Kamal Nabiollahi; Ahmad Haidari
Abstract
Arsenic has been recognized as a toxin element for human. Minerals frequency can affect on arsenic content and Sufficient mineralogical characterization of contaminated sites should assist geochemical models that assess the potential of natural attenuation remediation of a subsurface contaminated with ...
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Arsenic has been recognized as a toxin element for human. Minerals frequency can affect on arsenic content and Sufficient mineralogical characterization of contaminated sites should assist geochemical models that assess the potential of natural attenuation remediation of a subsurface contaminated with arsenic. In order to mineralogy investigation in the arsenic soil in Bijar area, 83 profiles were selected based on the prepared geopedology map and 229 soil and 15 parent material samples were collected. Routine physical and chemical characteristics and soil arsenic contents were measured in all samples. Relative quantity and types of clay and powder minerals were determined for 35 soil and 15 parent material samples by XRD analysis. Smectite, illite, kaolinite, chlorite and vermiculite were the most important clay minerals in the region. enargite, arsenoilte, sphalerite, nicoolite, conichalcite, arsenosulvanite and cobaltite based on the powdery mineralogy results were the most important arsenic bearing minerals in the region. The type and content of minerals were different and their content were higher in the profiles with very high arsenic. In the mudston and Fe-rich rock arsenic concentration are higher compared to the other parent materials. Also the minerals content were higher in the mudston and Fe-rich rock compared to the other parent materials.
Maral Khodadadi; Mohammad Sadegh Askari; Fereydoon Sarmadian; Hossein Gholi Refahi; Ali Akbar Norouzi; Ahmad Heidari; Hamid Reza Matinfar
Volume 1, Issue 2 , July 2009, , Pages 99-110
Abstract
Salinity is the major factors of soil degradation in semi arid and arid regions. The main aim of this study was to evaluate the capability of Landsat ETM+ data for soil Salinity mapping in the selected part of the Qazvin plain, an area of arid environment. In this study spectral classes carried out on ...
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Salinity is the major factors of soil degradation in semi arid and arid regions. The main aim of this study was to evaluate the capability of Landsat ETM+ data for soil Salinity mapping in the selected part of the Qazvin plain, an area of arid environment. In this study spectral classes carried out on remotely sensed data and with the help of field observation and soil analysis were regrouped to soil salinity classes to prepare soil salinity map.. Soil sampling was implemented using stratified random sampling method, depending on landscape complexity and homogeneity as well as on the representativeness of Landsat ETM+ data. Also in each soil map unit at least one profile was studied for subsoil salinity variations. Field samples taken by using augur and profiles were analyzed in laboratory for Na+ , Ca2+ , Mg2+ cations, as well as soil texture, ECe and pH. We have analyzed the effectiveness of additional data such as digital elevation model to improve the accuracy of classification. Also NDVI, SRVI, PVI, SAVI, SI, BI and NDSI indices, PCA and Tasseled cap were analyzed. Soil salinity map of each selected bands produced and with ground truth map crossed. The results indicated that combination of DEM with ETM+ bands has highest accuracy. This study addressed that thermal band of ETM+ can increase the classification accuracy which illustrated its effective role to classify the soil salinity. Tasseled cap and other indices had almost high accuracy among studied image processing techniques. The SI and BI indices had the highest correlation with EC and could distinguish the saline and non saline soils while the optimum index factor had overall low accuracy.
