The Study On The Investigation And Evaluation Of The River Habitat In The Fenghe River

The river system has great influence on maintaining the water cycle, the material and energy balance on the earth, and it is an important channel of biosphere material circulation. Nowadays, with the rapid growth of world population and development of industrial civilization, the irrational utilization of water resources caused the destruction of river ecological system. River ecological system have become an increasingly prominent problem which serious threat harmonious development of natural ecological system. As an important component of river ecosystem, river habitat is the foundation of the river for biological survival, thus effective evaluation for the river habitat is of great importance in maintaining the river health.This paper take the case of the Fenghe River as research object, which is a tributary on right bank of the Weihe River and also the third largest river in Xi’an City. By inducte the relevant practices on river habitat assessment and analysise the related assessments of river habitat in China. Using the River Habitat Survey (RHS) method investigating the river habitat of the Fenghe River, and then analyses and evaluate the habitat status of the Fenghe River based on the field research combined Habitat Quality Assessment (HQA) and Habitat Modification Score(HMS). Furthermore, processing the HMS and HQA data can describe the river health status ("F" score).Research show that Habitat Quality Assessment score was significantly negative correlated with the Habitat Modification Score. There are obvious differences between HQA and HMS, in the upstream and midstream reach of the Fenghe River, this is because the upstream of the Fenghe River is a typical mountainous river but the midstream and downstream mainly through plains area, and human activities in different degree have the direct influence on this relationship. The results show that:the river habitat quality index ranged from 22 to 56 scores from 43 sites’ in the Fenghe River, and the river Habitat Modification Score ranges from 4 to 61, the results combined with the "F" score show that that:the reaches health degree with "excellent" is 1 reach, the 10 reaches in the Fenghe River are "good", the 10 reaches are "general", the 17 reaches are "poor", and 5 reaches are "extremely poor", and those preparation are accounting for 2.3%,23.3%,23.3% and 11.6%, respectively.The river habitat of the Fenghe River upstream reaches are mainly influenced by small hydro powers, highways along the Fenghe River and sand excavation. But the river habitat of midstream and downstream the reaches are significantly affected by different kinds of intensive land exploration. The river habitat in the upstream reaches of the Fenghe River is mainly influenced by agritainment, Holiday Villa, other Tourism facilities, Artificial reinforcement River basin and highway construction along the river. The midstream and downstream of the Feng River, along the densely populated and developed economy, the habitat in which is mainly affected by high strength development of land use, such as influence from the expansion of agricultural land use and industrial construction, river sand mining, quarrying, construction of embankments for flood control, and a blowdown pipe, bridges and other hydraulic structures construction. Our research outcomes suggest that:the River Habitat Survey can efficiently detect the status of river habitats and help us to find out the dominant reasons of the deterioration. Through the study of interaction between human activities and the Fenghe River habitat, some reasonable suggestions on the management of the Fenghe River can be achieved, and then provide the foundation for comprehensive management of rivers and to promote a harmonious development of human and water resources.