Salman Mirzaee; Shoja Ghorbani Dashtaki; Jahangard Mohammadi; Hossein Asadi; Farokh Asadzadeh
Abstract
Understanding the spatial distribution and variability of erodibility and soil properties is essential for planning of water conservation methods, controlling of flood and runoff and managing of soil erosion or watershed. Selecting and using appropriate interpolation techniques for soil properties and ...
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Understanding the spatial distribution and variability of erodibility and soil properties is essential for planning of water conservation methods, controlling of flood and runoff and managing of soil erosion or watershed. Selecting and using appropriate interpolation techniques for soil properties and erodibility mapping by erosion models such as WEPP is essential. The objective of this study was regionalization of interrill erodibility and effective factors like clay, organic matter and lime using kriging and cokriging and remote sensing data (Landsat 7). For this purpose, 100 soil samples were selected randomly from 0-15 cm depth of Selin watershed in Kaleibar region of East Azerbaijan. Interrill erodibility of WEPP model and some soil properties as clay, organic matter and lime were measured. Correlation analysis between soil properties and digital number (DN) ETM+ image showed that clay, organic matter, lime and interrill erodibility had the highest correlation with DN of Band 7, 1, 1 and 3 ETM+ image (−0.406, -0.431, 0.291 and 0.299), respectively. Therefore, the DN of these bands used as auxiliary data for cokriging estimator. The spherical model was fitted the best model to calculate variogram of interrill erodibility, clay, organic matter and lime. No significant difference were noted between kriging and cokriging despite using remote sensing data as auxiliary data. This can be attributed no strong correlation between interrill erodibility, clay, organic matter and lime and remote sensing data.
Leila Mehdizadeh; Farrokh Asadzadeh; Abbas Samadi
Abstract
Particle size distribution of sediment is one of the key factors which affects many other physical and chemical characteristics of the sediments. In this study, particle size distribution of the sediments trapped behind successive check dams was evaluated. Two waterways (G1 and G2) were selected in Noshan ...
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Particle size distribution of sediment is one of the key factors which affects many other physical and chemical characteristics of the sediments. In this study, particle size distribution of the sediments trapped behind successive check dams was evaluated. Two waterways (G1 and G2) were selected in Noshan region of Urmia which have three and four check dams respectively. In each waterway, particle size distribution of sediment samples was compared with the original soil of the adjacent hill slope. Results indicated that the sediments have loamy-sand to sandy texture and have coarser particles than the adjacent soil samples. Selective deposition of sediment particles was observed in half full successive check dams of G1 waterway and the sediments of the check dam located at the downstream have a similar particle size distribution with adjacent soil sample. In filled dams of G2 waterway, considerable amounts of particles coarser than 0.124 mm in diameter were passed through dams. Some mathematical models were used to describe the particle size distribution of sediment samples and performance of them was evaluated by several efficiency criteria. Hierarchical cluster analysis of models, based on selected efficiency criteria, indicated that the Fredlund, ORL and ONL models have good performance in describing the particle size distribution of sediment samples. Coefficient of determination for these models was 0.99 and the Akaike’s Information Criterion (AIC) for these models were -44.13, -43.92, and -41.46 respectively. It can be concluded that these models are applicable for quantifying the particle size distribution of sediment samples.
