Because it destroyed the river equilibrium, sand excavation would cause river bederosion in large scale, which is danger our to the structure across the river.
由于采沙破坏了天然河床的平衡状态，可引起长距离河床整体下切，对已有跨河桥梁工程不利。
2
Bed planting improves soil fertility and structure and helps reduce erosion, water usage, herbicide use and facilitates mechanical and manual weeding.
垄播改善了土壤肥力和结构，对减少流失、水的利用和除草剂的施用也有帮助，也方便了机械和人工除草。
3
Bed planting and water management in the Yellow River: Serious water and soil erosion in the Yellow River has led to frequent basin-wide drought and floods.