Classification of rivers systems

Classification helps us create order out of chaos and be usually used as a means of ordering observation and descriptions. The river classification phase occurs during the newly early stages of development of hydroecology. The purposes and approaches of river classification are simply introduced and the mainly four types of classification schemes,i.e. morphological,hydrological,ecological and value-based schemes,are reviewed and commented. The integration and systematization are the trends of the development in the classification schemes,and the special progresses are made by linking the single factors to the multiplex ones,the qualitative analysis to quatitative ones,the structural features to processes ones,the linear rivers to the large-scale hierachical systems and the natural systems to social ones,etc. With the development of the empirically based laws and finally to the theoretical understanding,and the improvement of the multidiscipline cooperation and data availability,the descriptive classification schemes will give way to the predictive ones.The preexistent experiences from other large countries with a great diversity of aquatic ecosystem are beneficial to the nationwide forthcoming watershed restoration and management in China.