1,463 research outputs found
Detecting bark beetle infestation using plants canopy chlorophyll content retrieved from remote sensing data
The European bark beetle (Ips typographus, L.) is a potentially severe invasive species in the UK and North America. It is resulting in a high degree of fragmentation, forest productivity, and phenology. Understanding its biology, as well as developing early detection based on its behavior, is an important aspect of its successful management and eradication. Bark beetle infestation causes changes biochemical and biophysical characteristics such as chlorophyll water and nitrogen content. This study showcases the potential of the Canopy Chlorophyll Content (CCC) product derived from remote sensing datasets to detect early bark beetle infestation in Bavarian forest national park. We generated time series CCC maps from RapidEye and Sentinel-2 images of the study area through Radiative transfer model inversion. The CCC products were then classified into infested and healthy using CCC mean and variance collected in 2015 and 2016 from infested and healthy Norway spruce trees in the Park. Reference data obtained from processing and interpretation of high resolution (0.1m) color aerial photographs were used to validate the accuracy of the infestation maps. Our results demonstrated that CCC products as derived from remote sensing data were a rigorous proxy to early detect bark beetle infestation. Validation of the infestation maps revealed > 70% classification accuracy throughout the time-space. Hence, CCC products play a significant role to understand the dynamics of the infestation and improve the management of bark beetle outbreaks in forest ecosystem. Despite these promising results, other plant traits such as dry matter content and Nitrogen content will need to be investigated as additional predictors, which may considerably improve the accuracy of early detection of bark beetle infestation using remote sensing derived products
ZrO2 Based materials as photocatalysts for 2-propanol oxidation by using UV and solar light irradiation and tests for CO2 reduction
Bare ZrO2, Ce doped ZrO2 and Er doped ZrO2 samples have been prepared by a hydrothermal process and have been used as photocatalysts for 2-propanol oxidation reaction in gas solid regime. Moreover, some preliminary tests have been carried out for CO2 reduction. The samples were physico-chemically characterized and both bare and doped ZrO2 based materials resulted active for oxidation and reduction reactions by using UV and solar irradiation. The reactivity results have been correlated with the compositional, structural and morphological features of the photocatalysts
Earth Observation in Support of the City Biodiversity Index
Today, we are living in an urban world. For the first time in history, there are now more people living in cities than in rural areas. In Europe their share has reached almost three quarters. Urban areas supposedly will absorb almost all the population growth expected over the next decades. This will pose a range of challenges for cities and their surroundings, not only on resource availability and the quality of urban environments, but also on biodiversity in cities.
Capturing the status and trends of biodiversity and ecosystem services in urban landscapes represents an important part of understanding whether a metropolitan area is developing along a sustainable trajectory or not.
Actions to conserve biodiversity should start with stock-taking and identifying baselines, followed by regular monitoring of conservation initiatives. The City Biodiversity Index (CBI), also known as the Singapore Index on Cities‘ Biodiversity (or Singapore Index) because of Singapore‘s leadership in its development, has been adopted during COP-9 of the CBD in 2008. It is conceived as a self-assessment tool to evaluate the state of biodiversity in cities and to provide insights for improving conservation efforts. This includes an initial baseline measurement, the identification of policy priorities based on their measurements and then a monitoring at periodic intervals.
Today, the CBI includes 23 indicators from three categories such as the proportion of natural areas in the city or the budget allocated to conservation projects. The CBI is designed to be applied by many cities in the world to monitor their progress in conservation efforts and their
success in halting the rate of biodiversity loss.
The project provides support to 4 of the 23 indicators. The results illustrated below are based on satellite earth observation data combined with local in-situ information. The output of the data analysis (i.e. percentage or an area value) can be directly used to determine the relevant CBI score
Outlining where humans live -- The World Settlement Footprint 2015
Human settlements are the cause and consequence of most environmental and
societal changes on Earth; however, their location and extent is still under
debate. We provide here a new 10m resolution (0.32 arc sec) global map of human
settlements on Earth for the year 2015, namely the World Settlement Footprint
2015 (WSF2015). The raster dataset has been generated by means of an advanced
classification system which, for the first time, jointly exploits open-and-free
optical and radar satellite imagery. The WSF2015 has been validated against
900,000 samples labelled by crowdsourcing photointerpretation of very high
resolution Google Earth imagery and outperforms all other similar existing
layers; in particular, it considerably improves the detection of very small
settlements in rural regions and better outlines scattered suburban areas. The
dataset can be used at any scale of observation in support to all applications
requiring detailed and accurate information on human presence (e.g.,
socioeconomic development, population distribution, risks assessment, etc.)
Flavor Mixing Democracy and Minimal CP Violation
We point out that there is a unique parametrization of quark flavor mixing in
which every angle is close to the Cabibbo angle \theta_C \simeq 13^\circ with
the CP-violating phase \phi_q around 1^\circ, implying that they might all be
related to the strong hierarchy among quark masses. Applying the same
parametrization to lepton flavor mixing, we find that all three mixing angles
are comparably large (around \pi/4) and the Dirac CP-violating phase \phi_l is
also minimal as compared with its values in the other eight possible
parametrizations. In this spirit, we propose a simple neutrino mixing ansatz
which is equivalent to the tri-bimaximal flavor mixing pattern in the \phi_l
\to 0 limit and predicts \sin\theta_13 = 1/\sqrt{2} \sin (\phi_l/2) for reactor
antineutrino oscillations. Hence the Jarlskog invariant of leptonic CP
violation J_l = (\sin\phi_l)/12 can reach a few percent if \theta_13 lies in
the range 7^\circ \leq \theta_13 \leq 10^\circ.Comment: Latex 12 pages. Minor changes, references added. Accepted for
publication in Phys. Lett.
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