【摘要】 从洞庭湖区构造沉降地质背景入手,分析研究了洞庭湖区构造沉降表象特征指标。主要包括地层、河流类型、古文物、古建筑、地震活动等。利用前人采用的沉积速率法、大比例尺地形图对比法及局部少量重复水准测量资料对比法等成果,初步总结了洞庭湖构造沉降的时空分布特征。认为洞庭湖盆地周缘的丘陵山区处于相对缓慢抬升之中,其上升速率为0 32～2 29mm a;盆地区处于缓慢的沉降之中,其速率约为5～10mm a。在此基础上,为了定量研究洞庭湖区的构造沉降速率,在湖区相对较稳定的基岩上建立了基准点1个。在已知构造沉降量相对较大的地区建立了10个监测点。组成洞庭湖区高精度GPS构造沉降监测网。同时,为了检验GPS的测量精度,布设了Ⅰ等水准测量联测点。目前,监测工作已全面起动。更多还原

【Abstract】 Based on the geologic background of the tectonic subsidence in Dongting Lake area, the paper analyzes and researches on the presentational character index of tectonic subsidence in Dongting Lake area, which mainly includes stratigraphy, type of rivers, antiques, ancient architectures, earthquake activities etc. Using the achievements which former persons have obtained by adopting qualitative means of sedimentation speed measure, antithesis of large scale relief map, antithesis of little and repeated leveling information in local areas, the paper primarily summarizes temperal and spatial distribution characters of tectonic subsidence in Dongting Lake area. It considers that the hill near Dongting Lake basin is in the process of relatively slow uplifting with the speed of 0.32-2.29mm/a and the basin area is in the slow subsidence process with the speed of 5-10 mm/a. Based on these, in order to research quantitatively on the tectonic subsidence speed of Dongting Lake area, one datum point on the comparatively steady rock and 10 monitoring points in the known area which subsidence quantity is comparatively large in Dongting Lake area have been set up, which formed the monitoring network of tectonic subsidence with high precision of GPS in Dongting Lake area. At the same time, in order to test the measure precision of GPS, leveling monitoring points of Grade I have been laid out. At present, the monitoring work has been started.更多还原