Abstract:With the rapid development of computer vision and remote sensing technologies, video image flow measurement has become a research hotspot in hydrological measurement. This paper expounds the technical principles, research progress and application scenarios of Large-Scale Particle Image Velocimetry (LSPIV), Space-Time Image Velocimetry (STIV) and deep learning-based flow estimation methods, and compares their advantages and limitations. The results show that LSPIV is applicable to scenarios requiring high precision, STIV boasts outstanding efficiency in wide river channel monitoring, and deep learning provides new ideas for non-contact flow measurement under complex environments. Future studies shall break through the bottlenecks of environmental interference and algorithm efficiency, promote the integration of multi-source data and the development of adaptive algorithms.