• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.3
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• pp.23-43
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• 2020

The purpose of this paper is to create ecological values for urban rivers. For this, the paper looks into river bed structures and how nearby lands are used. This study was performed to set the specific sections for analysis through a field investigation of the infrastructure conditions, surrounding land use, and the inter habitat structure of Seongnaecheon(Stream). A total of 780 individuals from 31 species of wild birds appeared in Seongnaecheon(Stream). According to foraging guild's habitat, there were 9 species of water, 8 types of water edges, 5 types of crowns, 5 types of shrubs, 2 types of tree trunks, 2 types of birds of raptors, and 355 individuals of water, 243 shrubs, 90 crowns, 84 water edges and 5 raptors. Many water birds were observed at the site where the Seongnaecheon(Stream) sandy plains and wetland herbaceous area were developed and the open water was secured. Most of the forest birds appeared on levee slope connected with forest around and riverside with fewer facilities for use. The species diversity index of Shannon, the entire section of Seongnaecheon(Stream), was 2.2697 and the downstream ecological landscape conservation area of Seongnaecheon(Stream) was found to be useful as a habitat for wild birds in the city compared to other sections. Some sections of Seongnaecheon (Stream) had low species diversity index due to lack of green space and surrounding urbanization areas. In choosing target species, I researched the special features of the habitats and the habitation structure of wild birds in each zone. Regarding detailed plans, by classifying the breeding place & roosting site and the roosting site & shelter that took account of the inhabitation characteristics of the target species in different sections, this paper suggested the major plant species and multilayer planting structures. Moreover, this study proposed the development of habitats for water birds and forest birds along with the connection of the green network for improving the Eco-corridor linkage and inhabitation features in Seongnaecheon(Stream).

• Korean Journal of Ecology and Environment
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• v.43 no.3
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• pp.356-368
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• 2010

In this study, we applied approach of integrative star-plot area (SPA), chemical water quality and habitat conditions (QHEI) to diagnoze ecological conditions at the eight sampling sites of Sapkyo Stream. These outcomes were compared with biological health based on the Index of Biological Integrity (IBI) using fish assemblage. And then, we evaluated the integrative ecological health condition using the star-plot method. This approach based on the sum of all the star-plot areas over these water and habitat characteristics. It was developed to reflect an integrative assessment of the ecological health in the stream. The biological health, based on the model values of IBI indicating "fair-poor" condition according to the criteria. Physical habitat health, based on the QHEI, averaged 123 indicating a "good-fair" condition. Also, chemical health, based on simply BOD values indicating "poor grade" according to the criteria of the Ministry of Environment Korea (MEK). The SPA indicating that 50% of the all was impaired condition and the most sampling sites were downstream sites influenced by the point and non-point sources. Overall our results suggest that the ecological health impact was a combined effect of eutrophication and habitat degradations in the stream. The approach of SPA can be used as a tool to evaluate the integrative health of stream environment and to identify possible causes of observed effects.

• Journal of environmental and Sanitary engineering
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• v.5 no.1
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• pp.1.1-14
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• 1990

This study was conducted to investigate the contents of heavy metals in soils of the Kumho river basin, by analyzing soils according to the distance from edge of the river and to the soil layers. The contents of heavy metals in soils showed highly in its downstream. Namely there was shown a remarkably high contents of these heavy metals in the Kum-ho bridge areas where Kongdan stream joins Dalseo stream, such as 39.52ppm for zinc, 35.92ppm for copper, 97.90ppm for iron, 102.45ppm for manganese, 13.92ppm for lead, respectively, and 0.48ppm for cadmium. However, the heavy metals contents in soils around Kangchang bridge tended to gradually decrease in its contents, probably because its main soils consisting of sand. Based on their soil layers, the average contents of these heavy metals in the surface soils were higher than one of the subsurface soil. Its contents according to the distance from the river edge indicated some difference every individual area. Nevertheless, its contents showed lower contents in the area far away from the edge. And its contents tended to again increase in the outside bank. In addition, a remarkable positive correlation is shorten between individual heavy metals, except correlation between iron and lead. Also cadmium just shows reverses correlation in the statistics. With respect to comparison between soil layers, there was a remarkable positive correlation between surface layers and subsurface layers. Considering the above results, it seems that the pollution of river bed's soil is in proportion to it of stream.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.1
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• pp.121-129
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• 2008

