Open AccessArticle
Assessing the Long-Term Behaviour of the Industrial Bentonites Employed in a Repository for Radioactive Wastes by Studying Natural Bentonites in the Field
Geosciences 2017, 7(1), 5; doi:10.3390/geosciences7010005 -
Abstract
Bentonite makes an important contribution to the performance of the engineered barriers in most radioactive waste repository designs. The choice of bentonite results from its favourable properties for waste isolation and its stability in relevant geological environments. However, the longevity of bentonite (especially
[...] Read more.
Bentonite makes an important contribution to the performance of the engineered barriers in most radioactive waste repository designs. The choice of bentonite results from its favourable properties for waste isolation and its stability in relevant geological environments. However, the longevity of bentonite (especially the resistance to waste container sinking) has been little studied. Modelling results suggest significant bentonite deformation and associated canister sinking is unlikely and, here, long-term natural system data are used as a reality check on model predictions. Results indicate that bentonite from the investigated site shows no significant deviation in bulk physical parameters from repository bentonite. However, micro-scale shear planes can be seen throughout the sampled cores. The presence of multi-directional S- and C-type shears suggests they originate from loading from the overlying limestone, not gravitational tectonics. The plastic limits and angles of shearing resistance for natural and repository bentonites suggest both are susceptible to shearing. The impact of bentonite shear under load could be minimised by appropriate design, but existing lower activity waste container designs do not consider the potentially high external stresses from the bentonite backfill and this should be addressed in future. Full article
Figures

Figure 1

Open AccessEditorial
A Special Issue of Geosciences: Mapping and Assessing Natural Disasters Using Geospatial Technologies
Geosciences 2017, 7(1), 4; doi:10.3390/geosciences7010004 -
Open AccessEditorial
Acknowledgement to Reviewers of Geosciences in 2016
Geosciences 2017, 7(1), 1; doi:10.3390/geosciences7010001 -
Abstract The editors of Geosciences would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2016.[...] Full article
Open AccessArticle
Folded Basinal Compartments of the Southern Mongolian Borderland: A Structural Archive of the Final Consolidation of the Central Asian Orogenic Belt
Geosciences 2017, 7(1), 2; doi:10.3390/geosciences7010002 -
Abstract
The Central Asian Orogenic Belt (CAOB) records multiple Phanerozoic tectonic events involving consolidation of disparate terranes and cratonic blocks and subsequent reactivation of Eurasia’s continental interior. The final amalgamation of the CAOB terrane collage involved diachronous closure of the Permian-Triassic Solonker suture in
[...] Read more.
The Central Asian Orogenic Belt (CAOB) records multiple Phanerozoic tectonic events involving consolidation of disparate terranes and cratonic blocks and subsequent reactivation of Eurasia’s continental interior. The final amalgamation of the CAOB terrane collage involved diachronous closure of the Permian-Triassic Solonker suture in northernmost China and the Jurassic Mongol-Okhotsk suture in northeast Mongolia and eastern Siberia. The distribution, style, and kinematics of deformation associated with these two terminal collision events is poorly documented in southern Mongolia and northernmost China because these regions were later tectonically overprinted by widespread Cretaceous basin and range-style crustal extension and Miocene-recent sinistral transpressional mountain building. These younger events structurally compartmentalized the crust into uplifted crystalline basement blocks and intermontane basins. Consequently, widespread Cretaceous and Late Cenozoic clastic sedimentary deposits overlie older Permian-Jurassic sedimentary rocks in most basinal areas and obscure the deformation record associated with Permian-Triassic Solonker and Jurassic Mongol-Okhotsk collisional suturing. In this report, satellite image mapping of basinal compartments that expose folded Permian-Jurassic sedimentary successions that are unconformably overlapped by Cretaceous-Quaternary clastic sediments is presented for remote and poorly studied regions of southern Mongolia and two areas of the Beishan. The largest folds are tens of kilometers in strike length, east-west trending, and reveal north-south Late Jurassic shortening (present coordinates). Late Jurassic fold vergence is dominantly northerly in the southern Gobi Altai within a regional-scale fold-and-thrust belt. Local refolding of older Permian north-south trending folds is also evident in some areas. The folds identified and mapped in this study provide new evidence for the regional distribution and kinematics of Jurassic and Permian-Triassic contractional tectonism in the southern Mongolia-northern China borderland region. The newly mapped folds are also important potential targets for hydrocarbon exploration and vertebrate paleontological discoveries. Full article
Figures

