海面-地面系统中三维古地面反演计算的剥蚀算法研究

Research on Denudation Arithmetic of Three-Dimensional Paleosurface Inversion Algorithm in Sea Level-Land Surface System

三维古地面反演计算是海面-地面系统研究中的一个基础研究。该文在前人研究的基础上提出了三维古地面反演计算的剥蚀算法,并与传统的加积算法做了比较分析,得出剥蚀算法比加积算法有对时间序列离散判断简单、方便计算等优点。同时,在GIS平台下实现了该算法,并以长江三角洲地区为试验区,进行了古地面虚拟反演计算,取得了较好的效果。

Three-dimensional paleosurface inversion algorithm is a basic study in sea level-land surface system research. Based on previous studies,a denudation arithmetic of three-dimensional paleosurface inversion calculation is proposed. The algorithm is to peel off the layers of increased height which was caused by crustal movement, sedimentation, and sedimentary compaction, ete. in a certain geological period of time,and inverse the height of ancient terrain. Then,a datum conversion of the inversed height is conducted using the ancient sea surface height at that time,and get the value of discrete points of the ancient elevation. The al- gorithm is independent with the raw data, and can be widely used in the calculation of the inversion process mainly caused by deposition of ancient terrain changes. The calculation accuracy of denudation arithmetic depends on the accuracy of the data in study areas,especially the accuracy of sedimentary thickness. Compared with traditional aggradation arithmetic, the denudation arithmetic is much more convenient in time sequence discrete judgments. In addition,the Yangtze River Delta region is selected as a case study area to perform the denudation arithmetic,and better results are obtained when an inversion calculation to simulate 10 thousand years terrain changes in this region processed.