2017 年 23 巻 p. 233-238
Small and medium rivers have characteristics that are susceptible to localized and extreme precipitation. Therefore, the hydrologic data is important for river management of small and medium rivers. However, there are some problems which the shortage of financial resources for river management and chronic shortage of observer at the flood condition. In this study, the authors developed an unmanned river flow velocity measurement system using the space-time image velocimetry(STIV) on small and medium rivers using a low cost trail camera used for monitoring animals and plants. In addition, this camera could be taken a shot all day because it had the function that near-infrared image. Measurement results in four different rivers were within ± 10% error compared with the approval flow meter. This method is an effective method for river management of small and medium rivers.