• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.725-732
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• 2012

There is relatively high vulnerability of soil erosion in slope highland agriculture due to a reclamation of mountain as well as low surface covering during early summer with high rainfall intensity. Especially, in soybean cultivation, soil disturbance by conventional tillage and exposure of topsoil at the early stage of soybean have intensified soil loss. The aim of this study was to evaluate various surface covering methods for reducing soil loss in highland soybean cultivation. The experiment was conducted in 17% sloped lysimeter ($2.5m{\times}13.4m$) with 8 treatments. Amount of runoff water and eroded soil, and soybean growth were investigated. Surface covering through sod culture and plant residue showed 3.4~45.0 runoff water amount with $177{\sim}2,375m^3\;ha^{-1}$ compared with control ($5,274m^3\;ha^{-1}$). And the amount of eroded soil was also reduced by 95% in surface covering treatment with $0.02{\sim}1.94Mg\;ha^{-1}$ than control with $40.72Mg\;ha^{-1}$. Yields of soybean pod showed $0.3Mg\;ha^{-1}$ in rye sod culture, $1.3Mg\;ha^{-1}$ in Ligularia fischeri var. spiciformis Nakai, $0.7Mg\;ha^{-1}$ in Aster koraiensis Nakai, $0.2Mg\;ha^{-1}$ in red clover and $2.0Mg\;ha^{-1}$ in non-covering, on the other hand, covering with cut rye showed $3.8Mg\;ha^{-1}$. Conclusively, covering the soil surface with cut rye were beneficial for reduction of soil loss without decreasing soybean yield in highland sloped fields.

• Journal of Wetlands Research
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• v.18 no.3
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• pp.275-281
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• 2016

This study was conducted to analyze the runoff characteristics of the highway depending on the number of vehicles and to provide the installation proposal of an NPS pollution reduction facility. There were a total of 5 monitoring sites used for the study namely, Gyeongbu, Seohaean, Honam and Tongyeoung Dageon highway. Monitoring events started from 2006 until 2015 having a total of 44 storm events. According to monitoring statistics, the average antecedent dry days (ADD) and rainfall was 6.2 days and 19.2 mm, respectively. The Gyeongbu Highway (H-4) was recorded having the highest Average Daily Traffic and Catchment Area (ADT/CA) with $49.4car/day{\cdot}m^2$ while other site were less than $10car/day{\cdot}m^2$. The average concentration of the NPS pollutants generated from monitoring sites were 63.5 mg/L(TSS), 24.9 mg/L(BOD), 3.35 mg/L(TN), 0.63 mg/L(TP) and 298 ug/L(Total Zn). This exhibited lower values in comparison to the remarks of highway related runoff EMC values published in Korea. Moreover, through the results of the correlation analysis between the contaminant concentration and ADT/CA, $R^2$ value of SS showed the highest correlation with 585. Through the correlation equation between ADT/CA and EMC of TSS, when there is 73.7 mg/L of TSS EMC found from a domestic highway, ADT/CA ratio is normally $13car/day{\cdot}m^2$. Therefore, in a case of more than 13 cars passing through a certain area, the area can be considered and present as the point of generation of nonpoint source pollutants. Also, in this study, since it considered a unit area ADT indicated in previous studies, it was determined that it has a high applicability and utilization in generalized units than conventional study which were conventionally done.

• Journal of Wetlands Research
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• v.26 no.2
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• pp.168-181
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• 2024

