Research Of Fish Habitat Hydraulics Characteristics And Simulation Study,Han Zhong Pingchuan Segment,Han River

Han river, as a tributary belongs to the Yangtze river water system. Pingchuan segment flow through hanzhong basin of shaanxi, where the land is fertile in superior natural conditions.Thus, Pingchuan segment has important ecological functions. And the basin also is the most developed area of economy and society, which is important role in the han river upstream even south of Seamenxi Province.Based on the typical fish habitat about 10 km in Pingchuan as an example segment,downstreanm of the hanzhong city bridge sluice, the response relationship between flow rate change and representative dominant species Zacco platypus fish habitat was researchecd under the different operation modes of hanzhong city bridge sluice with different released water levels,using MIKE21 software with two-dimensional numerical simulation and ArcGIS software for the fish habitat quality-area simulation and atalyze. Then the law of fish habitat change under hydraulics characteristics was summarized. The main research content is as follows:(1)The aquatic ecological investigation of Pingchuan segment was conducted, to get aquatic ecological basic situation, especially the distribution of fish populatioss and fish halbitats which provide theory to study the target fish, representative dominant species Zacco platypus,habitat simulation.(2) Health evaluation system of segmentecd stream was established and current situation of Pingchuan segment was estimated. According to the situation of river, most period of main river for good health condition, 38% for the general status, only 11% of the river are unhealthy.Unhealthy sections mainly were coursed by river engineering construction and mining which destroied the original river hydraulics environment, thus to river has a harmful effect on the aquatic ecosystem.(3) Study of fish habitat response to changing flow simulation. Study found that as the simulation flow level starting from the larger flowr rate recducecd, fish habitat area of the overall increase gradually, till the maximum flow rate of 53.1 m3 / s. Then as traffic levels further reduce, fish habitat area began to decrease. At each level of the traffic, fish habitat area of medirum quality habitat area is the most the second is high quality habitat area, low cquality habitat area is the least. In the process of traffic levelsa fish habitat from low quality to high quality or high cquality to low quality transition will take precedence over the growth and eliminate of the area.