• Title/Summary/Keyword: Distribution charts of risk area

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Distribution of average intervent times between adjacent rainfall events for overflow risk-based design of storm-water infiltration basin (월류위험도 기반 침투형저류지 설계를 위한 평균무강우지속시간도 작성)

  • Kim, Dae Geun;Park, Sun Jung
    • Journal of Korean Society of Water and Wastewater
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    • v.22 no.2
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    • pp.195-203
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    • 2008
  • This study collected the latest 30-year (1976~2005) continuous rainfall data hourly recorded at 61 meterological observatories in Korea. The continuous rainfall data was divided into individual rainfall events. In addition, distribution charts of average intervent times between adjacent rainfall events were created to facilitate the application to the overflow risk-based design of storm-water infiltration basin. This study shows that the one-parameter exponential distribution is suitable for the frequency distribution of the average intervent times for the domestic rainfall data. Distribution charts of the average intervent times were created for 4 hour and 6 hour of storm separation time, respectively. The inland Gyeongsangbuk-do and Western coastal area had relatively longer average intervent times, whereas Southern coastal area and Jeju-do had relatively shorter average intervent times.

Distribution of average rainfall event-depth for overflow risk-based design of detention storage basin (월류위험도 기반 저류지 설계를 위한 평균강우량도 작성)

  • Kim, Dae Geun;Park, Sun Jung
    • Journal of Korean Society of Water and Wastewater
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    • v.22 no.1
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    • pp.15-22
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    • 2008
  • This study collected the latest 30-year (1976~2005) continuous rainfall data hourly recorded at 61 meterological observatories in Korea, and the continuous rainfall data was divided into individual rainfall events. In addition, distribution charts of average rainfall event-depth were created to facilitate the application to the overflow risk-based design of detention storage basin. This study shows that 4 hour is appropriate for SST (storm separation time) to separate individual rainfall events from the continuous rainfall data, and the one-parameter exponential distribution is suitable for the frequency distribution of rainfall event depths for the domestic rainfall data. The analysis of the domestic rainfall data using SST of 4 hour showed that the individual rainfall event was 1380 to 2031 times, the average rainfall event-depth was 19.1 to 32.4mm, and ranged between 0.877 and 0.926. Distribution charts of average rainfall event-depth were created for 4hour and 6 hour of SST, respectively. The inland Gyeongsangbuk-do, Western coastal area and inland of Jeollabuk-do had relatively lower average rainfall event-depth, whereas Southern coastal area, such as Namhae, Yeosu, and Jeju-do had relatively higher average rainfall event-depth.

Characteristics of Coagulants Distribution by the Pumping Rate in Pump Diffusion Mixer (Pump Diffusion Mixer에서 압력수량에 따른 응집제 확산분포 특성)

  • Park, Youngoh;Kim, Ki-Don;Park, No-Suk;Lim, Jae-Lim;Lim, Kyung-Ho
    • Journal of Korean Society of Water and Wastewater
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    • v.22 no.1
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    • pp.65-71
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    • 2008
  • This study collected the latest 30-year (1976~2005) continuous rainfall data hourly recorded at 61 meterological observatories in Korea, and the continuous rainfall data was divided into individual rainfall events. In addition, distribution charts of average rainfall event-depth were created to facilitate the application to the overflow risk-based design of detention storage basin. This study shows that 4 hour is appropriate for SST (storm separation time) to separate individual rainfall events from the continuous rainfall data, and the one-parameter exponential distribution is suitable for the frequency distribution of rainfall event depths for the domestic rainfall data. The analysis of the domestic rainfall data using SST of 4 hour showed that the individual rainfall event was 1380 to 2031 times, the average rainfall event-depth was 19.1 to 32.4mm, and ranged between 0.877 and 0.926. Distribution charts of average rainfall event-depth were created for 4hour and 6 hour of SST, respectively. The inland Gyeongsangbuk-do, Western coastal area and inland of Jeollabuk-do had relatively lower average rainfall event-depth, whereas Southern coastal area, such as Namhae, Yeosu, and Jeju-do had relatively higher average rainfall event-depth.

The Study on the Development of Flood Prediction and Warning System at Ungaged Coastal Urban Area - On-Cheon Stream in Busan - (미계측 해안 도시 유역의 홍수예경보 시스템 구축 방법 검토 - 부산시 온천천 유역 대상 -)

  • Shin, Hyun-Suk;Park, Yong-Woon;Hong, Il-Pyo
    • Journal of Korea Water Resources Association
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    • v.40 no.6 s.179
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    • pp.447-458
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    • 2007
  • In this study, the coastal urban flood prediction and warning system based on HEC-RAS and SWMM were investigated to evaluate a watershed of On-Cheon stream in Busan which has characteristics of costal area cased by flooding of coastal urban areas. The basis of this study is a selection of various geological data from the numerical map that is a watershed of On-Cheon stream and computation of hydrologic GIS data. Thiessen method was used for analyzing of rainfall on the On-Cheon stream and 6th regression equation, which is Huff's Type II was time-distribution of rainfall. To evaluate the deployment of flood prediction and warning system, risk depth was used on the 3 selected areas. To find the threshold runoff for hydraulic analysis of stream, HEC-RAS was used and flood depth and threshold runoff was considered with the effect of tidal water level. To estimate urban flash flood trigger rainfall, PCSWMM 2002 was introduced for hydrologic analysis. Consequently, not only were the criteria of coastal urban flood prediction and warning system decided on the watershed of On-Cheon stream, but also the deployment flow charts of flood prediction and warning system and operation system was evaluated. This study indicates the criteria of flood prediction and warning system on the coastal areas and modeling methods with application of ArcView GIS, HEC-RAS and SWMM on the basin. For the future, flood prediction and warning system should be considered and developed to various basin cases to reduce natural flood disasters in coastal urban area.