The Key Environmental Factors Sturgeon Breeding And Suitability Study

This paper through the literature search and data collection, and systematically summarizes the Chinese sturgeon propagation activities of the ecological hydrology, hydraulics research results on demand. On the basis of previous studies, selection of Pingshan hydrological station is a typical Chinese sturgeon spawning ground (JinDuiZi, PianYanZi and SanKuanShi) representative hydrologic station, Yichang hydrological station for Chinese sturgeon spawning ground of Gezhouba Dam representative hydrological stations, the Pingshan hydrological station (1956-1980) and the Yichang hydrological station (1983-2012) measurement hydrological data, reproductive activity survey and monitoring data of Chinese sturgeon spawning and spawning ground of Gezhouba Dam history based on, according to the statistics, comparison and analysis of the Chinese sturgeon spawning and spawning ground of Gezhouba Dam historical spawning water level, flow, temperature and sediment conditions, and discusses the Chinese sturgeon in the breeding year gonadal development and effective accumulated temperature may need.According to the actual terrain data, the establishment of the Gezhouba Dam Chinese sturgeon spawning field3-D hydrodynamic mathematical model in2004November, spawning measured flow field calibration and validation of the spawning grounds of three-dimensional hydrodynamic mathematical model parameters. According to the Gezhouba Dam Chinese sturgeon spawning ground monitoring data of51times1988-2010year Chinese sturgeon habitat location, using a three-dimensional hydrodynamic model to recover the previous monitoring activities of Chinese sturgeon spawning field, extraction of hydrodynamic characteristics of Chinese sturgeon habitat position, according to statistics, the Chinese sturgeon habitat velocity, depth, Buddha Ru de appropriate number curve and suitable area, the ecological flow of Chinese sturgeon suitable.The Three Gorges Reservoir vertical two-dimensional temperature model according to the real terrain data and measured data, the calibration and validation of the main parameters of the model. The spawning three-dimensional hydrodynamic mathematical model and the Three Gorges reservoir water temperature model, analyzes the impact of the Three Gorges project operation of the Chinese sturgeon propagation of hydrodynamic and temperature conditions. Based on the Three Gorges Reservoir vertical two-dimensional temperature model, the reason of the Three Gorges project operation after the Chinese sturgeon propagation delay. Discusses the role of different hydrological factor influence in the Chinese sturgeon propagation activities in the. The main research results in this paper for:1. Hydrological process needs inChinese sturgeon breeding activity is not clear.In the spawning ground of Gezhouba Dam. Chinese sturgeon spawning event occurs, water level range is suitable for40.05-46.17m. flow range is suitable for7000-16000m3/s, sediment content is suitable for0.095-0.638kg/m3,the suitable17.9-20.9℃. Then according to the spawning and existing spawning of Chinese sturgeon hydrological data analysis of history. Chinese sturgeon spawning days are in the calendar year October back water process. However, through the analysis and comparison of spawning day and the day before the hydrological data, found the water level, flow, temperature and sediment content downward trend is not obvious. Some egg, flow, water temperature and water level of sediment content in the rising process, some spawning in the fall.2, different hydrologic factors have different functions in Chinese sturgeon reproduction.Based on the analysis of the historical data, the hydrological indicators, the decision of the Chinese sturgeon spawning time season, water level, flow determines the specific time of spawning. However, in the Three Gorges reservoir impounding, affected by the reservoir "stagnation temperature effect", the water temperature factor becomes difficult to meet, obviously becomes the key factor influencing Chinese sturgeon spawning time, in most cases, water level, flow condition is easier to satisfy the water temperature.3. Chinese sturgeon fish from the river mouth into the mainstream, have accumulated certain the gonadal development demand of water temperature.Based on the analysis of Gezhouba Dam under the Chinese sturgeon spawning ground multiple spawning activity propagation of annual water temperature at13℃accumulated temperature, initial temperature for gonadal development, the construction of the Three Gorges reservoir, movable insulation is5475±250℃·d, the effective accumulated temperature of2043±54℃·d; in the Three Gorges reservoir, the movable temperature to6039±194℃·d, the effective accumulated temperature of2273±87℃·d. After the Three Gorges reservoir, affected by the reservoir "stagnation temperature effect", water temperature temperature increase.4, Chinese sturgeon breeding ecological flow requirement for specific.According to the analysis of the monitoring of Chinese sturgeon position of hydrodynamic characteristics of Chinese sturgeon habitat restoration, preference to high velocity, water depth deep position. Comprehensive analysis of the relationship between Chinese sturgeon habitat and spawning preference scale and spawning flow, deduce the breeding period suitable flow is about 7000-16000m3/s, the ecological flow better for9000-11000m3/s.5, Chinese sturgeon spawning time may have some relationship with the effective accumulated temperature of Chinese sturgeon gonad development required.Through the study found that, in the2003-2009period of Chinese sturgeon spawning, most effectively accumulated temperature2273℃·d and5d. According to the development of effective accumulated temperature of year, can roughly infer the spawning time. The ecological flow scheduling can be found for the Chinese sturgeon propagation period of biological monitoring and improve Chinese sturgeon propagation conditions provide support.The main innovative points of this paper are:1, this study analyzed the effects of main environmental factors on Chinese sturgeon breeding activity.Study on the influence of environmental factors on Chinese sturgeon breeding activity, have important significance for the protection of Chinese sturgeon, Acipenser sinensis breeding environment improvement. This study analyzes the impoundment of the Three Gorges Reservoir before and after spawning field hydrological conditions in Chinese sturgeon spawning ground of hydrological conditions. Gezhouba Dam native, reveals the different locations, different time, different hydrological factors in the Chinese sturgeon propagation activities.2, this study through the method of mathematical model that Gezhouba Dam Chinese sturgeon breeding activities postponed.Research by using the method of mathematical model, analyzed the reason of Chinese sturgeon propagation delay. Through the analysis of the statistical characteristics of date sequence after conversion of Chinese sturgeon spawning of Chinese sturgeon natural reproduction and demand, although the water temperature is the key factor of the sturgeon breeding, but it only determines the upper and lower limits of Chinese sturgeon spawning season. The lower reaches of the Jinsha River and the upper reaches of the Yangtze River "from autumn", is a major cause of Chinese sturgeon spawning, transport it from the upper reaches of the Yangtze Three Gorges reservoir caused by stagnant time to Yichang after the shift, a main reason is caused by the date of Chinese sturgeon natural reproduction after the impoundment of Three Gorges Project shift.3, this study through the analysis of the data, the required Chinese sturgeon breeding activity of active accumulated temperature and effective accumulated temperature and spawning date inference method.Study through the analysis of the data, puts forward the Chinese sturgeon gonad development required the active accumulated temperature and effective accumulated temperature, and then to infer the probable date of production of eggs occurred. In the Three Gorges reservoir, the Chinese sturgeon propagation of annual effective accumulated temperature of2273±87℃·d, Chinese sturgeon spawning days in the most effective accumulated temperature of2273℃·d and5d. Thus according to the effective accumulated temperature of development then, deduce the spawning time.