• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.91-97
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• 2005

This study was conducted to evaluate the influence of pollutant loads on the water quality in the Dongjin River area from January 2003 to December 2004. The average value of BOD and T-N showed the highest peak in Yongho, Dukcheon watershed among Dongjin River. Concentrations of BOD, T-N and T-P in Jeongeup watershed were 2.29 mg $L^{-1}$, 4.40 mg $L^{-1}$ and 0.27 mg $L^{-1}$, respectively. Concentration of BOD in Chilbo was 1.19 mg $L^{-1}$ which would be in the grade I according to water quality criteria by Ministry of Environment. The BOD level in Wonpeung and Sinpeung watershed ranged from 4.06 to 7.35 mg $L^{-1}$. The T-N effluent loads of non-point pollutants were high in Wonpeung, Gobu, Yongho Dukcheon, Jeongeup and Sinpeung watershed in order. The major sources of BOD, T-N and T-P effluent loads were Livestock. The T-P effluent load of non-point pollutant was 68 kg $day^{-1}$ in Wonpeung, 58 kg $day^{-1}$ in Yongho Dukcheon and 45 kg $day^{-1}$ Jeongeup watershed. The delivered loads of BOD was high in Gobucheon, while both T-N and T-P were high in Yongho Dukcheon. The delivery ratio of BOD and T-N at dry season was below 100% in all watershed of Dongjin River. The delivery ratio of T-N at raining season was high in Yongho Dukcheon and Chilbo watershed

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.301-310
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• 2008

This study was to analyze characteristics of fish compositions and longitudinal distribution, based on trophic and tolerance guild at 22 sampling sites of Yeongsan River watershed during 2003$\sim$2006, and also to compare before and after the estuary dam construction. The collected fishes, based on catch per unit effort (CPUE), were 44 species in the watershed and dominant fishes were Zacco platypus, Acheilognathus macropeterus, Zacco temminckii and Carassius auratus. According to comparative analysis of fish in the non polluted sites (NPS) vs. polluted sites (PS), the number of species and individuals was lower by 70% in the PS than the NPS, indicating ecological degradations by chemical pollutions or/and habitat modifications. The relative abundance of sensitive and insectivore species decreased as the stream order increases, while tolerant and omnivore species increased with the stream order. In this survey, largemouth bass (Micropterus salmoides), which is a top-carnivore and exotic species, may influence trophic guild system throughout active predations on endemic species, resulting in modifications of ecological functions. The construction of estuary dam on Yeongsan River in 1981 resulted in wider lacustrine zone and desalinated through limitation of seawater input. These physical changes have caused increases of lentic dwelling species and limited fish migrations (i.e., eel). Overall, fish fauna and composition analyses showed that the number of species and individuals in this water body may be reduced due to inputs of pollutants from the watershed, habitat modifications, and increases of exotic species (largemouth bass). For these reasons, effective lake management strategies are required for the ecosystem conservation.

• Korean Journal of Ecology and Environment
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• v.43 no.3
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• pp.428-436
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• 2010

