Determination the grain-size of riverbed material using image processing technique instead of expensive and time-consuming traditional soil mechanics experiments for river engineering studies
This Research With 172 Page And PDF Format Ready To Download
Determination the grain-size of riverbed material using image processing technique instead of expensive and time-consuming traditional soil mechanics experiments for river engineering studies abstract
River engineering studies require particle size distribution for modeling
hydraulic and sediment transport in order to simulate and predict changes in the
streams using numerical modeling techniques. Due to difficulties and problems
in field sampling from different parts of the riverbed and to perform timeconsuming
and expensive soil mechanics analysis, it seems that image processing
techniques development is very important to obtain information needed for river
modeling. In this research, an algorithm was developed in MATLAB software to
process images of the riverbed and extraction of the characteristics of the
riverbed surface grain-size. Pre-processing operation has been performed prior to
the image processing using ImageJ Software. To evaluate the developed
algorithm, a 5-km length of Sirch River located in the North East of Kerman was
photographed and 13 images were taken in dry and shallow water flow conditions
using four different cameras with resolutions of 6, 10, 12.1, and 14 megapixels.
Images were taken in two different square frame sizes 0.5 and 1 meter then the
curves obtained from image processing were evaluated. The results of image
processing showed that photographs should not captured whilst sunrise or sunset
when the sunlight angularly strikes the earth's surface. Our studies indicate a
direct relationship among the image dimensions parameters (frame), the
resolution of the camera and its distance from the riverbed in a way by reducing
the resolution of the camera in a fixed frame, the distance of the camera to the
riverbed must be increased and vice versa. It should be noted that water depth
and reflection of sunlight should be low and also water fluctuation should be
negligible in the imaging of the riverbed below water surface. According to the
results, in case of the rivers that have relatively uniform grain-size distribution,
any camera can be used. However, it is better to use low and high resolution
cameras, in the rivers with coarse or fine riverbeds, respectively.
فهرست مطالب Research
Determination the grain-size of riverbed material using image processing technique instead of expensive and time-consuming traditional soil mechanics experiments for river engineering studies Keywords:
Determination the grain-size of riverbed material using image processing technique instead of expensive and time-consuming traditional soil mechanics experiments for river engineering studies authors