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.