Spatial distribution and geophysical characterization of natural pipes in Ultisols

2020 ◽  
Author(s):  
Miguel Cooper ◽  
Renata Cristina Bovi ◽  
Cesar Augusto Moreira ◽  
Raquel Stucchi Boschi ◽  
Lucas Moreira Furlan ◽  
...  
Keyword(s):  
Network Architecture ◽  
Water Saturation ◽  
Subsurface Water ◽  
Integrated Analysis ◽  
Surface Mapping ◽  
Spatial Continuity ◽  
Geophysical Surveys ◽  
Pipe Systems ◽  
Elevation Model

<p>Piping is a type of subsurface erosion caused by subsurface water and is considered one of the most difficult erosive processes to study. The nature of this erosion process makes it very difficult to study and quantify.  The aim of this study was to characterize the surface and subsurface distribution of the pipes and to understand the network architecture of pipe systems in tropical forested areas.The study area is situated at the Experimental Station of Tupi, state of São Paulo, Brazil. We conducted a Digital Elevation Model allied to a superficial pipe mapping, and 2D and 3D geophysical surveys. The subsurface erosion identified by surface mapping and geophysical surveys appeared at two depths: one more superficial, in the upper part of the study area, and one at greater depth, in the lower part of the study area. The higher topographical positions presented the pipes at less developed stages (closed depressions and simple sinkholes), while the lower topographical positions showed the most advanced features (multiple sinkholes and blind gullies). The method of electroresistivity showed zones where low resistivity values correspond to water saturation (~ 70 omh m) and high values (> 4040 ohm m) that define the pipe; this method was efficient in detecting the presence of collapsed and non-collapsed pipes. We concluded that the use of different methods (superficial and subsuperficial) was essential for the characterization of pipe systems. The integrated analysis of the results obtained from the superficial and 2D subsurface mapping allowed us to infer the spatial continuity of the pipes. The 3D geophysical survey was efficient in mapping soil pipe and the connectivity in situ. The 3D modeling of the pipes revealed the connection and connectivity of the pipe network’s complexity and morphology.</p>

scholarly journals Geostatistical inversion of electromagnetic induction data for landfill modelling

2020 ◽  
Author(s):  
João Narciso ◽  
Leonardo Azevedo ◽  
Marc Van Meirvenne ◽  
Ellen Van De Vijver
Keyword(s):  
Spatial Distribution ◽  
Physical Properties ◽  
Water Saturation ◽  
Raw Materials ◽  
Borehole Data ◽  
Near Surface ◽  
Spatial Continuity ◽  
Simultaneous Inversion ◽  
Geophysical Surveys ◽  
Geostatistical Inversion

<p>The characterization and monitoring of landfills has become a major concern, not only for assessing the associated environmental impact (e.g., groundwater contamination) but also for evaluating the potential for recovery of secondary resources, in particular for the production of raw materials and energy. For both objectives, it is crucial to have knowledge of the waste composition and the current landfill conditions (e.g. water saturation level). Near-surface geophysical surveys have been proven effective for the non-invasive investigation of landfills, in which different methods have been used depending on the specific survey targets.  Because of its sensitivity to two subsurface physical properties, electrical conductivity (EC) and magnetic susceptibility (MS), frequency-domain electromagnetic (FDEM) induction has been successfully applied to the qualitative characterization of urban and industrial landfills, including mine tailings. Yet, due to the generally complex composition and strongly heterogeneous spatial distribution of waste deposits, reconstructing a reliable landfill model from surface geophysical measurements remains challenging. Geostatistical inversion emerges as powerful tool to improve the landfill modelling from geophysical data, allowing for a more detailed description of the spatial distribution of the properties of interest and the associated uncertainty. Additionally, it provides a flexible framework for integrating data from geophysical surveys and conventional sampling from drilling or trenching.</p><p>In this work, we present a new geostatistical inversion technique able for the simultaneous inversion of FDEM data for EC and MS, which optimize the landfill modelling procedure and is sensitive towards change on the physical properties of interest. This method is based on an iterative procedure where ensembles of subsurface models of EC and MS are generated with stochastic sequential simulation and co-simulation. These simulated models are conditioned locally by existing borehole data for these properties and by a spatial continuity pattern imposed by a variogram model. Synthetic instrument response data, including both the in-phase and quadrature-phase components of the FDEM response, are generated from each model using a forward model connecting the data domain (FDEM data) with the model domain (subsurface physical properties). The misfit between the observed and forward-modelled FDEM data, weighted according to the depth sensitivity of the FDEM response toward changes in EC and MS, is used to drive the generation of a new set of models in the next iteration. We illustrate the inversion procedure with synthetic landfill example data sets which were created based on real data collected at a mine tailing in Portugal and a municipal solid waste landfill in Belgium.</p>

