• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.8-14
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• 2007

Water quality in Lake Rotorua, New Zealand, deteriorated since the 1960s because of excessive phytoplankton growths due principally to increasing nitrogen and phosphorus in the lake waters. Nutrient concentrations in eight of the nine major streams feeding Lake Rotorua have increased since 1965. The groundwater system has a key role in the hydrology of the Lake Rotorua catchment and the groundwater system is probably the control on the time delay between intensification of agricultural land use and response of surface water quality. All major, and many minor streams, in the catchment are fed by springs. Two lithological units are most important to groundwater flow in the Lake Rotorua catchment: Mamaku Ignimbrite, erupted in about 200,000 years ago and Huka Formation sediments which filled the caldera left by the Mamaku Ignimbrite eruption. Rainfall recharge to groundwater in the groundwater catchment of Lake Rotorua is estimated as approximately 17300 L/s. A calibrated steady-state groundwater flow model estimates that approximately 11100 L/s of this flow discharges into streams and then into the lake and the balance travels directly to Lake Rotorua as groundwater discharge through the lake bed. Land use has impacted on groundwater quality. Median Total Nitrogen (TN) values for shallow groundwater sites are highest for the dairy land use (5.965 mg/L). Median TN values are also relatively high for shallow sites with urban-road and cropping land uses (4.710 and 3.620 mg/L, respectively). Median TN values for all other uses are in the 1.4 to 1.5 mg/L range. Policy development for Lake Rotorua includes defining regional policies on water and land management and setting an action plan for Lake Rotorua restoration. Aims in the action plan include: definition of the current nutrient budget for Lake Rotorua, identification of nutrient reduction targets and identification of actions to achieve targets. Current actions to restore Lake Rotorua water quality include: treatment of Tikitere geothermal nitrogen inputs to Lake Rotorua, upgrade of Rotorua City sewage plant, new sewage reticulation and alum dosing in selected streams to remove phosphorus.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.3
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• pp.41-57
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• 2021

This study evaluated the application of water quality management measures using the SWAT model and the effectiveness of the measures using the load duration curve targeting the Seohwacheon watershed located upstream of Daecheongho. As water quality management measures, artificial wetlands, reduction of neglected livestock, reduction of runoff from greenhouses, restoration of ecological rivers, application of LID technology, and management of point sources were applied. The applied technology evaluated the efficiency of water quality improvement measures by using the target water quality excess rate and the degree of load reduction for each sulfur through the load duration curve. The load duration curve was created by creating a long-term flow duration curve using SWAT and multiplying it by the target water quality. For the target water quality, the value corresponding to the 60th percentile was set as the target water quality using the 10-year data from the Okcheoncheon water quality observation point located in the downstream of Seohwacheon. Through this study, it was possible to confirm the applicability of various water quality measures through the SWAT model, and to examine the applicability of each period according to the sulfur through the load retention curve.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.903-909
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• 2010

The purpose of this study was evaluated on the applicability of Load Duration Curve Method (LDC Method) using HSPF watershed model and sampling data for efficient TMDLs in Korea. The LDC Method was used for assessment pollutant characteristics in watershed and water quality variation in each water flow level. Load Duration Curve is applied for judge the level of impaired water-body and can be estimated the impaired level by pollutant, such as BOD, T-N, and T-P in this study depending on variation of stream flow. As a result, BOD, T-P was usually exceed the standard value at low flow and dry hydrologic period. Improvement of effluent concentration from WWTP and riparian buffer protection zone are effective to improve the water quality. T-N showed the worst condition at mid-range hydrologic period and moist hydrologic period. Therefore, soil erosion control program and BMPs for non-point source pollution control is effective for recovery the water quality, which can be useful method for management of water quality in the plan of recovery water quality spontaneously. Applicability of LDC Method was evaluated in the Nakbon A watershed. However, we need to consider more detailed and accumulated data set such as accurate GIS data and detail pollution data, and WWTP discharge water quality data for accurate evaluation of watershed. Overall, The LDC Method is adequate for evaluation of watersheds characteristics, and its application is recommended for watershed management and TMDL Implementation.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.10
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• pp.691-697
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• 2014

Though the upper stream basin area of Gwanpyung-Cheon in Daejeon, Korea is protected as Green Belt Zone, the stream is under constant environmental pressure due to current agricultural practices and infrastructure development in its basin area. To develop appropriate integrated water resources management plan for the stream, it is necessary to consider not only water quality problems but also water quantity aspect. In this study, Storm Water Management Model (SWMM) was calibrated and validated with sets of field measurements to predict for future water flow and water quality conditions for any rainfall event. While flow modeling results showed good agreement by showing correlation coefficient is greater than 0.9, water quality modeling results showed relatively less accurate levels of agreements with correlation coefficient between 0.67 and 0.87. Hypothetical basin development scenarios were developed to compare effect on stream water quality and quantity when Low Impact Development (LID) technologies are applied in the basin. The results of this study can be used effectively in decision making processes of urban development Gwanpyung-Cheon area by comparing basin management alternatives such as LID methods.

