Research On The Geological Condition Of The Ecological Environment In Qinghai Lake Area

Qinghai lake basin is rich in ecological resources,it is an important channel for water vapor circulation and a sensitive area for climate change in China,it is also an important body of water to maintain ecological security in the northeast of the qinghai-tibet plateau and a natural barrier to control desertification in the west and spread eastward.Its ecological environment quality not only affects this river basin,but also has the pivotal control and the adjustment function to the surrounding area.This paper takes qinghai lake basin as the research object,The relationship between geology and ecology was studied based on the results of 1:50,000 investigation and study along the belt of two major rivers,the buha river and the salu river.The effect of geological environment on ecological environment in large time and space scale is shown as follows: Crustal movement-landform shape-climate change-ecological environment evolution process is a set of dependent function is integrated,the crustal movement determines the slow evolution and pattern formation of the regional scale ecological environment.In the process of uplift,topography and geomorphology of the plateau,the climate characteristics of regional scale and the water and gas migration pattern gradually formed.The uplift of the nanshan mountains in qinghai caused the water and air from the northwest to be blocked,resulting in a significant difference in the dry and wet conditions in the region.The qinghai lake basin is moderately humid,while the gonghe and chaka basins in the south are abnormally dry.The difference of soil and water environment determines the ecological environment pattern of the alpine meadow steppe and brackish lake basin in qinghai lake basin compared with gonghe chaka dry salt basin and qaidam gobi desert basin.He relative drought in the northwest of qinghai lake basin affected by geomorphology further determines the difference of ecological environment in the basin.The effect of geological environment on ecological environment is shown in regional and modern time scale as follows: In the current climate.Each vegetation type in the study area is a characteristic community formed under the combination of different topographic and geomorphic conditions,stratigraphic lithology,groundwater and permafrost.Under the current climatic conditions,the geological environment conditions determine the appearance and pattern of the ecological environment,and the change of any one geological element will cause the change of vegetation succession.For land ecology,desertification,desertification,vegetation coverage reduction and land cover change are the macro manifestations of ecological environmental problems.The reverse succession(degradation)of all kinds of grassland in terrestrial ecology is the concrete process and substance of the ecological environment problem.Human activities and climate are mainly through the change of geological environment and then affect the ecological environment.Geology,climate and human activities are the driving forces,and the variation of soil and water environment such as groundwater and topsoil is the intermediate process.Exodynamic erosion plays a significant role in this process,and vegetation succession and desertification are the end of the process.Based on the above driving forces--soil and water environment variation--vegetation succession process,the ecological and geological environmental problems in the basin are divided into 12 categories,including: Climate-surface water change/permafrost change-groundwater decline-degradation type 2,climate-vadose zone dryness-degradation type 1,engineering construction-groundwater decline/stratigraphic soil variations-degradation type 2,ranching-wind erosion-stratum soil variation-degradation type 1,crustal uplift-river cutting,aquifer drainage-groundwater decline-degradation type 1,crustal uplift-terrain cutting steepening-external dynamic erosion-stratigraphic soil variation-degradation type 1 and relatively static geological environment-groundwater or stratigraphic soil conditions-degradation type 4.