Detecting drought induced environmental changes in a Mediterranean wetland by remote sensing
Water is a vital resource for supporting agriculture and wetlands in semiarid environments and can play an important role in minimizing greenhouse gas emissions in wetlands. When droughts occur, serious social conflicts become apparent in relation to water management practices, i.e. whether to use water for irrigation of croplands or for wetland conservation. Mediterranean wetlands in south-eastern Spain are extremely valuable due to the biodiversity and their role as water reservoirs. In this study, land-cover changes in an artificial wetland are analysed for a drought-affected hydrologic year (2004–2005) in comparison to an average hydrologic year (2000–2001) by means of remote sensing techniques. Land-cover components (vegetation, soil and water) obtained from linear spectral unmixing (LSU) were used to detect temporal changes within and outside the “El Hondo” Natural Park wetland. During the drought period significant differences in vegetation, soil and water components were observed within the protected area with respect to outside. This suggests different water management practices within and outside the Park during the drought. The land-cover maps of 2001 and 2005 that were derived from the LSU components highlight these significant land-cover changes, especially within the protected area.