Satellite data analysis for identification of groundwater salinization effects on coastal forest for monitoring purposes
- 1DICAM – Civic, Chemical, Environmental and Materials Engineering Deptartment, University of Bologna, Via Risorgimento 2, I-40136 Bologna, Italy
- 2CIRSA – Interdepartmental Research Centre for Environmental Sciences, University of Bologna, via St. Alberto 163, I-48100, Ravenna, Italy
Keywords: NDVI, groundwater salinity, coastal aquifer, ASTER, WorldView–2, stressed vegetation
Abstract. In the phreatic aquifer below the San Vitale pinewood (Ravenna, Italy), natural and anthropogenic land subsidence, the low topography and the artificial drainage system have led to widespread saltwater intrusion. Since changes in the groundwater concentration induce variations in the vegetation properties, recognizable by different spectral bands, a comparison between satellite images, ASTER and Worldview-2, was made using the NDVI. The aim was to identify the portions of pinewood affected by salinization through a procedure that could reduce the expensive and time consuming ground monitoring campaigns. Moreover, the Worldview-2 high resolutions were used to investigate the Thermophilic Deciduous Forest (TDF) spectral behaviour without the influence of the allochthonous Pinus pinea species that is scattered throughout the pinewood. The NDVI, calculated with traditional bands, identified the same stressed areas using both satellite data. Instead, the new Red-Edge band of the Worldview-2 image allowed a greater correlation between NDVI and groundwater salinity.