This study was to evaluate water quality characteristics and ecological health using a mulimetric fish model in Taehwa-River watershed during May~September 2009. The ecological health assessments were based on the Index of Biological Integrity (IBI) using fish community and the multimetric model of Qualitative Habitat Evaluation Index (QHEI). For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. We also analyzed spatial patterns of chemical water quality over the period of 2000~2009, using the water chemistry dataset, obtained from the Ministry of Environment, Korea. Values of BOD and COD averaged $1.7\;mg\;L^{-1}$ (scope: $0.1{\sim}31.8\;mg\;L^{-1}$) and $3.6\;mg\;L^{-1}$ (scope: $0.4{\sim}33\;mg\;L^{-1}$), respectively during the study. Total nitrogen (TN) and total phosphorus (TP) averaged $2.8\;mg\;L^{-1}$ and $96.8\;{\mu}g\;L^{-1}$, respectively, indicating an eutrophic-hypertrophic state. Also, TN and TP showed longitudinal increases toward the downriver reach. In the watershed, QHEI values varied from 67.5 (fair condition) to 164.5 (good condition) by the criteria of US EPA (1993). There was a abruptly decreasing tendency from T9 site in the QHEI values. According to 1st and 2nd surveys of Taewha River, multimetric model values of IBI was averaged 26.1 (n=14) with "good" condition (B) and the spatial variation was evident. Our results suggest that the mainstream sites was getting worse health condition along the river gradient due to inputs of the point and non-point sources from the urban (Ulsan city). Overall, dataset of IBI, QHEI, and water chemistry indicated that the ecological river health showed a downriver decline and the pattern was closely associated with habitat degradations and chemical pollutions as the waters pass through the urban region.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.5
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• pp.1-12
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• 2019

It is important to measure the height of trees as an essential element for assessing the forest health in urban areas. Therefore, an automated method that can measure the height of individual tree as a three-dimensional forest information is needed in an extensive and dense forest. Since airborne LiDAR dataset is easy to analyze the tree height(z-coordinate) of forests, studies on individual tree height measurement could be performed as an assessment forest health. Especially in urban forests, that adversely affected by habitat fragmentation and isolation. So this study was analyzed to measure the height of individual trees for assessing the urban forests health, Furthermore to identify environmental factors that affect forest growth. The survey was conducted in the Mt. Bongseo located in Seobuk-gu. Cheonan-si(Middle Chungcheong Province). We segment the individual trees on coniferous by automatic method using the airborne LiDAR dataset of the two periods (year of 2016 and 2017) and to find out individual tree growth. Segmentation of individual trees was performed by using the watershed algorithm and the local maximum, and the tree growth was determined by the difference of the tree height according to the two periods. After we clarify the relationship between the environmental factors affecting the tree growth. The tree growth of Mt. Bongseo was about 20cm for a year, and it was analyzed to be lower than 23.9cm/year of the growth of the dominant species, Pinus rigida. This may have an adverse effect on the growth of isolated urban forests. It also determined different trees growth according to age, diameter and density class in the stock map, effective soil depth and drainage grade in the soil map. There was a statistically significant positive correlation between the distance to the road and the solar radiation as an environmental factor affecting the tree growth. Since there is less correlation, it is necessary to determine other influencing factors affecting tree growth in urban forests besides anthropogenic influences. This study is the first data for the analysis of segmentation and the growth of the individual tree, and it can be used as a scientific data of the urban forest health assessment and management.

• Journal of Ecology and Environment
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• v.36 no.1
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• pp.73-83
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• 2013

The object of this study was to evaluate lotic ecosystem health using multiple eco-metric approaches such as water chemistry diagnosis, physical habitat health evaluations, and biological integrity modeling at 100 streams of four major watersheds. For the study, eight chemical water quality parameters such as nutrients (N, P) and organic material were measured and 11-metric models of Qualitative Habitat Evaluation Index (QHEI) and multiple eco-metric health assessment model (MEHA) were applied to the four major watershed. Nutrient analysis of nitrogen (N) and phosphorus (P) in all watersheds indicated a eutrophic state depending on the locations of sampling streams. Physical habitat health, based on the QHEI model, averaged 114 (range: 56 - 194), judging as a "good condition" by the criteria of Plafkin et al. (1989). In addition, primary (H1 - H4), secondary (H5 - H7), and tertiary habitat metric variables (H8 - H11) were analyzed in relation to the physical habitat degradations. The plots of tolerant species ($P_{TS}$) and sensitive species ($P_{SS}$) to water quality showed that the proportions of $P_{TS}$ had positive linear functions with nutrients, and that the $P_{SS}$ had inverse linear relations with the chemical variables. The model of eco-metric health assessment showed that mean MEHA was 20.4, indicating a fair condition. Overall, our data suggest that water chemistry, based on nutrients and organic matter, directly modified the trophic structures in relation to food chain in the aquatic ecosystems, and then these directly influenced the compositions of tolerance/sensitive species, resulting in degradations of overall ecological health.

