Multitemporal Remote Sensing for Monitoring Highly Dynamic Phenomena: Case of the Ephemeral Lakes in the Chott El Jerid, Tunisia

In the last 20 years, a number of Earth observation satellite missions has been launched, resulting in a considerable improvement in the spatiotemporal capabilities of applied remote sensing. In order to survey the main recent flooding events in Chott El Jerid, Tunisia, dated to April 2007, September 2009, June 2014 and February 2015, time-series of MODIS-Terra data have been used. The maximum surface area of the water bodies reached 660 km² in 2007 and 2014. The flooding event of September 2009 was the longest event (88 days) compared to only 35 days for the exceptional June event in 2014. The daily acquisition of images, the spectral range and the large swath of the sensor are well-adapted to estimate the extent of the ephemeral lake in an area that is difficult to investigate in the field. It remains difficult to decipher the part of water from direct precipitation, runoff from the reliefs and aquifer resurgence.