河流健康综合评价指数法的改进及其在昌江的应用

摘要

River health comprehensive assessment index ( RHCAI) is integrating the conditions of a river, such as hydrology, physical morphology, riparian zone, water quality parameters and aquatic organisms, for assessment of health status of rivers. Compared with river hydrology index land other indices, the index of aquatic organism is too simple to quantify the health status of a complex river ecosystem. Hereby EPT ( Ephemeroptera, Plecoptera and Trichoptera) relative abundance index and family biotic index are added as secondary indices of the aquatic organism index. Both the original and modified RHCAIs were used to evaluate river health of Changjiang River for comparison. Results show that the river was generally good in health with all scores > 60 and all the observation sites were either in good health or subhealth. However, it was also found that the health condition of the river declined significantly with the flow from the upstream to the downstream of Changjiang River and its major tributary-Donghe River. All the three sites being the lowest in RHCAI scores were found in the main stream of Changjiang River, while the sites being the highest in RHCAI scores were located in the headwater region. These findings demonstrate that the modified RHCAI is able to show slight differences between the observation sites in health status, and fully and objectively reflect health condition of rivers.%目前普遍采用的河流健康综合评价指数法中水生生物指标相对简单,不能准确度量复杂河流生态系统的健康状态.通过增加蜉蝣目、襀翅目和鞘翅目相对丰富度以及科级生物指数2项指标,改进水生生物指标中的二级指标,并采用改进前后的河流健康综合评价指数法对鄱阳湖人湖支流——昌江进行评价对比.结果表明,昌江总体健康状况较好,各样点均处于健康或亚健康状态；从河流上游至下游,昌江干流及主要支流东河健康状况明显下降,得分最低的3个样点都位于昌江于流,而健康样点大都接近源头；改进后的河流健康综合评价指数法可更好地区分昌江不同样点的水体健康状态.