Scientific Issues on Ideas of River Health

A healthy river means that it can bring its natural function and social function into play in a relevant period.The signs are as follows: It has unblocked and permanent bed,good water quality,sustainable ecosystem and an appropriate amount runoff.The index of river health can basically reflect the natural function of a river and the category and quantity varies with each river and;the determination of healthy standard should fully consider the requirements of natural function and social function development and the variations of river background condition.All the human activities of overuse of runoff,overdevelopment of hydropower,inappropriate regulation and control of floods and sediment,overmuch discharge of polluted water to the river and the changes of habitat environment of key species would harm the health of a river.