Impact Of The Reservoirs On Downstream Water Temperature Variation Research Based On River Temperature Remote Sensing

Water temperature is an important indicator of river health in river ecosystem,and also a key factor in river ecological environment and water metabolism.Changes in water temperature affect the health of river ecosystem and also effect the fish spawning and breeding that rely on the stable water temperature.The impact of the impoundment of reservoirs on the water temperature of its downstream river band has drawn a lot of attentions nowadays.The researches of the water temperature changes usually use the actual site temperature data,but water temperature measurement sites are rare,and the existing data are insufficient,generally,there is no actual measured data in a specific research area.Therefore,this paper proposed to use the thermal remote sensing inversion of the river surface temperature to study the impact of the reservoirs on its downstream river temperature and the impact of the water temperature change on the ecology.It can provide the water temperature distribution of any area of the river,which is comprehensive and intuitive,and can be a proper way to solve the problem of the lack of data.With the rapid development of spatial information,computer technology and earth science,remote sensing as a science that can provide a large amount of information on the earth surface has been increasingly valued by researchers and applied in many fields.The thermal remote sensing can be used to inverse the water surface temperature and can save a large amount of manpower.This paper starts with the theory of thermal remote sensing inversion of water temperature,introduced the algorithm,parameter estimation and some key technical issues of remote sensing inversion of water temperature.In terms of theory,started from Plank's law and blackbody theory,and introduced the algorithm,formula and parameters needed to achieve the thermal remote sensing inversion.In terms of application,the choice of data source and algorithm are introduced,and an improved water body extraction method is proposed.This paper takes the downstream river band of the Three Gorges and Gezhouba Reservoirs as the research area,and achieve the inversion of its river surface temperature.The inversion results were divided into two groups by different time periods to study the water temperature change.The impact of the impoundment of the upstream reservoir on the water temperature change of downstream river was studied,and the effects of water temperature change on the spawning of Chinese sturgeons and four famous domestic fishes were concluded.The method of thermal remote sensing inversion of river surface temperature introduced in this paper and the idea of using river remote sensing inversion result to study the change of water temperature can provide support for future researchers of water temperature more comprehensive.