Research On Geologic Environment In Three Parallel Rivers Region

Located in the southeast edge of contact zone between the Eurasian Plate and the India Plate, the Three Parallel Rivers Region (TPRR) was included in the World Natural Heritage List by UNESCO in 2003. Although TPRR is extremely vulnerable in geologic environment and very backward in social and economical development, TPRR is rich in hydro-energy, mineral, tourism and biological resources. The paper proposes several important geological environment topics and case study on major geological environment, according to development choice of development with protection respected in TPRR proposed by Yunnan Provincial Government and combining with regional geological environment condition.(1)Based on analysis on regional climate features, field investigation and geological ecology environment characters, the ecology environment can be divided into four zones. Analysis is made on formation cause of natural ecology environment in TPRR and ecology environment protection and improving methods are proposed.(2)The paper systematically discusses geologic hazard development mechanism in TPRR, mainly involving various collapse, landslide and debris flow. The geologic hazard development mechanism attributes to various geological acting force during landform and topographic feature alteration and evolvement in TPRR. The difference value is used as geologic hazard development strength index (GHDSI) between various influence factors summation-dynamical potential accelerating geological hazard development and various influence factors summation-resistance potential mitigating geological hazard development, which is used for quantifying evaluation of geological hazard risk extent. By means of investigation of and analysis on typical geological hazard points, value assignments are made to various factors. A multivariable linear regression method is adopted to solve linear equation between GHDSI and influence factors, which is used as a quantifying evaluation model of geological hazard risk, to evaluate geological hazard extent in typical section in TPRR. According to geological hazard development extent and rule, the geological hazard distribution is divided into four zones. Control and mitigation are proposed for geological hazard based on geological hazard development rule and zoning characteristics.(3)Based on geological hazard development mechanism and distribution characteristics and combined with regional geological environment condition, the paper specifically discusses geological environment issues related to hydropower, road, and mine projects and tourism development.(4)Lastly, all geological environment factors are synthesized and such five geological environment factors are selected as a geological environment quality evaluation basis to build geological environment quality index calculation model as land use condition, water resource availability and guarantee, natural safety guarantee, ecological environment condition, and air environment needed by human being. Based on geological environment quality index calculation, an evaluation is made to geological environment quality in typical sections and main towns in TPRR and geological environment region suitable for town development is selected and evaluated.The paper indicates the major geological environment issues faced in social economical development in TPRR, systematically analyzes natural and artificial causes to form various geological environment and proposes solution method and mitigation to impact of economic activities to various geological environment issues. The paper reaches the expected target and facilitates local social and economic development and environment protection.