Landsat monitoring of playa-lakes in the Spanish Monegros desert

Abstract

Small playa-lakes in Monegros, Spain, are high-value habitats for endemisms, threatened by landscape transformations and development of newly irrigated lands. The purpose of monitoring these fragile habitats is to detect their future disturbance, i.e. the effects of changing their natural hydrological regime, such as increasing their flooding surface area and habitat degradation by fresh and polluted water flow inputs. Landsat imagery is used for this purpose, facing the lack of regular ground data about their hydrological regime and the land covers with ecological meaning. Five meaningful thematic classes have been established grouping spectral classes obtained from unsupervised classification together with the visual interpretation of the original bands, the IHS transformation and the principal component analysis. The scarce ground data were confronted with the images. Compared to field work, remote sensing is advantageous for monitoring these playa-lakes, providing reliable insight to understand these habitats. Examples of how this research advances our knowledge about the nature and response of this ecosystem to adverse environmental changes are presented. r

Evidence of Hydroperiod Shortening in a Preserved System of Temporary Ponds

“…Satellite images have been used to map large permanent wetlands [see 14 for a review] and, occasionally, to reconstruct their temporal dynamics over the past decades [15][16][17]. However, its application on seasonally flooded systems has been scarce [18][19][20][21], and, in particular, for small-sized wetlands [22] due to the difficulty of identifying waterbodies if below pixel size, e.g., [23]. High spatial resolution remote sensing may be an alternative for the delineation of small-sized wetlands.…”

Simplified Flood Inundation Mapping Based On Flood Elevation-Discharge Rating Curves Using Satellite Images in Gauged Watersheds

“…ISODATA used in this study is an unsupervised method for image processing, and the detailed information on a target land cover is not needed for classification. For this reason, ISODATA has frequently been used in waterbody classification [42,43]. However, unsupervised methods are limited by spectrally homogeneous groupings identified by the classification process.…”

Non-Vegetated Playa Morphodynamics Using Multi-Temporal Landsat Imagery in a Semi-Arid Endorheic Basin: Salar de Uyuni, Bolivia

“…As a common feature of internal drainage basins, playas are vital for understanding the natural habitats of endemic microbes, plants and animals [1] and for interpreting the interrelation between climate and tectonic activity within continents [2]. Studies also proved that playas sediments could be potential hydrocarbon reservoirs [3], as they may contain significant numbers of thin fluvial sheetflood deposits.…”

“…Many researchers have suggested that a framework for surface sedimentary facies or depositional environments is needed in playas [4][5][6][7]. Over the past decades, a number of studies have applied remote sensing techniques to study playas and have demonstrated the usefulness of remote sensing in such studies (e.g., [1,2,[8][9][10][11][12][13][14][15]). However, most of these studies have focused on mapping evaporite minerals and water bodies.…”