Assessing the Perspectives of Ground Penetrating Radar for Precision Farming

The United Nations 2030 Agenda for Sustainable Development highlighted the importance of adopting sustainable agricultural practices to mitigate the threat posed by climate change to food systems around the world, to provide wise water management and to restore degraded lands. At the same time, it suggested the benefits and advantages brought by the use of near-surface geophysical measurements to assist precision farming, in particular providing information on soil variability at both vertical and horizontal scales. Among such survey methodologies, Ground Penetrating Radar has demonstrated its effectiveness in soil characterisation as a consequence of its sensitivity to variations in soil electrical properties and of its additional capability of investigating subsurface stratification. The aim of this contribution is to provide a comprehensive review of the current use of the GPR technique within the domain of precision irrigation, and specifically of its capacity to provide detailed information on the within-field spatial variability of the textural, structural and hydrological soil properties, which are needed to optimize irrigation management, adopting a variable-rate approach to preserve water resources while maintaining or improving crop yields and their quality. For each soil property, the review analyses the commonly adopted operational and data processing approaches, highlighting advantages and limitations

Non-destructive Testing in Civil Engineering

This Special Issue, entitled “Non-Destructive Testing in Civil Engineering”, aims to present to interested researchers and engineers the latest achievements in the field of new research methods, as well as the original results of scientific research carried out with their use—not only in laboratory conditions but also in selected case studies. The articles published in this Special Issue are theoretical–experimental and experimental, and also show the practical nature of the research. They are grouped by topic, and the main content of each article is briefly discussed for your convenience. These articles extend the knowledge in the field of non-destructive testing in civil engineering with regard to new and improved non-destructive testing (NDT) methods, their complementary application, and also the analysis of their results—including the use of sophisticated mathematical algorithms and artificial intelligence, as well as the diagnostics of materials, components, structures, entire buildings, and interesting case studies

Testing of Materials and Elements in Civil Engineering

This book was proposed and organized as a means to present recent developments in the field of testing of materials and elements in civil engineering. For this reason, the articles highlighted in this editorial relate to different aspects of testing of different materials and elements in civil engineering, from building materials to building structures. The current trend in the development of testing of materials and elements in civil engineering is mainly concerned with the detection of flaws and defects in concrete elements and structures, and acoustic methods predominate in this field. As in medicine, the trend is towards designing test equipment that allows one to obtain a picture of the inside of the tested element and materials. Interesting results with significance for building practices were obtained

Ground penetrating radar surveying and sediment coring analysis of a post-glacial lake, Eastern Newfoundland

Ground penetrating radar (GPR) is a relatively newly developed high-frequency electromagnetic technique that has been widely used in the shallow subsurface investigation for the last few decades. Recently, a GPR survey of a small organic-rich post-glacial lake (Grassy Pond) in Eastern Newfoundland shows significant continuous laminations within the lake sediments in the GPR profiles. Since there have been very few GPR stratigraphy studies of lacustrine sediments, the main focus of this project is on the correlation between the sediment stratigraphy and the GPR sub-bottom profiles. Secondary interests are: to estimate the carbon content of a typical small inland lake to help assess how such bodies have contributed to the carbon budget since the last glaciation; and to investigate chemical variability within the sediments. The work in this project includes GPR surveying, sediment coring, and sediment physical, geochemical and chronostratigraphic data acquisition, calibration and correlation. First of all, 50 and 100 MHz GPR surveys were completed on Grassy Pond when the lake surface was frozen in the winter. Bathymetric and depth-to-bedrock maps were created from the GPR profiles. Based on these two maps, a sediment distribution map was also created and this was used to choose sediment coring locations. Four sediment cores were collected by using a rod-driven piston corer, and additional GPR profiles were collected over these core locations. The cores were then scanned by a Multi-Sensor Core Logger (MSCL) to determine the physical properties. After that, the cores were sub-sampled and geochemically analyzed by ICP-OES. Selected sediment samples were also analyzed for C and N contents and isotopes, and radiocarbon dated. Lastly, the linkage was made between the geophysical and geochemical data, and a simple GPR forward model was created based on the sediment physical properties to enhance the data interpretation and correlation. The results show that the lake sediments of Grassy Pond are highly-organic and water-rich. Forward models of EM wave reflections show that the laminated GPR reflections within the sediments are caused by variations in water content. The geochemical analysis shows that the water content is anti-correlated to the lithic elemental concentrations. Since the lithic inputs can reflect past climate changes, we suggest that paleoclimatic changes may ultimately be responsible for the laminations seen in the GPR profiles. The carbon budge of Grassy Pond is calculated based on the sediment volume and average carbon content of the sediments, and it is estimated as 29 kg/m², which is significantly higher than forest soils. Besides these major results, one of our basal sediment samples is dated back to 8.6 radiocarbon years ago, which corresponds to the end of last glaciation in the same region of Newfoundland. The sediments of Grassy Pond are found to be highly enriched in arsenic (As) and molybdenum (Mo), likely associated with the erosion of iron oxide minerals in the surrounding land, as Grassy Pond overlies the alteration zone of a gold prospect. In the deepest sediment core, many elements show a concentration peak near 6.3k years ago when the regional climate started to become drier, and erosion rates increased