Major factors affecting water quality in rivers are transportation, input of pollutant loads and kinetic transformation of pollutants. Government level decision makings on water quality management are based on steady state water quality modeling. However, it is more than often that such a steady state assumption is far from real situations in rivers. Therefore, it is unavoidable to have modeling errors in water quality modeling especially for steady state modeling for longer period of time. Authors attempted to identify sources of errors in results of steady state models and thus tried to find out ways to minimize those errors. Three water quality models, QUAL2E (Brown et al., 1983), QUAL2K (Chapra et al., 2006) and CAP (Seo and Lee, 2000) were applied to the lower stream of the Geum River. $BOD_5$ and COD tend to underestimate observed data while TN and TP showed relatively smaller errors. QUAL2E model provided best calibration results for BOD5 and TP and QUAL2K model showed best calibration results for TN. Since these errors are only relative values, it was difficult to conclude which model is better performing in certain situations. The most probable reasons for errors in water quality modeling are; 1) inappropriate consideration on flow characteristics, 2) lack of information on incoming pollutant load and 3) inappropriate location of sampling for water quality analysis.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.5 s.112
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• pp.43-56
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• 2005

This study was conducted to examine the inhabitation of wild birds at the World Cup Park and to offer the Park ecological management data. Land use md actual vegetation were examined to analyze the inhabitation of wild birds. Characteristics of bird communities were analyzed by dominance, density, diversity index and guild concept. You compare inhabitation before and after the Park was built. We classified the land use and actual vegetation into twenty-six types. Robinia pseudoacacia dominated the study area. Pyeonghwa Park and Nanji-cheon Park were simple-layer structures composed of alien woody species. The observed birds after the World Cup Park included 33 families 77 species, and 9,751 individuals. Among Wild Life types, the shrub and bush type was dominant. There were 26 species of resident birds, 20 species of summer visitors, 18 species of winter visitors, and 12 species of passage migrants. The following numbers of species and individuals were observed: in Hanul park, 38 species, 3,151 individuals; in Noul park, 45 species, 2,061 individuals; in Nanji-cheon park, 42 species, 2,742 individuals; in Pyeonghwa park, 29 species, 875 individuals; and in Maebongsan(Mt.) area, 35 species, 922 individuals. Species diversities for each area were as follows: Noul park, 2.613; Hanul park, 2,301; Nanji-cheon, 2.228; and Pyeonghwa park, 2,019; and each season: summer, 2.652; spring, 2.650: winter, 2.561; and autumn 2.176. The diversity of species increased from 1.135 in 1994 to 2.324 in 2001. We recommended that the park be differented into different ecological areas in order to encourage the appearance of wild birds at the World Cup Park. The management area was divided into three districts(conservation area, preservation and restoration area, use area). The conservation area was established to the west of a waste landfill and in the downstream area of NanJi-cheon, the preservation and restoration area was established in the midstream area of Nanji-cheon, and the use area was established in the buffer zone of Pyeonghwa Park and the Nanji pond greenspace.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.159-159
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• 2017

