The Maoxian landslide as seen from space: detecting precursors of failure with Sentinel-1 data   总被引：1，自引：0，他引：1  

Emanuele Intrieri  Federico Raspini  Alfio Fumagalli  Ping Lu  Sara Del Conte  Paolo Farina  Jacopo Allievi  Alessandro Ferretti  Nicola Casagli 《Landslides》2018,15(1):123-133

Post-event Interferometric Synthetic Aperture Radar (InSAR) analysis on a stack of 45 C-band SAR images acquired by the ESA Sentinel-1 satellites from 9 October 2014 to 19 June 2017 allowed the identification of a clear precursory deformation signal for the Maoxian landslide (Mao County, Sichuan Province, China). The landslide occurred in the early morning of 24 June 2017 and killed more than 100 people in the village of Xinmo. Sentinel-1 images have been processed through an advanced multi-interferogram analysis capable of maximising the density of measurement points, generating ground deformation maps and displacement time series for an area of 460 km² straddling the Minjiang River and the Songping Gully. InSAR data clearly show the precursors of the slope failure in the source area of the Maoxian landslide, with a maximum displacement rate detected of 27 mm/year along the line of sight of the satellite. Deformation time series of measurement points identified within the main scarp of the landslide exhibit an acceleration starting from April 2017. A detailed time series analysis leads to the classification of different deformation behaviours. The Fukuzono method for forecasting the time of failure appear to be applicable to the displacement data exhibiting progressive acceleration. Results suggest that satellite radar data, systematically acquired over large areas with short revisiting time, could be used not only as a tool for mapping unstable areas, but also for landslide monitoring, at least for some typologies of sliding phenomena.  相似文献   

Reply to discussion on “Guidelines on the use of inverse velocity method as a tool for setting alarm thresholds and forecasting landslides and structure collapses” by F. Bozzano,P. Mazzanti,and S. Moretto     

Tommaso Carlà  Emanuele Intrieri  Federico Di Traglia  Teresa Nolesini  Giovanni Gigli  Nicola Casagli 《Landslides》2018,15(7):1443-1444

■■■The paper “Discussion to: Guidelines on the use of inverse velocity method as a tool for setting alarm thresholds and forecasting landslides and structure collapses by T. Carlà, E. Intrieri, F. Di Traglia, T. Nolesini, G. Gigli and N. Casagli” by Bozzano et al. brings forward new considerations on an issue of extreme concern in landslide risk management. To this day, the ability to predict catastrophic landslide failures from slope surface displacements is a problem dictated more by practical constraints rather than by theoretical uncertainties. In this sense, the development of data interpretation practices is crucial. This short reply provides a few further insights with regard to this subject, also in the context of the recently published literature.  相似文献   

Phytoremediation of Pyrene Contaminated Soils by Different Plant Species     

Valeria D'Orazio  Alaà Ghanem  Nicola Senesi 《洁净——土壤、空气、水》2013,41(4):377-382

Polycyclic aromatic hydrocarbons (PAHs) present serious problems in the environment because they may affect negatively human health and alter native ecological communities. Phytoremediation has long been recognized as an efficient method of eliminating PAH pollutants from soil. A pot experiment was conducted in greenhouse conditions to investigate the capability of three plant species, Medicago sativa, Brassica napus, and Lolium perenne, to promote the degradation of pyrene by measuring their growth on pyrene‐contaminated soils. After 90 days, pyrene concentration in soils declined by 32, 30, and 28%, respectively, with M. sativa, B. napus, and L. perenne, whereas it decreased only by 18% in the control soil without plants. These results indicated that pyrene was successfully removed by plants used. In particular, M. sativa showed the highest capacity for pyrene dissipation in soil, whereas L. perenne was more efficient in limiting adverse effects of pyrene contamination. In addition, the contaminant pyrene was undetectable in shoots and roots of the three species, likely because plant roots can stimulate soil microbial biomass and oxygen transport to the rhizosphere, thus facilitating indirectly the degradation process of pyrene. Further studies are in progress to evaluate the possible adsorption of pyrene to soil organic matter.  相似文献   

Ruinon landslide (Valfurva, Italy) activity in relation to rainfall by means of GBInSAR monitoring     

