Mineral climate indicators on paleoflooded and emerged areas around lake marshes (Tablas De Daimiel, Spain) using hyperspectral DAIS 7915 Spectrometer data

Abstract

Hyperspectral imagery has been able to distinguish paleoflooded areas related to a receding wetland due to differential mineralogical contents associated with variable humidity available in the past, and palustrine and fluvial processes, through maps performed using hyperspectral image processing. Gypsum, carbonate and organic matter are paleoclimate indicators spectrally recorded by the imagery in the visible and near infrared. Saline soils with gypsum, both on occasionally overflooded areas adjacent to shallow river bands and on mudflats around standing water pools, have been mapped using DAIS data. Originally deeper areas, rich in organic matter where marshes develop at times of low water movement, are also shown. Sediments permanently exposed to the atmosphere dehydrate and oxide, developing different mineralogical associations. Increase of the iron oxide/hydroxide rate and decarbonation can be spectrally followed on the sands framing the nowadays-marshy area. A general outline of the past pools is drawn in the area surrounding the actual marsh, providing priceless data to use in further paleoclimate limnological research and in the development of new techniques for that research. Therefore, hyperspectral imagery is a new tool to estimate paleogeographical processes on wetland environmental studies.