川滇地区GPS速度场聚类分析

以川滇地区GPS水平速度场为研究对象，首先采用层次聚类法对其进行直接聚类，然后对在地理空间中出现错分的GPS站点利用F统计检验来纠正分类。在此基础上，考虑DB指标以及层次聚类的不可逆性，对分类结果进行二次聚类，最终将川滇地区划分为6个块体：藏东块体（BYw）、阿坝块体（BYe）、川滇菱形块体（CD）、华南块体（SC）、腾冲-保山块体（DSw）和印支块体（DSe）。其中，CD块体的西、北边界分别是“三江并流”三江断裂区域和巴塘地区的一条速度阶跃线，且巴颜喀拉主峰断裂将巴颜喀拉块体（BY）分为BYw和BYe两个块体。本文给出的川滇地区块体划分模型是数学意义上的一种合理方案，与基于地质资料的结果相吻合，可为该地区的块体划分提供另一维度的解释。

GPS Velocity Field Clustering in the Sichuan-Yunnan Region

In this study, the hierarchical clustering method is adopted to classify GPS horizontal velocity field of the Sichuan-Yunnan region, then the F statistic test is employed to correct the misclassification of the GPS site in the geographical space. On this basis, taking account of the DB index and the irreversibility of the hierarchical clustering, the former classification is re-clustered. Finally, the Sichuan-Yunnan region is ultimately divided into six blocks: Tibet block (BYw), Aba block (BYe), Sichuan-Yunnan rhombic block (CD), south China block (SC), Tengchong-Baoshan block (DSw) and Indosinian block (DSe). Among them, the west and north boundaries of the CD block are the three-river fault area of “three-river parallel flow” and a velocity step line in the Batang region, respectively. Moreover, main Bayan Har fault divides the Bayan Har block (BY) into two blocks: BYw and BYe. The block division model of the Sichuan-Yunnan region is a reasonable scheme in mathematical sense, which is basically consistent with the results from geological data, can provide an explanation in another dimension for the division of the Sichuan-Yunnan region.