Hydraulic characterization of volcanic rocks in Pahute Mesa using an integrated analysis of 16 multiple-well aquifer tests, Nevada National Security Site, 2009–14

2017 ◽  
Author(s):  
C. Amanda Garcia ◽  
Tracie R. Jackson ◽  
Keith J. Halford ◽  
Donald S. Sweetkind ◽  
Nancy A. Damar ◽  
...  
Keyword(s):  
National Security ◽  
Volcanic Rocks ◽  
Integrated Analysis

Mechanical characterization of LM25 alloy matrix composite reinforced with boron carbide

2021 ◽  
pp. 002199832110055
Author(s):  
Zeeshan Ahmad ◽  
Sabah Khan
Keyword(s):  
Tensile Strength ◽  
Boron Carbide ◽  
Mechanical Characterization ◽  
Stir Casting ◽  
Surface Mapping ◽  
Alloy Matrix ◽  
Casting Technique ◽  
The Matrix ◽  
Carbide Particles

Alumnium alloy LM 25 based composites reinforced with boron carbide at different weight fractions of 4%, 8%, and 12% were fabricated by stir casting technique. The microstructures and morphology of the fabricated composites were studied by scanning electron microscopy and energy dispersive spectroscopy. Elemental mapping of all fabricated composites were done to demonstrate the elements present in the matrix and fabricated composites. The results of microstructural analyses reveal homogenous dispersion of reinforcement particles in the matrix with some little amount of clustering found in composites reinforced with 12% wt. of boron carbide. The mechanical characterization is done for both alloy LM 25 and all fabricated composites based on hardness and tensile strength. The hardness increased from 13.6% to 21.31% and tensile strength 6.4% to 22.8% as reinforcement percentage of boron carbide particles increased from 0% to 12% wt. A fractured surface mapping was also done for all composites.

scholarly journals Data for the subsurface characterization of Pahang River Basin with the application of Transient Electromagnetic geophysical surveys

Data in Brief ◽  
2020 ◽  
Vol 30 ◽  
pp. 105491 ◽  
Author(s):  
Hariri Arifin ◽  
John Kayode ◽  
Khairul Arifin ◽  
Zuhar Zahir ◽  
Manan Abdullah ◽  
...  
Keyword(s):  
River Basin ◽  
Subsurface Characterization ◽  
Transient Electromagnetic ◽  
Geophysical Surveys

scholarly journals Spatial continuity of soil attributes in an Atlantic Forest remnant in the Mantiqueira Range, MG

2013 ◽  
Vol 37 (1) ◽  
pp. 68-77 ◽  
Author(s):  
Marcela de Castro Nunes Santos ◽  
José Marcio de Mello ◽  
Carlos Rogério de Mello ◽  
Léo Fernandes Ávila
Keyword(s):  
Atlantic Forest ◽  
Spatial Dependence ◽  
Soil Bulk Density ◽  
Exchange Capacity ◽  
Dependence Structure ◽  
Spatial Continuity ◽  
Soil Attributes ◽  
Forest Remnant ◽  
Spatial Dependence Structure

