• Journal of Environmental Science International
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• v.21 no.3
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• pp.277-287
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• 2012

The MFFn(Mass First Flush) was analyzed for various rainy events(monitoring data from 2008 to 2009) in Transportation area(Highway, National road, Trunk road). Estimated MFFn using SWMM was evaluated by comparison with observed MFFn. MFFn was estimated by varying n-value from 10% to 90% on the rainy events. The n-value increases, MFFn is closed to '1'. As time passed, the rainfall runoff was getting similar to ratio of pollutants accumulation. The result of a measure of the strength of the linear relationship between observed data and expected data under model was good ($R^2$=0.89). Pollutants runoff loads by volume showed Highway 26.6%, National road 44.8%, Trunk road 35.0% at the MFF20(20% by total runoff). A case of MFF30, pollutants runoff loads by volume showed Highway 40.2%, National road 54.3%, Trunk road 46.8%. According to the results, Initial precipitation basis were Highway MFF30, National road MFF20, Trunk road MFF30 when the Non-Point source control facilities set up.

• Journal of Korean Society on Water Environment
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• v.26 no.2
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• pp.311-316
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• 2010

We estimated the nitrogen and phosphorus loads of wintering waterfowl feces in Lake Paldang. The average number of individual birds that belonged to Anatidae species was 2,852.5 from 2005 to 2008 in Lake Paldang. The number of Anatidae reached 97.4% of the total number of individual birds. For evaluating the loading amounts of N and P by waterfowl to Lake Paldang, the feces dry weight (g/day) of each Anatidae species was estimated by multiplying the body weight of the each bird by 2.25% and assumed that N and P in feces contain 1.46% and 0.33%, respectively. We assigned probability 1/3 to the nutrient decomposition of the bird feces in water. The nitrogen loading by wintering waterfowl feces was 0.06 ton/year and the phosphorus loading was 0.001 ton/year. These amounts were 0.0002% of all N loadings and 0.0001% of all P loadings. Therefore the wintering waterfowl might have little impact on the water quality in terms of eutrophication in Lake Paldang.

• Journal of Korean Society of Rural Planning
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• v.23 no.4
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• pp.39-48
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• 2017

National Institute of Environmental Research (NIER) has proposed new methodology for estimating unit load in order to overcome the limitations of past unit load based on short-term and local area based data. In the case of agricultural land, however, the results presented by NIER are still limited because of various agricultural activities and farmland characteristics. In this study, liquid manure treated paddy field and organic farming upland were selected for considering agricultural diversity. Four different methods for evaluating unit load were used for comparing previous research results. The results of different methods presented various trends compared with those of existing studies. Paddy field treated liquid manure was 1.3 times higher for T-N load and 3.1 times for T-P load than conventional paddy field. Conventional upland was 4.4 times higher for T-N load and 1.8 times higher for T-P load than organic farming upland. In the case of non-conventional farmland, this study showed different values with the unit loads presented by NIER. This implies that it is necessary to review and apply the unit loads considering various agricultural conditions when establishing environmental policy and rural planning.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.913-919
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• 2007

This study was conducted to develop a model equation to estimate the delivered point and nonpoint pollutant loads, which are critical factor to determine the water quality of watersheds. The model equation was developed by considering various factors such as biological removal and delivered distance of pollutants, basin shape and geomorphic runoff condition. The parameters for the model equation were estimated in 3 periods, which are October to March, April to June, and July to September. As a parameter, ${\alpha}_p$, ${\alpha}_n$, ${\beta}$, a and b for $BOD_5$-delivered pollutant loads were estimated to be 0.010~0.0155, 0.051, -0.033, 0.018~0.050 and 0.93, respectively. For T-N, ${\alpha}_p$, ${\alpha}_n$, ${\beta}$ a and b were estimated to be 0.0060~0.0140, 0.014, -0.02, 0.044~0.079 and 0.93, respectively. The same parameters for T-P were estimated to be 0.0160, 0.014, -0.0250, 0.015 and 1.21, respectively. The relationship, $E^2$ (Model efficiency), between observed and calculated delivered pollutant loads showed 0.65 for $BOD_5$, 0.81 for T-N, and 0.66 for T-P, respectively. Consequently, the model equation is effective to estimate delivered pollutant loads for TMDL.

