Total Sand Research Articles

Data correlation structure controls pedotransfer function performance

Soil hydraulic properties are essential for modeling and evaluating several soil–water processes. The use of pedotransfer functions (PTFs) is a viable alternative in the analysis of these processes due to the high costs or difficulty in measuring these properties. We aimed to (1) examine the performance of a physically-based PTF and a pool of empirical PTFs from both temperate and tropical climates to estimate soil water retention under subtropical climate and (2) performed correlation analysis between PTF inputs, outputs and estimation residuals to help gain understanding why some PTFs are more successful than others in a given study area. The study was carried out in the Pelotas River Watershed, Southern Brazil, where samples were taken at 100 locations in the 0–0.20-m soil layer along a 25-km-spatial transect. For each point, clay, silt, fine sand, total sand, and organic carbon contents were measured along with bulk and particle density, macro, micro, and total porosity, and the soil water retention curve. The PTFs were used to estimate field capacity, permanent wilting point, and the available water (AW) content. The performance of PTFs from different climate zones was mixed, and similarity in the data correlation structure between PTF development and application data sets appeared to be a good predictor of their predictive power. There was no clear grouping in such correlation structures within climate-zones, and we conclude that the often claimed geoclimatic difference or similarity between an empirical PTF’s origin and its application site is not, or at least not the sole driver of a PTF’s expected performance.

Goods and Services and Equivalent Economic Benefits of Sand Dunes of India

Sand dunes are simply an extension of the beach which is a reservoir of sand, during storms when the waves erode the dune and carry the sand into the sea. They are providing habitat for shellfish, birds, rodents, and ungulates. They have been used for coastal defense, water catchment areas, agriculture purposes, mining, and housing. Many of the goods and services produced by the sand dunes are not easily quantified and accounted for since they are not being traded in the formal market. Hence, many of the environmental benefits have been often neglected or even ignored by the economy, industry, coastal communities, and other stakeholders. Systematic accounting of the benefits shall enlighten the relationship between environmental function, human dependency, and economics. Though there are many goods and services, economic assessment of sand dune landforms is scarce. Estimated values of sand dune landforms allow policymakers to assess the benefits that society gains from the environmental feature. The monetary value of sand dune landforms goods and services shall be a tool to raise awareness and convey the (relative) importance of the environmental feature to the general public and policymakers. In addition, the monetary value shall support decision-making on the allocation of resources for competing uses. This policy paper analysis assesses the economic value of sand dune landforms to wise use of the sand dune and sustainable management of the coastal environment. This policy paper used the Benefit Transfer method to estimate the equivalent economic benefit of the sand dune landforms. The monetary benefit of sand dunes in a one-hectare area of the sand dune has been estimated at Rs.8220002/ha./yr =US$ 176103.66(average). Sand dunes have been distributed in 1231 patches with a total area of 32445 ha. Using the average value of sand dune benefits, the equivalent economic benefit from sand dunes of India cost Rs. 26670 crore/yr.=US$ 5.71 billion. Among the coastal States and UTs, Andhra Pradesh State has a huge area (11594 ha.) of sand dunes which share Rs. 9530 crore/yr.=US$ 2.04 billion which occupies 36% of the total sand dunes of India.

Peelu (Salvadora oleoides Decne.): An Unexplored Medicinal Fruit with Minerals, Antioxidants, and Phytochemicals.

The Peelu (Salvadora oleoides Decne.) fruit is well known for its nutritional and medicinal values. The current study analyzed the chemical composition of Salvadora oleoides fruit. Fresh Peelu fruits were harvested, and physicochemical properties, proximate composition, macro- and micronutrients, and phytochemical properties were determined. Moreover, ethanol and methanol fruit extract was analyzed for physicochemical properties. The Peelu fruit seemed to be a potential source of essential macro- ((nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg)) and micronutrients (zinc (Zn), manganese (Mn), iron (Fe), and copper (Cu)). The fruit had significant biochemical properties (total soluble solids (TSS), total acidity (TA), and TSS : TA ratio) with appreciable moisture, crude fiber, and ash contents. The fruit extracts demonstrated significantly higher antioxidants and phenolics, ascorbic acid contents, and carotenoids. Phytochemical screening of fruit revealed the presence of coumarins, flavonoids, phlobatannins, tannins, and terpenoids. Physicochemical and sensory evaluation of extracts indicated its potential for further in vivo study trials. The Peelu fruit was found to be a good source of mineral nutrients, proximate contents, vitamins (ascorbic acid and carotenoid), phytochemicals (total phenolic sand antioxidant contents), and pharmaceutically important metabolites that can be used as functional drink.

