Long time series of Landsat images to reconstruct River surface temperature and turbidity regimes of Guadalquivir Estuary

In the last century the Guadalquivir River in Andalusia has been dramatically transformed affecting its ecological and hydrological functioning. In view of a new dredging plan to increase ship size and number arriving to Seville, a research consortium has started to study the state of the Guadalquivir Estuary. The Remote Sensing and GIS laboratory of Doñana Biological Station participates in the project with the aim to reconstruct the last 35 years regime of turbidity and river surface temperature (RST), both parameters revealing the estuarine response to natural and human-driven dynamics. Based on a long time series of Landsat images (TM and ETM+), we have developed accurate methods to systematically map RST and turbidity gradients across the last 100 km stretch of the River. We present the results of applying an empirical model for river turbidity mapping and a physical model to map RST by using optical and thermal bands of TM and ETM + sensors. Both models were validated with ground-truth data and are used to reconstruct the historical dynamics of the Guadalquivir Estuary.