மின் பொறியியல் மற்றும் மின்னணு தொழில்நுட்ப இதழ்

Morphological River Changes by using Satellite Images

Donatella Termini

The processes controlling the fluvial morpho dynamics have been the focus of research seeking to evaluate river’s dynamics. The knowledge of the river’s pattern changes is fundamental in designing adequate restoration projects and in preserving the ecological equilibrium in fluvial environment and neighboring areas. Some researchers [among others 1, 2] exalted the role of vegetation on river’s dynamics, others [see as an example 3] suggest to consider the flood effects as fundamental to understand the controlling processes on fluvial morphology. The difficulty in investigating the controlling mechanisms of river’s dynamism is related to the difficulty in stream monitoring: many river floodplains are inaccessible and often densely vegetated [4, 5, 6]. Over the last two decades the use of technologies such as near-infrared Light Detection and Ranging (LIDAR) and Experimental Advanced Airborne Research LIDAR (EAARL) has improved our ability to map of sub-aerial topography and fluvial environments. But, these technologies has shown uncertainties in rivers because of the reflection in the air-water interface. Image-based techniques (LSPIV) have been increasingly used for surface velocity measurements in field. These techniques are non-intrusive and allow obtaining simultaneous spatial information about the instantaneous velocity components also in unsteady flows. Thus, it is possible to yield a large amount of data in a rather short measuring time and to calculate simultaneously the average values for identical spatial windows over many images.