Determination And Confirmation Of Key Index On River Health Evaluation

The concept of river health has been raised over20years in order to achieve the sustainable development, utilization and protection of water resources within river basins. The relative theories and methods on river health were being as core issues in the research of the ecological restoration and environmental management of watershed. Based on the clear understanding of the connotation on river health, more and more evaluation systems of river health are put forward, and the adopted index within them are getting more, getting more complex and professional. In order to find the important, basic and easily observed indicators to display the general situation on river health, around199research papers, documents and standards in1972-2010were reviewed,60evaluating systems with1066index were gotten. According to the showed river characteristics, the idex were divided into six groups:water quality, hydrology, biology, riparian zone, river structure and service function. The adopted numbers and rate of each indicator in the above systems were combinated, concualted and analysis, based on the showed meanings, correlations and characteristic, the indicators with higher adopted/approved rate which can explain fully river condition were determined as the key ones in river health evaluation. Finally, the Buyuan river as the confirmation case, its river health status is evaluated. The conclusions as follows:(1) Through the selection and analysis, seven indicators are determined as the key ones of river health evaluation, which are runoff under hydrological group, the ratio of reaching water quality standard in water function area in water quality group, fish index of biotic integrity of biotic group, coverage rate of riparian vegetation in riparian zone group, river continuity of river structure group, the ratio of water utilization and land use condition in ecological function group.(2) Above the7key indicators, runoff was showed by twelve specific indicators in the reviewed60systems, such as annual average runoff, month average runoff in the dry period, one of them can be selected to show the runoff index; between fish-IBI and invertebrate-IB I, one of the two can be choiced in the river health evaluation on the basis of existing informations; there are some overlays between land use and the coverage rate of riparian vegetation, both or one of them can be assessed based on the needs in the evaluation implementation. (3) The Bunyuan River’ health, is evaluated by the determined7key indicators, the final score is0.94, the meaning is that it is in the pink. According to the scores of the seven, four of them are located at the first level/very healthy, two of them are at the second level/healthy. The general status on the Bunyuan river basin can support the needs of human development and water utilization in2006, it is a very healthy river with rational natural structure, integrated ecological function.(4) On the base of reviewing the research papers, documents and regulations on river health and its evaluation systems in1972-2010, the evaluated index used in the60evaluating systems were gotten. Through classification, statistics and correlation analysis,7key indicators were screened and finial determined. The author considers that:there are more or less douts on the7indicators as key ones in river health evaluation from the60systems, but the ultimacy mistake doesn’t emerge; the Bunyuan River is being constructed as an fish natural reserve, the meaning is that it has an important ecological value and is an important ecological barrier, it is used as the case to confirm the7key evaluating indicator, is feasible, possible and available, and the final evaluated result fits the fact, and the selected key indicators can be used in the actual river health evaluation.