Multiscale Soil Salinity Assessment at the Southern Margin of the Venice Lagoon, Italy

Saltwater intrusion affects many coastlands around the world contaminating fresh-groundwater and decreasing soil quality. In order to manage saline soils one should understand the spatiotemporal dynamics of salinity in the soil profile and its spatial variability at field scale. In the last decades, soil and pore-water salinity have been assessed using geophysical techniques, most commonly with the use of apparent electrical conductivity (ECa) measurements. At point-scale, pore-water salinity can be estimated once its relationship with ECa, soil properties, and water content is understood. Moreover, most sensors for water content estimation normally provide biased readings in saline conditions and in soil with high clay and organic carbon contents. At field-scale proximal-sensing can be used to characterize large portions of land from a relatively small number of soil samples. Sometimes, characterizing salinity is however not sufficient to understand crop yield spatial variability, which can be also influenced by other soil properties. Understanding the influence of salinity and other soil properties on crop productivity can be useful in the identification of areas that can be managed site-specifically. The general aim of this dissertation is to evaluate some sensor-based methodologies for monitoring and characterizing salinity and other related soil properties both at point- and field-scale. In particular, at point-scale the dissertation will deal with the issues regarding the use of capacitive-resistive technology for water content and pore-water salinity estimation. At field-scale some methodologies will be proposed in order to characterize the spatial variability of salinity and other soil properties influencing maize (Zea mais L.) yield using soil proximal-sensing. All the material presented in this manuscript regard the soils of an area affected by saltwater intrusion located at the southern edge of the Venice Lagoon (Italy). The dissertation is structured in five chapters. The first one includes a review on commonly used methodologies for point- and field-scale salinity assessment. An overview on the environmental issues concerning the coastland at the southern margin of the Venice Lagoon is also presented. The second chapter deals with the calibration of a low-cost capacitance-resistance probe for simultaneous monitoring of soil water content and salinity. In the third chapter an ECa-directed soil sampling scheme optimization procedure is proposed. The forth chapter analyzes maize yield as a function of soil chemical and physical properties and investigates on the use of soil-proximal sensing correlated to soil spatial variability for site-specific management units. The final chapter presents the general conclusions of the work

New innovations in pavement materials and engineering: A review on pavement engineering research 2021

Sustainable and resilient pavement infrastructure is critical for current economic and environmental challenges. In the past 10 years, the pavement infrastructure strongly supports the rapid development of the global social economy. New theories, new methods, new technologies and new materials related to pavement engineering are emerging. Deterioration of pavement infrastructure is a typical multi-physics problem. Because of actual coupled behaviors of traffic and environmental conditions, predictions of pavement service life become more and more complicated and require a deep knowledge of pavement material analysis. In order to summarize the current and determine the future research of pavement engineering, Journal of Traffic and Transportation Engineering (English Edition) has launched a review paper on the topic of “New innovations in pavement materials and engineering: A review on pavement engineering research 2021”. Based on the joint-effort of 43 scholars from 24 well-known universities in highway engineering, this review paper systematically analyzes the research status and future development direction of 5 major fields of pavement engineering in the world. The content includes asphalt binder performance and modeling, mixture performance and modeling of pavement materials, multi-scale mechanics, green and sustainable pavement, and intelligent pavement. Overall, this review paper is able to provide references and insights for researchers and engineers in the field of pavement engineering

New innovations in pavement materials and engineering: A review on pavement engineering research 2021

Sustainable and resilient pavement infrastructure is critical for current economic and environmental challenges. In the past 10 years, the pavement infrastructure strongly supports the rapid development of the global social economy. New theories, new methods, new technologies and new materials related to pavement engineering are emerging. Deterioration of pavement infrastructure is a typical multi-physics problem. Because of actual coupled behaviors of traffic and environmental conditions, predictions of pavement service life become more and more complicated and require a deep knowledge of pavement material analysis. In order to summarize the current and determine the future research of pavement engineering, Journal of Traffic and Transportation Engineering (English Edition) has launched a review paper on the topic of “New innovations in pavement materials and engineering: A review on pavement engineering research 2021”. Based on the joint-effort of 43 scholars from 24 well-known universities in highway engineering, this review paper systematically analyzes the research status and future development direction of 5 major fields of pavement engineering in the world. The content includes asphalt binder performance and modeling, mixture performance and modeling of pavement materials, multi-scale mechanics, green and sustainable pavement, and intelligent pavement. Overall, this review paper is able to provide references and insights for researchers and engineers in the field of pavement engineering