Drought, a common environmental constraint, induces a range of physiological, biochemical and molecular changes in plants, and can cause severe reductions in crop yield. Consequently, understanding the molecular mechanisms of drought tolerance is an important step towards crop biotechnology. Here, we report that the rice (Oryza sativa) homeodomain-leucine zipper class IV transcription factor gene, ${\underline{R}ice}$ ${\underline{o}utermost}$ ${\underline{c}ell-specific}$ gene 10 (Roc10), enhances drought tolerance and grain yield by increasing lignin accumulation in ground tissues. Overexpression of Roc10 in rice significantly increased drought tolerance at the vegetative stages of growth and promoted both more effective photosynthesis and a reduction in water loss rate, compared with non-transgenic controls or RNAi transgenic plants. Importantly, Roc10 overexpressing plants had a higher drought tolerance at the reproductive stage of growth and a higher grain yield compared with the controls under field-drought conditions. Roc10 is mainly expressed in outer cell layers including the epidermis and the vasculature of the shoots, which coincides with areas of cell wall lignification. Roc10 overexpression elevated the expression levels of lignin biosynthetic genes in shoots, with a concomitant increase in the accumulation of lignin, while the overexpression and RNAi lines showed opposite patterns of lignin accumulation. We identified downstream target genes of Roc10 by performing RNA-seq and chromatin immunoprecipitation (ChIP)-seq analyses of shoot tissues. Roc10 was found to directly bind to the promoter of PEROXIDASEN/PEROXIDASE38, a key gene in lignin biosynthesis. Together, our findings suggest that Roc10 confers drought stress tolerance by promoting lignin biosynthesis in ground tissues.

• Ecology and Resilient Infrastructure
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• v.7 no.1
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• pp.1-14
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• 2020

In fluvial and riparian ecosystems, biogeomorphological research has considered the complex, multi-way relationships between biological and hydro-geomorphological components over a wide range of spatial and temporal scales. In this review, we discussed the scope and processes of fluvial biogeomorphology by explaining (1) the multi-lateral interactions between organisms and hydrogeomorphic conditions, (2) the relationships between biodiversity and habitat heterogeneity, and (3) the effects of disturbance on ecosystem patterns. Over time, an organism-landform complex along streams transitions in the sequences of geomorphic, pioneer, biogeomorphic, and ecological stages. Over space, water flow and sediment distributions interact with vegetation to modify channel topography. It is the habitat heterogeneity in streams that enhances riparian biodiversity. However, in the areas downstream of a dam, habitat types and conditions are substantially damaged and biodiversity should be reduced. In South Korea, riparian vegetation flourishes in general and, in particular, invasive species actively colonize in accordance with the changes in the fluvial conditions driven by local disturbances and global climate change. Therefore, the importance of understanding reciprocal relationships between living organisms and hydrogeomorphic conditions will ever increase in this era of rapid climate change and anthropogenic pressure. The fluvial biogeomorphic framework reviewed in this article will contribute to the ecological management and restoration of streams in Korea.

• Ecology and Resilient Infrastructure
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• v.7 no.3
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• pp.171-180
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• 2020

With the increase in industrialization and urbanization, scarcity of space for leisure life has become an important issue. Opportunities such as natural scenery and ecological experiences provided by waterfront spaces around streams are fundamental factors in the development of the community and creation of a hydrophilic park. In the past, on-site surveys have been conducted using human resources to quantify the number of river visitors, but the accuracy of the results was not sufficient owing to limitations in expenses, manpower, space, and time. In this study, to overcome this problem, we estimated the number of visitors using the location information related to hydrophilic parks. The study areas were Samrak Ecological Park and Daejeo Ecological Park located downstream of the Nakdong River. We compared and analyzed the pattern of the visitors by using the large communication data and the visiting pattern based on GPS location information. The GPS location information is based on Google Popular Times and Kakao visitor data. When the GPS location data were used, the pattern for weekday and weekend visitors was clearer than when the large communication data were used. Therefore, it is expected to be similar to the result of GPS location information if the number of visitors is extracted under the condition of precision of pCELL size and residence time of 30 minutes or more when using future communication big data. In addition, if revisions such as the Personal Information Protection Act are made to extract more accurate data, by estimating the number of visitors based on GPS data, more accurate indicators of the number of visitors can be derived.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.18-18
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• 2011

