spatiotemporal Windblown sand Patterns in the Bon lanuar Region (Mauritania): Insights from InsaR coherence and K-means clustering

Wind erosion and sand accumulation in the Bon Lanuar region of northwest Mauritania pose significant threats to infrastructure, including railways, high- ways, housing, and solar farms. Understanding the dynamics of wind and sand in this region is crucial for promoting sustainable development in similar arid areas worldwide. This study analyzes 31 Sentinel-1 interferometric coherence images acquired between March and December 2020. We applied an unsupervised k- means clustering algorithm to these images and their coherence ratios to map spatiotemporal changes in eolian sand accumulation patterns. Three areas par- ticularly affected by sand activity were identified: a field of barchan dunes west of Bon Lanuar, the city itself, and the railway and highway lines crossing it. The k-means classification revealed that 19.4% of the dunes in the barchan field exhibit high activity levels, with an annual erosion rate of 3.84% in the northern and western directions. Additionally, 15.56% sedimentation was observed along transport routes and near urban areas. Coherence ratio analysis indicated higher levels of sand activity during spring and summer, driven by prevailing northeast winds, compared to autumn and winter.

Keywords: Aeolian Processes, InSAR Coherence, Spatiotemporal Monitoring, K-Means Classification, Nasa Meteorological Data.