Search results for "Moisture"
showing 10 items of 290 documents
Effect of ultraviolet and moisture action on biodegradable polymers and their blend
2020
In this work, the suitability of polylactic acid (PLA), polybutylene adipate terephthalate (PBAT) and PBAT/PLA blend samples to outdoor applications were investigated in terms of mechanical, morphological and visual properties in presence of ultraviolet action and water, finding that PLA in particular can be actually considered for such applications.
The influence of fire history, plant species and post-fire management on soil water repellency in a Mediterranean catchment : The Mount Carmel range,…
2017
Fire is a key factor impacting soil hydrology in many Mediterranean catchments. Soil water repellency (SWR) can stimulate land degradation processes by reducing the affinity of soil and water thereby triggering a reduction in soil fertility and increasing soil and water losses. The effects of two consequent fires (1989 and 2005) on SWR were assessed in the Carmel Mountains, Israel. Fire history, plant recovery and post-fire management (14 treatments) were investigated as determining factors in a time dependent system. In total 210 locations were investigated 9 times from October 2011 to February 2012, which totals 1890 water drop penetration tests that were performed. During each visit to t…
First evaluation of the simultaneous SMOS and ELBARA-II observations in the Mediterranean region
2012
Abstract The SMOS (Soil Moisture and Ocean Salinity) mission was launched on November 2, 2009. Over the land surfaces, simultaneous retrievals of surface soil moisture (SM) and vegetation characteristics made from the multi-angular and dual polarization SMOS observations are now available from Level-2 (L2) products delivered by the European Space Agency (ESA). Therefore, first analyses evaluating the SMOS observations in terms of Brightness Temperatures (TB) and L2 products (SM and vegetation optical depth TAU) can be carried out over several calibration/validation (cal/val) sites selected by ESA over all continents. This study is based on SMOS observations and in situ measurements carried …
L-Band radiative properties of vine vegetation at the MELBEX III SMOS Cal/Val Site
2012
Radiative properties at 1.4 GHz of vine vegetation are investigated by measuring brightness temperatures with the ETH L-band Radiometer II (ELBARA II) operated on a tower at the Mediterranean Ecosystem L-band Characterisation Experiment III (MELBEX III) field site in Spain. To this aim, experiments with and without a reflecting foil placed under the vines were performed for the vegetation winter and summer states, respectively, to provide prevailingly information on vegetation transmissivities. The resulting parameters, which can be considered as "ground truth" for the MELBEX III vineyard, were retrieved from brightness temperature at horizontal and vertical polarization measured at observa…
Convergence in critical fuel moisture and fire weather thresholds associated with fire activity in the pyroregions of Mediterranean Europe
2021
Wildfires are becoming an increasing threat to many communities worldwide. There has been substantial progress towards understanding the proximal causes of increased fire activity in recent years at regional and national scales. However, subcontinental scale examinations of the commonalities and differences in the drivers of fire activity across different regions are rare in the Mediterranean zone of the European Union (EUMed). Here, we first develop a new classification of EUMed pyroregions, based on grouping different ecoregions with similar seasonal patterns of burned area. We then examine the thresholds associated with fire activity in response to different drivers related to fuel moist…
Exploring the use of Unmanned Aerial Vehicles (UAVs) with the simplified ‘triangle’ technique for soil water content and evaporative fraction retriev…
2020
Participation of Dr. Petropoulos has been funded by the ENViSIoN-EO Marie Skłodowska-Curie grant (grant No 752094), part of the European Union’s Horizon 2020 research and innovation programme. Part of the present collaborative work was also materialised in the framework of a short Term Scientific Mission (STSM) of the HARMONIOUS Cost Action which financially supported Dr Petropoulos’ visit between 4 to 15 February 2020 to the Department of Engineering of the University of Palermo, Italy. Η συμμετοχή του Δρ. Πετρόπουλου χρηματοδοτήθηκε από το πρόγραμμα της Ευρωπαϊκής Ένωσης για Έρευνα και Καινοτομία «Oρίζοντας 2020», δράση Marie Sklodowska - Curie , έργο ENViSIoN-EO (αριθ. 752094). Επίσης μέ…
Post-fire soil functionality and microbial community structure in a Mediterranean shrubland subjected to experimental drought.
2016
Fire may cause significant alterations in soil properties. Post-fire soil dynamics can vary depending, among other factors, on rainfall patterns. However, little is known regarding variations in response to post-fire drought. This is relevant in arid and semiarid areas with poor soils, like much of the western Mediterranean. Furthermore, climate change projections in such areas anticipate reduced precipitation and longer annual drought periods, together with an increase in fire severity and frequency. This research evaluates the effects of experimental drought after fire on soil dynamics of a Cistus-Erica shrubland (Central Spain). A replicated (n = 4) field experiment was conducted in whic…
Re-evaluation of moisture sources for the August 2002 extreme rainfall episode in central Europe: Evaporation from falling precipitation included in …
2015
Summary Discriminating moisture sources with precision is an important requirement to better understand the processes involved in extreme rainfall episodes. In a previous contribution by Gangoiti et al. (2011b), an innovative technique was presented to assess surface moisture sources contributing to a target precipitation within a Lagrangian framework. The technique was based in transporting parcels of vapor, representing the target precipitation, across a set of nested grids covering a large area at different resolutions. A mesoscale model estimated the meteorological variables to transport and redistribute the vapor back into its original sources, all of them assumed to be at the surface.…
The SMOS mediterranean ecosystem L-band characterisation experiment (MELBEX) over natural shrubs
2010
10 páginas, 5 figuras, 7 tablas.
Evaluation of the most recent reprocessed SMOS soil moisture products: Comparison between SMOS level 3 V246 and V272
2015
International audience; Soil Moisture and Ocean Salinity (SMOS) satellite has been providing surface soil moisture (SSM) and ocean salinity (OS) retrievals at L-band for five years (2010–2014). During these five years, the SSM retrieval algorithm i.e. the L-MEB (L-Band Microwave Emission of the Biosphere [1] model has been progressively improved and hence results in different versions of the SMOS SSM products. This study aims at evaluating the last improvement in the SSM products of the most recent SMOS level 3 (SMOSL3) reprocessing (SMOSL3_2.72) vs. an earlier version (SMOSL3_246). Correlation, bias, Root Mean Square Difference (RMSD) and unbiased RMSD (unbRMSD) were used as perform…