The spatial characterization of soil attributes is fundamental for the understanding of forest ecosystems. The objective of this work was to develop a geostatistical study of chemical and physical soil attributes at three depths (D1 - 0-20 cm; D2 - 20-50 cm; D3 - 50-100 cm), in an Experimental Hydrographic Micro-catchment entirely covered by Atlantic Forest, in the Mantiqueira Range region, Minas Gerais. All the considered variables presented spatial dependence structure in the three depths, and the largest degrees of spatial dependence were observed for pH in the three depths, soil cation exchange capacity potential in D3, soil organic matter in D1 and D3 and clay and soil bulk density in D2. The method most used for the adjustments of semi-variogram models was the Maximum Likelihood and the most selected model was the Exponential. Furthermore, the ordinary kriging maps allowed good visualization of the spatial distribution of the variables.

scholarly journals The UAS-Based 3D Image Characterization of Mozarabic Church Ruins in Bobastro (Malaga), Spain

2020 ◽  
Vol 12 (15) ◽  
pp. 2377
Author(s):  
Carlos Enríquez ◽  
Juan Manuel Jurado ◽  
Alexandro Bailey ◽  
Danilo Callén ◽  
María José Collado ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Archaeological Site ◽  
Semantic Classification ◽  
Spatial Features ◽  
Digital Elevation ◽  
Dense Point ◽  
Critical Slope ◽  
Rgb Images ◽  
Elevation Model

In recent years, the application of geomatics tools in archaeology has proved to be very useful to obtain meaningful knowledge of the 3D reconstruction of archaeological remains and semantic classification of the 3D surface. These techniques have proven to be an effective solution for the 3D modeling and the extraction of many spatial features on an archaeological site. However, novel methodologies as well as new data exploitation strategies are required to exploit these geospatial data for natural and cultural heritage documentation, monitoring, and preservation. In this paper, we have studied unique archaeological ruins, a Mozarab church in Al-Andalus, using high-resolution RGB images, which was taken by a drone. Thus, a 3D reconstruction of the ruins and the surrounding environment is carried out in order to characterize it on a dense point cloud. Then, a digital elevation model (DEM) was calculated in order to identify critical slope lines, which are significant to determine where the structure of the church was built. Our results can be used for the development of an architectural project and thus a virtual recreation of these archaeological ruins was performed.

scholarly journals MORPHOMETRIC CHARACTERIZATION OF THE HYDROGRAPHIC BASIN OF JAUQUARA RIVER IN THE TRANSITION BETWEEN THE CERRADO AND AMAZON BIOMES IN MATO GROSSO-BRAZIL

FLORESTA ◽  
2019 ◽  
Vol 49 (2) ◽  
pp. 325
Author(s):  
Gabriel Americo Cassettari ◽  
Tadeu Miranda De Queiroz
Keyword(s):  
Shuttle Radar Topography Mission ◽  
Mato Grosso ◽  
Digital Elevation ◽  
Circularity Index ◽  
Elevation Model ◽  
Basin Area ◽  
Morphometric Characterization ◽  
Effective Water ◽  
Unpublished Information

This study aimed to perform the Jauquara river watershed morphometric characterization. To watershed delimitation was used SRTM 30 type Digital Elevation Model (Shuttle Radar Topography Mission, with spatial resolution of 30 m) provided by USGS Earth Explorer platform. The geographic information system used to watershed delimitation process and maps generation was ArcGIS 10.1 from ESRI®. The morphometric variables calculus was based on classic methodologies of Applied Hydrology. The watershed has an area of 1408,03 km2 and perimeter of 288,43 km with compactness coefficient and circularity index of Kc = 2.15 and Ic = 0.21, respectively, which show an elongated shape. The drainage was classified as 5th order, reinforcing the configuration of the drainage network with a wide hydric distribution. The predominant altitude range is between 368 and 552 m, which corresponds to an area of 478.10 km2. It was observed that there is a predominance of smooth-wavy and undulated reliefs (3-8%, 8-20% slope), which correspond to 38,05% and 23,04% of the total basin area respectively. The morphometric characterization of the basin made it possible to obtain unpublished information that contributes to the decision making regarding the effective water management in the studied area, being this a guiding study for other works

Sign in / Sign up

Export Citation Format

Share Document