Constructed wetlands (CWs) deliver a range of ecosystem services, including the removal of contaminants, sequestration and storage of carbon, and enhancement of biodiversity. These services are facilitated through hydrological and ecological processes such as infiltration, adsorption, water retention, and evapotranspiration by plants and microorganisms. This study investigated the correlations between microbial populations, soil physicochemical properties, and treatment efficiency in a horizontal subsurface flow constructed wetland (HSSF CW) treating runoff from roads and parking lots. The methods employed included storm event monitoring, water quality analysis, soil sampling, soil quality parameter analysis, and microbial analysis. The facility achieved its highest pollutant removal efficiencies during the warm season (>15℃), with rates ranging from 33% to 74% for TSS, COD, TN, TP, and specific heavy metals including Fe, Zn, and Cd. Meanwhile, the highest removal efficiency was 35% for TOC during the cold season (≤15℃). These high removal rates can be attributed to sedimentation, adsorption, precipitation, plant uptake, and microbial transformations within the CW. Soil analysis revealed that the soil from HSSF CW had a soil organic carbon content 3.3 times higher than that of soil collected from a nearby landscape. Stoichiometric ratios of carbon (C), nitrogen (N), and phosphorus (P) in the inflow and outflow were recorded as C:N:P of 120:1.5:1 and 135.2:0.4:1, respectively, indicating an extremely low proportion of N and P compared to C, which may challenge microbial remediation efficiency. Additionally, microbial analyses indicated that the warm season was more conducive to microorganism growth, with higher abundance, richness, diversity, homogeneity, and evenness of the microbial community, as manifested in the biodiversity indices, compared to the cold season. Pollutants in stormwater runoff entering the HSSF CW fostered microbial growth, particularly for dominant phyla such as Proteobacteria, Actinobacteria, Acidobacteria, and Bacteroidetes, which have shown moderate to strong correlations with specific soil properties and changes in influent-effluent concentrations of water quality parameters.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.4
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• pp.12-31
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• 2010

The objective of this study is to evaluate the applicability of GIS based multi-directional flow allocation model. In order to evaluate the suggested model in this study, it was applied to real watersheds, Pyeongchang and Soyang river basin. The simulation results were compared with observed values, and showed good agreements. The improvement of accuracy and reduction of simulation time were carried out by applying multi-directional flow allocation. Accordingly, the applied methodologies presented in this study will be used to predict accurate runoff, which plays a major role in integrated flood management. If this model is combined with the techniques of rainfall forecasting, it will contribute to the real-time flood forecasting and warning in the future.

• Journal of Korean Society on Water Environment
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• v.28 no.4
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• pp.495-504
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• 2012

In recent years, urbanization has been a hot issues in watershed management due to increased pollutant loads from impervious urban areas. The Soil and Water Assessment Tool (SWAT) model has been widely used in hydrology and water quality studies at watershed scale. However, the SWAT has limitations in simulating water flows between HRUs and hydrological effects of LID practices. The Storm Water Management Model (SWMM) has LID capabilities, but it does not simulate non-urban areas, especially agricultural areas. In this study, a SWAT-SWMM coupled model was developed to evaluate effects of LID practices on hydrology and water quality at mixed-landuse watersheds. This coupled SWAT-SWMM was evaluated by comparing calibrated flow with and without coupled SWAT-SWMM. As a result of this study, the $R^2$ and NSE values with SWAT are 0.951 and 0.937 for calibration period, and 0.882 and 0.875 for validation period, respectively. the $R^2$ and NSE values with SWAT-SWMM are 0.877 and 0.880 for validation period. Out of four LID scenarios simulated by SWAT-SWMM model, the green roof scenario was found to be most effective which reduces about 25% of rainfall-runoff flows.

• KIEAE Journal
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• v.5 no.2
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• pp.11-18
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• 2005

The Purpose of this study is development and analysis of Effluence Characteristic of the Rainfall in the IRMA Green Roof System(developed in KICT) Plus 50 program is an internal research project at KICT(Korean Institute of Construction Technology) which has it as an object ; to lengthen the building's life 50-year or more and reduce energy conception 50% than present. Green roof system is one of the most important theme in the Plus 50 program. Generally, a Green Roof System has a positive effect on the thermal conductivity in winter, the micro cooling effect on building and city by evaporation in summer, the flood-control effect by runoff-reduction or the treated rainwater-quality of green roof system and so on. However, inspection of the physical effect of green roof system does not consider in Korea. Above all, long-term monitoring and a whole observation of green roof system is needed to probate the effect. So a new experimental method could be tried in this research, which is never attempted in Korea. The measurement by a bucket with a great volume, 1L, gives a new dimension of measuring green roof effect to measure the permanent running flood from a wide roof. This offers a reasonable result on a long-term measuring of a running water. Additionally, the thermal behavior of the IRMA(Insulated Roof Membrane Assembly), known in the western europe as a reasonable solution at green roof system by economical benefits and easy construction, would be experimented.