• Journal of Environmental Impact Assessment
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• v.26 no.6
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• pp.431-444
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• 2017

This study was carried out to review the guidelines being used by law and national policy concerned on river environments management and suggest the applicability of newly developed river environment assessment system. In the current legal system, the national river environment management system is insufficient in securing an independent status in the legal institutional system which is separated to the Ministry of Land, Transport and Infrastructure and the Ministry of Environment. And the river environment assessment system of the national standard, which is a core matter, has not been established yet. In particular, there is a lack of integrated approach between the upper and lower plan or related plans on water resources, water quality, river environment and aquatic ecosystem management. In addition, the consistency and effectiveness as the process of planning and design according to the current status and comprehensive analysis and evaluation of the river environment were not secured either. To integrate national river environment management system and improve efficiency, I proposed the establishment of hierarchy and connection between national river plans, and the adoption and application of developed assessment system based on characteristics of river environment in Korea. Finally, I proposed the separated application with dividing the developed assessment system including the naturalness of river environment and suitability of water friendly activity into both assessment method for management plan of water resources of river basins & basic river plan respectively.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.3
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• pp.27-45
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• 2018

Both the national land plan and the environmental plan reflect the need for sustainable land use and management. However, the linkage between the plans is reduced due to the lack of integrated management. Therefore, this study developed indicators to achieve integrated management. A total of 59 environmental plans were reviewed for the development of indicators, and a total of 74 integrated management indicators were derived through a three-stage process. In this process, the relevance of the integrated management indicators of this study to the UN 's sustainable development goals (SDGs) is presented in order to derive indicators that meet the level of international consultation. In order to facilitate the utilization of the indicators, the final indicators are divided into seven areas: natural ecology, water resource and quality, urban and green space, atmospheric, energy, landscape, resource circulation and waste. Furthermore, the indicators were classified into national, regional, and city level. Accordingly, the final indicator can be adapted to the field of influence of the planned to be established, and the indicator can be selected and applied to the level of the plan. The final indicators can be used to examine the extent to which the national plan reflects the contents of the environmental plan and can be used as an aid to confirm the contents to be included in the plan when establishing a new national plan.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.11-18
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• 2005

When it is raining or snowing, floating debris flows into a lake and raises its turbidity. High level of turbidity in the lake often causes eutrophication, which pollutes the water. In order to collect and present some essential information for effective management plan for water quality, we carried out our research at the watershed of Mandae-cheon located at the upstream of Soyang Lake. We examined water quality at the time of rainfall or snowfall to analyze the changes in the amount of suspend soils(SS) in the lake.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1248-1252
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• 1999

To provide electricity power of good quality, it is essential to establish generation of electricity plan in electric power system based on accurate power-demand prediction and cope with changes of power-need fluctuating constantly. The role of hydraulic-power generation of electricity in electric power system is of importance because responding to electric power-demand counts or reservoir-type hydraulic-power generation of electricity which is designed for additional load in electric power system. So hydraulic-power generation of electricity must have fast start reserve. But the amount of water, resources of reservoir-type hydraulic-power generation of electricity is restricted and multi-used, so the scheduling of management by exact forecasting the amount of water is critical. That is why efficient hydraulic-power generation of electricity makes a main role on pumping up the utility of energy and water resource. This thesis introduced the example of optimal generation of electricity plan establishment which is used in managing reservoir-type hydraulic-power generation of electricity.

• Journal of Environmental Science International
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• v.25 no.2
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• pp.217-229
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• 2016

The government has conducted a plan of total maximum daily loads(TMDL), which divides with unit watershed, for management of stable water quality target by setting the permitted total amount of the pollutant. In this study, BOD concentration trends over the last 10 years from 2005 to 2014 were analyzed in the Geumho river. Improvement effect of water quality throughout the implementation period of TMDL was evaluated using the seasonal Mann-Kendall test and a LOWESS(locally weighted scatter plot smoother) smooth. As a study result of the seasonal Mann-Kendall test and the LOWESS smooth, BOD concentration in the Geumho river appeared to have been reduced or held at a constant. As a result of quantitatively analysis for BOD concentration with exploratory data analysis(EDA), the mean and the median of BOD concentration appeared in the order of GH8 > GH7 > GH6 > GH5 > GH4 > GH3 > GH2 > GH1. The monthly average concentration of BOD appeared in the order of Apr > Mar > Feb >May > Jun > Jul > Jan > Aug > Sep > Dec > Nov > Oct. As a result of the outlier, its value was the most frequent in February, which is estimated 1.5 times more than July, and was smallest frequent in July. The outlier in terms of water quality management is necessary in order to establish a management plan for the contaminants in watershed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.4
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• pp.451-458
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• 2018

The coast of Incheon reaches Incheon itself, Gimpo, Siheung, and Ansan of Gyunggi-do. Because this area has been seriously polluted, the Ministry of Oceans and Fisheries has established the Incheon Special Area Management Plan (SAMP) to preserve sea water quality as a marine environment asset. However, there is concern that actions taken in this area may change the surrounding marine ecology, being effected by farms, via a river that flows from waste lands, abandoned fishing activities and fishing nets, etc. Given this background, this study estimates the value of SAMP sea water quality using a choice experiment (CE). A CE survey of 1,000 households was undertaken, investigating trade-offs involving price and four attributes for selecting a preferred alternative to obtain a marginal willingness to pay (MWTP) estimate for each attribute. The estimation results showed that MWTP for a 1 %p improvement in sea water quality, the diversity of fauna species, the diversity of flora species, and a 1 %p reduction in marine litter as a result of conserving Incheon coastal sea water quality are estimated to be KRW 75, 135, 309 and 72 per household per year, respectively. All estimation results were statistically significant at the 1 % level. These findings can provide policy makers with useful information for evaluating and planning marine environmental management policies.