上游的重金属总弱酸可提取态要比下游高，可见上游沉积物中重金属的活性和迁移性较强，而下游沉积物中重金属的活性和迁移性较差；
Acid soluble in the upper reaches higher than downstream and migration of heavy metals is strong, while it is poor in the downstream.
然而，自从四十年前建起格兰峡谷大坝，仅大峡谷上游唯有能从微小的、无坝的支流中收集到沉积物。
However, in the four decades since thebuilding of the Glen Canyon dam, just upstream of the Grand Canyon, the onlysediment that it has collected has come from tiny, undammed tributaries.
这个滑坡沉积物大可以排除远离上游的沉积物是冰川沉积的想法。
This landslide deposit pretty much rules out the idea that the deposits farther upstream are glacial outwash.
应用推荐