Figure 1

Open AccessArticle
Bentonite Permeability at Elevated Temperature
Geosciences 2017, 7(1), 3; doi:10.3390/geosciences7010003 -
Abstract
Repository designs frequently favour geological disposal of radioactive waste with a backfill material occupying void space around the waste. The backfill material must tolerate the high temperatures produced by decaying radioactive waste to prevent its failure or degradation, leading to increased hydraulic conductivity
[...] Read more.
Repository designs frequently favour geological disposal of radioactive waste with a backfill material occupying void space around the waste. The backfill material must tolerate the high temperatures produced by decaying radioactive waste to prevent its failure or degradation, leading to increased hydraulic conductivity and reduced sealing performance. The results of four experiments investigating the effect of temperature on the permeability of a bentonite backfill are presented. Bentonite is a clay commonly proposed as the backfill in repository designs because of its high swelling capacity and very low permeability. The experiments were conducted in two sets of purpose-built, temperature controlled apparatus, designed to simulate isotropic pressure and constant volume conditions within the testing range of 4–6 MPa average effective stress. The response of bentonite during thermal loading at temperatures up to 200 °C was investigated, extending the previously considered temperature range. The results provide details of bentonite’s intrinsic permeability, total stress, swelling pressure and porewater pressure during thermal cycles. We find that bentonite’s hydraulic properties are sensitive to thermal loading and the type of imposed boundary condition. However, the permeability change is not large and can mostly be accounted for by water viscosity changes. Thus, under 150 °C, temperature has a minimal impact on bentonite’s hydraulic permeability. Full article
Figures

Figure 1

Open AccessArticle
A Mineralized Alga and Acritarch Dominated Microbiota from the Tully Formation (Givetian) of Pennsylvania, USA
Geosciences 2016, 6(4), 57; doi:10.3390/geosciences6040057 -
Abstract
Sphaeromorphic algal cysts, most probably of the prasinophyte Tasmanites, and acanthomorphic acritarch vesicles, most probably Solisphaeridium, occur in a single 20 cm thick bed of micritic limestone in the lower part of the Middle Devonian (Givetian) Tully Formation near Lock Haven, Pennsylvania. Specimens
[...] Read more.
Sphaeromorphic algal cysts, most probably of the prasinophyte Tasmanites, and acanthomorphic acritarch vesicles, most probably Solisphaeridium, occur in a single 20 cm thick bed of micritic limestone in the lower part of the Middle Devonian (Givetian) Tully Formation near Lock Haven, Pennsylvania. Specimens are composed of authigenic calcite and pyrite crystals about 5–10 µm in length. Some specimens are completely calcitic; some contain both pyrite and calcite; and many are composed totally of pyrite. The microfossils are about 80 to 150 µm in diameter. Many show signs of originally containing a flexible wall composed of at least two layers. Some appear to have been enclosed in a mucilaginous sheath or membrane when alive. The acanthomorphic forms have spines that are up to 20 µm in length, expand toward the base, and are circular in cross-section. The microflora occurs with microscopic molluscs, dacryoconarids, the enigmatic Jinonicella, and the oldest zooecia of ctenostome bryozoans known from North America. The microalgal horizon lacks macrofossils although small burrows are present. Microalgae and acritarchs have been preserved via a complex preservational process involving rapid, bacterially-mediated post-mortem mineralization of dead cells. The microfossil horizon, and possibly much of the Tully Formation at Lock Haven with similar lithology, formed in a relatively deep, off-shore basin with reduced oxygen availability in the substrate. Full article
Figures

