• Journal of Environmental Science International
• /
• v.27 no.10
• /
• pp.883-899
• /
• 2018

In this study, water quality data of eight main sites in the Geumho River watershed were collected and analyzed for long-term changes in water quality over the period from 2005 to 2015. The results showed that BOD concentration was gradually improved by the Total Maximum Daily Load (TMDL), stages 1 and 2. Recently, a tendency of increasing BOD concentration was observed in the downstream section of the river. The concentration of COD was analyzed to be contaminated throughout the water system regardless of the water quality improvement project, and the TN concentration tended to increase in the midstream of the river from 2013. The TP concentration has clearly decreased from 2012 after the second stage of TMDL. For the statistical analysis of PCA ordination, monthly water qualities (pH, DO, Electrical Conductivity (EC), Water Temperature (WT), BOD, COD, TN, TP, TOC, and SS) and flow rate data for 5 years from 2012 to 2016 were used. Seasonally the Geumho River showed an increase in the TN concentration at point sources during the dry season (December to February). TP showed the effect of non-point sources in the summer, because rainfall has caused a rise in flow rate in the upstream. Besides, the origin of pollution source was changed from non-point sources with BOD, COD, and TOC.

• Journal of Korean Society on Water Environment
• /
• v.31 no.3
• /
• pp.313-318
• /
• 2015

To study the influence of changes in river discharge on water quality of the main stem of the Geum River, we investigated variation of inflow load from tributaries with river discharge. We also studied the mixing behavior of pollutants during mixing of waters of the main stem and Gap Stream. For this study, we collected water quality data such as suspended solids (SS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) representing pre-monsoon, monsoon, and post-monsoon events of 2013 from a website of Water Information System. Based on inflow load, the Gap and Miho streams may be ones of tributaries which may largely influence water quality of main stem in upper river region. The Suksung and Nonsan Streams seemed to further affect water quality downstream. Results of modified EMMA indicated SS and TP may have another source(besides Gap Stream) at pre-monsoon, monsoon, and post-monsoon period. In contrast, TN and organic matter (BOD, COD, TOC) were conservative at pre-monsoon and post-monsoon. However, when river discharge increased, these pollutants may also came from unspecified non-point sources. Therefore, we need to attempt to find non-point sources for the pollutants in the main channel of upper Geum River region.

• Journal of Environmental Health Sciences
• /
• v.24 no.1
• /
• pp.80-86
• /
• 1998

Seom River was major branch of Namhan river, consist of primary basin that Wonjoo-city, Hoingsung-gun and primary contamination source was sewage from human lives. This study was evaluated production contamination loading of each branch basin and water quality grade and water quality simulation by QUAL2E to provide efficient contaminations source control. Rusult of survey, production loading of BOD, T-N, T-P were 26,591 kg/day, 4,560 kg/day, 731 kg/day resectively. Water quality analysis in 17 points of main stream were appeared that 1st grade(BOD 1 mg/l under) was 6 point, 2nd grade was 9 point and 3rd grade was 2 point. And result of water quality analysis for branch steram, first grade was evaluated 68.7%. Based of field data, calibration and verification result were in good agreement with mesured value within coefficient of variance were from 2.59% to 18.73%, from 6.39%, to 28.46%, respectively.

• Korean Journal of Ecology and Environment
• /
• v.45 no.4
• /
• pp.347-355
• /
• 2012

In this study, non-point pollution sources in the Yeongsan river basin are analyzed; then, the priority regions (areas divided on a small scale) of management are selected for efficient water management of the Seungcheon and Jooksan reservoirs, which were constructed as one of the 4 major rivers restoration projects. The priority regions are decided by using the criteria of the excessive rate of target water quality, non-point pollution load per unit area, total TP load and down flow distance. The results of this study are as follows. The upper 10% of the priority regions for non-point pollution management includes YB15, YB05, YB10, YB24, YB14 and YB11 for the Seungcheon reservoir watershed, and YC24, YC25, YC30, YC34, YC22 and YC17 for the Jooksan reservoir watershed. However, a few regions in each of the Seungcheon and Jooksan reservoirs need to be selected in higher order, and the non-point pollution removal facilities in the regions need to be installed with respect to budget, urgent matter, and so on.

• Journal of Korean Society on Water Environment
• /
• v.35 no.1
• /
• pp.9-18
• /
• 2019

Recently, it was realized that a significant portion of pollution from urban areas originates from non-point sources such as construction sites, washoff from impervious surfaces, and sewage input from unsewered areas and combined sewer overflows. Especially, Urban stormwater runoff is one of the most extensive cause of the deterioration of the water quality in streams located in urban area. The objective of this study was to investigate runoff characteristics of non-point pollutants source at the urban area in the Suyeong River. Water quality variations were investigated at two points of Suyeong River during a period of 10 rainfall events. Concentration difference of non-point pollution source appeared big by precedent number of days of no rainfall. In addition, Event mean Concentration (EMCs) that well represents runoff characteristics of storm water during rainfall, was calculated, and runoff pollutants loading was also examined. The probability distribution of EMCs of BOD, COD, TOC, T-N, T-P, and TSS were analyzed and the mean values of observed EMC and the median values of estimated EMCs compared through probability distribution. Other objectives of this study were the characterization of discharge from non-point source, the analysis of the pollutant loads and an establishment of a management plan for non-point source of Suyeong River. Also, It was established that the most important thing for the administration of non-point pollution source is to come up with the solution for the reduction of effluent at the beginning.

