Abstract: In this paper, a comprehensive description of the environmental geoscience background of the hanging river and the streamflow break in the lower reaches of the Yellow River is made from a combination of geology and geography, meteorology and climatology, hydrology and sediment, vegetation and soil, as well as human and population. The history of the change of course of the Lower Yellow River and its present state are analysed from an integration of flood and dam defence, dam breach and change of course, distributary and canal, as well as hanging river and flow break. It is proposed that countermeasures against water depletion and the resulting streamflow break flood, environmental deterioration etc. be immediately taken to improve the land in the Middle and Upper Yellow River Valley including observation of the natural law, reorientation of thoughts on water/soil conservation increase of local ponds to impound water control of surface evaporation and gully/valley development and stream-harnessing.