Impact Assessment
• /
• v.20 no.6
• /
• pp.845-856
• /
• 2011

In order to establish fundamental data for stream restoration and environmental flow, we investigated inhabitation and species diversity of fish to substrate size in the typical streams of Geum River Basin. Field monitoring including fish sampling was conducted from October 2007 to October 2009. Substrate size was determined according to six different : silt (Si), sand (Sa), fine gravel (Fg), coarse gravel (Cg), cobbles (Co) and boulders (Bo). A total number of fish caught in the 18 sites was 7,649 representing 10 families 50 species, and Si, Sa, Fg, Cg, Co and Bo stations occupied 30, 29, 38, 30, 27 and 17 species, respectively. The most frequently found species in number was pale chum (Zacco platypus, 29.7%, n=2,275) followed by Z. koreanus (22.5%, n=1,720) in total stations. Biological diversity with increase of substrate size from the dominance of part species showed higher values as dominance index, lower and diversity, richness and evenness index. Index of biological integrity (IBI) and qualitative habitat evaluation index (QHEI) scores decreased with increase of substrate size. Therefore, it is necessary to make an effort on stream rehabilitation with evaluation of physical habitat condition by indicator species in order to maintain biodiversity and perform ecological restoration.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.3
• /
• pp.987-995
• /
• 2013

The purpose of this study is to examine the hydraulic stability of non-toxic revetment technique for eco-friendly design of the domestic river restoration. Recently, instead of the flood control function-oriented river management policy for the engineering efficiency, the improvement of the environmental performance for the ecological river restoration project is implemented. However, the inappropriate hydraulic design criteria of the new revetment technique happen to the economic losses at flood season frequently. The hydraulic stability of the riprap and the block include the banks of rivers, riverbed protection, scour protection and so on. In this study, the high speed experimental channel was developed, which has the maximum velocity of 3.5 m/s, to perform the hydraulic experiments of the block method with non-toxic glue with various conditions to find the critical velocity of the revetment block for the hydraulic stability.

• Journal of Environmental Impact Assessment
• /
• v.4 no.1
• /
• pp.65-78
• /
• 1995

The resident attitude for preservation and development of amenity in Eulsuk island and its downstream area at estuary of Nakdong river in Korea were investigated by the questionnaires and the field surveys. Based on the results, the characteristics of this study area are the natural ecological preservation area, natural environmental preservation area and curtural assets for migratory birds. And there are a estuary bank, a Dadae beach and a Molundae park. Special amenities are (1) the light (sunrise, sunset etc), (2) the water(river, sea etc.), (3) the air(fresh wind, beautiful sound etc.), (4) the land space(beautiful view, recreation field, reed area, pine forest etc.) and (5) the stream(dancing of migratory birds, water flow, folk dance, history remains etc.). But at present, the environmental qualities as health, aesthetics safety, amenity and culture are deteriorated by development. So the number of migratory birds are decreasing. The residents desired that in future this area be use for the recreation space, the park and the natural leaning fields etc, as well as the restoration of destroyed resources.

• Journal of Korean Society on Water Environment
• /
• v.28 no.4
• /
• pp.561-573
• /
• 2012

The object of this study was to analyze long-term water quality gradients during 1992-2008 at six sites of Geumho River and near-by two sites of Nakdong River and their influences on fish trophic guilds and tolerance guilds along with ecological health. Water quality including biological oxygen demand (BOD), chemical oxygen demand (COD), conductivity, total phosphorus (TP), total nitrogen (TN), and total suspended solids (TSS) varied largely depending on the sampling locations and seasons. Values of ambient BOD, COD, TP, and TN were greater in the downstream than in the upstream reach, and seasonal and interannual variabilities were also higher in the downstreams. This phenomenon was evident due to a dilution by the Asian monsoon rainfall during the monsoon. These outcomes indicate that point sources near the downstream are important for the chemical conditions, but also seasonal stream runoff was considered as an important factor regulating the chemical conditions. Conductivity decreased rapidly during the summer due to ionic dilution, and nutrients (N, P), BOD, COD had an inverse function of seasonal precipitation. Based on the water quality, we selected two sites (control site = $C_s$ vs. impacted site = $I_s$) for impact analysis of water chemistry on fish community and trophic/tolerant guilds. Fish guild analysis showed that species diversity was higher in the headwater stream ($C_s$) than the impacted downstream ($I_s$), and that the proportion of tolerant and omnivore species were greater in the impacted site of downstream. Comparisons of water quality between Geumho River and Nakdong River indicated that Geumho River was considered as a point source which degradated water quality to the Nakdong River. Overall, chemical water quality and fish guild analysis suggest that even if current chemical quality got better after 1996 due to continuous constructions of wastewater disposal plants near the downstreams, fish compositions of tolerant and omnivores were still dominated the community. Thus, biological restoration based on ecological health is required for the ecosystem conservation.

• Journal of Wetlands Research
• /
• v.17 no.2
• /
• pp.124-129
• /
• 2015

In order to get as ecological basic data for river restoration, vegetation investigation was conducted in natural river and analysed it synecological methods, such as ordination cluster. 29 plant communities units were identified and the major dominant plant communites were Quercus mongolica community, Pinus densiflora community, Populus davidiana community, Q. variabilis community and Prunus sargentii community. River vegetations were classified into ravine and gorge forest type and riverine softwood forest type. Ravine and gorge forest was dominanted by hardwood which located in steep slope and in high elevation, and riverine softwood forest by softwood, salix spp. Naturality was an important criterion for the selection of rivers, so many of the selected rivers are located in the upper stream and mid stream rather than the lower stream, where more human intervention is involved. Plant communities were consisted of hardwood forest(44 plots, 92%) and softwood forest(4 plot, 8%), respectively. PCA with total layer data showed 5 groups of communities: Q. mongolica community group, Prunus sargentii community group, Pinus densiflora community group, Prunus sargentii community - Pinus densiflora community group and the rest communities group. PCA with tree layer showed 3 groups: Q. mongolica community group, Prunus sargentii community group, and the rest community group. Cluster analysis also a showed a similar communities group to PCA ordination, but Magnolia sieboldii community and Prunus sargentii community were distinguished from the PCA result. From the result, it can be concluded that the plant communities of riparian be divided into hardwood and softwood forest by statistical techniques. It was appropriate to plant species such as Quercus mongolica, Pinus densiflora, Populus davidiana, Quercus variabilis and Prunus sargentii, at levee zone and high water level. And Sliax spp. were appropriate for planted plants at waterfront and low water level. The herb species to be planted on the floodplain were recommanded in the species composition co-occurred with the woody species.