8 . a simplified 3 - d natural river flow and sediment transport model is developed based on hydrostatic pressure distribution . the model has been applied to investigate the 3 - d flow and suspended - load transport in nanjing river reach with two branches ( 8 )天然三维水流泥沙简化数值模型,成功地模拟南京某河段水流运动和多分汊河道水沙计算,结果可靠并满足精度。