关键词: 约束三角网, 断层, 有效点, 递归, 等值线追踪

Abstract: Researching isoline with fault lines is significant for analyzing terrain and searching minerals，but at present，in most cases，the fault information is not adequate，and it is difficult to get detail information of fault.So it is complex and hard to estimate elevation values of both sides of points on fault lines when generating isolines map.Combined with topological structure of triangulation，an algorithm of searching points and interpolation is proposed.This algorithm can effectively resolve problems of estimating elevation values of both sides of fault lines，especially can be adapt to less data and less information of fault lines.Besides it can be implemented by programs easily and performs effectively，and can accord with requirements of the project.

Key words: constrained triangulations, fault, available points, recursion, isoline tracing