Establishment Of Spectral Data Base In Liaohe Estuary Wetland And Application Of Decision Tree Classification

Wetland is known as the kidney of the earth and an important ecosystem.Monitoring wetland environment is an important basis for wetland management and protection,making correct analysis and decision-making.3S technology has been widely used in wetland protection and monitoring due to its fast and reliable characteristics.Hyperspectral remote sensing technology has further deepened the application scope and ability of remote sensing resources.Based on the background of Liaohe Estuary Wetland,remote sensing image and field spectral data measured by field spectrometer as data sources,and Visual Fox Pro as platform,this study explores how to establish a small customized spectral database for individuals or research teams under the premise of reducing costs and developing difficulties.On this basis,the land types of wetland in Liaohe Estuary were classified by decision tree.The main contents of this paper are as follows:(1)Function determination of database,selection of compiler tools and data collection.According to the requirements,the main functions of the database are data storage and display,data import and export,data modification and encryption,storage and accurate retrieval,and linkage with other professional software.By comparing several commonly used database compiling tools and analyzing their details,VFP is selected as the database compiling tool in combination with the actual situation and objective factors of establishing small database.The Liaohe estuary wetland was surveyed three times and more than 1000 spectral curves were obtained.The obtained information mainly includes spectral information,geographic coordinate information and image auxiliary information.The information was stored properly and ready for input into the database.(2)The realization process of database function.Visual Fox Pro is used to realize the functions determined by the spectral database of wetland features in Liaohe Estuary.The realization of database function mainly depends on two parts,namely,a series of functions such as data storage,display,import,export and modification through object-oriented form design in VFP,and data matching,analysis and processing through linkage with other professional software.Reasonable cooperation between database and other software can not only increase the reliability and accuracy of data processing,but also reduce the corresponding cost for the establishment of database,which is in line with the original intention of establishing a small database suitable for a specific research area at low cost.(3)The application of database in decision tree classification.Using OLI image as data source and spectral information of specific objects collected for specific seasons as prior knowledge,decision tree classification based on expert knowledge for Wetland Land Types in Liaohe Estuary was carried out by means of Popper resampling,band fusion calculation and SPSS data analysis,and good results were achieved.The overall accuracy was 90.84%,and the Kappa coefficient was 0.897.The methods of expansion and update in the process of using database are also discussed.