金沙江流域区域地壳稳定性分区与定量评价

金沙江中、下游横穿横断山南北构造带, 新构造运动强烈, 地震活动频繁, 各种内动力地质灾害比较严重, 该区区域地壳稳定性相对较差。为服务于金沙江水电工程规划建设和减灾防灾的需要, 本文对金沙江流域沿江地区进行了地壳稳定性的评价与分区。文中依据地壳稳定性定量评价的原则和方法, 建立地质构造背景、地壳结构、地震以及地球物理等指标, 并将地壳稳定性划分为四个等级:稳定、基本稳定、次稳定和不稳定。然后按照上述系统进行地壳稳定性分区。最后, 综合各项研究资料来确定各区的定量评价指标, 并采用模糊数学方法对各区地壳稳定性进行综合评价。

QUANTITATIVE ASSESSMENT AND ZONATION OF REGIONAL CRUSTAL STABILITY IN THE JINSHAJIANG RIVER BASIN

The middle and lower reaches of Jinshajiang River, flowing across the Hengduan south north tectonic belt, marked by intense neotectonism and frequent seismic activity, has relatively strong active tectonism accompanied with various endogenic geological hazards. In this case it seems necessary to conduct a quantitative assessment and zonation of the regional crustal stability for planning and construction of hydropower projects along the Jinshajiang river valley. Based on the quantitative system of classifying crustal stability, a number of elemental parameters, including tectonic background of the region, the crustal structure model, as well as seismological and geophysical parameters, are studied and the crustal stability is classified as stable, basically stable, sub stable, and unstable. Based on this system, Jinshajiang River basin is divided into 13 subzones. Finally, the stability for each subzone is determined as a grade by using comprehensive fuzzy mathematic method.