Figure 1

Open AccessArticle
Anomaly Detection from Hyperspectral Remote Sensing Imagery
Geosciences 2016, 6(4), 56; doi:10.3390/geosciences6040056 -
Abstract
Hyperspectral remote sensing imagery contains much more information in the spectral domain than does multispectral imagery. The consecutive and abundant spectral signals provide a great potential for classification and anomaly detection. In this study, two real hyperspectral data sets were used for anomaly
[...] Read more.
Hyperspectral remote sensing imagery contains much more information in the spectral domain than does multispectral imagery. The consecutive and abundant spectral signals provide a great potential for classification and anomaly detection. In this study, two real hyperspectral data sets were used for anomaly detection. One data set was an Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data covering the post-attack World Trade Center (WTC) and anomalies are fire spots. The other data set called SpecTIR contained fabric panels as anomalies compared to their background. Existing anomaly detection algorithms including the Reed–Xiaoli detector (RXD), the blocked adaptive computation efficient outlier nominator (BACON), the random selection based anomaly detector (RSAD), the weighted-RXD (W-RXD), and the probabilistic anomaly detector (PAD) are reviewed here. The RXD generally sets strict assumptions to the background, which cannot be met in many scenarios, while BACON, RSAD, and W-RXD employ strategies to optimize the estimation of background information. The PAD firstly estimates both background information and anomaly information and then uses the information to conduct anomaly detection. Here, the BACON, RSAD, W-RXD, and PAD outperformed the RXD in terms of detection accuracy, and W-RXD and PAD required less time than BACON and RSAD. Full article
Figures

Figure 1

Open AccessArticle
Network Modelling of the Influence of Swelling on the Transport Behaviour of Bentonite
Geosciences 2016, 6(4), 55; doi:10.3390/geosciences6040055 -
Abstract
Wetting of bentonite is a complex hydro-mechanical process that involves swelling and, if confined, significant structural changes in its void structure. A coupled structural transport network model is proposed to investigate the effect of wetting of bentonite on retention conductivity and swelling pressure
[...] Read more.
Wetting of bentonite is a complex hydro-mechanical process that involves swelling and, if confined, significant structural changes in its void structure. A coupled structural transport network model is proposed to investigate the effect of wetting of bentonite on retention conductivity and swelling pressure response. The transport network of spheres and pipes, representing voids and throats, respectively, relies on Laplace–Young’s equation to model the wetting process. The structural network uses a simple elasto-plastic approach without hardening to model the rearrangement of the fabric. Swelling is introduced in the form of an eigenstrain in the structural elements, which are adjacent to water filled spheres. For a constrained cell, swelling is shown to produce plastic strains, which result in a reduction of pipe and sphere spaces and, therefore, influence the conductivity and retention behaviour. Full article
Figures

Figure 1

Open AccessArticle
Magnetic Materials: Novel Monitors of Long-Term Evolution of Engineered Barrier Systems
Geosciences 2016, 6(4), 54; doi:10.3390/geosciences6040054 -
Abstract
Most safety cases for the deep geological disposal of radioactive waste are reliant on the swelling of bentonite in the engineered barrier system as it saturates with groundwater. Assurance of safety therefore requires effective monitoring of bentonite saturation. The time- and fluid-dependent corrosion
[...] Read more.
Most safety cases for the deep geological disposal of radioactive waste are reliant on the swelling of bentonite in the engineered barrier system as it saturates with groundwater. Assurance of safety therefore requires effective monitoring of bentonite saturation. The time- and fluid-dependent corrosion of synthetic magnets embedded in bentonite is demonstrated here to provide a novel and passive means of monitoring saturation. Experiments have been conducted at 70 °C in which neo magnets, AlNiCo magnets, and ferrite magnets have been reacted with saline (NaCl, KCl, CaCl2) solutions and alkaline fluids (NaOH, KOH, Ca(OH)2 solutions; pH = 12) in the presence of bentonite. Nd-Fe-B magnets undergo extensive corrosion that results in a dramatic change from ferromagnetic to superparamagnetic behaviour concomitant with bentonite saturation. AlNiCo magnets in saline solutions show corrosion but only limited decreases in their magnetic intensities, and ferrite magnets are essentially unreactive on the experimental timescales, retaining their initial magnetic properties. For all magnets the impact of their corrosion on bentonite swelling is negligible; alteration of bentonite is essentially governed by the applied fluid composition. In principle, synthetic magnet arrays can, with further development, be designed and embedded in bentonite to monitor its fluid saturation without compromising the integrity of the engineered barrier system itself. Full article
Figures

