黄河下游地处冲积平原之上 ,为地上“悬河” ,除东平湖至济南等局部河段有山岭外 ,其余河段均由堤防约束洪水。历史上 ,一直是堤防加高和泥沙淤积“赛跑”。小浪底水库的拦沙运用 ,可使下游河床 2 0年左右的时间不淤积抬升 ,应利用小浪底水库赢得的宝贵时机 ,大力开展放淤固堤建设 ,初步形成相对地下河的雏形 The lower reaches of the Yellow River are located above the alluvial plain, which is the “hanging river” on the ground. Except for the part of the Dongping Lake to Jinan, there are mountains outside, and the rest of the river are confined by dikes. Historically, there have been “races” of dikes and sedimentation. Xiaolangdi reservoir sediment blocking, the downstream river bed does not sedimentation uplift time of about 20 years, should take advantage of Xiaolangdi Reservoir won the precious opportunity to vigorously carry out the construction of silt dam solidification, the initial formation of relative underground river prototype