Study On Water Information Extraction Method Of Multi-scale Remote Sensing Data In Xi'an City

At present,the process of urbanization in China is speeding up.In the process of urbanization and urbanization,the local government should start from the overall situation,plan and manage the water resources in the aspects of water storage,drainage,flood control and so on.Therefore,in order to obtain water resources information in time,the information of water resources management should be realized,and space information technology is also used.It is the basis of the construction of geographic information and "Intelligent City".It is also the basis for the modernization of national undertakings.Then,how to establish a rapid,efficient and accurate monitoring and management mechanism for water resources,and timely understand the dynamic change information of water resources,and then take and take fast water resources protection and management countermeasures.To provide scientific basis for the state and local management departments,it is inseparable from the application of remote sensing technology in water resources management.Take the central and northern part of Xi'an City,Shaanxi Province as the research area.It covers several main rivers,such as Wei River,Jingshui River,Chan River and Ba River.The data sources are 1 m GF-2,10 m Sentinel-2A,16 m GF-1 WFV and 30 m Landsat 8,respectively.The method of object-oriented classification is used to extract water body of high density building area,small area of plaque water body,linear narrow water body and open river water body in the study area.The actual water body distribution of the study area is obtained from the remote sensing image of 0.5 resolution by human computer interaction.Finally,the extraction accuracy of the four kinds of water information and the standard data is compared,and the extraction accuracy of the four types of water information under four data source scales is calculated,and the accuracy of the extraction results is compared and analyzed.The results show that the accuracy of the extraction of water body spatial information is proportional to the spatial resolution of the satellite sensor.For the urban water body,the influence of the shadow from the high-rise building is still the most important factor of the extraction precision.This experiment can be used for reference in the selection of data sources and extraction method for urban water extraction in the future.