Embley

Rio Tinto AlcanEnvironmental Impact StatementSouth of Embley Project2.0Cape Wessel trnjDolak Island [m]Shethoume Bay [m]Bramble Cay [m]1.0E0.0Co7C0 -1.0IA,p -2.0,r)-3.0-4.000:00 00:00 00:00 00:00 00:00 00:00 00:002007-05-22 05-24 05-26 05-28 05-30 05-01 06-03Figure 6-4Global Tide Model Prediction at Outer Model Open Boundary ExtentsAcoustic Doppler Current Profiler (ADCP) instrument deployment at the proposed port site(location indicated in Figure 6-3) provided measurements of current speed, current direction,and water level useful for hydrodynamic model verification. Additional water level data for theWeipa region collected by the Queensland Department of Environment and ResourceManagement (DERM, formerly the Queensland Environmental Protection Agency, EPA) wasprovided by Maritime Safety Queensland (MSQ). The data included both the Weipa storm tidegauge predictions and observations (MayJune 2007) and a time-series (JulyAugust 2003) ofobservational data from "Beacon 2", located toward the western extent of the existing Weipashipping channel (refer Figure 6-3).Three model simulations were performed, with each simulation covering a differentobservational data period. Outer model verification plots of MSQ observed/predicted versussimulated water levels are presented in Figure 6-5 and Figure 6-6. Model verification at theWeipa storm tide gauge (MayJune 2007) and at Beacon 2 (JulyAugust 2003) was generallygood in terms of the magnitude and timing of flood and ebb tide peaks, noting some overpredictionof peak water levels during neap tides. Small discrepancies between the observedand predicted water levels may be attributed to meteorological effects (e.g. atmosphericpressure or local wind effects) which are not typically included in the simulations during modeldevelopment and/or the Outer model boundary conditions not incorporating the minor tidalconstituents.Section 6 Marine Page 6-5