Abstract: As there is a trend of deterioration of the water resource and environmental quality in China, the interconnected rivers system, which is an important target for river health and enhancing water resource utilization, was emphasized by National 12th Five-year Plan (2011-2015). Currently, we are lack of knowledge in characteristics on drainage connectivity and river health. Thus, the aim of this paper is to clarify the definition of interconnected rivers system, classification, evaluation indicators, impact factors and the effects on water environment health. The interconnected rivers system can improve wetland ecological environment, maintain biodiversity, and safeguard flood control security and sustainable utilization of water resources. However, interconnected rivers system has eclogical and environmental adventure, including: (1) because of interconnected rivers, the water quality, wherein original river is good, will be worse due to mixing with poor water quality; (2) interconnected rivers will increase the competition of fish and other species in the rivers; (3) through interconnected rivers system, the rivers and lakes which have plenty of rainwater supplement those lack of rainwater, which will greatly reduce the effective water resource; (4) reducing runoff from the rivers and lakes which are plenty of rainwater will result in reducing evaporation in the area of the land surface and the water cycle, and then, lead to climate change in the region; (5) the connectivity of upstream and downstream will result in dramatic increase in sand and sediment in downstream rivers.

Key words: ecological effect, interconnected rivers system, river health, water environment