The lower shoreface of the Dutch coast – An overview

The lower shoreface, defined here as between about 8 and 20 m water depth, forms the transition between the inner shelf and upper shoreface. Knowledge of lower shoreface hydro- and morphodynamics is essential for coastal management and maintenance.The shoreface of the Dutch coast is a complex area. It is partly determined by its evolution in the past, whereas present-day processes are influencing or even changing it. The present situation and large-scale anthropogenic supply of sediment will determine its future development.The shoreface morphology varies along the Dutch coast, depending on the coastal slope and superposition of ridges (central Holland coast) and ebb-tidal deltas (Delta area, Wadden Sea). The architecture of the shoreface-connected ridges off the central Holland coast indicates that they are still active today. The development of most ebb-tidal deltas along the Dutch coast is largely influenced by interventions in the tidal inlets and tidal basins.The Kustgenese 2.0 Lower Shoreface project comprised both field data collection in 2017 and 2018 and numerical modelling. Field data was collected in study areas at Ameland Inlet, Terschelling and Noordwijk. Sediment cores and multibeam sonar surveys provided information on the Holocene deposits, geomorphology and sediments. Instrumented frames placed at the seabed collected a wealth of process data.The variation in shoreface composition and morphology is larger than anticipated previously. In general, the lower part of the shoreface consists of older Holocene deposits overlain by an active sand layer that responds to variations in tidal, wave and wind conditions. The deposits at the lower shoreface of Terschelling were comparable to the ebb-delta channel deposits at the ebb-delta front at Ameland Inlet. At Noordwijk, deposits of the Late-Holocene prograded barrier shoreface overlie those of back-barrier tidal channels and river channels. The large-scale morphology of the lower shoreface seems rather stable. Decadal time series show an erosional trend. Small-scale bedforms can change over an interval of days to weeks.The multibeam surveys revealed unexpected details such as geology-based shoreface irregularities between −12m and −18m that probably act as conduits for downslope currents and sand transport. After a high-energy wave event, more erosional features were discovered that suggest seaward sand transport.Measured orbital velocities at the seabed at 14–16 m depth reached 1.5 m per second under high-wave events. This caused high sediment mobility under sheet-flow conditions with abundant sediment suspension. It is not clear what this means for the net sand transport at the lower shoreface.The modelled alongshore-directed sand transport is much larger than the cross-shore transport. The largest transports at the 20m depth contour occurs along the northern part of the Holland coast. Here, transport is parallel to the coast or directed to deeper water. Transports at 20 m depth along the other parts of the coast are directed to shallower water.The modelled total landward sand transport over the −20m contour is c. 4 million m3 per year and c. 7 million m3 per year over the −16m contour. This suggests a yearly erosion of c. 4 million m3 in-between, in case of no alongshore transport gradients.The results of the sand transport calculations imply a net landward sediment transfer that needs to be further tested against the morphological changes in the shoreface.

Porcelain waste from electrical insulators in self-leveling mortar: Materials characterization and properties

The addition of waste in building materials is a technical and economical alternative for modern construction. Self-leveling mortar (SLM) is a material used in floors because it is able to flow and fill a base area without using extra energy. The present studied SLMs using porcelain insulator waste (PIW) as partial and total sand replacement. Different methods were used to characterize the PIW (e.g. X-ray fluorescence, X-ray diffraction (XRD), and pozzolanic activity index) and tests were made in SLMs in fresh and hardened states. XRD results revealed that PIW presented pozzolanic characteristics and increased the compressive strength of mortars. Tests also not verified alkali-aggregate reaction (AAR) when PIW was added. SLMs containing PIW presented compressive and flexural strengths of 24.11 MPa and 7.07 MPa, respectively. The spread diameter reached values found in the literature.

Evaluation of Susceptibility Status of Phlebotomus papatasi, the Main Vector of Zoonotic Cutaneous Leishmaniasis, to Different WHO Recommended Insecticides in an Endemic Focus, Central Iran.

