Complex and rugged topography induces large variations in erosion and sediment delivery in the headwaters of alpine catchments. An effective connection of hillslopes with the channel network results ...in highly efficient sediment transfer processes, such as debris flows. In contrast, morphological conditions producing decoupling of hillslopes from channels (e.g. glacial cirques) may exclude large areas of the catchment from sediment delivery to its lower parts. Moreover, an efficient connection between hillslopes and channel network does not always ensure an effective downstream transfer of sediment. Low-slope channel reaches (e.g. in hanging valleys) cause sediment deposition, which often results in changes of the sediment transport processes, typically from debris flow to streamflow with low bedload and suspended load rates. The availability of high-resolution digital terrain models, such as those derived from aerial LiDAR, improves our capability to quantify the topographic controls on sediment connectivity. A geomorphometric index, based on the approach by Borselli et al. (2008), was developed and applied to assess spatial sediment connectivity in two small catchments of the Italian Alps featuring contrasting morphological characteristics. The results of the geomorphometric analysis were checked against field evidences, showing good performance and thus potential usefulness of the index.
► A sediment connectivity model was developed for applications in alpine catchments. ► The model was tested in basins featuring different sediment transfer processes. ► The model characterizes sediment dynamics in complex morphological settings. ► Connectivity pattern is consistent with the observed sediment delivery.
Multi-Temporal Interferometric Synthetic Aperture Radar (MT-InSAR) techniques are gaining momentum in the assessment and health monitoring of infrastructure assets. Amongst others, the Persistent ...Scatterers Interferometry (PSI) technique has proven to be viable for the long-term evaluation of ground scatterers. However, its effectiveness as a routine tool for certain critical application areas, such as the assessment of millimetre-scale differential displacements in airport runways, is still debated. This research aims to demonstrate the viability of using medium-resolution Copernicus ESA Sentinel-1A (C-Band) SAR products and their contribution to improve current maintenance strategies in case of localised foundation settlements in airport runways. To this purpose, “Runway n.3” of the “Leonardo Da Vinci International Airport” in Fiumicino, Rome, Italy was investigated as an explanatory case study, in view of historical geotechnical settlements affecting the runway area. In this context, a geostatistical study is developed for the exploratory spatial data analysis and the interpolation of the Sentinel-1A SAR data. The geostatistical analysis provided ample information on the spatial continuity of the Sentinel 1 data in comparison with the high-resolution COSMO-SkyMed data and the ground-based topographic levelling data. Furthermore, a comparison between the PSI outcomes from the Sentinel-1A SAR data—interpolated through Ordinary Kriging—and the ground-truth topographic levelling data demonstrated the high accuracy of the Sentinel 1 data. This is proven by the high values of the correlation coefficient (r = 0.94), the multiple R-squared coefficient (R2 = 0.88) and the Slope value (0.96). The results of this study clearly support the effectiveness of using Sentinel-1A SAR data as a continuous and long-term routine monitoring tool for millimetre-scale displacements in airport runways, paving the way for the development of more efficient and sustainable maintenance strategies for inclusion in next generation Airport Pavement Management Systems (APMSs).
Historical Geoanthropology in Venice Pietro Daniel Omodeo; Sebastiano Trevisani
Journal of Interdisciplinary History of Ideas,
01/2023, Letnik:
11, Številka:
22
Journal Article
Recenzirano
Odprti dostop
This essay deals with the natural-artificial reality of the lagoon of Venice, as a paradigmatic case that can contribute to an understanding of the broad cultural dimension of the Anthropocene. ...Indeed, we here deal with the low amplitude background signal of anthropogenic geomorphological and geoenvironmental agency. This should not be confused with the stratigraphic meaning of Anthropocene, since geologists are working towards the validation of the Anthropocene hypothesis by detecting specific markers which, from our perspective, correspond to high-intensity signal peaks at a geochemical level. Our geo-anthropological case, the geomorphology of Venice, has particular historical and symbolic relevance. Its environment has been transformed by humans and the elements over millennia to such an extent that it is impossible to neatly separate human agency from natural causes. We here discuss the entanglement of environmental factors, socio-economic drivers, and cultural-political elements of Venice as a paradigm of geo-anthropological processes in general. Keywords: Historical Geoanthropology, Anthropocene, Venice, Water Science
The spatiotemporal analysis and mapping of soil organic matter (SOM) play a pivotal role for evaluating soil health and for implementing preservation and restoration actions. In this context, the ...first aim of the study is to furnish a high-resolution mapping of current SOM content in eastern Croatia. The second aim is to perform a diachronic analysis of SOM content, comparing two datasets characterized by an extreme data imbalance. The more recent dataset (SOM2010), representative of 2010s, comprises 19,386 samples and the older dataset (SOM1970), representative of the 1970s, comprises 152 samples. The marked data imbalance and the different modalities in soil sampling and laboratory analysis of the two datasets are taken into consideration in performing the comparison. The study reveals a general depletion trend of SOM from the 1970s to the 2010s, more evident in with regard to Fluvisols and Gleysols. At a regional scale, the SOM2010 is characterized by lower variability compared to SOM1970, indicating a process of homogenization of SOM spatial distribution in recent years. Considering the local scale, there is limited information for the 1970s; for the 2010s the SOM spatial distribution is characterized by a high short-range spatial variability, with a characteristic spotty appearance, likely related to agricultural practices.
