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The major goal of this research was to assess the ability of visible-near-infrared (VIS-NIR) spectroscopy combined with multivariate regressions based on four modeling algorithms, namely partial least squares regression (PLSR), principal component regression (PCR), support vector regression (SVR), and random forest (RF) to quantify some quality soil parameters. Saturated electrical conductivity (ECe), organic carbon (OC), and texture (including sand, silt, and clay) were measured. Overall, 114 soil samples were taken from 30 profiles (0–100 cm) in Doviraj plain, western Iran. For improving spectral data, various preprocessing techniques including Savitzky-Golay first deviation (SGD), Normalization (N), and Standard Normal Variate transfor
This paper evaluates the capability of visible-near-infrared (VIS-NIR) spectroscopy to estimate soil organic carbon (SOC) at multiple depths including 0–15, 15–40, 40–60, and 60–80 cm. Four modeling algorithms, namely partial least squares regression (PLSR), principal component regression (PCR), support vector regression (SVR), and random forest (RF) were implemented calibrated to process the spectroscopy data. Overall, 120 soil samples were taken from 30 profiles at the depth of 0–80 cm. We implemented the four models considering different pre-processing techniques including Savitzky-Golay first deviation (SGD), normalization (N), and standard normal variate transformation (SNV). Results revealed that the RF model outperforme
Lake Urmia is one of the most important salt lakes in the world and the largest in Iran. At present, because of the recession of Lake Urmia and deposition of lacustrine sediments on the lake bed, a large part of the surrounding areas has become flat with several playa surfaces. So far, there have been very few studies related to Lake Urmia playa and its geomorphology. Therefore, the aim of this research was to field study of playa surfaces of Lake Urmia in its eastern part and also to identify areas susceptible to wind erosion. In this study, different playa surfaces from the northeast to the south of the lake were identified and mapped using satellite imagery. Then, boundaries of the mapped surfaces were checked during field observations.
Soil formation is a complex phenomenon. The role of geology is mostly prominent through the influence of lithology in the production of parent material and tectonics in the geoform of structural origin. Geomorphology plays an important role in soil formation through relief, surface morphodynamics, morphoclimatic context, weathering and time (age). The geological zones and their related geomorphic features are dealt with as related to soil distribution. The Iranian Plateau is divided to eight structural zones. The Zagros mountain chain contains the most important sedimentary basins comprised mainly of calcareous detrital sediments. Karst features are the major expression of the Zagros landscape. The other mountain chain—Alborz zone—is co
Soil formation is a complex phenomenon. The role of geology is mostly prominent through the influence of lithology in the production of parent material and tectonics in the geoform of structural origin. Geomorphology plays an important role in soil formation through relief, surface morphodynamics, morphoclimatic context, weathering and time (age). The geological zones and their related geomorphic features are dealt with as related to soil distribution. The Iranian Plateau is divided to eight structural zones . The Zagros mountain chain contains the most important sedimentary basins comprised mainly of calcareous detrital sediments. Karst features are the major expression of the Zagros landscape. The other mountain chain—Albo
In the high plateau region of central Iran, there is both a lack of information on calcic soil processes and aspects of Quaternary paleoclimate. Thus, the research discussed here was undertaken as a first step to assess the utility of calcic soil research in the region. The properties and isotope composition of calcic soils was studied on a complex of alluvial fans, located about 50 km SE of the city of Isfahan. At least three geomorphic surfaces have formed during an interval from the middle Pleistocene to the Holocene. These geomorphic surfaces contain calcareous soils and paleosols. Interpretation of the pedogenic evidence indicates that there have been multiple periods of clay formation and carbonate accumulation over time, with an over
The Urmia Lake recession, and the resulting increase in vast barren area around it, has been rapid in recent decades and thus has attracted attention of environmentalists and geoscientists alike. However, evidence for its different strandlines and the largest extension of the lake during the late Quaternary has not been reported yet. The principal goals of the current research were to figure out pedological evidence of its maximum expansion during the late Quaternary and mapping out the different strandlines along the western shores of Urmia Lake over time. Thirty-two soil pedons at different landscape positions, geomorphic surfaces and distances from Urmia Lake were studied during autumn in 2013 and 2014. Micromorphological and mineralogic
Alluvial fans are one of the most important landforms in geomorphological and paloenvironmental studies. The objective of this study was the application of clay mineral assemblages and micromorphological properties of the studied paleosols in the geomorphic surfaces of an alluvial fan in the eastern Isfahan as proxies for paleoenvironmental and paleoclimatic changes. Micromorphology, X-ray diffraction, and scanning electron microscopy approaches were used to study the representative pedons. The results indicated that the illuviation process in the calcareous soils of the arid regions of the eastern Isfahan was probably in response to Quaternary moist conditions. There was no significant difference between clay coating propert
Soil salinity and its mapping are of great importance in arid and semiarid regions, especially where continued monitoring of soil salinity changes is costly. The aim of the present paper was to compare measured error resulted from calibration equations in different sampling campaigns and their use in soil salinity prediction with soft data in several time instants. Study area was located in western part of Urmia Lake, northwest Iran. Soil samples were taken from 0-20 cm during seven sampling campaigns between 2009-2015. Samplings were done on a grid of 500 meters for the first sampling campaigns and 250 meters and less for other time intervals. Soil electrical conductivity was measured in the field for all times series and in the laboratory