Among neglected zoonotic diseases, leishmaniases caused by Leishmania parasite through infected female sand fly bite, are a group of diseases found in 98 countries and territories representing a critical burden of disease worldwide. Vector management plays a crucial role in reducing the burden of vector-borne diseases by WHO's global plan. The objective of the current study was to assess the susceptibility status of wild phlebotomine sand flies from Esfahan Province, central Iran, to the recommended insecticides by WHO. Sand flies were collected by mouth aspirator in Matin Abad desert Eco-resort and were tested using WHO adult mosquito test kit against Dichlorodiphenyltrichloroethane (DDT) 4%, Deltamethrin 0.05%, Malathion 5% and Propoxur 0.1%. The number of knockdown sand flies were recorded during exposure time in ten minutes interval for DDT and Deltamethrin and they were allowed to recover for 24 hours. Knockdown Time50 (KD50) and KD90 were generated for them using Probit software. They were mounted and identified by valid keys. Among the tested insecticides against female Phlebotomus papatasi, DDT, Deltamethrin, and Malathion recorded the highest mortality rate of 100%, followed by Propoxur with 92.2% mortality for a one-hour exposure. For DDT, KD50 and KD90 were calculated 21.87 and 42.93 and for Deltamethrin, they were 23.74 and 56.50 minutes respectively. Total sand flies exposed with DDT and Deltamethrin shed their leg(s). It is concluded that Ph. papatasi from central Iran is susceptible to DDT, Deltamethrin, Malathion, and Propoxur.

Proximal sensor data fusion and auxiliary information for tropical soil property prediction: Soil texture

• Does combining proximal sensor always bring synergy for predicting soil texture? • Vis-NIR, NixPro TM , and pXRF data were tested for soil texture predictions. • PXRF provided key information to create accurate prediction models. • Smoothed Vis-NIR data preprocessing and dry NixPro TM condition positively influenced the results. • Soil texture and textural classes were accurately predicted by at least one approach. Soil texture is a primary variable influencing many soil chemical-physical-biological processes, providing important information for decision-making regarding sustainable soil management. The standard traditional methods for determining soil texture, however, are performed manually and are time-consuming, costly, and generate chemical wastes. As an alternative, portable X-ray fluorescence (pXRF) spectrometry and visible near-infrared spectroscopy (Vis-NIR) have been increasingly used worldwide to predict soil attributes. Other sensors (e.g., NixPro TM color sensor) are also promising, but less evaluated to date. Thus, investigations towards proximal sensor data fusion for prediction of soil textural separates (clay, silt, and total, coarse, and fine sand contents) and soil textural classes (loam, loamy sand, etc) in tropical soils are rare. Therefore, this study aimed to evaluate proximal sensor data for predicting soil particle size fractions and soil textural classes (both Family particle size classes and USDA soil texture triangle) via random forest algorithm in tropical regions. A total of 464 soil samples were collected from A (n = 208) and B (n = 256) horizons in Brazil. Soil samples were submitted to laboratory analyses for soil texture and proximal sensor (pXRF, Vis-NIR, and NixPro TM ) scanning. Samples were randomly split into 70% for modeling and 30% for validation. The best approach varied according to the predicted attribute; however, pXRF data were key information for soil texture prediction accuracy. The best results delivered highly accurate predictions via the aforementioned proximal sensors for rapid assessment of soil texture (total sand R 2 = 0.84, RMSE = 7.60%; silt 0.83, 6.11%; clay 0.90, 5.64%; coarse sand 0.87, 6.30%; fine sand 0.82, 5.27%). Categorical prediction accuracy for soil textural classes (Family particle size classes, overall accuracy = 0.97, Kappa index = 0.95; USDA soil texture triangle, 0.83, 0.73) was enhanced when the predictions were made by soil order sub-datasets. Smoothed Vis-NIR preprocessing and dry NixPro TM color data positively influenced the results. The results reported here represent alternatives for reducing costs and time needed for evaluating soil texture, supporting agronomic and environmental strategies in Brazilian conditions. Further works should extend the results of this study to temperate regions to corroborate the conclusions presented herein regarding the fusion of these three proximal sensors.

