- Geosciences, Vol. 7, Pages 91: Accurate Reconstruction of the Roman Circus in Milan by Georeferencing Heterogeneous Data Sources with GIS
This paper presents the methodological approach and the actual workflow for creating the 3D digital reconstruction in time of the ancient Roman Circus of Milan, which is presently covered completely by the urban fabric of the modern city. The diachronic reconstruction is based on a proper mix of quantitative data originated by current 3D surveys and historical sources, such as ancient maps, drawings, archaeological reports, restrictions decrees, and old photographs. When possible, such heterogeneous sources have been georeferenced and stored in a GIS system. In this way the sources have been analyzed in depth, allowing the deduction of geometrical information not explicitly revealed by the material available. A reliable reconstruction of the area in different historical periods has been therefore hypothesized. This research has been carried on in the framework of the project Cultural Heritage Through Time—CHT2, funded by the Joint Programming Initiative on Cultural Heritage (JPI-CH), supported by the Italian Ministry for Cultural Heritage (MiBACT), the Italian Ministry for University and Research (MIUR), and the European Commission.
- Geosciences, Vol. 7, Pages 90: Quantitative Examination of Piezoelectric/Seismoelectric Anomalies from Near-Surface Targets
The piezoelectric and seismo-electrokinetic phenomena are manifested by electrical and electromagnetic processes that occur in rocks under the influence of elastic oscillations triggered by shots or mechanical impacts. Differences in piezoelectric properties between the studied targets and host media determine the possibilities of the piezoelectric/seismoelectric method application. Over a long time, an interpretation of obtained data is carried out by the use of methods developed in seismic prospecting. Examination of nature of piezoelectric/seismoelectric anomalies observed in subsurface indicates that these may be related (mainly) to electric potential field. In this paper, it is shown that quantitative analysis of piezoelectric/seismoelectric anomalies may be performed by the advanced and reliable methodologies developed in magnetic prospecting. Some examples from mining geophysics (Russia) and ancient metallurgical site (Israel) confirm applicability of the suggested approach.
- Geosciences, Vol. 7, Pages 89: Taking into Account the Role of the Weathering Profile in Determining Hydrodynamic Properties of Hard Rock Aquifers
The present study aims at understanding the role of the structure and the geometry of the weathering profile on the hydrodynamic behavior of hard rock aquifers. We first described 2D geophysical cross sections of weathering profiles realized and validated on an experimental site. Next, we implemented five long-term pumping tests in wells drilled at various locations of these cross sections. Finally, we chose the appropriate analytical solutions to determine the hydrodynamic parameters in consistence with the structure and the geometry of the weathering profile. Results reveal that land covers, weathering type and thickness, presence of no flow boundaries, etc. are all factors that explain the flow regime, which appears therefore much less unpredictable. In other words, the 2D geophysical data are enough to locate the best permeable areas, or the areas where the structure of the aquifer without impervious boundaries and with leakage favor a good long-term behavior of the well. The values of aquifer’s transmissivity vary between 5.10−3 and 4.10−5 m2/s. The storage varies between 0.06 and 7.10−7. The variability of these parameters from site to site reflects the high heterogeneity of hard rock aquifers.
- Geosciences, Vol. 7, Pages 88: Comparison of Flood Frequency Analysis Methods for Ungauged Catchments in France
The objective of flood frequency analysis (FFA) is to associate flood intensity with a probability of exceedance. Many methods are currently employed for this, ranging from statistical distribution fitting to simulation approaches. In many cases the site of interest is actually ungauged, and a regionalisation scheme has to be associated with the FFA method, leading to a multiplication of the number of possible methods available. This paper presents the results of a wide-range comparison of FFA methods from statistical and simulation families associated with different regionalisation schemes based on regression, or spatial or physical proximity. The methods are applied to a set of 1535 French catchments, and a k-fold cross-validation procedure is used to consider the ungauged configuration. The results suggest that FFA from the statistical family largely relies on the regionalisation step, whereas the simulation-based method is more stable regarding regionalisation. This conclusion emphasises the difficulty of the regionalisation process. The results are also contrasted depending on the type of climate: the Mediterranean catchments tend to aggravate the differences between the methods.
- Geosciences, Vol. 7, Pages 87: Ground Stability Monitoring of Undermined and Landslide Prone Areas by Means of Sentinel-1 Multi-Temporal InSAR, Case Study from Slovakia
Multi-temporal synthetic aperture radar interferometry techniques (MT-InSAR) are nowadays a well-developed remote sensing tool for ground stability monitoring of areas afflicted by natural hazards. Its application capability has recently been emphasized by the Sentinel-1 satellite mission, providing extensive spatial coverage, regular temporal sampling and free data availability. We perform MT-InSAR analysis over the wider Upper Nitra region in Slovakia, utilizing all Sentinel-1 images acquired since November 2014 until March 2017. This region is notable for its extensive landslide susceptibility as well as intensive brown coal mining. We focus on two case studies, being impaired by recent activation of these geohazards, which caused serious damage to local structures. We incorporate a processing chain based on open-source tools, combining the current Sentinel Application Platform (SNAP) and Stanford Method for Persistent Scatterers (StaMPS) implementation. MT-InSAR results reveal substantial activity at both case studies, exceeding the annual displacement velocities of 30 mm/year. Moreover, our observations are validated and their accuracy is confirmed via comparison with ground truth data from borehole inclinometers and terrestrial levelling. Detected displacement time series provide valuable insight into the spatio-temporal evolution of corresponding deformation phenomena and are thus complementary to conventional terrestrial monitoring techniques. At the same time, they not only demonstrate the feasibility of MT-InSAR for the assessment of remediation works, but also constitute the possibility of operational monitoring and routine landslide inventory updates, regarding the free Sentinel-1 data.
