• Title/Summary/Keyword: Dong River

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An Investigation of Vascular Plant Life Forms in the Amsa-dong Ecological and Landscape Conservation Area - A Floodplain along the Han River in Seoul, South Korea - (한강 범람원인 암사동 생태·경관보전지역의 식물생활형 특성 연구)

  • Yun, daum;Oh, Choong-Hyeon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.26 no.6
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    • pp.1-19
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    • 2023
  • This study aimed to identify the characteristics of the plant growth forms within the Amsa-dong Ecological and Landscape Conservation Area, a floodplain along the Han River, based on 20 years of flora monitoring data. The analysis revealed that there were 106 taxa identified in 2003, 158 taxa in 2006, 107 taxa in 2013, and 202 taxa in 2020. Compared to 2003 and 2013, the number of taxa increased significantly by approximately 50 taxa in 2006 and around 100 taxa in 2020. It is presumed that this is due to the influx of seeds caused by the flooding of the Han River due to record-breaking heavy rains during the rainy seasons of 2006 and 2020, leading to a rapid increase in the number of taxa. This was also confirmed in aquatic plants(HH) as a result of comparison of life style analysis by year. The analysis revealed that there were 19 aquatic plant(HH) in 2003, 32 aquatic plant(HH) in 2006, 9 aquatic plant(HH) in 2013, and 30 aquatic plant(HH) in 2020. The number of aquatic plants(HH) increased slightly in 2006 and 2020 compared to 2003 and 2013, and the influx of rare aquatic plants in urban rivers was confirmed. Consistent with the results of the vascular flora analysis above, these plants are believed to have been introduced from the upper reaches of the Han River when the Han River flooded due to heavy rains during the record-breaking rainy season in 2006 and 2020.

Analysis and Comparison of Flow Rate Measurements Using Various Discharge Measuring Instrument and ADCP (다양한 유량 측정기기와 ADCP를 이용한 유량 비교 분석)

  • Ji, Ju-Yeon;Park, Seung-Yong;Lee, Gwang-Woo;Park, Gyeong-Min;Hwang, Soon-Hong;Kim, Dong-Ho;Lee, Young-Joon
    • Journal of Environmental Science International
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    • v.22 no.2
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    • pp.251-257
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    • 2013
  • Discharge data examine the process of hydrologic cycle and used significantly in water resource planning and irrigation and flood control planning. It makes high quality discharge data, they carry out research on standard and method of discharge measurement, and equipment improvement. Now various flow meters are utilized to make discharge data in Korea. However, accuracy of equipment and exprerimental research data from measurement are not enough. ADCP(Acoustic Doppler Current Profiler) have been introduced and utilized for flow measurements since the end of 1980's. ADCP flow method is a formal method for flow measurement can easily applyd to relatively large rivers gradually recognized. This equipment can measure the non-contact three-dimensional velocity and water depth data very quickly and efficiently. Also, spatial and temporal resolution of the data is more accurate than any other flow measurement methods which measure flow rate by velocity - area measurement method. In this paper, the velocity is measured using various flow meter and verified the effectiveness by applying from the ADCP in Geum-river. Various flow meters which are med for discharge measurements are VALEPORT002, FLOW TRACKER, PRICE AA and ADCP. The average of five times flow measurement result by ADCP was $10.412m^3/s$, with a standard deviation of 0.68. The repeat test by ADCP and comparison between ADCP and other flow devices to verify the most import factor, flow measurement accuracy. In the result, repeat test of the ADCP showed similar values, flow values were similar to other velocity device results and the average error is 7.7%.

Delivered Pollutant Loads of Point and Nonpoint Source on the Upper Watershed of Lake Paldang - Case Study of the Watershed of Namhan River and Gyeongan Stream (팔당호 상류유역의 점·비점오염원 유달부하 특성 - 남한강·경안천 수계를 대상으로)

  • Park, Ji Hyoung;Kong, Dong Soo;Min, Kyung Sok
    • Journal of Korean Society on Water Environment
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    • v.24 no.6
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    • pp.750-757
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    • 2008
  • This study is conducted to characterize and evaluate delivered pollutant loads of point and nonpoint source on the upper watershed of lake paldang. The study area consists of 12 watersheds in Namhan-river and Kyungahcheon, which are approximately 80% of total area of Namhan-river and Kyungahcheon. Based on daily delivered loads from watersheds, 61% of $BOD_5$, 81% of T-N and 70% of T-P were from nonpoint sources, suggesting that delivered loads of nonpoint pollutants be crucial to water quality. On the other hand, 78% of $BOD_5$, 92% of T-N and 87% of T-P as delivered load were from nonpoint sources in an upper watershed of Namhan-river, while 48% of $BOD_5$, 70% of T-N and 57% of T-P as delivered load were from nonpoint sources in a lower watershed of Namhan-river, suggesting higher dependency of point sources than upper watershed of Namhan-river. In the characteristic of delivered loading pollutants from point and nonpoint pollution sources, delivered load of nonpoint pollutants differed significantly by seasonal flow, and as though discharged load of point pollutants were yearly uniform, delivered load of point pollutants was found to be flow-dependent because its delivery ratio was changed.