Comparison of solution extraction methods for estimating electrical conductivity in soils with contrasting mineralogical assemblages and textures

Characterization of the soil solution is of fundamental importance for monitoring plant nutrient availability, environmental contamination, and evaluation of salt-affected soils. Due to the diversity of methodologies adopted in various parts of the world, comparison of the most common extraction methods in different types of soils is warranted. This study compared the efficiency of five soil solution extraction methods for five soils with different mineralogical assemblages and textures with the most commonly used saturated paste extract method. The extraction methods compared were: centrifugation, porous extractor capsules, and soil–water extracts (soil:water ratio of 1:2, 1:5, or 1:10). The soil types evaluated were: Regosol, Luvisol, Gleysol, Nitisol and Ferrosol in the soil surface and subsurface horizons. Linear regression equations were developed that allowed accurate estimation of electrical conductivity of the saturated paste extract (ECse). Ten equations were developed for the porous capsule method, eight were developed for the centrifugation method (with the exception of the Regosol with 900 g k−1 of total sand, which was not suitable for this method due to the high sand content), and 30 equations were developed for the soil–water extract method (at each of the soil:water ratios tested). The diversity of equations developed for soils with different mineralogical assemblages and textures should assist growers and extension workers who need to know the soil electrical conductivity for making soil management decisions.

Influence of abiotic factors on phytochemical diversity of Anacardiumoccidentale L.

To understand the influence of environmental factors on the metabolic diversity of phytochemical compounds from extracts of leaves and bark of Anacardium occidentale, collected in two different geographic areas, ultra-performance liquid chromatography and mass spectrometry were used, as well as the composition of physicochemical properties of both soils at the collection site (“Lavras da Mangabeira” and “Crato”). It was possible to observe physicochemical differences between the soils of the two collection areas and some similarities. Both present granulometry with a sandy texture, with high values of total sand, with acid pH, and variation in porosity rates. The micronutrients with the highest accumulation in the soil, with emphasis on the predominance of P (Phosphorus) and Al (Aluminium) mainly in the 20–40 cm layer in Crato. Thirty-three phytochemical compounds were identified in the leaf and bark extracts, of which 28 were present in the leaves and 20 in the bark part. Of this total, 13 were present in at least one of the parts of the plant (leaf or bark), and most were present in both Crato and Lavras da Mangabeira, presenting mainly phenolic acids, flavonoids and tannins in all extracts evaluated. Both extracts showed similarities between the groups of compounds. Taken together, this study may be relevant to assess environmental influences on the production of secondary metabolites.

Microbially/CO2-derived CaCO3 cement strengthens calcareous sands and its cementation mechanism

In this text, a method to use CO2 for the treatment of calcareous sand is presented. Carbon dioxide solidification-bacteria (Streptomyces microflavus) was obtained by screening and applied to the mechanical strengthening of calcareous sand through a microbial mineralization/carbonization process. Experiments in both liquid phase and sand were carried out. The optimal mass ratio of carbon dioxide solidification-bass cteria to calcium oxide was found to be 2:1. The optimal dosage of bacterial powder was 30% of the total dry sand mass. Using the optimal recipe, the average uniaxial compressive strength of treated sand columns was 3.67 MPa and the average permeability coefficient was 4.90 × 10−3 cm/s. Compared to the other microbial induced carbonate precipitation (MICP) approaches, the proposed method does not release harmful by-products such as ammonia. The chemical composition and microstructure of the treated calcareous sand were characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD results showed that the CO2 carbonized product contained mainly calcite.Graphical abstract

Mechanisms Responsible for Sand Hazards Along Desert Highways and Their Control: A Case Study of the Wuhai–Maqin Highway in the Tengger Desert, Northwest China

Highways in deserts usually suffer from severe sand hazards under the effect of wind-blown sand. In this article, the author has revealed the disaster-causing mechanisms of the Wuhai–Maqin Highway in the Tengger Desert, Northwest China. A sand control system with six belts was proposed and established for the highway, and its sheltering effect was examined through on-site monitoring. The results showed that from 2018 to 2019, the sand drift potential was dominated by northwest, northeast, and south winds, which indicated a low-energy windy environment, with a resulting southeast direction of sand transport. The particle size of surface sediments was mainly distributed between 1.26Φ and 2.5Φ, indicating fine sand and medium sand. The sand flux was mainly concentrated below 30 cm, accounting for 89.46% of the total sand transport. Airflow around the control system was significantly attenuated, with a maximum wind speed decreasing rate of 95.88%. The windproof efficiency of the control system against the near-surface wind-blown sand was more than 90%. This study provides a significant reference for the control of highway sand hazards in other deserts.

