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Transnational Access: Yes |
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Aircraft name: DO228 - NERC - ARSF
Airport: The programme of research will focus on the island of Mallorca, because this area provide important examples and paradigms of the problems that many Mediterranean areas will probably face in the near future. Mallorca clearly illustrates the transformation of the economy, society, and environment of Mediterranean tourist resorts. Moreover, these hotspots exemplify the need for holistic land use policy and management of ecogeomorphological systems. In order to assess the impacts of global change in the ecology and hydrology of Mediterranean environments, three contrasting catchments have been specifically selected: 1. The Na Borges River were instrumented in 2004. A lowland catchment (319 km2) which collects water from south-eastern parts of Central Ranges and from western slope of Llevant Ranges of the island. The altitude ranges from 300 to 500 m a.s.l. in the catchment headwaters where average slope of the channels is 8%. The Na Borges River mainstem is characterized by a very gentle average gradient (0.29%) along its 26.8 km course to the sea, where it enters the Gorg de na Borges, a coastal lagoon of 2 ha included in the European NATURA 2000 network as a Site of Community Importance. At present, dryland agriculture is the dominant land use, covering 82% of the catchment. Forest cover accounts for 16% of the catchment and urban areas 2%. The agriculture has modified the lower areas through the installation of subsurface tile drainage covering 12% of the catchment. On steep slopes, transverse walls and terracing cover 9% of the catchment. 2. The Sant Miquel River were instrumented in 2011. It is a mountainous catchment (151 km2) which collects water from the south-eastern parts of Tramuntana Ranges. Altitude ranges from 1,000 to 1,300 m a.s.l. in the catchment headwaters where the average gradient of the channels is >20%. Currently, both agriculture and forest land use occur in equal proportions (49%), whilst urban areas also occupy 2% of the catchment. However, the lowest part of the catchment (i.e., 7%) is occupied by the most important irrigated area on the island, providing concern for the deterioration of the Sant Miquel fluvial system and the SâAlbufera (1,708 ha), the wetland situated at the outlet of the catchment and protected by the Ramsar list of wetlands of international importance. Moreover, the main headwater subcatchments situated in the World Heritage Site of Serra deTramuntana are regulated by the presence of check-dams constructed in the 1980âs, in addition to traditional terracing and transverse walls. 3. Pariatge county affected by the wildfire occurred in July 2013 (25 km2). It were instrumented in 2013 with two nested gauging stations. It is a mountainous region located in the southern part of Tramuntana Ranges. Altitude ranges from 1,062 m a.s.l. at headwaters to 0 m a.s.l. It is characterized by the massive presence of traditional soil conservation structures (65% of the study area), indicative of intense âalthough preteritâ agricultural activity. Nowadays, forests represent 71% of the area. Moreover, in the last twenty years two severe wildfires affected the area. The first, in 1994, affected 845 ha; while the second, in 2013, affected 2,470 ha, of which an important part was burnt in 1994. The need to obtain long-term monitoring programmes provides the key value of the scientific knowledge of the research teams in the University of the Balearic Islands. In this way, practical field knowledge is needed to complete what is provided by modelling approach and to achieve a better understanding of ecogeomorphological connectivity it is essential to open a dialogue among numerical and conceptual approaches.
Project theme: Use airborne hyperspectral, LiDAR and SfM to improve process understanding by monitoring and modelling changing patterns of ecogeomorphological connectivity in Mediterranean insular catchments
Science context: The production of high-resolution topographic datasets is of increasing interest and application throughout the geomorphic and ecologic sciences. 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 simultaneous acquisition of accurate LiDAR data allows retrieving detailed terrain and vegetation information. The main aim of this project study is (1) to derive spatial information on vegetation, soil and terrain for ecogeomorphological connectivity model input by combined hyperspectral and LiDAR data, (2) to carry out a spectral fingerprinting approach allowing to trace back sources and pathways of sediments and (3) to calibrate and compare the results of modelling with the values obtained from the spatial distribution of isotopic environmental tracers in soils and vegetation as well as the images obtained from Unmanned Aerial Vehicle (UAV) and aircraft. Thus, airborne data acquisition will be accompanied by an extensive field campaign at ground and also air (Unmanned Aerial Vehicle-UAV) levels in which GIS modelling, sediment-tracer techniques and continuous monitoring of water, sediment and associated contaminant fluxes are being used to build a sediment budget of three catchments representative of Mediterranean environments but with contrasting characteristics.
