| Daocheng, a county of Ganzi Tibetan Autonomous Region, Sichuan, China, is geographically located on the southeast margin of the Qinghai-Tibet Plateau, and on the east side of the Hengduan Mountain Range. This area boasts of abundant unique geological features which are very valuable for scientific research and protective development. Therefore, due attention shall be paid to theoretical and application research of the geological features, resource value, formation mechanism, risk assessment of geological hazards, landscape protection and so on.This thesis is based on the comprehensive application of literature review, on-the-spot investigation, quantitative study, qualitative examination, empirical study and other methods, under the frame of which several on-the-spot surveys have been made successively in Daocheng, and a good deal of first-hand data have been collected and taken hold of, and the analytical hierarchy process (AHP) method, the geographic information system (GIS) spatial analysis technology and other technological methods in researching into the formation system of the geological features and its protection. This thesis mainly has the following components:First, the domestic and international literature of geological features is comprehensively reviewed to show the latest research development, and the research status quo of the development and protection of the basic geology and geological features of Daocheng is summed up, based on which the research perspective and technical route are put forward and the overall thesis framework of "landscape formation background-landscape formation system-risk assessment of the hazards of the landscape formation system-protection of landscape system".Second, the landscape formation background of the geological features of Daocheng area is systemically reviewed. The area under investigation, located in the south-central section of Dege-Zhongdian microblock Yidun paleo-island arc belt, is part of the collided combination of the Songpan-Ganzi belt of folded strata and Yidun volcanic arc belt of the west margin of the Yangtze platform. The area sees complex geological structure and intense structural deformation. Since the Triassic-epoch, the area has experienced the passive continental margin transformation period, the retroarc-foreland subducted orogenic process, large-scale thrusting-nappe and left-lateral strike-slip fault tectonic movement and other structural evolution process. Especially, since the Quaternary Pleistocene, the last glaciation has left over the numerous resources of glacial geological features in the area under investigation. Therefore, the area under investigation boasts of the combination of various abundant unique physical geographic features such as landform, climate, hydrology, soil, biology and so on. The regional geological background and physical geographical environment are the geological landscape formation background of Daocheng area, and the basis for forming the typical higher mountain landscape and systematically complete quaternary glacial remnants geomorphologic landscape.Third, the thesis makes the original achievments:Firstly, it puts forward the scientific classification scheme, overall geomophogensis and natural attributes of the geological features of Daocheng area, in accordance with which the geological features of Daocheng area are classified two categories, four subclasses, and11geological landscape types. Secondly, it systematically relates and analyzes the main geological features of Daocheng area in the six aspects of glacial landform, fluvial process, magmatic process, stratigraphic section, geological structure features and orogenic landform. Third it makes qualitative evaluation of the geological features of Daocheng area from the four dimensions of scientific value, aesthetic value and science-popularization value, and with application of the AHP method, the thesis puts forward the development value of main geological landscape, and the Minya Konka mountain, the Blue Moon Valley, the Xingyicuo Lake group, and the Holy Mt. Cowboy, in particular, demonstrates comparatively high landscape value. Finally, it systematically expounds the formation mechanism and evolution of typical geological features of Daocheng area, which provides scientific basis for informed recognition and rational utilization of geological features.Fourth, the typical geological features (glacial landform features) of Daocheng area are compared with some cases at home and abroad. The distribution regularity of glacial landforms at home and abroad is analyzed, and the glacial landform-related national geological parks and natural heritages at home and abroad are compared, based on which the advantages of the geological landscape of Daocheng area are worked out:The glacial activities of Daocheng area feature multi-stage development, which forms all kinds of outstanding glacial geomorphologic features and demonstrates that the area under investigation sees completely preserved distribution of a series of glacial-eroded landform and glacial drift landforms formed during the process of glacial formation and ablation; therefore, compared with general simple contemporary glaciers and glacial remains, the glacial remains of Daocheng area has clear advantages of landform combination, and provides an important basis for scientific survey of the glacial-eroded landforms and quaternary glacial evolution on the eastern margin of the Qinghai-Tibetan Plateau, and an important window to investigation of the crust uplifting and ancient climate change of the west Sichuan mountainous area.Fifth, this thesis originally puts forward the "three dimensional" evaluation system for the risks of the geological landscape hazards in the Daocheng area, i.e. the the risk influencing factors of geological landscape hazards can be divided into the three categories of natural factors, human engineering factors and human economic activities factors. It further picks up the eight evaluation factors of topographic condition, stratum lithology, geological structure, curvature, river distribution, road, settlement place and land utilization, and makes use of the GIS technology and the AHP method to have comprehensive evaluation to work out the evaluation outcome through the scientific classification of the four level zones of high, intermediate, low and non dangers.Sixth, it finally puts forward the "GST" protective mode for the geological features in the Daocheng area, i.e. supported by numerous geological landscape features in the Daocheng area, application can be made to declare it as a national geological park, which serves as a carrier for protecting the geological landscape of Daocheng area, based on which the macro control security strategy and micro special defending and harnessing technology of the geological landscape in the Daocheng area. |
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