Loading...

Investigating Engineering Solutions to Preserve Goragan Bay:Dreding Ashouradeh Channel

Givehki, Mahdieh | 2020

386 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 53917 (09)
  4. University: Sharif University of Technology
  5. Department: Civil Engineering
  6. Advisor(s): Raie, Mohammad
  7. Abstract:
  8. Gorgan Bay, registered as a biosphere reserve, has environmental value in the country and the world. The bay is separated from the Caspian Sea by sedimentation in the sandy spit of Miankaleh. Due to the declining water level of the Caspian Sea and the possibility of hydraulic connection disruption and closure of its openings, this water body may face many problems in the future. Main problems are the increase in water retention time and, consequently, the decrease in water quality and the problem of local access during the seasons when the water level drops. In this study, engineering solutions have been studied in proportional with the current conditions of the Gorgan Gulf, which include dredging of natural channel, transfer of water from the Caspian Sea by pipeline and creation of artificial channels. Among these solutions, the dredging solution of Ashuradeh channel is evaluated in order to obtain the required intervals for periodic dredging. Using numerical modeling and limited volume analysis, the Caspian Sea current and wave model is simulated and after obtaining the boundary conditions for open boundary, the local current and sediment transport model for Gorgan Bay area was simulated. Simultaneously with the local current model, the local sediment model was implemented and the results were calibrated with the available limited data. After calibration, the absolute mean error was 68%. After validation, by using a calibrated model, the dredging effects of Ashuradeh channel and its inlet to the Caspian Sea, have been investigated. Finally, using different scenarios (including decrease and increase of water level) in one year, the amount of sedimentation and erosion in the dredged area has been obtained. Based on the results of these scenarios and considering the conditions of water level decline in recent years in the Caspian Sea, the scenario of gradual decrease of water level has been selected for a five-year simulation. The results of 5-year simulation show that the rate of sedimentation in the channel, taking into account the 68% confidence margin, reaches 0.4 m and in a part of the channel ‘inlet reaches 1.68 m in five years. Due to the difference in sedimentation rate in the channel and its inlet, the time for dredging the channel and its inlet to the Caspian Sea is estimated 8-9 years and 3-4 years
  9. Keywords:
  10. Dredging ; Sediment Transport ; Mike 21 Flow Model ; Flow Modeling ; Goragan Bay

 Digital Object List

 Bookmark

No TOC