Chiara Del Ventisette  Nicola Casagli  Joaquim Fortuny-Guasch  Dario Tarchi 《Landslides》2012,9(4):497-509

The active Ruinon rockslide is located on the left bank of the Frodolfo River valley (Valfurva, Italian Alps) and is developed on the Confinale deep-seated gravitational slope deformation. Ruinon landslide is a major hazard for valley inhabitants in that rapid movement might dam the stream and create a debris flow. The landslide is strongly controlled by preexisting structural features and is believed to have been triggered by postglacial debuttressing. Ground-based radar interferometry has been used to map surface deformation over time of the entire unstable zone of Ruinon landslide with high spatial resolution and at a very high temporal acquisition rate (about five images per hour). The activity of the landslide shows strong periodicity, with summer and autumn accelerations and winter deceleration. From a correlation between the landslide acceleration and a class of rainfall event, we deduce the specific rainfall conditions that accelerate the instability of the landslide area. The study results suggest an improved tool for early warning of events of potentially catastrophic landslide instability.  相似文献   

Thinking creative clusters beyond the city: People,places and networks   总被引：1，自引：0，他引：1  

David C. Harvey  Harriet Hawkins  Nicola J. Thomas 《Geoforum》2012,43(3):529-539

This paper develops an ethnographic study of a small rural based ‘creative cluster’, called Krowji, situated in the town of Redruth in West Cornwall, UK. The dominant geographies of creative industries research and policy in recent years have an acknowledged urban bias together with a focus on narratives of agglomeration. This paper sits alongside research that brings to the fore ‘other’ geographies of cultural production, and reflects an increasing interest in work on creativity in rural areas. Following work by Storper and Pratt, we explore Krowji’s complex interdependencies, investigating ‘the relations within, without and across the cluster’. We focus on the relationships between Krowji and its surrounding area together with the spatialities and temporalities of the relations that occur across and beyond the cluster. We address the dynamics and durability of relations formed within the cluster also paying attention to their disconnections. In offering this analysis we develop a valuable counterpoint to the urban bias of much work on creative clusters and we contribute to work that is looking more closely at the temporalities and spatialities of cultural production. Further, we point towards the value of ethnographical research on the creative industries.  相似文献   

Reconstructing temporal changes and prediction of channel evolution in a large Alpine river: the Tagliamento river,Italy     

Luca Ziliani  Nicola Surian 《Aquatic Sciences - Research Across Boundaries》2016,78(1):83-94

  相似文献   

Characterization of Clay‐ and Silt‐Sized Fractions and Corresponding Humic Acids Along a Terra Rossa Soil Profile          下载免费PDF全文

Gennaro Brunetti  Giuseppe Natale Mezzapesa  Andreina Traversa  Eleonora Bonifacio  Karam Farrag  Nicola Senesi  Valeria D'Orazio 《洁净——土壤、空气、水》2016,44(10):1375-1384

  相似文献   

Allochthonous individuals in managed populations of the fire-bellied toad Bombina bombina: Genetic detection and conservation implications     

Christiane Schröder  Ina Pokorny  Nicola Dolgener  Christoph Herden  Hauke Drews  Ralph Tiedemann 《Limnologica》2012,42(4):291-298

The ongoing global amphibian decline calls for an increase of habitat and population management efforts. Pond restoration and construction is more and more accompanied by breeding and translocation programs. However, the appropriateness of translocations as a tool for conservation has been widely debated, as it can cause biodiversity loss through genetic homogenization and can disrupt local adaptation, eventually leading to outbreeding depression. In this study, we investigated the genetic structure of two translocated populations of the critically endangered fire-bellied toad Bombina bombina at its north western distribution edge using supposedly neutral genetic markers (variation in the mitochondrial control region and microsatellites) as well as a marker under selection (major histocompatibility complex (MHC) genes). While one of the newly established populations showed the typical genetic composition of surrounding populations, the other was extremely diverged without clear affinity to its putative source. In this population we detected a profound impact of allochthonous individuals: 100% of the analyzed individuals exhibited a highly divergent mitochondrial haplotype which was otherwise found in Austria. 83% of them were also assigned to Austria by the analysis of microsatellites. Interestingly, for the adaptive marker (MHC) local alleles were predominant in this population, while only very few alleles were shared with the Austrian population. Probably Mendelian inheritance has reshuffled genotypes such that adaptive local alleles are maintained (here, MHC), while presumably neutral allochthonous alleles dominate at other loci. The release of allochthonous individuals generally increased the genetic variability of the affected population without wiping out locally adaptive genotypes. Thus, outbreeding depression might be less apparent than sometimes thought and natural selection appears strong enough to maintain locally adaptive alleles, at least in functionally important immune system genes.  相似文献   

