Potential Source-to-Sink Spatial Correspondence in a Martian Analog Environment of the Qaidam Basin Based on GF-5A Hyperspectral Imagery

Abstract

Alluvial fan source-to-sink (S2S) systems in Mars-analog environments are crucial for investigating planetary surface processes. However, traditional S2S analyses lack continuous regional coverage and topographic physical constraints. This study integrates GF-5A spaceborne hyperspectral imagery with DEM data to establish a regional-scale hyperspectral mineral spatial correspondence framework on the western margin of the Qaidam Basin. Using the Sequential Maximum Angle Convex Cone and Spectral Angle Mapper algorithms, we mapped two representative mixed mineral endmembers: clay–mica and Fe2+-bearing silicate mineral assemblages. A terrain-derived hydrological network was constructed to evaluate sub-catchment mapped mineral extents, potential source supply conditions, and potential near-source S2S relationships. The results indicate that the Fe2+-bearing silicate mineral assemblage exhibits a close spatial correspondence between source zones and near-source depositional zones, with broadly comparable mapped areas in the source region and proximal areas. Conversely, the clay–mica mineral assemblage displays strong spatial heterogeneity, showing a large-scale reduction in the central core channel. Synergistic validation combining DEM topographic dynamics with vertical spectral profiles from a single ground-based in-situ borehole provides preliminary support for the hypothesis that this surficial mineral differentiation may reflect hydrodynamic sorting and/or multi-stage continuous aggradation. While currently constrained by two-dimensional mapped surface area rather than mineral mass, an evaluation of three proximal pathways, and a preliminary single-core profile without extensive regional ground-truthing, this integrated framework provides a prospective terrestrial analog reference and methodological support for evaluating potential source-to-sink spatial correspondence and reconstructing paleohydrology on Mars.