According to the transformation of alterable scale, the important location of the map can be kept precise and the inferior location is led to partial distorting, the mapping region can be enlarged 玶 scaled down purposefully, which reaches the aim of extending region signed by mapping in the limited mapping domain.
According to the fact of existing mapping relations between cartographic region and the subjective cognition structure, this paper brings forth the definitions of imitative map symbol and virtual map symbol, studies the rule of their evolution, puts foward the mathematical model for maps of planning and forecasting as well as the definition for geo-cyberspace.
According to the element of non-degenerate interval being equipollence set,the authors proofed that the mapping and compound mapping from the cartographic region to two-dimensional map plane are bi-jection.
At t>t0 time,according to the condition that the cartographic body belonging to different state of cartographic region we can define the up-to-date planimetric feature,die out planimetric feature and newborn planimetric feature.
In this paper, we apply the theory of "Nature objects existed being excellent and washed out being of feebleness" to automated map generalization basing on thinking of the conditions of Map Use, Characters of Map Regions and Map Scale. Two generalization models which are called "Constrained Delaunay Triangle Net Generalization Model(CDTNGM)" and "Circle Generalization Model(CGM)" are created.
Charting of land desertification is a forward domain of the thematic charting of ecological environment. According to the fundamentals of modern cartography and the classification system of land desertification, to chart the thematic maps of the different periods can reveal the great application potentials of the numerical charting technology in the thematic charting of land desertification by synthesizing the temporal and spatial characteristics of the natural and artificial factors and by combining the application of remote sensing and geographical information system (GIS).
and contains all major vegetation coverage types. The average reliability reaches as high as 97.71% for the classification on the dynamic land usage types and 99.85% for the demarcation of patch boundaries.
Due to special demands of processing soundings, there might appear some problems, which are difficult to deal with by conventional methods, such as depth contour′s extending towards shallow side, irregular plotting area, arbitrary direction of depth grids, and different scale between horizontal and vertical grids.