Research On The Applicability Of SBAS-InSAR In The Badan Jaran Desert Lake Area

The Badain Jaran Desert is located in Alashan Plateau,which is bounded by the mountains to the south and southeast and by palaeo-lake basins and lowlands to the west and north,and it is the second largest desert in China.There are magasanddunes in the Badain Jaran Desert and a lot lakes in inter-dune depressions.Although great progresses had made on field investigation,short-term in situ observation and numerical simulation in the Badain Jaran Desert researth,most of them were qualitative and semi-quantitative due to the lack of the long-term meteorological and sanddune movement data.To deeper understanding sanddune and environment evolution in this region,radar interferometry(InSAR)technique is introduce to invert the surface deformation,and to explore the application of InSAR in desert researth.With the development of radar remote sensing,sentinel-1 radar satellite image data are ideal for the observation and understanding of the surface deformation of the Badain Jaran Desert combined with the Google Earth scenes and ASTER GDEM.In this paper,we discussed temporal changes of the surface deformation about the Miaohaizi(scientific name is Sumu Jilin),which is located in the southeast of the Badain Jaran Desert and then pushed forward Nuoertu,Yindeertu and dry lake of Yikeri.The result showed that the SBAS-InSAR was available in these areas through the inversion of different types of lakes.The extent of application and the influence of space-time baseline on coherence in desert areas were discussed.The SBAS-InSAR can be used in the Badain Jaran Desert Lake due to the high coherence points around the lakes.Nevertheless,when the study area is expanded to a certain extent,decoherence will lead to the failure of the inversion in relative height time series changes,so the extent of the study area should not be too large.The threshold of time baseline should be 120 days and spatial baseline needs to be adjusted according to the atual situation.The distribution of surface deformation in the Miaohaizi of the Badain Jaran Desert is characterized by erosion reduction in the northwest and accumulation increase in the southeast.Based on the above extent and space-time baseline,the changes of the surface deformation in the Miaohaizi are retrieved.The results are analyzed based on the maximum wind speed data obtained from the Scientific Observation and Experiment Station combined with the surface deformation of the Miaohaizi.The changes of the surface deformation are highly consistent with the maximum wind speed.In addition,the inversion about Yikeri not only reflects the changes of itself,but also can indirectly reflect the sedimentation rate of the lake without drying up to a certain extent.