Open AccessEditorial
Developing Lyell’s Legacy: Contributions to the Geosciences of the Anthropocene
Geosciences 2016, 6(4), 53; doi:10.3390/geosciences6040053 -
Abstract In this new edition of the Geoscience of the Built Environment [1], we hope to continue our contribution to the development of Geosciences studies in the Anthropocene, considering classical issuesthatareatleastasoldasCharlesLyell’smajorworks[2,3],whichcanbeconsideredthefounding literary works of modern Geology.[...] Full article
Open AccessReview
Mineral Mapping for Exploration: An Australian Journey of Evolving Spectral Sensing Technologies and Industry Collaboration
Geosciences 2016, 6(4), 52; doi:10.3390/geosciences6040052 -
Abstract
This paper describes selected results from over a dozen collaborative projects led by Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia spanning a 30-year history of developments in satellite, airborne, field and drill core sensing technologies and how these can assist explorers
[...] Read more.
This paper describes selected results from over a dozen collaborative projects led by Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia spanning a 30-year history of developments in satellite, airborne, field and drill core sensing technologies and how these can assist explorers to measure and map valuable mineral information. The exploration case histories are largely from Australian test sites and describe how spectral sensing technologies have progressed from early “niche creation” systems, such as the field PIMA-II (Portable Field Mineral Analyzer) and airborne Geoscan, HyMap™ and OARS-TIPS (Operational Airborne Remote Sensing – Thermal Infrared Profiling Spectrometer) systems and drill-core HyLogger™ systems, to the current expanding array of pubic and commercial mineral mapping sensors, including the ASTER (Advanced Spaceborne Thermal Emission and Reflectance Radiometer) satellite system which has acquired imagery spanning the entire Earth’s land surface (<83° latitude). These sensors are delivering voluminous spectral data from different parts of the visible to the thermal infrared (400 to 14,000 nm) spectrum at different spectral, radiometric and spatial resolutions. Two critical exploration challenges are central to the case histories, namely: (i) can surface cover, such as vegetation, regolith or transported materials, be characterized and accounted for so that the target geology is accurately revealed; and (ii) does this revealed geology show evidence of alteration footprints to potential economic mineralization. Spectrally measurable minerals important to solving these challenges include white micas, kaolinite and garnets, with measurement of their respective physicochemistries being key. For example, kaolin disorder is useful for mapping transported versus weathered in situ materials, while the chemical substitution in white micas and garnets provide vectors to potential economic mineralization. Importantly, appropriate selection of the optimum sensor/data type for a given geological application depends primarily on the level of detail/accuracy of the mineral information required by the user. A major opportunity is to now harness the many sensor/data types and deliver to users consistent, accurate mineral information products, that is, creation of a number of valuable global mineral product standards. As part of this vision, CSIRO has been developing improved sensor/data calibration processes and information extraction methods that for example, unmix the target mineralogy from green and dry vegetation cover in remote sensing data sets. Emphasis to date has been on generating public spectral-mineral product standards, especially at ASTER’s limited but geologically-valuable spectral resolution. The results are showing that scalable, global, three-dimensional (3D) mineral maps are achievable which will only improve our ability to more accurately characterize regolith and geological architecture, increase our understanding of formative processes and assist the discovery of new economic mineral systems. Full article
Figures

Figure 1

Open AccessArticle
Electrical Resistivity Tomography and Induced Polarization for Mapping the Subsurface of Alluvial Fans: A Case Study in Punata (Bolivia)
Geosciences 2016, 6(4), 51; doi:10.3390/geosciences6040051 -
Abstract
Conceptual models of aquifer systems can be refined and complemented with geophysical data, and they can assist in understanding hydrogeological properties such as groundwater storage capacity. This research attempts to use geoelectrical methods, Electrical Resistivity Tomography and Induced Polarization parameters, for mapping the
[...] Read more.
Conceptual models of aquifer systems can be refined and complemented with geophysical data, and they can assist in understanding hydrogeological properties such as groundwater storage capacity. This research attempts to use geoelectrical methods, Electrical Resistivity Tomography and Induced Polarization parameters, for mapping the subsurface in alluvial fans and to demonstrate its applicability; the Punata alluvial fan was used as a case study. The resistivity measurements proved to be a good tool for mapping the subsurface in the fan, especially when used in combination with Induced Polarization parameters (i.e., Normalized Chargeability). The Punata alluvial fan characterization indicated that the top part of the subsurface is composed of boulders in a matrix of finer particles and that the grain size decreases with depth; the electrical resistivity of these deposits ranged from 200 to 1000 Ωm, while the values of normalized chargeability were lower than 0.05 mS/m. The bottom of the aquifer system consisted of a layer with high clay content, and the resistivity ranged from 10 to 100 Ωm, while the normalized chargeability is higher than 0.07 mS/m. With the integration of these results and lithological information, a refined conceptual model is proposed; this model gives a more detailed description of the local aquifer system. It can be concluded that geoelectrical methods are useful for mapping aquifer systems in alluvial fans. Full article
Figures

