INFLUENCE OF MARINE AGGREGATES MINING ON SUBMARINE TOPOGRAPHY OFF SOUTH MIAODAO

A comparative study on the change in submarine topography and geomorphology is made for the marine aggregate mining area to the south of Miaodao with the measured data in the past years. It is found that the mining of marine aggregates has not changed much of the water depth of this area, because of dynamic compensation. Sands from nearby regions brought by tide and wave to the area is enough to fill or partly fill the deep notches caused by submarine mining. Calculation of sediment budget shows that the net input of sands into the offshore Changdao island is 9.0×10⁴ m³/a and the current production of marine aggregate is less than 3.3×10⁴ m³/a. If the production of marine aggregates remains on this level, the exploitation of marine aggregates will not bring noticeable effects on submarine topography and coastal landform.