Hyperspectral Monitoring of a Mediterranean Ecosystem – Castro Verde 2011

Abstract

We conducted two flight campaigns in 2011 in a typical Mediterranean ecosystem in southern Portugal. The study site is particularly interesting because of the gradient in land-use characterized by an agri-environmental scheme (within the borders of a Special Protected Area for birds) to support steppe bird populations in the northwest of the area and extensive shrub encroachment processes, outside the SPA, in the southeast. Hyperspectral AISA Eagle & Hawk data, laser scanning data, and aerial photography were acquired for a coverage of 37km by 7 km. Atmospheric conditions, including water vapour and aerosol contents, were measured during the over-flights. Data went through atmospheric and geometric correction, and were pre-processed in a reasonable quality. The flight campaign was joined by comprehensive ground activities: field spectroscopic measurements for calibration, validation and analysis, top-of-canopy photos for shrub cover fraction derivation and allometric measurements to calculate shrub biomass (plot level), and data on the bird communities at the landscape level. Several studies were or are still being conducted on basis of the collected data, of which some also have been published or presented at conferences and workshops, while others are still undergoing. This includes studies on mapping shrub cover fractions on sub-pixel scale, estimating vegetation biomass, or mapping beta diversity. All of these aim at assessing the use of hyperspectral data for monitoring natural ecosystems and ecosystem transitions, in the frame of the pre-launch activities of the EnMAP hyperspectral satellite mission. The project was supported by equipment loans from the NERC Geophysical Equipment Facility (GEF) and Field Spectroscopy Facility (FSF). The Leica System 1200 GPS borrowed from the GEF was used as a base station for the flight campaign.