Dynamic generation method of environmental protection monitoring map point position identification

Abstract

The invention provides a dynamic generation method of environmental protection monitoring map point position identification, which is based on a combination of a GIS engine and an HTML 5 Canvas technology, and comprises the following steps of: 1, designing a plurality of vector plots according to environmental monitoring point position types, wherein each type of monitoring point positions corresponds to one type of icon, and respectively obtaining vertex pixel coordinate data of the icons; 2, dividing the monitoring indexes into different grades, determining the color corresponding to each grade, and obtaining a color array; 3, creating an HTML 5 Canvas layer; 4, requesting, by a browser, to obtain monitoring point position data; and 5, traversing the monitoring point position data, and rendering symbols into a map according to the types of the monitoring point positions and the monitoring index grades to achieve the purpose of symbolized display. Only a small number of basic icons need to be designed, and the workload is small; the environment monitoring points can be dynamically drawn, the icon drawing efficiency is improved, less browser memory is occupied, and finally the stability and usability of the system are improved.

Description

technical field [0001] The invention relates to the field of GIS online monitoring, in particular to a method for dynamically generating point marks on an environmental protection monitoring map. Background technique [0002] The display of map-based environmental monitoring points (air quality monitoring equipment) has become an important part of the environmental monitoring visualization system. In the prior art, the map symbolization is mainly performed through div (the dom element of HTML) to display the environmental monitoring points: [0003] Through the combination of elements such as div, img (as a background image), p (filling value) and other elements, a dom element is formed that is a combination of point icons and values, and through css (Cascading Style Sheets, cascading style sheets, is a method used to represent HTML files style computer language) adjust the positions of the combined dom elements to display the environmental monitoring points on the map. ...

AI Technical Summary

Problems solved by technology

[0005] First of all, there are many kinds of environmental monitoring points, such as national control points, provincial control points, city control points, township air monitoring stations, construction site dust monitoring points, enterprise pollution source monitoring points, TVOC monitoring points, straw burning monitoring points, etc. 8 Therefore, map symbolization requires 40 kinds of symbolic icons (8 kinds of symbolic icons, each index can be divided into five grades of excellent, good, medium, severe, and serious, and five colors), which leads to Icon design workload is heavy, drawing progress is slow, etc.

[0006] Secondly, when there are few monitoring points, this method can basically meet the demand, but as the number of monitoring points increases, thousands of DOM elements are loaded into the browser, which will occupy a large amount of server and browser memory, reaching a certain The amount will cause the screen to freeze or crash

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