• Journal of Ocean Engineering and Technology
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• v.33 no.6
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• pp.597-606
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• 2019

Due to climate change, coastal areas are being flooded with torrential rain, typhoons, and tsunamis. In addition, non-point source pollutants (NPSs) that accumulated on the ground, streets, and buildings during the dry season are washed off by rain and stormwater runoff, which adds to the damage associated with environmental pollution, e.g., pollution that makes its way into the ocean. Recently, low impact development (LID) has been considered as a means of controlling water circulation and NPSs. In the coastal area, permeable blocks have been constructed mainly to reduce the flood damage caused by waves. Some important design factors that must be considered to ensure long-term performance are the permeability coefficient, clogging, and the efficiency of the removal of total suspended solids (TSS), but currently there are no standardized design criteria or testing techniques that are used worldwide. Herein, we analyzed the permeability coefficient and the TSS removal efficiency tendency according to the permeability area ratio with an easily-detachable, permeable block filled with calcinated yellow soils as the filter media. Our lab-scale tests indicated that, when the permeability area ratio was 25%, the reduction of the permeability coefficient after clogged was 11%, which was a significant decrease compared to other cases. Permeability persistence increased when the permeability area ratio increased from 50% to 75%. The TSS removal efficiency decreased as the permeability area ratio increased. Our pilot-scale test indicated that the TSS removal efficiency was more than 80% higher in all cases. We also found that the permeability persistence was excellent as the permeability area ratio increased, and, in actual construction, it is effective to set 5.3% of the total area as permeable area in terms of permeability and economic feasibility.

• Korean Journal of Environment and Ecology
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• v.18 no.1
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• pp.53-60
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• 2004

This study was carried out to investigate the effect of green area in apartment complexes to variation of temperature. The inside temperature of each site was estimated by analyzing Landsat ETM＋ image data. The factors on variation of temperature were landcover type, building density, and Normalised Difference Vegetation Index(NDVI). The results of correlation between inside temperature of apartment complex and land cover type showed that the green area ratio had negative(－) correlation and impermeable pavement ratio had positive(＋) correlation. Building-to-land ratio was not significant with inside temperature. A coefficient of correlation between the temperature value and the value of permeable pavement ratio added up green area ratio was higher than a coefficient of correlation between the temperature value and the value of permeable pavement ratio added up impermeable pavement ratio. Thus we may define that permeable pavement area decrease urban temperature with green area in apartment complex. Floor area ratio had no significant correlation with inside temperature. Inside temperature was decreased as the NDVI was increased. To establish the temperature distribution model in a development apartment complex, As the result of regression analysis between inside temperature as dependent variable and permeable pave ratio+green area ratio, green area ratio, building-to-land ratio and NDIT as independent variables, only permeable pavement ratio added up green area ratio of the independent variables was accepted fur regression equation in both two seasons and adjusted coefficient of determination was 41.4 on September, 2000 and 40.4 on June,2001.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.3
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• pp.105-119
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• 2020

The purpose of this study is to analyze the hydrologic cycle environment of Gyeongui Line Forest Park, a linear city park, in order to improve hydrologic cycle systems in urban areas. The method of the study is the Biotope Area Ratio and the Permeable ratio survey. The study subject is the Gyeongui Line Forest Park, created in 2016 as a linear park in Seoul. The results showed that the Biotope Area Ratio improved by 31.2% (31,927㎡) from 35.7% (36,480㎡) in 2000 to 66.9% (68,407㎡) in 2019 on a site area of 102,117㎡. Next, the Permeable ratio improved by 43.8% from 29.0% to 72.8%, and the impermeable ratio decreased by 43.8% from 71.0% to 27.2%. The Biotope Area Ratio exceeded the target ratio of 60% by 6.9%, set by the Ministry of Environment. The ratio of green space exceeded the target ratio of 60%, by 4.0%. And so they contributed to the improvement of the hydrologic cycle by the creation of the Gyeongui Line Forest Park. Urban parks need to exceed the Biotope Area Ratio and the green area ratio of the legal standards, especially when creating large parks of over 100,000 square meters, in the era of climate change. It is necessary to continuously plant trees in the space where trees can be planted, and to contribute to the improvement of the hydrologic cycle system and urban heat island effect by conducting three-dimensional.

