Assessment Of Aquatic Ecological Health Of Huaihe River Basin

With a variety of ecosystem services, river ecosystem has played an important role in the process of human society development. Due to the interference of human activities, health condition of the most aquatic ecosystems is seriously threatened. Restoring and maintaining a healthy ecosystem has already become a vital goal of river management. Against this background, river health assessment is particularly important as a basis for the river management. In this paper, based on the extensive research literatures, we explained the meaning and ecosystem service functions of the river, explored the pluralistic understandings of the concept of river ecosystem health. And river health assessment research progress has been comprehensively generalized to facilitate the study of aquatic ecological health assessment in Huaihe River Basin, such as providing a theoretical basis.According to the related theories and practices at home and abroad, a comprehensive evaluation system of aquatic ecological health, which is suitable for the situation of Huaihe River Basin, is established in this paper based on indices of physics, chemistry and aquatic organisms. The system includes 6 factors, they are the riparian zone, river morphology, nutrients, oxygen balance, periphyton, benthic macroinvertebrates, totaling 19 defined indices, which can reflect the aquatic ecological health from different aspects. We applied the indicator system to aquatic ecological health assessment of Huaihe River Basin. And the health condition of overall basin was compared and analyzed in different aspects, such as different regions, different location, different widths and major rivers. Based on the study of level III aquatic ecological function regionalization in Huaihe River Basin, we discussed the aquatic ecological health characteristics of different regions and put forward the corresponding protection advice. In the end of the paper, the correlations between different health assessment indicators were also analyzed.The assessment results indicated that the health condition of overall basin was fair and varied in different parts of the region. Within the indices, the nutrients and benthic macroinvertebrates were the major constraint factors to the health condition of Huaihe River Basin, for they got the worse health condition; The health condition in Anhui was better than that in Jiangsu and Henan, while Shandong showed the worst health condition, but there were no significant difference among different regions (p>0.05); Suffering the disturbance and transformation of human activities, the riparian zone and aquatic organism in different locations of Huaihe River Basin tend to be consistent, and the health conditions of aquatic ecosystems were close to each other; Channel widths had no obviously effect on the health condition, so there were no significant health condition difference between difference channel widths; The health condition of aquatic ecosystem in Shiguan River was best among major rivers, while others successively were in Shu River, Huaihe River, Hongru River, Yi River and Guo River. Shaying River had the poorest health condition; 26 level III aquatic ecological function regions got fair health conditions, while only 3 were in good level; The aquatic ecological health of Huaihe River Basin was affected by many factors, among which urban and industrial sewage, agricultural non-point source pollution were the main causes.There were significant relationship between nutrients, oxygen balance and most indicators of the riparian zone, river morphology (p<0.05); Affected by the disturbance of human activities, indicators of aquatic organism showed different responses to the change of the riparian zone, river morphology, nutrients and oxygen balance; The results also showed that there was a significant correlation with RHI and oxygen balance, nutrients, river morphology, periphyton, riparian zone, benthic macroinvertebrates (p<0.05), the correlation coefficients were 0.677,0.506,0.398, 0.356,0.334,0.210.