river r bed河床
river r bed placer河床砂矿
river-Bed form河床地貌
river-bed scouring河床冲刷
river-bed profile河流纵剖面
river-bed evolution河床变迁
river-bed河床
river r bed conservation河床保护
They caused delta environmental variations, such as coastal erosion, decline of ground water table, salty water intrusion, soil salinization, river bed erosion, deposition in the river courses in the estuary, and so on. I also tried to predict the evolution of the delta environment and put forward some proposals to control the environmental variations in the Luanhe River Delta.
本文根据滦河三角洲地区的野外调查及收集的大量资料，以引滦工程对滦河水文的影响为基础，全面系统地分析、论述了三角洲自然环境的变化：三角洲海岸侵蚀后退，地下水位下降，滦河口盐水入侵，土壤盐渍化，河床冲刷、拓宽，河口淤积，预测了三角洲环境演变的趋势，提出了控制三角洲变化的决策。
参考来源 - 期刊学术社区N-COUNT（可数名词） A riverbed is the ground which a river flows over. 河床