• Journal of Korea Water Resources Association
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• v.55 no.11
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• pp.969-977
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• 2022

In order to respond to the increase in water disasters due to climate change and urbanization, research on low impact development (LID) techniques and application to cities are expanding. The LID technique is a technology that reduces rainwater runoff in the city, controls various water disasters such as flash floods, etc. in an eco-friendly way, and restores the urban water circulation system to a natural water circulation system. However, quantitative analysis of stormwater runoff reduction through the LID technique is insufficient. Therefore, this study analyzed the ratio of the permeable area required to reduce the surface runoff of rainfall (25 mm/hr, 50 mm/hr, 100 mm/hr) with respect to the impervious watershed area of the old city using the permeable pavement. As a result of the analysis, it was found that a permeable area ratio of 7.14 to 12.63% of the total area was required for 25 mm/hr, 15.79 to 26.97% for 50 mm/hr, and 30 to 55.81% for 100 mm/hr.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.2
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• pp.47-57
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• 2023

The increase of impermeable area ratio is causing hydrologic cycle problems in urban areas and groundwater depletion in rural areas, permeable pavements are getting attention to expand permeable areas. The performance of the permeable concrete block pavement, which is part of the permeable pavement, is greatly affected by the porosity. In addition, the permeability coefficient is a major factor when designing permeable concrete block pavement. Existing porosity and permeability test methods have problems such as uneconomical or poor field applicability. The object of this study was to develop a methodology for evaluating porosity and permeability coefficient using a surface image of a permeable concrete block. Specimens are manufactured with various porosity ranges and porosity and permeability tests are performed. After surface image preprocessing, normalization and binarization methods were compared. Through this, the method with the highest correlation with the lab test result was determined. From the results, the PDR (pore determined ratio) was obtained. Simple linear regression analysis is performed with PDR and lab test results. The results showed a high correlation of R² more than 0.8, and the errors were also low.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.193-198
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• 2011

This study aimed to provide basic data for permeable pavement application upon design and installation stages by analyzing the effect of permeable pavement used on the facility area rather than using non-point pollutants treatment facility upon development business in accordance with recent trend. To perform this study, the area of development target was separately applied as impermeable and permeable developments so as to compare and analyze the economics of cut pollution load and installation construction cost. Consequently, the processing amount and cut load of non-point pollutant sources are influenced much by permeable and impermeable developments, and it was turned out to be better to develop target river area as permeable area rather than installing non-point pollutants treatment facility of equipment type or natural type upon development to yield smaller discharge load. If we can prepare a countermeasure regulating impermeable area ratio to certain level to manage non-point pollutants upon development based on this result, we can minimize the source of pollution caused by the development.

• International Journal of Highway Engineering
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• v.17 no.4
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• pp.11-18
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• 2015

PURPOSES: This study aims to evaluate the runoff reduction with permeable pavements using the SWMM analysis. METHODS: In this study, simulations were carried out using two different models, simple and complex, to evaluate the runoff reduction when an impermeable pavement is replaced with a permeable pavement. In the simple model, the target area for the analysis was grouped into four areas by the land use characteristics, using the statistical database. In the complex model, simulation was performed based on the data on the sewer and road network configuration of Yongsan-Gu Bogwang-Dong in Seoul, using the ArcGIS software. A scenario was created to investigate the hydro-performance of the permeable pavement based on the return period, runoff coefficient, and the area of permeable pavement that could be laid within one hour after rainfall. RESULTS : The simple modeling analysis results showed that, when an impervious pavement is replaced with a permeable pavement, the peak discharge reduced from $16.7m^3/s$ to $10.4m^3/s$. This represents a reduction of approximately 37.6%. The peak discharge from the whole basin showed a reduction of approximately 11.0%, and the quantity decreased from $52.9m^3/s$ to $47.2m^3/s$. The total flowoff reduced from $43,261m^3$ to $38,551m^3$, i.e., by approximately 10.9%. In the complex model, performed using the ArcGIS interpretation with fewer permeable pavements applicable, the return period and the runoff coefficient increased, and the total flowoff and peak discharge also increased. When the return period was set to 20 years, and a runoff coefficient of 0.05 was applied to all the roads, the total outflow reduced by $5195.7m^3$, and the ratio reduced to 11.7%. When the return period was increased from 20 years to 30 and 100 years, the total outflow reduction decreased from 11.7% to 8.0% and 5.1%, respectively. When a runoff coefficient of 0.5 was applied to all the roads under the return period of 20 years, the total outflow reduction was 10.8%; when the return period was increased to 30 and 100 years, the total outflow reduction decreased to 6.5% and 2.9%, respectively. However, unlike in the simple model, for all the cases in the complex model, the peak discharge reductions were less than 1%. CONCLUSIONS : Being one of the techniques for water circulation and runoff reduction, a high reduction for the small return period rainfall event of penetration was obtained by applying permeable pavements instead of impermeable pavement. With the SWMM analysis results, it was proved that changing to permeable pavement is one of the ways to effectively provide water circulation to various green infrastructure projects, and for stormwater management in urban watersheds.