Figure 1

Open AccessArticle
Maya Lime Mortars—Relationship between Archaeomagnetic Dating, Manufacturing Technique, and Architectural Function—The Dzibanché Case
Geosciences 2016, 6(4), 49; doi:10.3390/geosciences6040049 -
Abstract
Researchers have related the manufacturing technique of plasters and stucco in the Maya area with their period of production but not with their architectural function. In this paper, we establish a relationship between those three features (manufacturing technique, age, and architectural function) in
[...] Read more.
Researchers have related the manufacturing technique of plasters and stucco in the Maya area with their period of production but not with their architectural function. In this paper, we establish a relationship between those three features (manufacturing technique, age, and architectural function) in the plasters of the Maya site of Dzibanché in southern Quintana Roo. Dzibanché has abundant remains of stuccos and plasters found mainly in three buildings (Plaza Pom, Pequeña Acrópolis, and Structure 2). We used thin sections, SEM and XRD, and archaeomagnetic dating processes. The pictorial layer of Structure 2 was the earliest (AD 274–316 and the stuccoes and plasters of the other two buildings were dated to the Middle Classic (AD 422–531), but we obtained different archaeomagnetic dates for the red pigment layers found in the buildings of the Pequeña Acrópolis and thus we were able to determine their chronological order of construction. The raw materials and proportions were carefully chosen to fulfil the mechanical necessities of the architectonic function: different proportions were found in plasters of floors, in the external walls, and inside the buildings; differences between earlier and later plasters were also detected. Full article
Figures

Figure 1

Open AccessArticle
When the Crime Scene Is the Road: Forensic Geoscience Indicators Applied to Road Infrastructure and Urban Greening
Geosciences 2016, 6(4), 50; doi:10.3390/geosciences6040050 -
Abstract
Common to most cities with tree-lined roads, streets, and sidewalks is damage to paved surfaces caused by the growth of roots over time. Sub-surface root growth creates potential hazards for people driving motor vehicles and pedestrian traffic. In large urban centers like Rome
[...] Read more.
Common to most cities with tree-lined roads, streets, and sidewalks is damage to paved surfaces caused by the growth of roots over time. Sub-surface root growth creates potential hazards for people driving motor vehicles and pedestrian traffic. In large urban centers like Rome (Italy), roads are vital infrastructure ensuring the mobility of citizens, commercial goods, and information. This infrastructure can become a crime scene when serious injuries or deaths result from the poor monitoring and management of urban trees. Sustainable management of road infrastructure and the associated urban greening is supported by a forensic geoscientific approach. In particular, the use of the GPR (Ground Penetrating Radar) technique allows (i) to control and detect anomalies in the root architecture beneath asphalt in a non-destructive way; and (ii) to plan actions to repair and avoid the possibility of further catastrophic scenarios and need for forensic investigations. Full article
Figures

Figure 1

Open AccessArticle
Identifying Spatio-Temporal Landslide Hotspots on North Island, New Zealand, by Analyzing Historical and Recent Aerial Photography
Geosciences 2016, 6(4), 48; doi:10.3390/geosciences6040048 -
Abstract
Accurate mapping of landslides and the reliable identification of areas most affected by landslides are essential for advancing the understanding of landslide erosion processes. Remote sensing data provides a valuable source of information on the spatial distribution and location of landslides. In this
[...] Read more.
Accurate mapping of landslides and the reliable identification of areas most affected by landslides are essential for advancing the understanding of landslide erosion processes. Remote sensing data provides a valuable source of information on the spatial distribution and location of landslides. In this paper we present an approach for identifying landslide-prone “hotspots” and their spatio-temporal variability by analyzing historical and recent aerial photography from five different dates, ranging from 1944 to 2011, for a study site near the town of Pahiatua, southeastern North Island, New Zealand. Landslide hotspots are identified from the distribution of semi-automatically detected landslides using object-based image analysis (OBIA), and compared to hotspots derived from manually mapped landslides. When comparing the overlapping areas of the semi-automatically and manually mapped landslides the accuracy values of the OBIA results range between 46% and 61% for the producer’s accuracy and between 44% and 77% for the user’s accuracy. When evaluating whether a manually digitized landslide polygon is only intersected to some extent by any semi-automatically mapped landslide, we observe that for the natural-color images the landslide detection rate is 83% for 2011 and 93% for 2005; for the panchromatic images the values are slightly lower (67% for 1997, 74% for 1979, and 72% for 1944). A comparison of the derived landslide hotspot maps shows that the distribution of the manually identified landslides and those mapped with OBIA is very similar for all periods; though the results also reveal that mapping landslide tails generally requires visual interpretation. Information on the spatio-temporal evolution of landslide hotspots can be useful for the development of location-specific, beneficial intervention measures and for assessing landscape dynamics. Full article
Figures

