Abstract:

Development of cities has caused changes to the natural hydrology and environment of many rivers，and resulted in decrease of water quality,physical habitat and biological integrity of river ecosystems.Physical and chemical parameters as well as impacts on biological structure,biodiversity and biological process should be taken into considerations when the effect of river ecological remediation was to be evaluated.In this article，an index system including 15 indicators in five aspects of river hydraulics,water quality,aquatic biota,river coast and physical structure was established for evaluating the effect of ecological remediation of urban rivers.A group decisionmaking model of AHP was employed to determine the weights of the indicators and the first five important ones were average pollution index of water quality,fish IBI,water recharge volume,algal diversity and water transparency in sequence.The Qijiang River in a southern city of China was studied as a case for comprehensively evaluating the effect of river ecological restoration.The result was “acceptable”,which showed that remediation engineering would make improvements on the water quality and ecosystem of river,though this could be a rather slow process and the river ecosystem would still be in a state of damage at the early stage of remediation.〖