This opinion paper discusses some of the challenges and opportunities that earth scientists face today in connection with environmental problems. It focuses on aspects that are related to the role of ...geocomputational approaches and new technologies for geoenvironmental analysis in the context of sustainable development. The paper also points out a “data imbalance” effect, a key issue in the analysis of environmental evolution and of geosphere-anthroposphere interactions in the long-term. In connection with this, it stresses the importance of geoenvironmental information which can be derived from environmental humanities and related disciplines, such as history and archeology. In this context, the complexities and potentialities of a dialogue between earth sciences and the humanities are outlined.
This paper illustrates the main results of a statistical analysis performed on a data set obtained by integrating experimental observations collected during many oceanographic research projects on ...the northern Adriatic Sea (NAS). The observations cover the last 20 years and provide a robust base for the assessment of the current state and scales of variability for temperature, salinity, nutrients, dissolved oxygen, and chlorophyll. The results confirmed a clear seasonal cycle and marked spatial gradients for most parameters in all seasons. The largest proportion of the river Po input flows south along the coast, but significant eastward freshwater fluxes are also present in all seasons, more markedly in winter. The coastal belt south of the Lagoon of Venice is the most eutrophic area, mainly because of river inputs, while an oligotrophic condition prevails along the eastern part of the basin. Small‐scale structures, including eddies and jets, are permanent features of the system. In order to test the existence of significant trends of variation in the physical and biogeochemical parameters, the data set has been enlarged by including observations from 1976. Analyses of trends over 30 years show an increase in salinity, which might be a consequence of both reduced outflows from rivers and a more sustained inflow of water along eastern coast, and a clear reduction in concentrations of phosphate and ammonia in coastal areas, probably due to new regulations regarding the control of nutrient loads and possibly suggesting the occurrence of cultural oligotrophication. No decrease is instead observed for concentration of nitrate.
The assessment of the areas endangered by debris flows is a major issue in the context of mountain watershed management. Depending on the scale of analysis, different methods are required for the ...assessment of the areas exposed to debris flows. While 2-D numerical models are advised for detailed mapping of inundation areas on individual alluvial fans, preliminary recognition of hazard areas at the regional scale can be adequately performed by less data-demanding methods, which enable priority ranking of channels and alluvial fans at risk by debris flows. This contribution focuses on a simple and fast procedure that has been implemented for regional- scale identification of debris-flow prone channels and prioritization of the related alluvial fans. The methodology is based on the analysis of morphometric parameters derived from Digital Elevation Models （DEMs）. Potential initiation sites of debris flows are identified as the DEM cells that
Extensive passive seismic prospecting has been conducted in the historical center of Venice (North Italy) aimed to map subsoil impedance contrast. Venice represents an emblematic study site of the ...challenging characteristics that can be encountered in historical sites, both stratigraphic and logistical, limiting the application of common microzonation techniques. A total of 82 single station passive HVSR acquisitions and passive surface wave arrays analysis have been performed to estimate the main impedance contrasts of the first subsoil, capable of interaction in terms of resonance with the monumental buildings. The results of the geophysical analysis have been integrated with available stratigraphic information derived from published researches and from hundreds of boreholes stored in an institutional database. The results have been then analyzed by means of a geostatistical approach based on cokriging interpolation, which permitted to map the impedance contrast beneath the ancient historical center. The adopted interpolation algorithm permitted to map the impedance contrast with an integrated use of existing information based on HVSR acquisitions and stratigraphic data. The map of impedance contrast is congruent with the literature geo-engineering evidences such as subsidence and geological reconstructions. The achieved results open new perspectives for the use and analysis of passive seismic techniques in challenging environments as historical urban centers characterized by high subsoil heterogeneity. Moreover, an improved knowledge of the shallow stratigraphy would permit to shed light on the complex interactions between anthropic activities and geoenvironmental processes, including climate change that characterized the long history of Venice.
Hacking the topographic ruggedness index Trevisani, Sebastiano; Teza, Giordano; Guth, Peter L.
Geomorphology (Amsterdam, Netherlands),
10/2023, Letnik:
439
Journal Article
Recenzirano
The topographic ruggedness index (TRI) is widely adopted for the analysis of digital elevation models, providing information on local surface spatial variability. In this work, the TRI is interpreted ...according to a geostatistical perspective, highlighting its main characteristics and drawbacks. TRI can be interpreted as an omnidirectional short-range spatial variability index, computed according to a pixel centered perspective. The simplicity and interpretability of the index, free from user-dependent selections, promoted its implementation in several software environments and its application in a wide set of case studies. However, the index has several drawbacks for its application in earth sciences, such as a strong dependency on local slope (it is basically an average adjacent neighbor slope algorithm) and the selection of different lag distances in the computation of spatial variability along the main directions and the diagonal ones. We propose a new metric radial roughness index (RRI) in order to solve the main drawbacks of TRI but maintaining its main philosophy (i.e., pixel centered perspective and simplicity of the algorithm). The new index corrects for the differences in lag distances and resolves the dependency on trend using increments of order 2. The code of the index, implemented in R statistical language, and test data are provided with the paper (https://doi.org/10.5281/zenodo.7132160) to promote its implementation in other software environments.
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