Mapping complex patterns of erosion and stability in dry Mediterranean ecosystems

Parametrizing soil reflectance spectra with variables related to specific s hape characteristics of the spectral profile permits organic carbon concent rations in soils to be estimated on the basis of regionally validated regre ssion models. An important feature of the approach is that it can not only be applied to continuous spectra but, without notable loss in accuracy, als o to the spectral resolution of operational earth observation satellites su ch as the Landsat-TM or -ETM systems. Using this type of imagery, it can al so be shown that soil organic matter is positively correlated to growth con ditions for cereal crops in dryland agriculture. Strong correlations with q ualitative erosion indicators that can be derived through spectral unmixing approaches demonstrate that soil organic matter is an important indicator for assessing land degradation processes in dry ecosystems from space. (C) Elsevier Science Inc., 2000.