• Journal of Environmental Health Sciences
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• v.31 no.6
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• pp.467-474
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• 2005

The runoff characteristics of combined sewer overflow(CSO) in the urban area of Jeonju were investigated and analyzed by using the SWMM (Storm Water Management Model) and GIS. From August to November 2004, investigations on two rainfall events were performed and flowrate, pH, BOD, COD, SS, T-N and T-P were measured. these data were used for model calibration. Using GIS technique, watershed characteristics of study area were calculated. that is, divide into sub_basin, total width, slope, make soil map etc. On the basis of the measured data and the simulation results by SWMM, it could be known that the $80-90\%$ of pollution load are discharged in early-stage storm runoff. SMC(site mean Concentration) for combined sewer system area were BOD 28.1, COD 31.5, SS 186 ppm etc. this is shown that during the rain fall, high concentration of waste was loaded to receiving water. Unit loads of combined sewer system area were BOD 306, COD 410, SS 789, T-N 79, T-P 6.8 kg/ha/yr.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.4
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• pp.19-31
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• 2022

The definition of urban forest is described as all forest and trees except the Natural Parks throughout whole territory in Urban Forest Act. But the concept of urban forest in the law differs from general awareness by Korean citizen and from definitions of other countries. For discussing such differences of urban forest definition, it was tested how much urban forest area would be changed according to the various definition of urban area. The urban area was defined to be four scenarios in this study in consideration of "urban area" by National Land Planning and Utilization Act (NLPUA), 300m buffered boundary from the "urban area" proposed by World Health Organization (WHO) and forest watershed area. In the scenario 1, including forest watershed intersected with "urban area" by NLPUA, urban forest area was estimated at 1.83 million ha in which urban forest area per person was 386㎡. In the scenario 2, including forest watershed intersected with 300m buffered boundary from the "urban area" by NLPUA, urban forest area was estimated at 1.92 million ha in which urban forest area per person was 405㎡. In the scenario 3, including forest watershed intersected with "urban area" placed within administration boundary (Eup·Dong districts), urban forest area was estimated at 1.08 million ha in which urban forest area per person was 230㎡. In the scenario 4, including forest watershed intersected with 300m buffered boundary from "urban area" placed within administration boundary, urban forest area was estimated at 1.20 million ha in which urban forest area per person was 256㎡. Therefore, the boundary of urban area should be agreed clearly prior to defining the urban forest area for avoiding unclear area calculated according to different definitions.

• Journal of Environmental Impact Assessment
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• v.21 no.5
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• pp.631-648
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• 2012

The integrative ecological approaches of chemical assessments, physical habitat modelling, and multi-metric biological health modelling were applied to Gwanpyeong Stream within Gap-Stream watersheds to evaluate environmental impacts on the constructions of residential and commercial complex. For the analysis, the surveys conducted from 45 sites of reference streams within the Gap-Stream watershed and 3 regular sites during 2009 - 2010. Physical habitat health, based on the habitat model of Qualitative Habitat Evaluation Index(QHEI) declined from the headwaters(good - fair condition) to the downstream(poor condition). Chemical water quality, based turbidity and electric conductivity(EC), was degraded toward to the downstream, and especially showed abrupt increases, compared to the values of control streams(CS). Also, concentrations of chlorophyll-a in the downstreams were greater compared to the control stream(CS), indicating an eutrophication. Biological health conditions, based on the Index of Biological Integrity(IBI) using fish assemblages, averaged 19.3 which is judged as a fair condition by the biological criteria of the Ministry of Environment, Korea. The comparisons of model metric values in sensitive species and riffle-benthic species on the Maximum Species Richness Line(MSRL) of 45 reference streams indicated a massive disturbances in all sampling locations. Also, tolerance guild and trophic guild analyses suggest that dominances of tolerant species and omnivores were evident, indicating a biological degradation by habitat disturbances and organic matter pollutions. There was no distinct longitudinal variations of IBI model values from the headwater to the downstream in spite of slight chemical and habitat health gradients among the sampling sites. Overall, integrative ecological health(IEH) scores, based on the chemical, physical, and biological parameters, were low compared to the 45 reference streams due to physical and chemical disturbances of massive constructions of the residential and commercial complex. This stream, thus showed a tendency of typical urban streams which are disturbed in the chemical water quality, habitat structures, and biological integrity. Effective stream management plans and restoration strategies are required in this urban stream for improving integrative stream health.

