• Journal of Wetlands Research
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• v.18 no.1
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• pp.32-38
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• 2016

The purpose of this study is to investigate the effects of the natural river conservation work and to find remedies for them, targeting Jangsu-cheon with high frequency of use by citizens among the rivers in Incheon Metroplitan City, Korea; for this, this study conducted investigations and analyses of Jangsu-cheon completed in December, 2008. As a result of investigating 3 spots for the water system of Jangsu-cheon over a total of 3 years (2009, 2010, 2014), it was found that benthic macro-invertebrates of a total of 3 phyla, 5 classes, 11 orders, 26 families, 56 species, and 980 specimens were distributed there. When they were analyzed by year, 18 families and 30 species in 2009, right after the natural river conservation work, and 22 families and 37 species in 2010, 2 years after the work, were found, with 7 species increasing in number; after that, as a result of the investigation in 2014, 22 families and 38 species were found, which tells the river has entered the stabilization stage since the recovery in 2010.Therefore, this study could identify: the water environment of the river was improved due to the natural river conservation work for Jangsu-cheon; in addition, Jangsu-cheon showed good ecological environment due to the continuous maintenance of the good wetlands in Incheon Grand Park in the upper area of the river; and the natural river conservation work of Jangsu-cheon created positive effects.

• Journal of Wetlands Research
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• v.7 no.3
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• pp.75-85
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• 2005

The Construction of industrial complex areas means the increase of imperviousness rate and the increase of nonpoint pollutant emissions during a rainfall. Generally the retention basin can become the alternative for removing and controling these nonpoint pollutants. Recently Ministry of Environment are trying to change the purpose of retention basins from flooding control to nonpoint pollutant control. In order to propel the stormwater management program, administration plan of stormwater management is enacted in Spring, 2005. Hereafter, in a newly developing area, the best management practices should be established to control the nonpoint pollutant. Landuses of the research area are classified to the categories of the 1st manufacturing industry, metal industry, fiber and chemical product manufacturing industry, etc. Therefore, this research was performed to understand washed-off characteristics of stormwater and to suggest the controling method of nonpoint pollutants. The optimum capacity of the retention basin can be determined by analyzing the relationships among data of rainfall, runoff, washed-off pollutants from the areas. The rainfall analysis using the data of normal year, recent 2, 5 and 10 years shows that the 80% rainfall frequency was occurred on 10mm accumulated rainfall, but which is not considered the first flush effect. However, by considering the first flush effect, the appropriate treatment capacity of rainfall can be decreased to 4-5mm accumulated rainfall. Using the criteria, the optimum capacity of retention basin is determined to $12,000m^3$ in the research area. The washed-off nonpoint pollutant loading from the areas have beeb calculated to 435ton/yr for TSS, 238ton/yr for COD, 8,518kg/yr for TKN and 1,816kg/yr for TP. The mass of 78.3ton/yr for TSS, 20.4ton/yr for BOD, 128.6ton/yr for COD, 4.6ton/yr for TKN and 980kg/yr for TP can be reduced by constructing the retention basin. The sediment accumulation rate is also calculated by $6.53kg/m^2-hr$.

• Journal of Wetlands Research
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• v.8 no.4
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• pp.41-47
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• 2006

