As a scientist who has worked on this topic for some years, it is my judgment that 80 to 95 percent of the direct sediment contributions into the headwaters of these rivers are now attributable to road erosion and landslides.

• 作为一名曾在该领域工作多年的科学家，我判定，这些水系上游的直接泥沙排放量中，有80%25到95%25来自于道路侵蚀和滑坡。