Climate change is impacting and will increasingly impact both the quantity and quality of the world's water resources in a variety of ways. In some areas warming climate results in increased rainfall, surface runoff, and groundwater recharge while in others there may be declines in all of these. Water quality is described by a number of variables. Some are directly impacted by climate change. Temperature is an obvious example. Notably, increased atmospheric concentrations of $CO_2$ triggering climate change increase the $CO_2$ dissolving into water. This has manifold consequences including decreased pH and increased alkalinity, with resultant increases in dissolved concentrations of the minerals in geologic materials contacted by such water. Climate change is also expected to increase the number and intensity of extreme climate events, with related hydrologic changes. A simple framework has been developed in New Zealand for assessing and predicting climate change impacts on water resources. Assessment is largely based on trend analysis of historic data using the non-parametric Mann-Kendall method. Trend analysis requires long-term, regular monitoring data for both climate and hydrologic variables. Data quality is of primary importance and data gaps must be avoided. Quantitative prediction of climate change impacts on the quantity of water resources can be accomplished by computer modelling. This requires the serial coupling of various models. For example, regional downscaling of results from a world-wide general circulation model (GCM) can be used to forecast temperatures and precipitation for various emissions scenarios in specific catchments. Mechanistic or artificial intelligence modelling can then be used with these inputs to simulate climate change impacts over time, such as changes in streamflow, groundwater-surface water interactions, and changes in groundwater levels. The Waimea Plains catchment in New Zealand was selected for a test application of these assessment and prediction methods. This catchment is predicted to undergo relatively minor impacts due to climate change. All available climate and hydrologic databases were obtained and analyzed. These included climate (temperature, precipitation, solar radiation and sunshine hours, evapotranspiration, humidity, and cloud cover) and hydrologic (streamflow and quality and groundwater levels and quality) records. Results varied but there were indications of atmospheric temperature increasing, rainfall decreasing, streamflow decreasing, and groundwater level decreasing trends. Artificial intelligence modelling was applied to predict water usage, rainfall recharge of groundwater, and upstream flow for two regionally downscaled climate change scenarios (A1B and A2). The AI methods used were multi-layer perceptron (MLP) with extended Kalman filtering (EKF), genetic programming (GP), and a dynamic neuro-fuzzy local modelling system (DNFLMS), respectively. These were then used as inputs to a mechanistic groundwater flow-surface water interaction model (MODFLOW). A DNFLMS was also used to simulate downstream flow and groundwater levels for comparison with MODFLOW outputs. MODFLOW and DNFLMS outputs were consistent. They indicated declines in streamflow on the order of 21 to 23% for MODFLOW and DNFLMS (A1B scenario), respectively, and 27% in both cases for the A2 scenario under severe drought conditions by 2058-2059, with little if any change in groundwater levels.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.17-24
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• 2020

This study examined the spectral information and reflectance of cracks of an embankment with drone-based hyperspectral imagery for crack detection. A Nano-Hyperspec mounted on a drone was used as a sensor, and hyperspectral videos of different intensities of illumination of the cracks on the embankment located in the downstream of Andong-Dam were obtained. An analysis of the data value of the illumination and peak data-value, the coefficients of determination were calculated to be 0.9864 of the uncracked areas and 0.9851 of the cracked area. The reflectance of each area showed a similar value and pattern, regardless of the intensity of illumination. This result may have occurred because the reference values of the white reference as the calculation criteria of reflectance varied according to the intensity of illumination. The reflectance at the cracked area was 5.65% lower in visible light and 4.58% lower in near-infrared light than that at the uncracked area. The detection of cracks may offer more precise results in further studies when the gimbal direction and camera angles of the drone are calibrated. Because hyperspectral imagery enables the detection of crack depths and types of clay minerals, which are difficult to identify in general RGB imagery, it can serve as a preemptive measure for evaluating the embankment stability.