| 2003 Sediment Trasport Modelling by G. Parker and Y. Cui |
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Report: PDF (5746kB) Author: Drs G. Pickup and Y. Cui Date: December 2003 This sediment transport modelling study examines possible effects of disposal of additional waste rock and tailings on sedimentation processes and water levels in the Ok Tedi and Middle Fly River, adopting the 'null scenario' of 2010 as the end of mine life (with continuation of dredging to mine closure) but also examining scenarios for 2015 and 2020. It also evaluates the likely impact of changing dredging rates to 25%, 50%, 75% and 125% of current rates as well as stopping dredging from mid-2003. Two sediment transport models were used. Runs with OkGrav6 covered effects in the Mine Area Creeks and the Upper and Middle Ok Tedi. Runs with HEC-6 examined likely changes in the Lower Ok Tedi and Middle Fly. OkGrav was updated in this process and recalibrated using new data on flow durations, sediment characteristics, sidewall erosion and deposition. HEC-6 was calibrated using observed water levels and patterns of deposition from cross section surveys. Floodplain deposition could not be modelled with available data and technology. However, some estimates of future patterns of levee growth and floodplain inundation were obtained from cross-section data and HEC-6 water surface profiles. |