Measurements to be made by aircraft: MEDhy2CON: Geoecologically, islands are individually unique and all are considered to be hotspots of ecosystems at a global scale. Over the past few decades, changes in land uses (e.g. urban expansion and the increase in irrigated agriculture) have transformed hydrological systems. Tourism has led to migration from rural to urban areas with consequences on land uses and the increased pressure on coastal ecosystem (Scapini, 2002). The impacts of tourism on environmental degradation, with excessive demands on water supplies and problems of waste management are common issues throughout the coastal areas of the Mediterranean basin, but in islands they are amplified (Vogiatzakis et al., 2008). Many of these problems will be compounded by global change and may, in turn, affect socio-economic activities including tourism. In addition, the Mediterranean landscape arguably may be the most human-impacted terrain on Earth. Dedkov and Mozzherin (1992) noted that around 75% of the average sediment yield (1100 t km2 yr-1) of Mediterranean headwater river catchments may be attributed to human activity with severe land degradation. In consequence, Mediterranean environments, and particularly the islands, are currently under significant threat from increasing variability in seasonal and inter-annual rainfall patterns (Candela et al., 2009). Furthermore, regeneration caused by global change impacts (i.e., wildfire, land uses and climate change) in an ecosystem it is a complex process between biological, anthropic and environmental factors. Plant physiological status (i.e., vigour, water stress) can be determined using different remote sensing indexes that can be obtained from hyperspectral cameras (canopy Leaf Area Index-LAI, 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 way, 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 to improve our understanding about the connectivity between biological processes and hydrological and geomorphological processes under different global change impacts in Mediterranean insular ecosystems. MEDhy2CON refers therefore to a series of hyperspectral campaigns intended at tackling specific research questions (e.g. degradation gradients, hydrological modelling, etc.). The present study MEDhy2CON is centred on monitoring and modelling ecological, hydrological and geomorphological fluxes along different landscapes compartments in contrasting Mediterranean insular catchments. The main objectives of this study are (1) to derive spatial information on vegetation, soil and terrain for ecogeomorphological connectivity model input by combined hyperspectral and LiDAR data, (2) to carry out a spectral fingerprinting approach allowing to trace back sources and pathways of sediments and (3) to calibrate and compare the results of modelling with the values obtained from the spatial distribution of isotopic environmental tracers in soils and vegetation as well as the images obtained from Unmanned Aerial Vehicle (UAV) and aircraft. Vrieling (2006) remarks a general lack of validation data in order to assess the accuracy of water erosion assessment by remote sensing and emphasizes the importance of a close collaboration between field-based erosion scientists and the remote sensing community. The here proposed study guarantees such a close collaboration. In addition, Walling (2013) in his recent publication emphasizes that the trajectory of sediment fingerprinting studies experimented a rapid growth during the last 5 years, in part due to technological advances which facilitated such work. Although these recent technological advances have, in some cases, reduced the cost of the analyses of sediment properties required by sediment source fingerprinting studies, such costs can still be appreciable. The potential for using rapid methods of characterising source materials and sediments is, therefore, one of the challenges in recent years for fluvial geomorphologists. In this way, the identification of major sources, stores and fluxes of sediments through remotely sensed data are expected to result in an enhanced process understanding of connectivity and modelling capability. Runoff response has been shown to be influenced by the variability of landscape characteristics, mainly introduced by the pattern of vegetated patches and bare soil surfaces (Müller et al., 2009). Thus, point sampling techniques, assessing suspended sediment concentrations by different means, should be coupled with spatial methods such as imaging spectrometry. In our study, the hyperspectral data (400-2500 nm) will be analysed with regard to vegetation and soil characteristics that mainly affect soil erosion. Spatial patterns of vegetation will be assessed including land use, vegetation height and fraction cover, LAI estimates and plant vigour. Soil will be mapped with respect to soil/bedrock spatial and spectral distribution. High altitude LiDAR data will be used to derive information on the topography being a main driver for soil erosion processes, while low altitude data will provide detailed information on vegetation structure and erosion rills, flow channel pattern and surface roughness for a subset area (i.e., three small subcatchments in which ground and UAV experiments are being intensely developed). In order to trace the sources and pathways of sediments, fingerprinting techniques will be used (Walling, 2013), considering the classical fingerprinting approach (i.e. using geochemical, organic and radionuclide