Analysis of the in‐plane response of earthen masonry infill panels partitioned by sliding joints          下载免费PDF全文

Marco Preti  Nicola Bettini  Laura Migliorati  Valentino Bolis  Andreas Stavridis  Giovanni A. Plizzari 《地震工程与结构动力学》2016,45(8):1209-1232

The vulnerability of infilled frames represents a critical issue in many regions with high seismicity around the world where infills are typically made of heavy masonry as they are used for thermal control of the buildings because of their thermal inertia. In this context, the use of earthen masonry infills can give a superior performance because of their ability to regulate thermal‐hygrometric performance of the building and sustainability of its life‐cycle. This paper presents a numerical study on the seismic behaviour of infill walls made of earthen masonry and partitioned with horizontal wooden planks that allow the relative sliding of the partitions. The combination of the deformability of earthen masonry and the sliding mechanism occurring along the wooden planks gives a high ductility capacity to the in‐plane response of the infill and, at the same time, significantly reduces its stiffness and strength, as compared with traditional solid infills made of fired clay units. As a result, the detrimental interaction with the frame and the damage in the infill when subjected to in‐plane loading can be minimized. The numerical model is validated with results from an experimental study and is used to perform a parametric analysis to examine the influence of variations in the geometry and mechanical properties of the infill walls, as well as the configuration of the sliding joints. Based on the findings of this study, design guidelines for practical applications are provided, together with simple formulation for evaluating their performance. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Flow recession as a driver of the morpho‐texture of braided streams          下载免费PDF全文

Yael Storz‐Peretz  Jonathan B. Laronne  Nicola Surian  Ana Lucía 《地球表面变化过程与地形》2016,41(6):754-770

Braiding has been widely studied in humid‐temperate climates though rarely in arid environments. Morpho‐texture of braided streams refers to the morphological‐textural organization in a braid‐cell (stream section including bars, anabranches and chutes) that may strongly relate to different processes and hydrological regimes. The objective of this study is to compare the morpho‐texture of braided streams governed by diverse flow recessions in different climates. Measurements were conducted in the wadis Ze'elim and Rahaf, southeast hyper‐arid Israel, in the Mediterranean Barranca‐de‐los‐Pinos, central Spain and in humid‐temperate braided systems, the La‐Bléone River, Haute‐Provence, France and in the Saisera and Cimoliana torrents, northeast Italy. Terrestrial laser scanning was used to produce point clouds and high resolution digital elevation models of the braid‐cells. Wet braid‐cells in humid‐temperate environments were surveyed by a Total Station. Roughness and the upper tail of grain size distributions were derived from the scanned point clouds or from Wolman sampling. We found that anabranches are commonly finer‐grained than the bars in dryland systems and in semi‐arid sandy braided systems, contrary to the humid‐temperate braided systems. In both climates, chutes are similar or coarser‐grained than the bars which they dissect, in accordance with their steeper gradients due to the considerable bar‐anabranch relief. The Saisera's morpho‐texture is similar to that of the dryland braided channels, despite the very humid‐temperate environment in which it is located, due to its short‐lived, ephemeral type hydrograph. Hydrograph shape, specifically the duration of flow recession, typical of a climate but not confined to it, determines the morpho‐texture of braided streams and the textural differentiation between a depositional bar and the adjacent anabranches. The morpho‐texture of chutes and bars results also from local erosional processes affected by local topography, i.e. ungraded longitudinal profiles, and is not solely determined by flow recession. This new morpho‐textural model enables identifying primary depositional and erosional braiding processes. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献