New systematically measured sand mining budget for the Mekong Delta reveals rising trends and significant volume underestimations

The river beds of the Mekong Delta are some of the most intensively sand mined places in the world. However, sand mining budgets remain limited to rough and indirect estimates. Here, we provide a first systematic, field-based estimation of the Mekong Delta’s sand mining budget. This budget overcomes the limitations of relying on officially declared statistics and bathymetric surveys of short channel reaches. We applied Sentinel-1 radar imagery to monitor the distribution of sand mining activities using boat metrics-driven mining intensity maps correlated with a field-based bathymetry difference map which were derived from two extensive bathymetric surveys conducted in 2014 and 2017. The two surveys cover ∼ 100 km in the Tiền River, reaching approximately 15% of the Mekong Delta. We then extrapolated the Tiền River findings to the broader Vietnamese Mekong Delta from 2015 to 2020 and measured a continuous increase of the extraction budget by ∼ 25% between 2015 (38 Mm3/yr) and 2020 (47 Mm3/yr). We estimated a total sand mining budget of 254 Mm3 during the 6-year study period with an average annual rate of ∼ 42 Mm3. Our field-based annual rates are higher than both official declarations provided and estimates from previous studies which implies that a substantial portion of the sand mining budget remains unaccounted for. Riverbed sand mining remains a key threat to the Mekong Delta as it contributes to a multitude of other environmental threats including dam construction effects on sedimentation, ongoing subsidence, sea level rise and recurring saltwater intrusion. This study offers a new approach that can be implemented elsewhere to allow for systematic monitoring and quantification of sand mining activities that are vital for assessing future projections on environmental impacts.

An experimental investigation on the utilization of crushed sand in improving workability and mechanical resistance of concrete

Sand/fine aggregate in concrete is a filler material that plays a key role on the mechanical properties of concrete. This experimental work focused on improving the mechanical properties of concrete by utilizing crushed sand, a byproduct in the manufacturing process of coarse aggregate, as an artificial sand material. Firstly, the combination of crushed sand and river sand in making concrete was investigated with an amount of river sand ranging from 0 to 100 mass-%. There was a synergy effect on improving the workability and mechanical properties of the concrete using the hybrid sand. The optimal amount of river sand was from 30 to 40 mass-% to generate the best workability and concrete resistance under compression and flexure. Moreover, crushed sand could completely replace river sand, with noticeable improvements in the mechanical properties of the concrete. Secondly, the concrete using mono crushed sand was added from 0 to 20 mass-% very fine crushed sand < 0.14 mm of total sand. The optimal amount of fine crushed sand was from 5 to 10 mass-% to possibly produce a favorable effect on the concrete’s workability and resistance under compression, flexure, splitting, and abrasion. The shrinkage strain developed rapidly and significantly within five hours after casting, and the abrasion resistance of the concrete increased as its compressive strength increased.

Floodplain evolution and its influence on liquefaction clustering: The case study of March 2021 Thessaly, Greece, seismic sequence

The March 2021 Thessaly, Central Greece, seismic sequence characterized by an Mw = 6.3 mainshock and five Mw > 5.0 aftershocks triggered extensive liquefaction in the floodplain of the Piniada Valley and localized phenomena along the riverbanks of the Titarissios River. In order to document these secondary effects, we carried out immediate post event surveys based on remote sensing techniques and field-based reconnaissance. The initial desktop-based approach succeeded in delineating in advance the extensive liquefaction surface manifestations and in saving time for the subsequent field survey. The field work was performed with ground-based surveys, and UAV aerial campaigns. The longest reported linear liquefaction feature was 26.7 m, while the total sand blow covered an area of 0.0325 km2. Over one of the liquefaction manifestations, we performed parallel 2D electrical resistivity tomography profiles in order to reconstruct the subsoil stratigraphy. The produced 3D resistivity model successfully detects and illustrates the subsurface disruption following the generation of liquefaction. From the comparison between the spatial distribution of liquefaction phenomena and the geomorphological conditions in the area, the direct influence of the historical evolution of Pinios River in clustering liquefaction phenomena was highlighted. Thus, it is confirmed that a detailed investigation of the historical and late Holocene evolution of a floodplain i.e., location of ox-bow lakes, meanders and former river channels, can identify sites prone to liquefaction. This could result in a reduction of the area where detailed engineering geology investigations (e.g., boreholes with in-situ tests) are required for the evaluation of the liquefaction hazard.