Global climatic changes are expected to influence various biogeochemical processes in wetland ecosystems. In particular, coastal mud flat is anticipated to be affected directly by temperature increase as well as indirectly by a sea level rise and changes in precipitation. This study aimed to determine changes in methane production under different temperature and salinity by employing a laboratory-scale manipulation experiment. Soil samples were collected from a mud flat in Dong-Gum Kang-Hwa island in winter and two types of experiments were conducted. In the first experiment soil samples at 0-5 cm, 5-10 cm depth were incubated under same salinity with pore water and diluted salinity to 50 % of natural condition for 20 days and methane production was measured every other days. In the second experiment, soil samples at 5-10 cm depth were incubated in different temperature, $5^{\circ}C$ and $15^{\circ}C$, under same salinity conditions with first experiment for 31 days and methane production was measured. Results of the first experiment revealed that higher amount of methane was produced at 5-10 cm depth, and salinity effect was predominant at the end of the experiment. The second experiment showed that methane production was higher in $15^{\circ}C$ than $5^{\circ}C$. In addition, methane production was higher when sea water diluted to 50 % compared to control. Global climatic changes are expected to influence various biogeochemical processes in wetland ecosystems. In particular, coastal mud flat is anticipated to be affected directly by temperature increase as well as indirectly by a sea level rise and changes in precipitation. This study aimed to determine changes in methane production under different temperature and salinity by employing a laboratory-scale manipulation experiment. Soil samples were collected from a mud flat in Dong-Gum Kang-Hwa island in winter and two types of experiments were conducted. In the first experiment soil samples at 0-5 cm, 5-10 cm depth were incubated under same salinity with pore water and diluted salinity to 50 % of natural condition for 20 days and methane production was measured every other days. In the second experiment, soil samples at 5-10 cm depth were incubated in different temperature, $5^{\circ}C$ and $15^{\circ}C$, under same salinity conditions with first experiment for 31 days and methane production was measured. Results of the first experiment revealed that higher amount of methane was produced at 5-10 cm depth, and salinity effect was predominant at the end of the experiment. The second experiment showed that methane production was higher in $15^{\circ}C$ than $5^{\circ}C$. In addition, methane production was higher when sea water diluted to 50 % compared to control. These results suggest that methane production is highly influenced by changes in temperature and salinity in coastal mud flat. And that global climatic change may induce biological feedback by affecting production of another greenhouse gas, namely methane from coastal mud flat.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.2
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• pp.110-126
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• 2024

This study conducted a classification of small-scale biological habitats created in Seoul to analyze and synthesize location characteristics, habitat structure, biological habitat functions, and threat factors of representative sites, as well as derive creation and management problems according to the ecological characteristics. The aim was to suggest improvement measures and management items. Data collected through a field survey was used to categorize 39 locations, and 8 representative sites were selected by dividing them into location, water system, and size as classification criteria for typification. Due to the characteristics of each type, the site was created in an area where amphibian movement was disadvantageous due to low or disconnected connectivity with the hinterland forest, and the water supply was unstable in securing a constant flow and maintaining a constant water depth. The habitat structure has a small area, an artificial habitat structure that is unfavorable for amphibians, having the possibility of sediment inflow, and damage to the revetment area. The biological habitat function is a lack of wetland plants and the distribution of naturalized grasses, and threats include the establishment of hiking trails and decks in the surrounding area. Artificial disturbances occur adjacent to facilities. When creating habitats according to the characteristics of each type, it was necessary to review the possibility of an artificial water supply and introduce a water system with a continuous flow in order to connect the hinterland forest for amphibian movement and locate it in a place where water supply is possible. The habitat structure should be as large as possible, or several small-scale habitats should be connected to create a natural waterfront structure. In addition, additional wetland plants should be introduced to provide shelter for amphibians, and facilities such as walking paths should be installed in areas other than migration routes to prevent artificial disturbances. After construction, the management plan is to maintain various water depths for amphibians to inhabit and spawn, stabilize slopes due to sediment inflow, repair damage to revetments, and remove organic matter deposits to secure natural grasses and open water. Artificial management should be minimized. This study proposed improvement measures to improve the function of biological habitats through the analysis of problems with previously applied techniques, and based on this, in the future, small-scale biological habitat spaces suitable for the urban environment can be created for local governments that want to create small-scale biological habitat spaces, including Seoul City. It is significant in that it can provide management plans.

• Journal of Wetlands Research
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• v.17 no.3
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• pp.228-236
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• 2015