• Journal of environmental and Sanitary engineering
• /
• v.23 no.4
• /
• pp.65-71
• /
• 2008

To drive efficiently total water pollution load management, needs to calculate the exact load emissions, pollution load allocation and implementation evaluation in each unit area of watershed and accurate and regular flow of data. For these reasons, the Nakdong River TMDL Research Center has produced directly or indirectly in the average interval of eight days (30 times or more / year) 41 points for unit area of the total water pollution load management and 8-point of municipal requirement for a total of 49 branches as a flow data in 2004 from August. This acquired the survey flow is evidence of trends and changes each point in the Nakdong River based on time, such as 10 years based on average design flow available to the foundation of the summit as the major water policy is to be utilized. This study was performed on actual discharge measuring data and introduced performance results each drainage basin of Nakdong River from 2004 to 2008 over the total of past five years.

• KCID journal
• /
• v.14 no.2
• /
• pp.181-193
• /
• 2007

The characteristics of non-point source pollutant loads in middle-stream of Nakdong River Were studied through analysis of pollutant loads of 8 sub-watersheds divided based on administrative district. The pollutant concentration of each sub-watershed was collected from Nakdong-River Water Research Institute and Daegu Regional Environmental Office, respectively. Pollution items analysed in this study were BOD, SS, T-N and T-P. High degree of non-point pollution was observed from Gumi, Goryeong, Gyeongsan, Daegu and Sungju, and pollution was usually increased during rainy season. This result indicates that a given pollution condition within the watershed can be more sensitive than location factor to the level of water quality. The main sources of non-point pollution were population and livestock, as well as landuse factor, and were found to significantly contribute to the water pollution. Alternative solutions for controlling pollution sources, therefore, should be provided to meet target levels of water quality in this region.

• Journal of Korean Society on Water Environment
• /
• v.34 no.5
• /
• pp.487-493
• /
• 2018

Urban stormwater runoff is the one of the most extensive causes of deterioration of water quality in streams in urban areas. Especially, in the Suyeong River watershed, non-point sources from urban-residential areas are the most common cause of water pollution. Also, it has been ascertained that BOD and COD as indexes of organic matter, have limitation on management of Suyeong River's water quality. In this study, changes of organic matter properties of Suyeong River from inflow of non-point source during rainfall were investigated. Fractions of organic matters were analyzed using water samples collected at two sites (Suyeong River and Oncheon Stream) during a rain event. Variations of dissolved organic carbon (DOC) concentration by rainfall were similar to flow rate change in the river. Distribution of organic matter fraction according to change of rain duration revealed that while hydrophilic component increased at initial rainfall, the hydrophobic component was similar to change in dissolved organic carbon (DOC) concentration. Also, the relative proportion of hydrophilic components in organic matter in river water increased, due to rainfall. Results of biodegradation of organic matters revealed that decomposition rate of organic matters during rainfall was higher than that of during a non-rainfall event.

• Environmental Analysis Health and Toxicology
• /
• v.16 no.4
• /
• pp.161-170
• /
• 2001

In aqueous ecosystems, the level of toxicity is highly responsive dependant to multiple variables, including rainfall, sunlight, pH, adhesion, etc. Because Korea has particularly distinct wet and dry seasons, the toxicity of pollutants in rivers or streams is dependant on the sampling season and time. In order to examine the effects of rainfall on toxicity, sediment samples were collected from five sites along the Keumho river. It was found that Microtox toxicity levels were generally higher during the dry season than the wet season. It indicated that river pollutants are carried off more quickly by the water during the wet season. As a result, it was recommended that the point sources of pollutants of the Keumho river would be placed between KH3 (Paldalgyo) and KH4(Keumhogyo), KH4(Keumhogyo) and KH5(Dasa).

• Korean Journal of Remote Sensing
• /
• v.37 no.5_3
• /
• pp.1425-1434
• /
• 2021

Continuous and periodic data acquisition must be preceded to maintain and manage the river facilities effectively. Adapting the existing general facilities methods, which include river surveying methods such as terrestrial laser scanners, total stations, and Global Navigation Satellite System (GNSS), has limitation in terms of its costs, manpower, and times to acquire spatial information since the river facilities are distributed across the wide and long area. On the other hand, the Mobile Mapping System (MMS) has comparative advantage in acquiring the data of river facilities since it constructs three-dimensional spatial information while moving. By using the MMS, 184,646,009 points could be attained for Anyang stream with a length of 4 kilometers only in 20 minutes. Levee points were divided at intervals of 10 meters so that about 378 levee cross sections were generated. In addition, the waterside maximum and average slope could be automatically calculated by separating slope plane form levee point cloud, and the accuracy of RMSE was confirmed by comparing with manually calculated slope. The reference slope was calculated manually by plotting point cloud of levee slope plane and selecting two points that use location information when calculating the slope. Also, as a result of comparing the water side slope with slope standard in basic river plan for Anyang stream, it is confirmed that inspecting the river facilities with the MMS point cloud is highly recommended than the existing river survey.