From apex to shoreline: fluvio-deltaic architecture for the Holocene Rhine–Meuse delta, the Netherlands

Abstract. Despite extensive research on alluvial architecture, there is still a pressing need for data from modern fluvio-deltaic environments. Previous research in the fluvial-dominated proximal and central Rhine–Meuse delta (the Netherlands) has yielded clear spatial trends in alluvial architecture. In this paper, we include the backwater length to establish architectural trends from apex to shoreline. Channel-belt sand body width / thickness ratios and interconnectedness were determined, and the proportions of fluvial channel-belt deposits, fluvial overbank deposits, organics and intertidal deposits were calculated for the complete fluvio-deltaic wedge based on high-resolution geological cross sections. It was found that the average width / thickness ratio of channel-belt sand bodies in the proximal delta is 5 times higher than in the distal delta. Other down-valley trends include an 80 % decrease in the channel deposit proportion (CDP) and a near-constant proportion of overbank deposits. Additionally, interconnectedness in the proximal delta is 3 times higher than in the distal delta. Based on the Rhine–Meuse dataset, we propose a linear empirical function to model the spatial variability of CDP. It is argued that this relationship is driven by four key factors: channel lateral-migration rate, channel-belt longevity, creation of accommodation space and inherited floodplain width. Additionally, it is established that the sensitivity of CDP to changes in the ratio between channel-belt sand body width and floodplain width (normalized channel-belt sand body width) varies spatially and is greatest in the central and distal delta. Furthermore, the proportion of fluvial channel-belt sands is generally an appropriate proxy for the total sand content of fluvio-deltaic successions, although its suitability as a total sand indicator rapidly fades in the distal delta. Characteristics of the backwater zone of the Rhine–Meuse delta are (1) sand body width / thickness ratios that are lower as a consequence of channel narrowing (not deepening), (2) a rapid increase and then a drop in the organic proportion, (3) an increase in the total sand proportion towards the shoreline, and (4) a drop in the connectedness ratio. For this paper, unique high-resolution quantitative data and spatial trends of the alluvial architecture are presented for an entire delta, providing data that can be used to further improve existing fluvial stratigraphy models.

Funções de pedotransferência para predição da retenção de água em solo sob Cerrado Brasileiro

Abstract The objective of this work was to determine pedotransfer functions to predict water retention at the -33 and -1500 kPa matric potentials of soils under Cerrado, in the south of the state of Mato Grosso, Brazil. Samples (n=156) were collected for model calibration (n=124) and validation (n=32). A stepwise multiple regression was used to determine pedotransfer functions. Willmott’s index of agreement, root-mean-square error, Pearson’s correlation coefficient, and the confidence index were used to evaluate the performance of the functions and to compare them with those described in the literature. The most efficient variables to estimate water retention were: microporosity, total sand, and clay at -33 kPa; and total sand, silt and clay at -1500 kPa. The regional pedotransfer functions explained more than 94% of water retention variance in the studied soils. The reliability of the functions to predict water retention increased, at -33 kPa, with the use of the structural property microporosity and, at -1500 kPa, with the use of granulometric parameters. The studied regional pedotransfer functions predict water retention at the -33 and -1500 kPa matric potentials of soils under Cerrado, in southern Mato Grosso, better than the functions described in the literature.

Geophysical investigation in sediment cores and its relationship with the governing sedimentary processes at Bransfield Basin, Antarctica.

This research aims to investigate sediment cores from a glaciomarine environment based on their petrophysical parameters to elucidate lithological and sedimentary issues, as well as to identify a geophysical signature based on their parameter's response. To achieve this objective, six marine sediment cores were collected in the Central Bransfield Basin - Antarctica, the lengths ranging from 1.5 to 5.2 meters in water depths ranging from 304 to 1463 meters. The cores were submitted to different analyses and values from density, magnetic susceptibility, electrical resistivity, p-wave velocity, total gamma radiation, silt, clay and sand contents, and mean grain size for each core location were considered. Four large lithologies were identified according to their geological and geophysical characteristics. The first group is subglacial deformation till (GC16); the second is massive diamicton (GC13 and GC12), the third group is composed of diamictons from the basin (AM10) and lower slope (GC09); the fourth lithological group is composed of siliceous mud from an upper slope location (GC06A). The characteristics recorded across Central Bransfield Basin (from South Shetlands Islands to Antarctic Peninsula) highlighted the relationship between the lithological content and associated depositional processes with the geophysical proprieties as density and magnetic susceptibility.

