Flow quantification during urban floods, applying LSPIV

Abstract

In the last years, the probability of occurrence of urban floods has increased significantly. Recently, scientists have published several articles related to specific problems generated by surface runoff during urban floods, as for example, harmful effects on urban infrastructure produced by flooding and the negative impacts produced by the high flow velocities to people, roads and vehicles. Most published works are based on research based in numerical models and small scale physical models (the latter have scale effects). The methodology used in this work, which preserves the safety of staff and the reliability of the measurements, consists in implementing large-scale particle image velocimetry (LSPIV). In addition it is proposed to adapt this technology for implementation with amateur digital videos, generally made by neighbors during flood events using different electronic devices (cell phones, digital cameras, etc.). The method allows, from digital images recorded in these devices, calculate the superficial flow velocity fields, the transverse velocity distribution, the flow discharge, etc. The results presented in this work correspond to different urban flash floods in the urban area of Gran Asuncion, Paraguay (Arroyo Lambare and others). Finally it is proposed to use the results measured in the field for the future design of structural and non-structural management measures required to mitigate the flow risks.