The Research In The Drawing Of Contour Lines And Filling Which Is Based On The Rectangular Grid Method In Irregular Areas

Contour research is a fundamental and important part in Visualization and ScientificComputing, considering that contour can effectively express rainfall, business, groundwaterand other geometric field variable’s size and distributed information between which lines thedistance may reflect the gradient field variable. Contour line and surface are widely used inmany disciplines such as Earth Sciences, meteorology and medicine, especially in the field ofgeological disaster prediction by reason of the development of the computer technology andthe Internet of things technology in recent years. As an important matter in networkdevelopment, we apply it in geological hazard monitoring system which can change data thatis difficult to analyze into graphics and image visual which may bring great convenience tothe workers of geological hazard monitoring system. However the difficulty lies in that thecontour drawing region is often irregular in the monitoring of geological disasters, such as theadministrative area boundary and for the sake of this application, this paper studies theirregular region contour generation algorithm.The main work of this paper is that: to complete creating isograms and filling ofisograms in irregular areas which combine with practical application; to deal with the gridpoint which may also be called the special point in equivalent point by applying rectangulargrid method; to smooth the tracing contour through the application of Beizer curve method.Basing on the previous work, this paper analyzes the principle of the contour drawingand different algorithms. What’s more, methods are presented for the practical problemswhich realize the contour drawing of different parameters for variety of areas. This papermainly completes that: the basic principle’s analysis and the improvement of contour drawing;the putting forward of the basic ideas and methods in the drawing of contour lines and fillingbased on the rectangular grid method in irregular areas; the study on the realization in detailconcerning various basic algorithms in the process of contour structure; the software designand development using the object-oriented software technology. The research achievement,which has been applied in the “geological disaster monitoring platform” of BeijingMicromulti Technology Co., Ltd., has implemented drawing rainfall-contour, businessinformation-contour, groundwater-contour and so on by use of the rainfall, groundwater and business data according to different times and areas. No doubt the result can helpprofessionals make the right judgment through the analysis of the contour.