经百万年堆积起来的高原泥沙已达到180米~200米厚的黄土高原，经年累月被风吹雨淋，泥沙扩散入河，引黄色不变，泥沙堆积成“悬河”。
O B-Metric I-Metric I-Metric O O O O O B-Location I-Location B-Thing I-Thing O O O B-Metric I-Metric I-Metric I-Metric I-Metric I-Metric I-Metric I-Metric I-Metric O O B-Location I-Location I-Location I-Location O O O O O O B-Thing O B-Thing O O B-Thing I-Thing O O O B-Location O O O O O O O B-Thing I-Thing O O O O B-Location I-Location O O