• Journal of the Korea Institute of Building Construction
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• v.18 no.5
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• pp.447-453
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• 2018

Since 1960, Korea the town center was developed intensively due to rapid industrial development. As a result of the development, the population was concentrated in urban areas and the green area was decreased. Due to the decrease of the green area, the circulation system of the rainwater was changed, hence the rainwater was not introduced into the groundwater., On the other hand, the water on the surface of the road was changed into the water for flowing to the river and evaporation. The changes in the water flow cause many problems, and the depletion of the groundwater does not create an environment in which microorganisms and plants can live. in Korea, permeable pavement construction is increased to solve these problems, but existing pavement blocks have many problems. The pores of the permeable block are clogged due to the accumulation of dust or whitening phenomenon, and the permeability is lost. In this study, the solution of the problems of existing permeable block were suggested by using polymer and artificial permeable pipe, and strength, permeability and service life are increased, The relationship between the substitution rate of the polymer and the mixing ratio of the artificial permeable pipe was analyzed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.429-437
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• 1999

A mathematical model was established for estimating changes in pressure and volume of permeable kimchi packages. The model comprises the CO2 gas production from kimchi and permeation of O2, CO2 and N2 through the permeable film or sheet. Using the developed model, the effects of various packaging variables on the pressure and volume changes were analyzed for rigid and flexible packag es of kimchi(3% salt content) at 15oC, and then effect of storage temperature was also looked into. In case of rigid pack of 400g, using the plastic sheet of high CO2 permeability and initial vacuumizing can help to relieve the problem of pressure build up. The lower fill weight can further reduce the pressure, but will result in higher packaging cost. For the flexible package of 3 kg, highly permeable films such as low density polyethylene(LDPE) and polypropylene can reduce the volume expansion. Higher ratio of CO2 permeability to O2 and N2 permeabilities are effective in reducing the volume expansion. Increased surface area cannot contribute to reduction of volume expansion for highly permeable flexible packages of kimchi. For the impermeable packages, pressure and volume at over ripening stage (acidity 1.0%) increase with decreased temperature, while those at optimum ripening stage(acidity 0.6%) change little with temperature. Pressure of permeable rigid LDPE package increases with tem perature at any ripening stage, and temperature affects the volume of flexible LDPE package very slightly. Experimental verification of the present results and package design with economical consid eration are needed as a next step for practical application.

• Journal of Korea Water Resources Association
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• v.56 no.12
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• pp.905-918
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• 2023

This study aimed to assess runoff reduction performance and determine installation priorities for Permeable Pavement (PP) and Rain Barrel (RB) within the Mokgam Stream basin. Optimal design parameters were determined to maximize the effectiveness of PP and RB in reducing runoff. Furthermore, the optimal parameters were incorporated to compare the runoff reduction performance of PP and RB. Analysis of the runoff curve at the basin outlet indicated that PP demonstrated superior performance in reducing runoff during the rising limb of the curve. At the same time, RB excelled within the falling limb. Comparisons of total runoff and peak runoff reduction by sub-catchment revealed that in larger sub-catchment areas, PP outperformed RB in runoff reduction. In contrast, RB exhibited higher performance in areas with a higher impervious ratio. Based on the evaluation of runoff reduction performance for PP and RB, installation priorities were determined within the Mokgam Stream basin. The results showed that PP and RB installations were prioritized for sub-catchments with larger areas and a higher impervious ratio. Furthermore, the correlation between the ranking of runoff reduction performance and sub-catchment characteristics showed a high correlation with both the impervious area ratio and sub-catchment geometrical properties in sub-watersheds exhibiting the top 25% runoff reduction performance. These results emphasize that when determining the priority for installing LID facilities in developed urban areas, it is necessary to consider not only the impervious area ratio but also the geometrical properties of the sub-catchment.