Document Type : Research Paper
Authors
1 Professor, Faculty of Natural Resources, Tarbiat Modares University, Iran
2 MSc Student, Faculty of Natural Resources, Tarbiat Modares University, Iran
Abstract
Awareness of particle size distribution of river bed material plays an important role in studies of the organizing and analysis behavior of rivers. The traditional separation of particle sediments needs a lot of cost, time and fieldwork. Therefore, new methods such as image processing separation, is essential for studies on particle size distribution of riverbed sediments. It is necessary to maintain standards in reach to the goals and to justify the adoption of a new separation technique. Accordingly, the resolution of the camera is very important for standard image processing. However, it has not been considered, yet. Hence, the present study aimed to analyze the accuracy of the particle size distribution of bed sediments using the image processing of image taken by cameras with different resolutions. For this purpose, variety of cameras were applied to provide images with different resolutions. The direct samplings and measurement was also conducted for comparison purposes. The results showed that cameras with 3 and 10 megapixel resolutions had the highest and the lowest consistency with observed data with respective correlation coefficients of 0.65 and -0.51 for coarse sediment. The cameras with resolutions of 16 and 18 megapixel also had the highest and the lowest agreement with the observed data with correlation coefficients of 0.88 and 0.69 for fine-grained sediments, respectively. In principle, the results suggested that the most appropriate camera for image processing purposes born 10 to 16 megapixels of resolution. However, coarse-grained sediments ranged from 10 to 107 mm in diameter with the respective highest and the lowest standard deviation and mode of 98.455 and 89.7, and 21 and 14. The fine-grained sediments also ranged from 10 to 57 mm in diameter with the highest and the lowest standard deviation and mode of 33.143 and 17.10, and 12 and 48, respectively.
Keywords
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