In Europe, the most susceptible areas to land degradation and desertification (LDD) are found in the Mediterranean region. The present study focuses on the island of Lesvos (Greece) and maps the environmental sensitivity of the island to LDD between the years 1990 and 2000. Sensitivity is estimated with a modification of the MEDALUS Environmentally Sensitive Area Index (ESAI) approach, employing 21 quantitative parameters divided in five main quality indices: climate, vegetation, soils, groundwater and socio-economic quality. Parameterisation of these indices is achieved via remote sensing and ancillary data in a Geographical Information System (GIS). Results show that~85% of the island is fragile or critically sensitive in both epochs. Fragile areas are on the increase, covering an estimated 72% of the island in 1990 and 77% in 2000, whereas critically sensitive areas decrease from 214 to 113 km 2 . By modifying the ESAI to include 10 additional parameters related to soil erosion, groundwater quality, demographic and grazing pressure, and by applying the modified ESAI in two-rather than one-periods, this study was able to identify that, contrary to previous belief, critically sensitive areas are also found in the eastern side of the island mainly due to human-related factors. It is concluded that the proposed methodology is a useful tool for regional scale trend analyses of environmental sensitivity and the identification of LDD hot spots in Mediterranean environments.
We develop a primordial black hole (PBH) production mechanism, deriving non-Gaussian tails from interacting quantum fields during early universe inflation. The multi-field potential landscape may contain relatively flat directions, as a result of energetically favorable adjustments of fields coupled to the inflaton. Such additional fields do not contribute to CMB fluctuations given a sufficient large-scale decay, related to a gap in the critical exponents computed using stochastic methods. Along such directions transverse to the inflaton, the field makes rare jumps to large values. Mixing with the inflaton leads to a substantial tail in the resulting probability distribution for the primordial perturbations. Incorporating a large number of flavors of fields ensures theoretical control of radiative corrections and a substantial abundance. This generates significant PBH production for a reasonable window of parameters, with the mass range determined by the time period of mixing and the inflationary Hubble scale. We analyze a particular model in detail, and then comment on a broader family of models in this class which suggests a mechanism for primordial seeds for early super-massive black holes in the universe. Along the way, we encounter an analytically tractable example of stochastic dynamics and provide some representative calculations of its correlations and probability distributions.
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