fingerprints) was successfully applied in the Na Borges River basin to quantify the sediment contribution from various source areas (cf. Estrany et al., 2012; Estrany & MartÃnez-Carreras, 2013). Therefore, field spectrometer will be used to collect spectral characteristics of the source areas as well as of the sediment samples from the river sites to quantify the sediment contribution from various source areas. Additionally, hyperspectral imaging data will be processed in order to map the spatial distribution of the minerals in the non-vegetated parts of the source areas. Spectral unmixing methods allow determining not only the dominant mineral per pixel or sample but also the mineral composition. Airborne data acquisition at three different heights (i.e., UAV, aircraft, Landsat) offers an excellent possibility to study scale dependent effects. Spatial scale effects on classification accuracy as well as the transferability of algorithms across scales using data collected at different heights may be an additional outcome of this study. The results will be published in international peer-reviewed journals including Remote Sensing of Environment, Water Resources Research, Geomorphology and Earth Surface Processes and Landforms. An introductory plan for publication is as follows: + Study on the integration of airborne hyperspectral and LiDAR in the variability of topography, soil and vegetation characteristics in contrasting Mediterranean insular catchments; + Study on the ecogeomorphological connectivity modelling processes in contrasting Mediterranean insular catchments; + Study on the spectral fingerprinting method to trace back sediment sources in the contrasting Mediterranean insular catchments; + Study on the influence of fire severity on plant regeneration through remote sensing imagery and hydrological and sediment connectivity. References Candela L, von Igel W, Javier Elorza F, Aronica G. 2009. Impact assessment of combined climate and management scenarios on groundwater resources and associated wetland (Majorca, Spain). Journal of Hydrology 376(3-4), 510-527. Dedkov AP, Moszherin VI. 1992. Erosion and sediment yield in mountain regions of the world. In: DE Walling, T Davies, B. Hasholt (Eds.), Erosion, Debris Flows and Environment in Mountain Regions. IAHS press, Wallingford, pp. 29-36. Estrany J, Garcia C, MartÃnez-Carreras N, Walling DE. 2012. A suspended sediment budget for the agricultural Can Revull catchment (Mallorca, Spain). Zeitschrift für Geomorphologie, Supplementbände 56(3), 169-193. Estrany J, MartÃnez-Carreras N. 2013. Determining the sources of suspended sediment in a Mediterranean groundwater-dominated river: the Na Borges basin (Mallorca, Spain). Geophysical Research Abstracts 15, EGU2013-13180. Mueller EN, Batalla RJ, Francke T, Bronstert A. 2009. Modelling the effects of land-use change on runoff and sediment yield for a meso-scale catchment in the Southern Pyrenees. Catena79(3), 288-296. Scapini F. (ed.) 2002. Baseline research for the integrated sustainable management of Mediterranean sensitive coastal ecosystems. A Manual for Coastal Managers, Scientists and All Those Studying Coastal Processes and Management in the Mediterranean. IAO: Florence, 223 pp. Vogiatzakis IN, Mannion AM, Griffiths GH. 2006. Mediterranean Ecosystems: problems and tools for conservation. Progress in Physical Geography 30, 175-200. Vogiatzakis IN, Pungetti G, Mannion AM. 2008. Mediterranean island landscapes: natural and cultural approaches. New York: Springer. Vrieling A. 2006. Satellite remote sensing for water erosion assessment: A review. Catena 65, 2-18. Walling D. 2013. The evolution of sediment source fingerprinting investigations in fluvial systems. Journal of Soils and Sediments 13, 1658-1675.
Season: September/October 2014 and May/June 2015.
Weather constraints: The proposed activities require clear sky conditions. Some (cumulus) clouds (up to 1/8) can be accepted if not positioned on the target area (shadows).
Time constraints: The time schedule for the specific flights requested in the present EUFAR project is the months of September/October 2014 and May 2015. The base of operations for the DO228 - NERC - ARSF will be Palma-Son Bonet or Palma Son Sant Joan airports (see the attached map). Coincident times with the overpasses of LANDSAT scenes are desirable. The time of the flight should be as close as possible to local solar noon (i.e. from 10 AM to 2 PM local time for data acquisition) so as to minimize the effect of the anisotropy of the surface on reflectance measurements.
Flights (number and patterns): Two flights are planned with parallel flight lines in the optimum direction considering the shape of different study areas within the island of Mallorca at two altitudes (approx. 4,500 m and 1,500 m). The first one at the end of summer: September 2014. The second one at the mid of spring: May 2015. This accommodates for strong seasonal changes in vegetation cover characteristics and the development of erosion features to study the highly dynamic water and sediment transport processes in the study areas. Thus, both campaigns combined will greatly improve process understanding that cannot be captured with just one image that only provides a snapshot of the situation at a certain moment in time.
Instruments: Hyperspectral Imaging Sensors AISA Eagle and AISA Hawk, Airborne Laser Scanner Leica ALS 50 (II) LIDAR None
Other constraints: None
Name: Joan ESTRANY
PI email: joan.estrany@uib.cat
PI website: http://www.uib.cat