- How Alexander von Humboldt's life story can inspire innovative soil research in developing countries
How Alexander von Humboldt's life story can inspire innovative soil research in developing countries Johan Bouma SOIL, 3, 153-159, https://doi.org/10.5194/soil-3-153-2017, 2017 Alexander von Humboldt was an inspiring scientist in the early 1800s, traveling widely, making many measurements, and linking different scientific disciplines while keeping an eye open to the needs of society. This is particularly relevant today in our information society, and researchers in developing countries are advised to follow the von Humboldt example when planning their future research.
- A deeper look at the relationship between root carbon pools and the vertical distribution of the soil carbon pool
A deeper look at the relationship between root carbon pools and the vertical distribution of the soil carbon pool Ranae Dietzel, Matt Liebman, and Sotirios Archontoulis SOIL, 3, 139-152, https://doi.org/10.5194/soil-3-139-2017, 2017 Roots deeper in the soil are made up of more carbon and less nitrogen compared to roots at shallower depths, which may help explain deep-carbon origin. A comparison of prairie and maize rooting systems showed that in moving from prairie to maize, a large, structural-tissue-dominated root carbon pool with slow turnover concentrated at shallow depths was replaced by a small, nonstructural-tissue-dominated root carbon pool with fast turnover evenly distributed in the soil profile.
- Planning spatial sampling of the soil from an uncertain reconnaissance variogram
Planning spatial sampling of the soil from an uncertain reconnaissance variogram R. Murray Lark, Elliott M. Hamilton, Belinda Kaninga, Kakoma K. Maseka, Moola Mutondo, Godfrey M. Sakala, and Michael J. Watts SOIL Discuss., https//doi.org/10.5194/soil-2017-21,2017 Manuscript under review for SOIL (discussion: open, 1 comment) An advantage of geostatistics for mapping soil properties is that, given a statistical model of the variable of interest, we can make a rational decision about how densely to sample so that the map is sufficiently precise. However, uncertainty about the statistical model affects this process. In this paper we show how Bayesian methods can be used to support decision making on sampling with an uncertain model, ensuring that the probability of meeting certain levels of precision is high enough.
- Spatial variability in soil organic carbon in a tropical montane landscape: associations between soil organic carbon and land use, soil properties, vegetation, and topography vary across plot to landscape scales
Spatial variability in soil organic carbon in a tropical montane landscape: associations between soil organic carbon and land use, soil properties, vegetation, and topography vary across plot to landscape scales Marleen de Blécourt, Marife D. Corre, Ekananda Paudel, Rhett D. Harrison, Rainer Brumme, and Edzo Veldkamp SOIL, 3, 123-137, https://doi.org/10.5194/soil-3-123-2017, 2017 We examined the spatial variability in SOC in a 10 000 ha landscape in SW China. The spatial variability in SOC was largest at the plot scale (1 ha) and the associations between SOC and land use, soil properties, vegetation, and topographical attributes varied across plot to landscape scales. Our results show that sampling designs must consider the controlling factors at the scale of interest in order to elucidate their effects on SOC against the variability within and between plots.
- Decision support for the selection of reference sites using 137Cs as a soil erosion tracer
Decision support for the selection of reference sites using 137Cs as a soil erosion tracer Laura Arata, Katrin Meusburger, Alexandra Bürge, Markus Zehringer, Michael E. Ketterer, Lionel Mabit, and Christine Alewell SOIL, 3, 113-122, https://doi.org/10.5194/soil-3-113-2017, 2017 The classical approach of using 137Cs as a soil erosion tracer is based on the comparison between stable reference sites and sites affected by soil redistribution processes; it enables the derivation of soil erosion and deposition rates. The method is associated with potentially large sources of uncertainty with major parts of this uncertainty being associated with the selection of the reference sites. We propose a decision support tool to Check the Suitability of reference Sites (CheSS). Commonly, the variation among 137Cs inventories of spatial replicate reference samples is taken as the sole criterion to decide on the suitability of a reference inventory. Here we propose an extension of this procedure using a repeated sampling approach, in which the reference sites are resampled after a certain time period. Suitable reference sites are expected to present no significant temporal variation in their decay-corrected 137Cs depth profiles. Possible causes of variation are assessed by a decision tree. More specifically, the decision tree tests for (i) uncertainty connected to small-scale variability in 137Cs due to its heterogeneous initial fallout (such as in areas affected by the Chernobyl fallout), (ii) signs of erosion or deposition processes and (iii) artefacts due to the collection, preparation and measurement of the samples; (iv) finally, if none of the above can be assigned, this variation might be attributed to turbation processes (e.g. bioturbation, cryoturbation and mechanical turbation, such as avalanches or rockfalls). CheSS was exemplarily applied in one Swiss alpine valley where the apparent temporal variability called into question the suitability of the selected reference sites. In general we suggest the application of CheSS as a first step towards a comprehensible approach to test for the suitability of reference sites.