Urbanization causes many environmental, hydrological and ecological problems such as distortion of the natural water circulation system, increase in nonpoint source pollutants in stormwater runoff, degradation of surface water quality, and damage to the ecosystem. Due to the increase in impervious surface by urbanization, developed countries apply low impact development (LID) techniques as important alternatives to reduce the impacts of urbanization. In Korea, LID techniques were employed since 2012 in order to manage nonpoint source pollutants. LID technology is a technique for removing pollutants using a variety of physical, chemical and biological mechanisms in plants, microorganisms and filter media with the reduced effluence of stormwater runoff by mimicking natural water circulation system. These LID facilities are used in a variety of filter media, but an assessment has not been carried out for the comprehensive comparison evaluation of adsorption and desorption characteristics for the pollutant removal capacity. Therefore, this study was conducted to analyze the adsorption and desorption characteristics of various filter media used in the LID facilities such as sand, gravel, bioceramic, wood chips and bottom ash etc. in reducing heavy metals(Pb, Cu). In this study, the adsorption affinity for Pb in all filter media was higher than Cu. Pseudo second order equation and Langmuir-3 isotherm are more applicable in the adsorption kinetic model and adsorption isotherm model, respectively. As a result of the desorption experiment, the filter media does not exceed KSLT which is the hazardous substance leaching limit, showing the capability of the filter media in LID. The bioceramic and woodchip as filter medias were evaluated and exhibited excellent adsorption capacity for Pb.

• Journal of Wetlands Research
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• v.19 no.1
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• pp.30-36
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• 2017

SS(Suspended Solid) concentration by soil erosion into river at normal and flood season should be measured. However, to present the variation of SS due to various development project such as EIA(Environmental Impact Assessment), River Master Plan, and so on, it is necessary to estimate not measure SS, but there are not exist how to estimate SS. In the present study, therefore, we propose the hydrologic method of estimating SS concentration using the results of particular frequency flood discharge and sediment discharge by RUSLE method. SS consists of silty and clay soil and colloid particle etc. However, in the present study, silty and clay soils of sediment discharge except send set up SS standards. The flow discharge to estimate SS concentration are 1~2 years for normal season, 30~100 years for flood season. Meanwhile, analysis software for probable rainfall uses Fard2006, probable rainfalls under 2-year frequency are estimated using rainfall data and frequency factor of Gumbel distribution. The results of estimating SS concentration using runoff volume by sediment and flow discharges of silty and cray soils as above method show that reliable level of SS concentration is considered in predevelopment of natural condition and under development of barren condition. Especially, SS concentration takes notice that the value of sediment discharge makes a huge difference according to channel slope, it was confirmed that the value obtained by dividing the SS concentration by the channel slope is relatively constant even though the topographical factors are different. Therefore, if the present study will be proceeded for various watersheds, it will be developed as estimation method of SS concentration.

• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.236-244
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• 1999

A feasibility study was performed to examine the agronomic application of treated sewage on paddy rice culture by field experiment. The domestic sewage was treated by the constructed wetland system which was in subsurface flow type and consisted of sand and macrophyte. The effluent of the wetland system was adjusted to maintain the total nitrogen concentration below $25mgL^{-1}$ and used for irrigation water. Four treatments include (1) irrigation of treated sewage after concentration adjusted with conventional fertilization (TWCF), (2) irrigation of treated sewage after concentration adjusted with half of the conventional fertilization (TWHF), (3) irrigation of treated sewage after concentration adjusted without fertilization (TWNF), and (4) irrigation of treated sewage as it was without fertilization (SWNF). These cases were compared to the control case of tap water irrigation with conventional fertilization (Control). Generally, addition of the treated sewage to the irrigation water showed no adverse affect on paddy rice culture, and even improvement was noticed in both growth and yields. TWCF showed the best result and the yields exceed the Control in about 10%. Overall performance of the treatments was TWCF, Control, TWHF, TWNF, and SWNF in decreasing order. From this study, it appears that reuse of treated sewage as a supplemental irrigation water could be feasible and practical alternative for ultimate sewage disposal which often causes water quality problem to the receiving water body. For full scale application, further study is recommended on the specific guidelines of major water quality components and public health.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.327-341
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• 2021

