Establishment of SWAT Model Spatial Database Based on PSO Optimization Algorithm

Building the basic spatial database of Soil and Water Assessment Tool (SWAT) model is the foundation and key of cyclic simulation. The spatial database of SWAT model mainly includes DEM, soil type map and land use map. Spatial data clustering is an important part of the establishment of spatial database. In the past application system, relational database was used to store attribute data and spatial data in file form. Establish the application system by establishing the association between the spatial data file and the attribute data in the relational database. Clustering analysis is to group data according to the similarity between sample data, so as to discover the distribution law and typical patterns of spatial data. Spatial database has the basic connotation of general database, which is an ordered collection of a large number of data sets with the same characteristics. Basic geospatial database is managed by relational database. Basic geospatial database is the basic condition of building “digital area”. PSO optimization algorithm can realize batch optimization of SWAT model parameters. Compared with before parameter optimization, the relative error of SWAT model simulation runoff depth after parameter optimization is reduced by 5.7%, and the fitting coefficient of flow process is increased by 0.118. Therefore, when the spatial data dimension is high, data clustering will produce “dimension disaster”. In order to solve the problem of “dimensional disaster” of spatial data, based on previous studies, this paper discusses the establishment method of SWAT model spatial data in detail. The application of PSO optimization algorithm in SWAT model parameter optimization is analyzed, and then the PSO algorithm is optimized, which provides a new idea for the improvement of spatial data clustering algorithm.