MEDiterranean HYdrological and HYperspectral monitoring CONnectivity: ecogeomorphological connectivity in contrasting Mediterranean insular catchments (Mallorca, Spain).
The hydrological and sediment connectivity in contrasting Mediterranean catchments affected by global change impacts on hydrology (i.e., land abandonment, wildfire and forest transition; urbanization and contaminant transfer to wetlands and Mediterranean Sea) is currently the research topic under investigation at the University of the Balearic Islands. Research is focused on four catchments in a decreasing a priori range of connectivity and increasing size: the small Vallcebre catchment (4 km2) in the South-Eastern Pyrenees, the small Sa Font de la Vila catchment (5 km2) in the southern part of the Serra de Tramuntana -affected severely by wildfires- of Mallorca Island, the Sant Miquel catchment (151 km2) in the northern part of the Serra de Tramuntana of Mallorca Island, and the Na Borges catchment (319 km2) in the Central Depression of Mallorca Island. Within these catchments, fifteen gauging stations are fully operational, i.e., 2 in Sa Font de la Vila, 3 in Vallcebre, 4 in Na Borges and 6 in Sant Miquel. In this way, at each gauging station water stage, turbidity, conductivity and temperature are continuously measured and recorded using several sensors linked to data-loggers to provide spatial and temporal information on the water, suspended- and dissolved-sediment yields. Due to its high spectral and spatial resolution, airborne hyperspectral remote sensing is considered as a promising technique for assessing some of the required parameters for the spatial modelling approach. The concurrent acquisition of accurate LiDAR data allows retrieving detailed terrain and vegetation information. Focus of the present study is (1) to derive spatial information on vegetation, soil and terrain for hydrological model input by combined hyperspectral and LiDAR data, and (2) to conduct a spectral fingerprinting approach allowing to trace back sources and pathways of sediments. Airborne data acquisition will be accompanied by an extensive field campaign. Fire regeneration of an ecosystem it is a complex process between biological and environmental factors. Plant physiological status, as vigor, water stress… can be determined using different remote sensing indexes that can be obtained from hyperspectral cameras (canopy leaf area index, leaf pigments and the photobiochemistry as the photochemical reflectance index). However, this information is limited to 2D imagery, where the information for the full 3D structure of the canopy is not available. In this sense, LIDAR technology complemented the previous indices adding information about 3D canopy structure and highly accurate estimates of vegetation height, cover and biomass even from low to high-biomass ecosystems. Combination of both technologies could let us to improve our understanding about the connectivity between biological processes and hydric and geomorphological processes after fire in Mediterranean ecosystems. This information can be useful to develop management strategies for ecosystem regeneration after fire. HS data will provide relevant information to quantify spatio-temporal changes in albedo (a key variable of the surface energy balance governing the ablation processes at the glacier surface) at the moment of the year (late summer) when the snow cover on the glacier surface is minimal. In addition, airborne LiDAR will allow for the elaboration of a fine-grained digital elevation model. Combining HS and LiDAR data will also enable improved modeling and understanding of glacier mass balance through investigation of the effects of small-scale topography on surface radiation and energy balances. Finally, HS imagery has direct applications for questions in alpine plant ecology. Our overall objective is to obtain a fine-grained classification of the land cover, together with spatially distributed parameters of plant canopies (physical and biochemical).