Automatic cartographic generalization method of canal linear river system element considering density variation

Abstract

The invention relates to a cartographic method of a canal linear river system element considering density variation. The cartographic method of the canal linear river system element considering the density variation comprises the steps that firstly high-grade canals are selected according to a mainstream and branch relationship of a linear river system; then a canal with a large element length isselected in the candidate canals; according to the density variation of the density of the selected canal and the density of an original canal, a density variation sum of a canal element not being selected is counted, and a canal water body with the largest density variation sum is selected and the density of the selected canal is updated; the canal water body with the largest density variation isselected repeatedly until the number of selection reaches the number of canals required by cartographic generalization; and finally, simplified line processing is carried out on the selected canal element, canal details are abandoned, and the basic shape of the canal is reserved. According to the cartographic method of the canal linear river system element considering the density variation, canalwater body selection during the cartographic generalization can be automatically realized according to the density variation of the selected canal and the original canal, a density comparison relationship between different density areas of a cartographic area is kept, and complex manual intervention is not required, so that canal element cartographic generalization is more flexible and convenient.

Description

technical field [0001] The invention relates to a method for cartographically synthesizing linear water system elements according to density differences. Background technique [0002] With the in-depth development of geographic information systems and cartography, digital maps are more and more valued and applied by various industries due to their characteristics of convenient update, convenient modification and storage, and efficient transmission. The large demand for digital maps poses a challenge to the traditional long-period manual mapping methods. Cartographic synthesis is an important part of the research field of cartography. In a popular sense, it refers to the corresponding clustering, merging, and simplification of various map elements when the scale of the map changes. Finally, a map whose complexity meets the requirements of the corresponding scale and whose content is simplified meets the actual needs. The development of computer technology has promoted the a...

AI Technical Summary

Problems solved by technology

On the one hand, large-scale GIS mapping software often considers more universal methods, and the algorithms are less targeted, while the cartographic synthesis of various elements requires a large amount of map expert knowledge; on the other hand, GIS data itself has its own characteristics. The drawing requirements of various thematic maps are also different, which brings difficulties to the design of software algorithms

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