Vegetation canopy changes and use of SoilGrids data for assessing the effect of extreme rains on annual soil losses

Extreme rains can trigger natural hazard processes such as soil erosion, land sliding and flash floods. Climate change studies show that the frequency of extreme rains is in an increasing trend, resulting in the amplification of hazard processes. For assessing the magnitude of soil losses various models are available. While annual empirical models (e.g. USLE, RUSLE, MMF) are easy to use, they do not take into account the effect of extreme rains. The event based models (e.g. LISEM, WEPP) can simulate erosion processes in detail, but rainfall event data is simply not available everywhere. To solve this problem, Shrestha and Jetten, (2018)have developed a daily erosion model and demonstratedthat the effect of extreme rains can be incorporated easily in annual estimates. For running the model, daily rainfall, vegetation canopy changes, topography and soil dataare required. Daily vegetation canopy changes mapping is a challenge and soil data may not be available easily everywhere due to higher cost involved in soil survey. Recently, time series NDVI and SoilGrids data are available freely, solving data scarcity problem. But, we do not know how good is the data for hazard assessment. The objectives of the study are in assessing the effect of daily canopy coverchanges on rain interception, and in the use of SoilGrids data for erosion estimation.The study area is located in Sehoul, Morocco. Time series NDVI data at 1 Km resolution was obtainedfrom Vito, Belgium (http://free.vgt.vito.be), and resampled to 15mand at daily time step. Similarly, SoilGrids data at 250 m resolution was downloaded from ISRIC, The Netherlands (https://soilgrids.org). Pedotransfer functions were used to generate soil parameters and the daily erosion model was applied to assess soil losses. The results show that vegetation canopy cover plays an important role in the magnitude of soil losses. Canopy cover intercepts rain and protects the soil from raindrop impact. When canopy cover is lower, erosion rates are higher. During extreme rains, erosion can be very severe. The study shows that SoilGrids is a useful data source, and can be applied in daily erosion assessment in the semi-arid environment. The results also showthat daily erosion modelling gives better picture of annual soil losses since the effects of extreme rains are also incorporated

Land degradation modelling in inaccessible mountainous areas in the tropics

Land degradation processes in hilly areas are often directly related to land cover changes. At the same time, many hilly areas in the tropics are inaccessible and thus lack proper data. As a result, data scarcity is a crucial problem when trying to assess soil erosion. In this paper a method is described showing the use of digital elevation, remote sensing and field measurement techniques for deriving necessary land cover and topographic parameters as required for erosion modelling. The study shows that field measurements help in accurate estimation of cover factor. Similarly, the incorporation of DEM-derived parameters such as upslope catchment area and flow direction network in erosion modelling helps to identify the dominant erosion process active in the area. This makes the formulation of sound conservation measures for minimising soil losses and reducing off-site erosion effects in low lying areas much easier

Vegetation cover as an indicator for effective implementation of land use regulations in Sardinia

Land degradation is a worldwide issue which is often closely linked to human activity. In semi-arid environments common degradation processes are due to excessive soil losses, gully formation, surface sealing, and soil moisture depletion. Forest fire is increasingly an additional problem in the dry areas. In the present study, human interactions with land degradation are studied in a case study in Sardinia, Italy. Land degradation risk assessment was carried out using a desertification indicator method, the obtained result of which shows the prominent effect of vegetation cover. In the study area, high land degradation risk (and low vegetation cover) is found mostly in rainfed cultivation, overgrazed areas and those parts covered by olive groves or vineyards. Various strategies have been implemented, both deliberately and as a result of circumstantial effects, to alter vegetation cover over time. In the analysis, time series Normalized Difference Vegetation Index (NDVI) data was used for the period 1972 to 2009. Results show that not all human interactions with the environment are necessarily negative. The improvement of vegetation cover on the island is mainly due to good implementation of land use regulations. Three main factors seem to be responsible for the increase in vegetation cover: (1) government implementation policy on land uses; (2) reforestation in the over-grazed area; (3) the migration of the youngest generation of the population from the country side to the urban areas. The study demonstrates that vegetation cover on the island is improving as compared to the past, decreasing the land degradation risk even though the region is coping with climate change

Generation, characterization and application of atmospheric pressure plasma jet

The development of a non-thermal plasma jet with a capillary configuration working at atmospheric pressure is reported in this paper. The plasma jet is powered by a power source with frequency of several kilohertz. The working gas is argon. The plasma obtained has been characterized by optical emission spectroscopic measurements and electrical measurements of the discharge using voltage and current probes. The electron temperature has been estimated by using the modified Boltzmann plot method utilizing the Ar 4p-4s transition. The electron temperatures at various positions along the plasma jet length have been obtained and it is found that the electron temperature decreases at position further from orifice. The electron density has been estimated from current and voltage measurements using the power balance method. The effects of gas flow rate, applied voltage and frequency on the characteristics of the plasma jet have also been investigated. The applications of the atmospheric pressure plasma jet (APPJ) developed to modify the surface properties of Polyethyleneterephthalate (PET) and polycarbonate (PC) have been tested. Our results showed that the atmospheric pressure non-thermal plasma jet can be effectively used to enhance the surface wettability and surface energy of the PET and PC. The plasma jet has also been tested for inactivation of prokaryotic cells (Escherichia coli, Staphylococcus aureus). In the case of E. coli, better than 4 log10 reduction can be achieved. The effect of plasma jet on the pH of cell culture medium has suggested that the plasma species, particularly the electrons, are solely responsible for the effect of inactivation of living cells

From Finite to Infinite Range Order via Annealing: The Causal Architecture of Deformation Faulting in Annealed Close-Packed Crystals

We analyze solid-state phase transformations that occur in zinc-sulfide crystals during annealing using a random deformation-faulting mechanism with a very simple interaction between adjacent close-packed double layers. We show that, through annealing, infinite-range structures emerge from initially short-range crystal order. That is, widely separated layers carry structurally significant information and so layer stacking cannot be completely described by any finite-range Markov process. We compare our results to two experimental diffraction spectra, finding excellent agreement.Comment: 7 pages, 6 figures; See http://www.santafe.edu/projects/CompMech/papers/iro.htm

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters