#Ephemeral stream portable

Since the pioneering work by Takagi et al. In river systems, imagery has opened novel capabilities towards water level measurement in ephemeral settings (Schoener 2018). ( 2019) adopted time-lapse photography to show the absence or presence of flow in ephemeral and intermittent streams through image processing.īesides the detection of the flow status, imagery can be effectively used to quantitatively estimate water level. With regards to water level detection, Kaplan et al.

#Ephemeral stream portable

Portable and permanent implementations of image-based systems have demonstrated the suitability of photogrammetric approaches to characterize the surface flow velocity field and monitor floods in natural streams (Tauro et al.

Therefore, optic systems are increasingly being installed in existing monitoring stations to complement information gathered with and to assess the performance of traditional equipment (Pagano et al. 2019).Ĭameras have the potential to afford remote and continuous observations of relatively extended areas without affecting the flow field. On the other hand, remote sensing has been proposed as an efficient approach to monitor large areas with spatially continuous and frequent coverage (Borg Galea et al. Unfortunately, in-person observations are time consuming, and sometimes impossible in impenetrable natural environments. To improve identification of the causes of intermittency and to expand monitoring capabilities, visual inspection is often mandatory. In addition, most of these systems only allow researchers to distinguish between wet and dry conditions, without any additional information on the flow magnitude. Notably, ambiguities in detecting zero-flow readings have been shown to have far-reaching implications for hydrological and biogeochemical predictions (Leigh et al. ( 2020).ĭata collected from temperature-based or EC systems can be affected by the accuracy of positioning of the sensor at the deepest point in the channel cross-section and are generally difficult to interpret. A combination of electrical conductivity (EC) sensors, time-lapse imagery, and conventional gauging afforded monitoring at high spatio-temporal resolution in Assendelft and van Meerveld ( 2019) and van Meerveld et al. They include temperature sensors (Constantz 2008) and electrical resistance sensors (Peirce and Lindsay 2015, Jensen et al. Alternative methodologies have been conceived to automatically monitor the presence of water in ephemeral streams. Such passive instrumentation can be deployed onto the soil surface and then manually checked to assess the presence or absence of water. ( 1976) and modified versions have been applied in several field studies (Vertessy and Elsenbeer 1999, Elsenbeer and Vertessy 2000, Vertessy et al. Overland flow detectors were developed by Kirkby et al. Monitoring flow in headwater streams is key to unravelling the complex relationships between climatic and landscape features in temporary rivers.Ĭonventional observational approaches, including streamgauges and current meters, may often be inadequate to monitor streamflow in these dynamic and highly heterogeneous systems where highly variable cross-sections and water levels often hinder their applicability (Tauro et al. Seasonal and event-based variability of the climatic forcing in these uppermost catchment areas often originates intermittent and ephemeral streams, whereby discontinuous flow or sporadic flow in response to rainfall events poses severe challenges to a thorough characterization of network patterns (Borg Galea et al. Headwater streams govern runoff formation and debris/sediment mobilization, and thus are important controls for the ecological and geomorphic dynamics of catchments (Bishop et al. Our preliminary results are encouraging and support the scalability of the stage-camera in future implementations in a wide range of natural settings.

Maximum mean absolute errors between stage-camera and reference data are approximately equal to 2 cm in the worst scenario that corresponds to severe storms with intense rainfall and fog. The feasibility of the approach is demonstrated through a set of benchmark experiments performed in natural settings. The system encompasses a consumer-grade wildlife camera with near-infrared (NIR) night vision capabilities and a white pole that serves as reference object in the collected images. Motivated by the latest advancements in digital cameras and computer vision techniques, in this work, we describe the development and application of a stage-camera system to monitor the water level in ungauged headwater streams. On-site inspections may be impractical in difficult-to-access environments. Monitoring ephemeral and intermittent streams is a major challenge in hydrology.