Mapping Dynamics of Waterbirds Habitat in Relation to Water Level Changes in a Mediterranean Shallow Lake Using Multi-temporal Remote Sensing

The Lagoon of Fuente de Piedra in Andalusia, Spain, is a high-value habitat for waterbirds, threatened by expansion and irrigation of olive plantation. This research focuses on detecting the response of land-cover in the lake to water level variation using multi-temporal satellite data, so as to provide information for the nature park management. Objectives of this study are to identify the land-cover categories and to detect the change in area of different categories with water level. ASTER and Landsat TM images were obtained for a series of water levels, and classified using ISODATA into five land-cover categories: water, wet mudflat, dry mudflat, high density vegetation and low density vegetation. The overall accuracy was 87.8% with a Kappa of 83.9%. User accuracy, producer accuracy, mean accuracy and area difference were also calculated to assess the classification accuracy. Classified images and charts were generated to identify the spatial and area changes of these land-cover categories with water level. The area of water surface increases steadily, while the mudflat area decreases, with the increase of water level until water reaches the lake bank. Dry mudflat disappeared faster than wet mudflat with the increase of water level. The total area of vegetation varies in a range of 2.5 -3.5 km. The results proved that multi-temporal satellite data, unsupervised classification and visual interpretation are useful for detecting the land-cover response to water level variation in the shallow lake.