• Journal of Korea Water Resources Association
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• v.39 no.6 s.167
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• pp.533-544
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• 2006

The deposition of solids in combined sewer systems results in a loss of flow capacity that may restrict flow and cause a local flooding and enhanced solids deposition. In order to solve these problems and proper pipe management, estimation of solid loads from sewer and surface in a drainage basin is needed but this task is very difficult and extremely expensive. In this study, generalized procedures for estimating sewer solid loads during dry weather in combined sewer systems and for estimating solid loads on surface in a drainage basin developed by the U. S. Environmental Protection Agency were applied and analyzed in Gunja drainage basin in Korea. As result, the estimated solid loads from sewer and surface are 205.8,759kg/yr and 1,321,993kg/yr respectively, and total solid loads is 1,527,752kg/yr. The estimated solid removal from street cleaning, dredging from pipe system and pumping house is 1,486,636kg/yr. Therefore, the applied methods show resonable results. More reliable estimation can be achieved if long-term measurements and adjustment of estimation equations are carried out, and this estimation methods can be used usefully for the management of combined sewer system with reduction of cost and effort.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.508-512
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• 2015

Carbon emission calculation guidelines provided by the Korean Ministry of Land, Infrastructure and Transportation (MOLIT) and existing environmental load assessment studies have suggested a method for estimating based on the volume determined after the design development. Therefore they are not being helpful in the decision making of the environmental economics of road facilities in the planning stage in which specific information on construction output volume is lacking. Based on literature analysis of existing studies and consultation from a group of construction environmental professionals, 12 types of property information considered to be related to environmental load were selected from an inventory of information that will be available in the road planning stage. In addition, multiple regression analysis was performed based on the environmental load computed through the life cycle assessment (LCA) of 40 national highway project cases of Korea to deduce five impact factors of environmental load in the road facilities planning stage.

• Journal of Korean Society on Water Environment
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• v.28 no.6
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• pp.833-842
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• 2012

In this study Window interface to Hydrological Simulation Program-FORTRAN (HSPF) developed by the United States Environmental Protection Agency (EPA) was applied to the upstream of Namgang watershed to estimate its applicability for estimating Delivery Ratio (DR) of water pollutants for Total Maximum Daily Load (TMDL). BASINS/HSPF which is selected in this study, is found to be appropriate for simulation of daily flow and water quality in target basins. DR was estimated utilizing discharge loads of unobserved sub-basin and delivery load of unobserved locations obtained not by actual evaluation but by simulation through validation and verification. Annual average DR of BOD, TN and TP were 0.97 ~ 1.50, 2.23 ~ 3.21, and 0.81 ~ 1.09 respectively. Net DR of dependent basins excluding influence of upstream basin was 1.50 ~ 1.70, 0.55 ~ 0.69, and 0.24 ~ 0.31, all of which are lower than those of independent basins area. Utilizing the model selected by this research, DR and Net DR of unobserved basins will be estimated, which will help determine priorities in management of basin areas.

• Journal of the Korean GEO-environmental Society
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• v.17 no.10
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• pp.13-22
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• 2016

An optimized spudcan was designed for the Southwestern Sea, an area mostly comprised of sand and soft clay layers. The spudcan was designed using guidelines by SNAME, ISO, and InSafeJIP, as well as the yield surface for combined loads. The probe test method was applied to define a yield surface used in estimating spudcan stability. Numerical analyses that considered vertical, horizontal, and moment loads in Southwestern Sea resulted in a design of 8 m diameter spudcan. Additionally, the empirical equations suggested by previous studies can estimate a reasonable spudcan bearing capacity at shallow depth. Each yield surface calculated from Mohr Coulomb and Hardening soil model showed different shapes, however the yield surface also grew with increasing spudcan diameter. This yield surface is a useful reference, along with site investigation results and published guidelines, to estimate the stability of a spudcan in the Southwestern Sea.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.9
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• pp.830-839
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• 2010

This study presents a constituent load estimating procedure that can be operated with the present Korean TMDL monitoring system. The modified TANK model is used as a daily river flow simulation model whose parameters are estimated from 8-day intervals flow data. Constituent loads are estimated with the 7-parameter log linear model whose parameters are estimated by the minimum variance unbiased estimator. Results from Nakdong river basin reveals that the proposed procedure provides satisfactory TOC and BOD load estimates. As an application, a representative load duration curve is derived for working out a way to represent the overall hydrologic flux of BOD, COD and TOC at Nakdong river basin. The present water quality can be checked stochastically by Load Duration Curve through this study and presented visually.

• Environmental and Resource Economics Review
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• v.13 no.3
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• pp.417-440
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• 2004

For the behavior of the wholesale spot price, a regime switching model with time-varying transition probabilities was estimated using the data from the PJM (Pennsylvania-New Jersey-Maryland) market. By including the temperature as an explanatory variable in the transition probability equations, the threshold effect of changing regime is clearly enhanced. And hence the predictability of the price spikes was improved. This means that the model showed a very clear threshold effect, with a low probability of switching for low loads and low temperatures and a high probability for high loads and high temperatures. And temperature showed a clearer threshold effect than load does. This implies that weather-related contracts may help to hedge against the risk in the cost of buying electricity during a summer.