• Korean Journal of Ecology and Environment
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• v.49 no.2
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• pp.130-141
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• 2016

This study was conducted to elucidate the structure of river ecosystem in the watershed of the Seom River and Hoengseong Reservoir located in Hoengseong of Kangwon Province from February to October 2007. Topics of the survey were mainly rainfall, discharge, water quality in abiotic factors and attached algae, benthic macroinvertebrates, fish, birds and mammals of flora and fauna in a biotic factors, respectively. Specifically, the Seom River could be seen as a typical flow rate of the stream is controlled to the effect of the dam. Basic water qualities were great to seasonal effects, it was relatively clean. Diatom Achnanthes, Cymbella, Gomphonema, and Navicula were distributed predominantly in the periphytic algae. Benthic macroinvertebrates were mostly aquatic insects and freshwater shellfish, the aquatic insects were abundant Ephemeroptera and Trichoptera. Freshwater fish was the dominant Zacco platypus, fish species varied toward the downstream. Birds were mainly observed in four species, and species Egretta garzetta, which was distributed in a wide area of the Seom River. In mammals, Lutra lutra of Mustelidae was identified that the number of inhabit widely. In aspects of the ecological trophic level, the Seom River was maintained at a relatively stable state in the producer and the consumer relationship. The results of this study will expected to be utilized as a useful data for understanding the structure and function of the lotic and lentic ecosystems.

• Journal of Environmental Impact Assessment
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• v.21 no.1
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• pp.41-51
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• 2012

To select 10 representatives for the ecotourism networks around the areas bordering national rivers in Korea, the spatial ranges for ecotourism have been established, the ecotourism potential analyzed, and the ecotourism resources information collected by the Regional Environmental Offices and the Korea National Park Service has undergone reviews, amendments, supplements, and verification processes through familiarization tour previews, and the following main results have been derived. First, the spatial ranges of the eco-tourism networks have been set as the watershed areas that include areas around the four major rivers and the rivers. Second, the areas with high potential value for ecotourism were selected through the analysis of ecotourism potential. Since EGIS was used for the analysis, it was inevitable that insufficient amount of localized information was reflected, and the use of the results as reference for the potential would be feasible. Third, it was possible, by reviewing, amending and complementing the results of ecological resource information collected by the Regional Environmental Offices and the Korea National Park Service, to select 50 representative ecological resources around the national rivers. The selected resources were considered for the adjacency, attractiveness of ecological resources, and uniqueness of the national rivers, and they were derived by screening expert advice, official opinion, and geographical analysis information. Fourth, 10 representative ecotourism networks based on watershed areas were selected, and suitable themes were given based on the resource characteristics. Fifth, the appropriateness for ecotourism has been confirmed, with the familiarization tour previews and survey results, preservation of the future ecotourism resources, and the establishment of the foundation as the basis. In the future, the remaining 9 ecotourism networks would also need to undergo a verification process such as familiarization tours. It is deemed that, through future ecotourism contests, if the programs that select locally-pioneered tourism programs resulting from the capacities of local entities and residents, then it would be more effective in discovering resources that are more localized and of higher regional value.