Monitoring sediment accumulation in urban drainage systems with temperature measurements

Paper presented at NOVATECH 2023

Abstract:

Measuring sediment accumulation in urban drainage systems is still a challenge. Existing options include punctual inspection campaigns or solutions with high installation and maintenance costs. This work shows that through temperature measurements and the analysis of heat transfer processes in urban drainage systems it is possible to monitor sediment accumulation in sewer pipes as well as gully pots. As both systems show similar heat transfer processes at the sediment bed layer, the idea is to identify the sediment thickness from temperature differences in the water layer and the bottom of the sediment layer as well as applying physically-based heat transfer models. To obtain satisfactory predictions, we also developed experimental methods with active heating to characterize the thermal properties of different sediments. As an innovative result, references were provided for the thermal properties of organic sediments. Our results suggest that sediment thickness can be estimated with an accuracy of ±0.5 cm. The next steps include validating this methodology in real environments. Ultimately, the results illustrate the potential of these low -tech and -cost measurements to monitor sediments in urban drainage systems to optimise inspection and cleaning strategies.