The Determination of Lead and Cadmium Concentration in the Agricultural Soils Alongside Highway 080 of Igdir Province

Gases emitted from both industrial estates and automobile exhausts in agricultural areas cause heavy metal pollution and these metals accumulate in the soil and plants. In this study, 72 soil samples were taken at 5 km intervals from 24 points along the Tuzluca-Iğdır-Nakhchivan route, through which the 080 State Road passes, at 0-10-30 meters perpendicularly inwards from the road and at a depth of 0-20 cm. Total lead (Pb) and cadmium (Cd) accumulations were determined in the samples. The significant decrease in lead and Cd concentrations away from the road indicates that heavy metal deposits have being caused by traffic. The effect of prevailing winds on total Pb and Cd deposition in north and south of the State Highway 080 was statistically insignificant. As the relationships between heavy metal concentrations and soil physical properties were considered, significant negative correlations were found between total Cd concentrations and sand and organic matter contents. Heavy metal pollution index (PI) values were found to be slightly and moderately polluted for Pb and close to highly polluted for Cd according to treshold values. The pollution load index (PLI) values were calculated as a function of the pollution index and according to the PLI results, it was evaluated that Pb and Cd triggered each other in terms of increasing toxic effects. It has been concluded that, with the re-establishment of the Silk Road, the traffic-related pollution will increase in the region.

Widespread Megaripple Activity Across the North Polar Ergs of Mars.

The most expansive dune fields on Mars surround the northern polar cap where various aeolian bedform classes are modified by wind and ice. The morphology and dynamics of these ripples, intermediate-scale bedforms (termed megaripples and Transverse Aeolian Ridges [TARs]), and sand dunes reflect information regarding regional boundary conditions. We found that populations of polar megaripples and larger TARs are distinct in terms of their morphology, spatial distribution, and mobility. Whereas regionally restricted TARs appeared degraded and static in long-baseline observations, polar megaripples were not only widespread but migrating at relatively high rates (0.13 ± 0.03 m/Earth year) and possibly more active than other regions on Mars. This high level of activity is somewhat surprising since there is limited seasonality for aeolian transport due to surficial frost and ice during the latter half of the martian year. A comprehensive analysis of an Olympia Cavi dune field estimated that the advancement of megaripples, ripples, and dunes avalanches accounted for ~1%, ~10%, and ~100%, respectively, of the total aeolian system's sand fluxes. This included dark-toned ripples that migrated the average equivalent of 9.6 ± 6 m/yr over just 22 days in northern summer-unprecedented rates for Mars. While bedform transport rates are some of the highest yet reported on Mars, the sand flux contribution between the different bedforms does not substantially vary from equatorial sites with lower rates. Seasonal off-cap sublimation winds and summer-time polar storms are attributed as the cause for the elevated activity, rather than cryospheric processes.

Mapping the Available Water Capacity in tropical climate soils for soybean (Glycine max) cultivation in the state of Tocantins-Brazil

Brazilian soybean has undergone considerable economic growth. Its production depends on the demand for some inputs. One of these inputs is the soil water supply, which can be made artificially or obtained by natural rainfall. Knowledge of available water capacity (AWC), which depends on total water availability (TWA), is poorly accessible and difficult to measure in the field. This study aimed to map the AWC of the state of Tocantins, based on pedotransfer functions (PTFs), to evaluate the water availability of the soils of the microregions of that state. We used the Arya and Paris model, aided by a computer program, Qualisolo, made by Embrapa Instrumentação. One hundred fifty-seven tropical soil samples were extracted from the Embrapa Solos portal. Preliminarily, the soil water retention curve (SWRC) was obtained and, subsequently, the TWA and AWC for this oilseed were estimated. Multiple linear regressions show the correlation between TWA and clay (CL), Silt (ST) and total sand (TS) contents. The correlation established was TWA = 3.2993 – 0.0028TS – 0.0034CL. This main conclusion reflects a fruitful AWC for decision-making by the soybean agribusiness and exposes the regional weaknesses for this crop under a rainfed regime in some regions of Tocantins. We could observe that, in terms of water availability, agribusiness is a potential threat to the environment protection area (APA) of the Ilha do Bananal/Cantão, Formoso River microregion.