• Journal of the Korea Concrete Institute
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• v.19 no.2
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• pp.163-169
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• 2007

This study is focused on the proper mixture design of materials for the porous concrete with unsaturated polyester resin. The materials used in the mixture include the single-grade aggregates, unsaturated polyester resin as binder, and calcium carbonate as a filler. An experimental procedure has been carried out to select the best combination of the materials that satisfy both the required permeability and compressive strength. Various kinds of gravel size, the ratio of binder, and F/B ratios are tried to get proper mixture, and the permeability coefficient and compressive strength have been measured to find out the best combination of materials based on the proper Korean Standards. A promix design satisfied the standards of rainfall runoff reduction system with $3.5{\times}10^{-1}$ (cm/sec) of permeability, 34 % of porosity, 11 MPa of compressive strength can be obtained.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.62-71
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• 2012

Lake Doam watershed was surveyed to evaluate non-point source discharge characteristics and discharge load including several water quality parameters in Song Stream from July 2009 to July 2011. Concentrations of water pollutants were high during the rainfall period, especially, SS, TP and COD showed increasing tendencies toward cumulative water discharge but TN did not show much difference. SS, TP and COD had an initial flush effect of over 50 mm rainfall event but there was no clear tendency for rainfalls below that level. Event mean concentration (EMC) regarding the rainy and dry period showed large differences. Especially rainy season EMC (SS, TP, COD) demonstrated an increasingly high tendency. EMCs of COD, SS, TN and TP measured for twelve rain events were as high as 26.1, 866.0, 4.68 and 0.605 mg $L^{-1}$, respectively. COD, SS, TN and TP loadings from the highland agricultural region of the Song Stream watershed were 34,263, 1,250,254, 2,673 and 933 kg $yr^{-1}\;km^{-2}$, respectively, which were relatively higher than the results of other stream systems. Therefore, it is strongly recommended that long-term monitoring and non-point pollution reduction programs for the highland agricultural area to continue. Furthermore, this non-point source pollution loading research acquired from the highland agricultural area could be the base for reassessment.

• Journal of Korean Society on Water Environment
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• v.32 no.6
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• pp.528-536
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• 2016

The purpose of Total Pollution Load Control at Tributary is to obtain maximum improvement effect of water quality through finding the most impaired section of water-body and establishing the proper control measure of pollutant load. This study was implemented to determine the optimal management of reach, period, condition, watershed, and pollution source and propose appropriate reduction practices using the Load duration curve (LDC) and field monitoring data. With the data of measurement, LDC analysis shows that the most impaired condition is reach V (G4~G5), E group (flow exceedance percentile 90~100%) and winter season. For this reason, winter season and low flow condition should be preferentially considered to restore water quality. The result of pollution analysis for the priority reach and period shows that agricultural nonpoint source loads from onion and garlic culture are most polluting. Therefore, it is concluded that agricultural reuse of surface effluent (storm-water runoff with non-point sources) and low impact farming that includes reducing fertilization and controlling the height of drainage outlet are efficient water quality management for this study watershed.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.94-96
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• 2003

Since 1995, MOCT(Ministry of Construction and Transportation) and KOWACO(Korea Water Resources Corporation) have established the National Groundwater Monitoring Network in South Korea and also MOE(Ministry of Environment) has operated Groundwater Quality Monitoring network. Until 2001, 202 monitoring stations by MOCT and 780 monitoring wells by MOE have been constructed, measured groundwater level and analyzed water samples. Groundwater quality analysis has been conducted two times a year during last 6 years for all monitoring wells. The quality data has about 15 components including pH, COD, Count of Coliform group, and etc.. Trend analysis has been peformed for 6 components(Coliform, pH, COD, NO$_3$-N, Cl and EC) of water quality which are analyzed more than 7 times for total monitoring wells. Two test methods have been used ; Sen's test and Mann-Kendall test. These trend tests have been done at the 0.05 significance level. By the result of Sen's test, Count of Coliform group has either upward or downward trends at 4.3 percent of the monitoring points. pH does at 5.6 percent, COD does at 8.6 percent, Nitrate-Nitrogen does at 13.2 percent, Chloride does at 13.4 percent, and. EC does at 11.6 percent of the monitoring points. The exact causes of the groundwater quality trends are difficult to specify. Notable downward trends in nitrate at many monitoring points may be the result of reduction on some contamination sources. Potential causes include diminished agricultural areas, improvements in sewage treatment and a decrease in atmospheric deposition. Increase in chloride at many monitoring points may be the result of increased non-point source pollution such as road salting and runoff from sprawling paved developments and suburbs.