Sedimentary processes in the Isla Cristina salt-marshes: Geomorphological changes of landscape

The Isla Cristina salt marshes, located in the Southwest of Andalusia, constitute one of the most important nature reserves in the province of Huelva. In recent decades, as a consequence of climatic factors, and in addition to the loss of forest and agricultural formations adjacent to these wetlands, there has been a decline in biodiversity and productivity, resulting in a fragile and sensitive landscape. With the development of image processing techniques and of high-resolution satellite imagery, it is possible to obtain sufficiently precise patterns of erosion. In this paper, our new patented methodology is applied in order to measure the total volume of eroded soil in the Isla Cristina salt marshes. The various causes that give rise to this phenomenon are discussed, as well as the influence of intertidal processes. The results show how the erosion processes are related to both Land Use Change (LUC) and the morphometric characteristics of these tidal salt-marshes. The increased erosion levels are due to the influence of the Guadiana, Tinto, and Odiel rivers.