Improving the quantification of land cover pressure on stream ecological status at the riparian scale using High Spatial Resolution Imagery

The aim of this paper is to demonstrate the interest of High Spatial Resolution Imagery (HSRI) and the limits of coarse land cover data such as CORINE Land Cover (CLC), for the accurate characterization of land cover structure along river corridors and of its functional links with freshwater ecological status on a large scale. For this purpose, we compared several spatial indicators built from two land cover maps of the Herault river corridor (southern France): one derived from the CLC database, the other derived from HSRI. The HSRI-derived map was obtained using a supervised object-based classification of multi-source remotely-sensed images (SPOT 5 XS-10 m and aerial photography-0.5 m) and presents an overall accuracy of 70 %. The comparison between the two sets of spatial indicators highlights that the HSRI-derived map allows more accuracy in the quantification of land cover pressures near the stream: the spatial structure of the river landscape is finely resolved and the main attributes of riparian vegetation can be quantified in a reliable way. The next challenge will consist in developing an operational methodology using HSRI for large-scale mapping of river corridor land cover,, for spatial indicator computation and for the development of related pressure/impact models, in order to improve the prediction of stream ecological status

An OBIA for fine-scale land cover spatial analysis over broad territories: demonstration through riparian corridor and artificial sprawl studies in France

International audienceSpatial analysis using fine-scale information over broad territories is essential to define efficient restoration strategies from local to national scale. We designed an OBIA dedicated to produce operationally reliable fine-scale information over broad territories. The originality of our OBIA lies particularly in the top-down approach for the construction of the classification tree and the use of „knowledge-based rules‟ classification technique. The implementation of this OBIA over the two study areas – (i) the Normandy region for riparian area land cover mapping (5600 km² riparian area) and (ii) fours departments over the Languedoc-Roussillon region (22644 km²) – demonstrates the operability of our approach (time-efficient, reproducible, transferable, portable). Broad scale spatial analysis conducted from resulting maps demonstrate the interest of using fine-scale information and highlight that OBIA, following our approach, will be at very short run a broadly applicable method to carry out such analysis

Disorder- and magnetic field-tuned fermionic superconductor-insulator transition in MoN thin films. Transport and STM studies

Superconductor-insulator transition (SIT) driven by disorder and transverse magnetic field has been investigated in ultrathin MoN films by means of transport measurements and scanning tunneling microscopy and spectroscopy. Upon decreasing thickness, the homogeneously disordered films show increasing sheet resistance Rs, shift of the superconducting transition Tc to lower temperatures with the 3 nm MoN being the last superconducting film and thinner films already insulating. Fermionic scenario of SIT is evidenced by applicability of the Finkelsteins model, by the fact that Tc and the superconducting gap are coupled with a constant ratio, and by the spatial homogeneity of the superconducting and electronic characteristics. The logarithmic anomaly found in the tunneling spectra of the non-superconducting films is further enhanced in increased magnetic field due to the Zeeman spin effects driving the system deeper into the insulating state and pointing also to fermionic SIT.Comment: Manuscript (6 Figures) including Supplemental Materials (7 Figures

Variação espacial de cátions, ânions e variáveis físico-químicas no rio Solimões-Amazonas entre Manaus e Jutaí, bacia amazônica

Cátions e ânions majoritários são espécies químicas de grande importância nos diversos compartimentos aquáticos, porém, pouco abordados de forma exclusiva na bacia amazônica. Neste sentido, o objetivo deste estudo foi avaliar a dinâmica espacial de Na+, Ca2+, K+, Mg2+, Cl- e SO4 2- em um trecho do rio Solimões-Amazonas, levando-se em consideração a alcalinidade, potencial hidrogeniônico (pH), condutividade elétrica (CE), sólidos totais em suspensão (STS) e carbono orgânico total (COT). As coletas foram realizadas em maio, julho e setembro de 2012 em sete pontos na calha principal do rio Solimões-Amazonas e na foz de alguns dos principais tributários: rios Jutaí, Juruá, Japurá e Purus. Os cátions e ânions foram analisados por cromatografia de íons, STS por gravimetria, pH por potenciometria, alcalinidade por titulação potenciométrica, CE por condutimetria e o COT por oxidação catalítica por combustão. As concentrações médias dos cátions seguiram esta ordem Ca2+>Na+>Mg2+>K+ e dos ânions SO4 2->Cl-. De montante à jusante a tendência foi diminuição nas concentrações de cátions e ânions, das variáveis pH, CE, STS e alcalinidade, além do aumento das concentrações de COT. O presente estudo evidenciou mudanças nas características químicas sofridas pelo rio Solimões em seu curso. O aporte dos tributários pode ser apontado como um dos fatores responsáveis por essas modificações

