The Study For Geological Relics In Alxa Desert Global Geopark Based On RS And GIS

Badain Jaran Desert Scenic Area of Alxa Desert Global Geopark locates in Alxa Youqi,Inner Mongolia Autonomous Region.Systematic investigation and classification statistic to geological relics in study area,exploring the relationship between geological relics and environmental evolution are significant in theory and practice.According to Landsat data,using geographic information system and remote sensing technology comprehensively,we classified and extracted geological relics,analyzed variation characteristics and influence for monthly and annual change of desert lakes in research region based on field survey.The primal results showed as follows.1st,aeolian landform and water landscape constituted the main geological relic's types for Badain Jaran Desert Scenic Area of Alxa Desert Global Geopark.The aeolian landform included the moving compound chain megadune,the crescent dunes and chain of crescent dunes,the longitudinal dune,the shrub sandpile and the sandy land,which covered 96.08%of the total region.The water landscape included lake,dry salt lake and saline and alkaline land,which covered 3.92%of the scenic area.2nd,the area of aeolian landform in descending order was the crescent dunes and chain of crescent dunes,the moving compound chain megadune,the longitudinal dune,the sandy land and the shrub sandpile whose trends were nearly northeast to southwest.The area of water landscape in descending order was lake,dry salt lake and saline and alkaline land.The lake basins mostly distributed in the arc depression of the megadune leeward side.3rd,the lakes varied significantly monthly in research area.The number of lakes including big lakes and middle lakes were steady,but it fluctuated irregularly in small lakes in different months.The total area of lakes presented an initial increase and then a decrease,but the total perimeter of lakes decreased continuously from March to December.Besides,the dominant factors for the change of lake area were different in each month.4th,the lake varied significantly during the past 20 years.The two periods,1992 to 1995 and 2001 to 2009,when the number,the total area and total perimeter of lakes decreased,however,the number,the total area and total perimeter of lakes increased in 1995 to 2001 and 2009 to 2010.The major factors that influenced lakes area varied in different period.