Field Assessment of Automatic Device Performance for Estimating the River Suspended Sediment Concentration based on Opto-Electronic Technology

Nowadays, issues related to soil erosion are one of the most critical issues and one of the major concerns in watershed management. Accordingly, knowledge on soil erosion process at watershed scale needs proper, suitable, accurate, and desirable temporal resolution data collection using appropriate device. An innovative device is designed and manufactured through this research for automatic sampling and measuring suspended sediment concentration. This aimed at a better understanding of the processes of soil erosion and sediment yield through better time-distributed measurements. The background of studies and research related to the project has been reviewed worldwide and based on previous experiences, manufacturing the mechanical part of the system was carried out and completed. Also, the necessary laboratory practices for designing, formulating, and simulating the electronic parts were performed. Numerous tests and attempts were made to optimize the mechanical and opto-electronic parts based on determining different arrangements and sources of light. The field test of the device in several rivers in the northern Iran indicated a high agreement of more than 93.25% between the observed and estimated suspended sediment concentrations. The designed sampler is expected to provide suitable estimates on concentration of suspended sediment in the dominant range in watercourses with acceptable, affordable cost and energy, particularly in special conditions such as floods, in the entire day and night hours, and even for remote areas.