Phenomenology After Conceptual Art

The reception of phenomenology in art criticism reached its apex in the mid-1960s in its application to Minimalism in the United States. The focus was on the embodied, direct perceptual experience of Minimalist sculpture, but in light of Conceptual art’s ‘dematerialised’ practices, which developed as the decade progressed, the interest in phenomenology waned. This essay looks at the history of this reception and presents Merleau-Ponty’s late ontological work as a corrective to an inadequate understanding of phenomenology in critical discourses on art at the time. It argues that the late Merleau-Ponty offers tools for an effective critique of early conceptualism’s idealism, as well as a basis on which the ‘dematerialised’ and dispersed ontology of the art work shared by both Conceptual and more recent Post-Conceptual practices can be investigated

Biodiversity inventories in high gear: DNA barcoding facilitates a rapid biotic survey of a temperate nature reserve

Comprehensive biotic surveys, or ‘all taxon biodiversity inventories’ (ATBI), have traditionally been limited in scale or scope due to the complications surrounding specimen sorting and species identification. To circumvent these issues, several ATBI projects have successfully integrated DNA barcoding into their identification procedures and witnessed acceleration in their surveys and subsequent increase in project scope and scale. The Biodiversity Institute of Ontario partnered with the rare Charitable Research Reserve and delegates of the 6th International Barcode of Life Conference to complete its own rapid, barcode-assisted ATBI of an established land trust in Cambridge, Ontario, Canada

Construction de nouveaux indicateurs pour l'état écologique à partir de la télédétection

International audienc

Floodplain vegetation response to interannual flood regime through coupled in situ and remote sensing data: application on the lower Volga river (Russia)

International audienceThe Volga river basin includes 38% of the total agricultural area in Russia. Discharge regulation of the Volga river started in 1937. Guided by the large scale expansion of human economic activities in the basin, an additional 10 major dams were constructed between 1940 and 1986 along the course of the river. The Volga-Akhtuba floodplain extends downstream of the last dam. Surrounded by vast zones of dry steppe and semi-desert this floodplain is an oasis for all forms of life. However, it is very sensitive to human impact, and particularly to the change in river regime caused by flow regulation. Monitoring and understanding ecological processes and changes at the landscape scale is a major challenge for the preservation of this ecosystem The main objective of this work is to develop methods based on satellite imagery coupled with field observations to assess the impact of interannual flood regime on floodplain vegetation. This study is based on a combination of spatial data from satellite images and field observations of morphological features and vegetation in a number of cross-sections over the floodplain. Additionally, as flooding is a key driver for the development of floodplain morphology and vegetation, hydrologic data (water level time series) are analysed. Vegetation evolution from a bare surface up to soft-wood forest is a slow process, therefore two time scales are under consideration: 30 year evolution of the vegetation, using Landsat imagery (1974-2002) 7 year detailed analysis of the relation between hydrology and vegetation, using daily hydrologic data and 16 days MODIS images (2000-2006) Different types of water bodies were studied : permanent water in the main channel, permanent water in the lakes of the central floodplain, temporary water bodies in the inundated zone. NDVI index and Near Infra Red channels were used for separation of terrestrial ecosystems. Relation between the area of the inundated zone and the river discharge through Volgograd dam was calculated. Vegetation classification was made on the base of Landsat images with 25 legend classes, that included 18 general types of plant communities. Satellite images provide the basis for a reliable analysis of the flooding in the Lower Volga region over the last 7 years. MODIS images give possibilities for monitoring of vegetation changes both during seasonal cycles and at interannual time-scale. Area of inundation shows correlation with discharge from Volgograd dam

La végétation rivulaire et l'état écologique des cours d'eau : apport de la haute résolution spatiale

AutresComprendre l’influence de l’occupation des sols sur l’état écologique des cours d’eau est indispensable pour définir des stratégies de préservation de ces milieux (Directive cadre européenne sur l’eau). Une approche en trois étapes a été développée : (1) cartographie des corridors rivulaires par imagerie satellitaire à haute résolution spatiale, (2) calcul d’indicateurs de pression, (3) modèles statistiques reliant indicateurs d’état écologique des milieux aquatiques et indicateurs de pression.Characterizing land use along rivers and its impact on river ecology is a key issue to define aquatic ecosystems preservation strategies (European Water Framework Directive). A three-step methodological approach has been developed: (1) river corridor land use mapping based on high spatial resolution imagery, (2) definition of indicators to quantify land use pressures on rivers, (3) design of models relating river ecological indicators with land use pressure indicators