Open AccessArticle
Identifying the Risk Areas and Urban Growth by ArcGIS-Tools
Geosciences 2016, 6(4), 47; doi:10.3390/geosciences6040047 -
Abstract
Abouelreesh is one of the most at risk areas in Aswan, Egypt, which suffers from storms, poor drainage, and flash flooding. These phenomena affect the urban areas and cause a lot of damage to buildings and infrastructure. Moreover, the potential for the further
[...] Read more.
Abouelreesh is one of the most at risk areas in Aswan, Egypt, which suffers from storms, poor drainage, and flash flooding. These phenomena affect the urban areas and cause a lot of damage to buildings and infrastructure. Moreover, the potential for the further realization of dangerous situations increased when the urban areas of Abouelreesh extended towards the risk areas. In an effort to ameliorate the danger, two key issues for urban growth management were studied, namely: (i) estimations regarding the pace of urban sprawl, and (ii) the identification of urban areas located in regions that would be affected by flash floods. Analyzing these phenomena require a lot of data in order to obtain good results, but in our case, the official data or field data was limited so we tried to obtain it by accessing two kinds of free sources of satellite data. First, we used Arc GIS tools to analyze (digital elevation model (DEM)) files in order to study the watershed and better identify the risk area. Second, we studied historical imagery in Google Earth to determine the age of each urban block. The urban growth rate in the risk areas had risen to 63.31% in 2001. Urban growth in the case study area had been influenced by house sizes, because most people were looking to live in bigger houses. The aforementioned problem can be observed by considering the increasing average house sizes from 2001 until 2013, where, especially in risky areas, the average of house sizes had grown from 223 m2 in 2001 to 318 m2 in 2013. The findings from this study would be useful to urban planners and government officials in helping them to make informed decisions on urban development to benefit the community, especially those living in areas at risk from flash flooding from heavy rain events. Full article
Figures

Figure 1

Open AccessReview
Geoengineering in the Anthropocene through Regenerative Urbanism
Geosciences 2016, 6(4), 46; doi:10.3390/geosciences6040046 -
Abstract
Human consumption patterns exceed planetary boundaries and stress on the biosphere can be expected to worsen. The recent “Paris Agreement” (COP21) represents a major international attempt to address risk associated with climate change through rapid decarbonisation. The mechanisms for implementation are yet to
[...] Read more.
Human consumption patterns exceed planetary boundaries and stress on the biosphere can be expected to worsen. The recent “Paris Agreement” (COP21) represents a major international attempt to address risk associated with climate change through rapid decarbonisation. The mechanisms for implementation are yet to be determined and, while various large-scale geoengineering projects have been proposed, we argue a better solution may lie in cities. Large-scale green urbanism in cities and their bioregions would offer benefits commensurate to alternative geoengineering proposals, but this integrated approach carries less risk and has additional, multiple, social and economic benefits in addition to a reduction of urban ecological footprint. However, the key to success will require policy writers and city makers to deliver at scale and to high urban sustainability performance benchmarks. To better define urban sustainability performance, we describe three horizons of green urbanism: green design, that seeks to improve upon conventional development; sustainable development, that is the first step toward a net zero impact; and the emerging concept of regenerative urbanism, that enables biosphere repair. Examples of green urbanism exist that utilize technology and design to optimize urban metabolism and deliver net positive sustainability performance. If mainstreamed, regenerative approaches can make urban development a major urban geoengineering force, while simultaneously introducing life-affirming co-benefits to burgeoning cities. Full article
Figures