Dust phenomenon is one of the biggest environmental problems in arid and semiarid regions. In these areas, lakes and wetlands are natural dust traps and core sampling method can be an appropriate way to assess the phenomenon of the dust. Therefore, the purpose of this study is the study of frequency and characteristics of dust sediments in core samples from Hashilan wetlands, Kermanshah. Four intact core samples were taken from different parts of the Hashilan wetland in Kermanshah. Physical, chemical and micromorphological analysis were done. Also clay mineralogy was performed using X-ray analysis (XRD) and shape of particles was photographed by scanning electron microscope (SEM). Considering that four samples had been taken from different
Geochemical weathering indices are widely used in evaluating the stage of soil development. However, their compatibility with Soil Taxonomic Classes has not been studied yet. This study was conducted in a hilly region to illustrate the relations between soil development indices and topographic attributes and Soil Taxonomic Classes. A grid sampling method was carried out with 100?m intervals. Physico-chemical analyses and total elemental analyses were performed on 184 and 56 soil samples respectively. In addition, eight topographic attributes and 12 common soil development indices were determined. Results showed that among the topographic attributes, slope gradient and topographic wetness index (TWI) had the highest correlation with Soil Tax
Soil complexity and its multivariable nature restrict the precision of soil maps that are essential tools for soil sustainable management. Most methods developed for reducing impurities of soil map units focus on soil external properties. Taking into account the soil internal properties like geochemical weathering indices could increase the map unit’s purity. However, the compatibility of these indices with Soil Taxonomic Classes has not been studied yet. This study has been performed in a hilly region with different soil types, vegetation and diverse topographic attributes to illustrate the spatial variability of soil weathering indices and their compatibility with Soil Taxonomic Classes. The grid sampling is at 100 m inte
Background and objectives : Zeolite is a group of anionic hydrated aluminosilicates with a tridimensional structure which has great implications in remediation of water, sediment and soil resources. The present research aims at physicochemical investigation, clay mineralogy and micromorphology of soils along Rafsanjan-Sarcheshmeh lithotoposequence, southeastern Iran. Materials and methods: The study area starts from mantled pediments, southern west of Rafsanjan and extends to Sarcheshmeh town. Soil moisture and temperature regimes of the area were aridic and mesic, respectively. Topography and geology maps together with Google Earth images were used to investigate different landforms and geological formations in the area. Mantled pediment (
An important part of carbon cycling carries out in the soil and land use changes including changes in forestlands affects the SOC storage and CO2 flux into the atmosphere. The impacts of conversion of deciduous to coniferous forest and rangeland on the storage, dynamics, and isotopic changes in soil organic carbon in Kelardasht region (north of Iran) were investigated. Three land uses with minimum distances were delimited using landsat images. After description and sampling of three pedons (> 100 cm), surface horizons (O, A and AB) at five points were sampled. Physicochemical properties, organic carbon storage, aggregate stability, physical fractionation (density and size fractions), functional groups of organic matter (FTIR spectrometry),
Identifying the border of saline lands is the first step to deal with the problem of salinity in these regions. This research was aimed to investigate the relationship between edaphic, climatic and vegetative factors in each habitat and its extension to other similar areas. In the current research, the vegetation types were detected by Landsat satellite images. For this purpose, a soil profile was dug in each vegetation type and where water was found, samples were analyzed. In addition, a number of soil profiles were dug in areas without vegetation. Results showed that half of the studied vegetation types grew on saline soils and the other half grew on non-saline soils. The soil of the study area was classified as saline and alkaline soils.
Microbial calcium carbonate, by bridging sand particles, can play an important role in sand dune stability. A study was carried out on the cementation of sand grains and infilling of pore spaces by CaCO3. Two bacterial species (Sporosarcina pasteurii and
Drying of Urmia Lake in the north-west of Iran threatens all the agricultural lands around the Lake. Therefore, soil salinity appears to be the major threat to the agricultural lands in the area. The aim of the present study was to investigate the spatial variation of top soil salinity by taking into account of underground water quality data as secondary information. The research was performed on a grid of 500 m in an area of 5000 ha. Soil samples were gathered during the autumn of 2009 and were repeated in the spring of 2010. Electrical conductivity of soil samples was measured in a 1: 2.5 soil to water suspension. Then covariance functions were build for each data set and soil salinity prediction were done on a grid of 100 m using kriging
Biocalcite infilling and bridging in a sandy soil was studied in the present research. Effects of 2 bacterial species (Sporosarcina pasteurii and Sporosarcina ureae), 3 reactant concentrations (0.5, 1.0, and 1.5 M of urea and CaCl 2 mixture), and 6 reaction times (12, 24, 48, 96, 192, and 288 hr) on saturated hydraulic conductivity and mechanical strength of a sandy soil were studied as a factorial experiment. Soil samples were selected from sand dunes of Joopar area, Kerman Province. Bacterial inoculums and reactant solutions were daily added to soil columns. Results of the study showed that S. pasteuriihad had a higher effect on decreasing hydraulic conductivity of the treated samples (11.57 cm/h) compared to the blank (41.61 cm/h) than S