川滇地区垂直形变和主要断层活动性研究

Research on Vertical Deformation and Fault Activity of Sichuan-Yunnan Area

利用1990~2016年水准观测资料,以GNSS点的垂向速率作为先验值约束平差,利用距水准路线上距离小于10km的GNSS连续站的垂向速率检验,获取川滇地区的垂直运动速率场,可靠性优于0.87mm/a,且误差分布相对均匀。研究表明,川西地区处于快速差异性隆升阶段,位于鲜水河南东段的贡嘎山地区隆升速率最快,约5~6mm/a;四川盆地垂向运动不明显,约0~1mm/a;滇西南地区以0~2mm/a的速率下沉。同时,通过水准速率剖面分析了川滇地区主要断层的张压特性。

Based on precise leveling observation data, the vertical motion velocity field of western Si- chuan-Yunnan province is obtained using vertical velocity at GNSS point as an a priori value to con- strain adjustment and vertical velocity of GNSS continuous station less than 10 km away from level line to inspect. Residual statistical analysis at GNSS test point and benchmark suggest that vertical velocity precision at the benchmark is superior to 0.89 mm/a and error distribution is relatively uni- form. The vertical motion velocity field of the Sichuan-Yunnan region indicates that western Sichuan province is in the stage of rapid differential uplift, wherein the uplifting rate in Gongga mountain re- gion located to the southeast of Xianshui river is the fastest （5-6 mm/a）, that vertical motion in Si- chuan basin is not obvious, wherein the rate is between 0- 1 mm/a, and that sinking occurred in southwest Yunnan at the rate of 0-2 mm/a, which is consistent with the observations by GNSS. In addition,the tension characteristics of major faults inwestern Sichuan-Yunan province are analyzed through level velocity profile.