The riparian eco-belt is an efficient technique that can reduce non-point pollution sources in the basin and improve ecological connectivity and health. In Korea, a legal system for the construction and management of riparian eco-belts is in operation. However, it is currently excluded that rivers and floodplains in dam reservoir that are advantageous for buffer functions such as control of non-point pollutants and ecological habitats. Accordingly, this study presented and analyzed a plan to select a site for an integrated riparian ecol-belt that comprehensively evaluates the water quality and ecosystem characteristics of each dam floodplain and riparian zone for the Daecheong Dam basin in Geum River watershed. First, the Daecheong Dam basin was divided into 138 sub-basin with GIS, and the riparian zone adjacent to the dam floodplain was analyzed. Sixteen evaluation factors related to the ecosystem and water quality impact that affect the selection of integrated riparian eco-belt were decided, and weights for the importance of each factor were set through AHP analysis. The priority of site suitability was derived by conducting an integrated evaluation by applying weights to sub-basin by floodplains and riparian zone factors. In order to determine whether the sites derived through GIS site analysis are sutiable for actual implementation, five sites were inspected according to three factors: land use, pollution sources, and ecological connectivity. As a result, it was confirmed that all sites were appropriate to apply integrated riparian ecol-belt. It is judged that the riparian eco-belt site analysis technique proposed through this study can be applied as a useful tool when establishing an integrated riparian zone management policy in the future. However, it might be necessary to experiment various evaluation factors and weights for each item according to the characteristics and issues of each dam. Additional research need to be conducted on elaborated conservation and restoration strategies considering the Green-Blue Network aspect, evaluation of ecosystem services, and interconnection between related laws and policy and its improvements.

• Journal of Wetlands Research
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• v.21 no.2
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• pp.163-172
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• 2019

The USLE P factor is a factor that varies depending on how croplands are managed and cultivated. Previous studies tend to overestimate the amount of soil loss because the factor was estimated from the slope of the watershed rather than the estimate of each cultivated land. In addition, the accuracy of estimating the soil loss is decreasing due to the fact that the factor is calculated without considering various conditions of cultivated land defined by Wishmeier and Smith. In order to overcome these problems, the Ministry of Environment (MOE) has proposed to establish the topsoil notification and calculate the P factor according to the cultivation methods (e.g., tillage system, support practice). However, it is required to apply the conditions proposed in the United States to domestic circumstances as it is causing uncertainties. Thus, this study selected the watersheds where soil loss was serious (Haean, Jaun, Banbyeoncheon), measured the actual slopes and slope lengths, and examined the crop, tillage systems, and support practice for each cultivated land. The P factors were recalculated considering the actual conditions of cultivated land and compared to the factors proposed by the previous studies (MOE). As the result of the study, the P factors calculated based on the previous studies were 0.8 ~ 1.0 in three watersheds. On the other hand, it is confirmed that there is a significant difference between the factors notified by MOE and estimated by reflecting the topography and cultivation methods in this study. Therefore, it is considered that the research for developing the cultivation conditions to calculate the P factor suitable for the domestic environment should be continuously carried out.

• Korean Journal of Environment and Ecology
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• v.35 no.6
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• pp.609-620
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• 2021

This study surveyed six national parks that included a wide range of afforestation among national parks in Korea to analyze the vegetation structure of Larix kaempferi, which occupies the highest ratio among planted areas. Plots were established considering the dominant ratio, diameter at breast height and afforestation area of Larix kaempferi. The purpose of the study was to provide basic data for ecological management to promote diversity. A total of 51 plots were selected based on 400 m² quadrates. TWINSPAN was used for community classification, and each classified community was analyzed of importance percentage, species diversity, number of species, and populations. The community classification identified7 communities, all dominated by Larix kaempferi in the tree layer and classified by the appearance species of the subtree layer and shrub layer. In communities I, II, and VII that are located in the valley, Zelkova serrata, Morus bombycis, and Fraxinus rhynchophylla appeared, while dominated by Larix kaempferi were in the tree layer. Wetland deciduous broad-leaved species such as Fraxinus rhynchophylla and Morus bombycis frequently appeared in the subtree layer. In community III through VI is located on the slope, Quercus spp., such as Quercus mongolica and Quercus acutissima, mainly appeared while dominated by Larix kaempferi in the tree layer, and Quercus and wetland broad-leaved species frequently appeared in the subtree layer and shrub layer. The average species diversity of Larix kaempferi in the surveyed six national parks was 1.2090, with community III the highest at 1.5413 and community VI the lowest at 0.7042. The average number of species was 9.35±2.90, and the average population was 226.05±89.98.