Research And Implementation On Visual Expression Of Land Cover Temporal And Spatial Change

The rapid development of economy has brought a series of ecological and environmental problems,the situation of land use cover is closely related to the ecological environment,the study of temporal and spatial change of land cover can make correct guidance and planning for the allocation and organization of land use resources.At the same time,with the development of remote sensing and geographic information technology,it is possible to obtain multi-temporal interpretation data of a region quickly and accurately.How to deal with these data and effectively display to provide a visual platform for the study of spatio-temporal change of land cover is also an important research direction.At present,the display of temporal and spatial change of land cover over a period is generally listed together for comparison,this expression can not directly reflect the change,a large number of potential information has been ignored.The rational use of visualization technology can intuitively and comprehensively present the information by means of emap,table,interaction and so on,which is beneficial to the study of the temporal and spatial change of land cover.Based on the visualization theory,combined with data visualization and map visualization,this paper studies the expression content and method of land cover temporal and spatial change,and designs the visualization mechanism of land cover spatio-temporal change to provide support for related research.The main work includes the following three aspects:(1)Data visualization in time.This paper analyzes the characteristics and structure of the land use transfer matrix,and uses the structured and semantic Treemap diagram and Sankey diagram to visualize the pure digital transfer matrix to express the change of the quantitative variations of land types over time.Highlight the proportion,flow direction,and quantity order of the transfer.(2)Map visualization in space.The quantitative method of land use change intensity is studied from two aspects of sampling point selection and intensity calculation method.Spatial interpolation forms a change intensity grid layer showing the distribution of the intensity of the whole change in the study area.Reflect the pattern of change at the macro level.Based on the classification symbols of land use status,the design mechanism and model of land cover transfer symbols are studied,the transfer symbol library is established and the access interface is designed,and the symbols of multi-dimensional information are used to render maps at the micro level.Represents the location of the land spot and the properties of different phases(3)The expression of space-time integration.With the help of interaction theory,the expression content in time and space is correlated,and the statistical data in the transfer matrix are classified and mapped in the spatial data to achieve the comparison between the transfer quantity and the spatial location distribution.Based on the development of Arcgis Engine component library,the visualization function is developed,and a example data are used to test and evaluate the visualization effect.