Study On Spatiotemporal Characteristics And Influencing Factors Of Lake Area Variation In Badain Jaran Desert In The Past 35 Years

The study of lake area variation in the Badain Jaran Desert is of great significance for regional water resource utilization and local economic development.This study utilizes the GEE platform and Landsat series data,employing a collaborative method of MNDWI,NDVI,and EVI indices to obtain continuous lake area datasets for the Badain Jaran Desert from 1987 to 2021.Sentinel-2 data is used in conjunction with MNDWI,NDWI,and WVP band to obtain monthly continuous lake area datasets for the desert from 2019 to 2021.The spatiotemporal characteristics of lake area variation in the Badain Jaran Desert are analyzed in depth,revealing the relationship between lake area and influencing factors such as temperature,precipitation,and wind speed.The main results and conclusions are as follows:(1)On an interannual scale,117 lakes were identified in the study area of the Badain Jaran Desert from 1987 to 2021,including 93 perennial lakes and 24 seasonal lakes.The largest lake area was 20.51 km~2 in 1993,and the smallest was 17.37 km~2 in1995.The minimum resolution area of lakes was 0.000471 km~2.On an intra-annual scale,a total of 154 lakes were identified in the study area from 2019 to 2021,with an average monthly lake area of 23.27 km~2.The maximum number of lakes in a single month was 153,the minimum was 109,with 99 perennial lakes and 55 seasonal lakes.The smallest resolution area of lakes was 0.000103 km~2.(2)From 1987 to 2021,the lake area variation in the Badain Jaran Desert fluctuated,but overall showed a non-significant and weak shrinking trend.From 2019 to 2021,the lake area exhibited a growth trend,with the largest lake area occurring in April each year and the smallest around August.(3)Lakes in the Badain Jaran Desert are predominantly clustered in the eastern and southeastern regions.Larger lakes in the east are concentrated and exhibit an expansion trend,but there are exceptions such as Haonijing lake and Wutongtu lake.Smaller lakes in the southeast are concentrated and display a shrinking trend,but there are expanding lakes such as Zhaositu lake.Lake area variation are mainly controlled by perennial lakes with area smaller than 1.1 km~2.(4)On an interannual scale,the larger the lake area,the better the correlation between lake area variation and temperature variation.On a monthly scale,the smaller the lake area,the better the correlation between lake area variation and temperature variation.The correlation between annual-scale lake area variation and wind speed variation in the lake district is not significant,while monthly-scale lake area variation has a relatively good correlation with wind speed variation.The correlation between lake area variation and precipitation in the lake district is not significant.Lake area and evaporation have a significant negative correlation,but the main controlling factors are still temperature and wind speed in the lake district.This study obtains continuous multi-year lake area variation data for the Badain Jaran Desert through remote sensing monitoring methods and analyzes the response relationship between lake area variation and climate factors.This provides a methodological reference for obtaining high-quality Badain Jaran Desert lakes data,contributes to the study of groundwater sources in the desert lakes,and has certain reference significance for formulating regional water resource utilization strategies and economic development policies.