REMOTE SENSING CONTRIBUTIONS TO THE ASSESSMENT OF AQUIFER’S STRUCTURE, CONNECTIVITY, PATHWAYS, IMPEDIMERNTS, DISCHARGE, AND SUSTAINABILITY

Remote sensing data sets are providing opportunities to investigate aquifers in arid and semi-arid areas worldwide including the following: (1) hydrologic setting and aquifer connectivity, (2) distribution of structures in the surface and subsurface, (3) structural control (e.g., impediments and preferred pathways) on groundwater accumulation and flow, (4) areas of natural discharge, (5) aquifer response to wet and dry climates, (6) mass movement directions, (7) temporal variation in Terrestrial Water Storage (TWS) and Groundwater Storage (GWS), and (8) sustainable utilization scenarios. Using temporal and spatial GRACE, ERS-1, GGMs, TRMM, GPM, SMOS, and Landsat datasets, we investigated the above-mentioned tasks/issues over the Nubian Sandstone Aquifer System (NSAS) that extends for 2 × 10⁶ km² in Egypt, Libya, Chad, and Sudan. It consists of water-bearing Paleozoic and Mesozoic sandstone with intercalations of Tertiary shale and clay of shallow-marine and deltaic origin and is bounded by basement outcrops (east, south, and west), and by the saltwater-freshwater interface (north). Findings from the remotely-acquired data were substantiated by, or coupled with, outputs of Land Surface Models (LSMs), and geochemical, geochronological, field, and geophysical data.