Open AccessArticle
Feasibility Study of Land Cover Classification Based on Normalized Difference Vegetation Index for Landslide Risk Assessment
Geosciences 2016, 6(4), 45; doi:10.3390/geosciences6040045 -
Abstract
Unfavorable land cover leads to excessive damage from landslides and other natural hazards, whereas the presence of vegetation is expected to mitigate rainfall-induced landslide potential. Hence, unexpected and rapid changes in land cover due to deforestation would be detrimental in landslide-prone areas. Also,
[...] Read more.
Unfavorable land cover leads to excessive damage from landslides and other natural hazards, whereas the presence of vegetation is expected to mitigate rainfall-induced landslide potential. Hence, unexpected and rapid changes in land cover due to deforestation would be detrimental in landslide-prone areas. Also, vegetation cover is subject to phenological variations and therefore, timely classification of land cover is an essential step in effective evaluation of landslide hazard potential. The work presented here investigates methods that can be used for land cover classification based on the Normalized Difference Vegetation Index (NDVI), derived from up-to-date satellite images, and the feasibility of application in landslide risk prediction. A major benefit of this method would be the eventual ability to employ NDVI as a stand-alone parameter for accurate assessment of the impact of land cover in landslide hazard evaluation. An added benefit would be the timely detection of undesirable practices such as deforestation using satellite imagery. A landslide-prone region in Oregon, USA is used as a model for the application of the classification method. Five selected classification techniques—k-nearest neighbor, Gaussian support vector machine (GSVM), artificial neural network, decision tree and quadratic discriminant analysis support the viability of the NDVI-based land cover classification. Finally, its application in landslide risk evaluation is demonstrated. Full article
Figures

Figure 1

Open AccessArticle
Measuring Beach Profiles along a Low-Wave Energy Microtidal Coast, West-Central Florida, USA
Geosciences 2016, 6(4), 44; doi:10.3390/geosciences6040044 -
Abstract
Monitoring storm-induced dramatic beach morphology changes and long-term beach evolution provides crucial data for coastal management. Beach-profile measurement using total station has been conducted along the coast of west-central Florida over the last decade. This paper reviews several case studies of beach morphology
[...] Read more.
Monitoring storm-induced dramatic beach morphology changes and long-term beach evolution provides crucial data for coastal management. Beach-profile measurement using total station has been conducted along the coast of west-central Florida over the last decade. This paper reviews several case studies of beach morphology changes based on total-station survey along this coast. The advantage of flexible and low-cost total-station surveys is discussed in comparison to LIDAR (light detection and ranging) method. In an attempt to introduce total-station survey from a practical prospective, measurement of cross-shore beach profile in various scenarios are discussed, including: (1) establishing a beach profile line with known instrument and benchmark locations; (2) surveying multiple beach profiles with one instrument setup; (3) implementation of coordinate rotation to convert local system to real-earth system. Total-station survey is a highly effective and accurate method in documenting beach profile changes along low-energy coasts. Full article
Figures

Open AccessArticle
Applying a Hybrid Model of Markov Chain and Logistic Regression to Identify Future Urban Sprawl in Abouelreesh, Aswan: A Case Study
Geosciences 2016, 6(4), 43; doi:10.3390/geosciences6040043 -
Abstract
Urban sprawl has become a very complex process, because it has many factors affecting its directions and values. The study of relative research shows that the driving forces that lead and redirect future urban sprawl require the application of a statistical method. In
[...] Read more.
Urban sprawl has become a very complex process, because it has many factors affecting its directions and values. The study of relative research shows that the driving forces that lead and redirect future urban sprawl require the application of a statistical method. In our study, logistic regressions were used to analyze and class the driving forces for urban sprawl. Identifying the driving forces, which is the most important step in predicting the future of urban sprawl in 2037, was performed using the cellular automata models. This study takes the Aswan area as a case study in the period from 2001 to 2013 by analyzing the official detailed plan and Google Earth historical imagery. Almost all data was prepared for logistic regression analysis using ArcGIS software and IDRISI® Selva. In our study, a hybrid model of the Markov chain and logistic regression models was applied to identify future urban sprawl in 2037. The findings of this paper simulate the increase in urban area over 24 years from 1.85 to 2.59 km2. These findings highlight the growing risks of urban sprawl and the difficulties opposing the sustainable urban development plans officially proposed for this area. Full article
Figures

Figure 1