Tools - ADOT/USGS Partnership
Tools - ADOT/USGS Partnership
The partnership between USGS and ADOT has allowed for rapid installation of gages and sensors to monitor stages of stormwater runoff, peak flow, velocity, and magnitude among other hydrologic parameters, as well as timely surveys of channel and bank topography to inform bank stabilization projects and bridge and culvert design. Local and national transportation departments will likewise benefit from the increase in hydraulic data to inform hydraulic engineering design and from the opportunity the data provides to more efficiently and effectively manage and maintain infrastructure to ensure public safety.
The accuracy of modeling depends in part on the quality of the observations and on the process of data assimilation. To improve modeling dynamics the model must know the state of the conditions before, during and after events. By having most of the inputs in the model data assimilation numerical forecasting can deliver what can be referred to as a “first guess.” If the initial conditions used in the model contain significant errors, the errors can magnify by the extent of the observed data. This in turn can encourage the continued design input usage of standard given 25, 50, 100 year parameters.
Therefore, the addition of real-time data, computing power, numerical modeling and improved GIS can now allow for better initial condition inputs and superior prediction reliability.
Data Collection and Storage
ScienceBase Database - The one stop shop – the database houses and publishes the partnerships work. As water data collection, 1-D, 2-D, 3-D modeling, and UAS and terrestrial LiDAR land survey possess very big data sets, the need to house all of this was possibly the most important part of all. It will house links/data so that all the end users will have direct access to the complete datasets that are collected at all sites. The GPS and total station survey data will be within ScienceBase. This may also be the storage spot for velocity video going forward. Links within ScienceBase to USGS national hydraulic database will direct the user to be able to download all the depth data from all the sensors, velocity data, discharge, and all the other hydraulic data we collect at the site.
EROS Database - Earth Resources Observation and Science (EROS) - USGS has done great work to streamline the large data set transfer, storage, sharing process problem and come up with a national USGS procedure to store/publish these data. Using USGS Arizona geographers and hydrographers as a resource, EROS creates all the metadata for all the drone derived projects and store it on USGS servers for viewing and downloading. That way all users will know exactly how each product was collected/processed/published. Our sciencebase webpage will have links to all the site specific information that relates to all the other hydraulic data we have collected so that users can easily piece together and download the complete datasets.
Rapid Deployment Streamgage
A Rapid Deployment Gage (RDG) was installed on the bridge structure on U.S. Highway 160 at Laguna Creek to monitor streamflow from February to September 2016. The RDG is a self-contained unit of precision streamflow monitoring equipment that is designed to be deployed quickly at sites of interest, for example, in the event of a flood. The streamgage consists of a battery powered electronic data logger that records the water level (stage) in the stream using a non-contact radar sensor. The recorded data are transmitted via GOES satellite to provide real-time results through the internet to USGS cooperators, including ADOT, and the public at large. Streamflow data is critical to understanding the hydrologic and hydraulic properties at a site.
Non-Contact Velocity Radar Sensor
A newly developed velocity sensor was deployed in conjunction with the RDG streamgage. The sensor measures the velocity of the water at the stream surface during periods of flow without coming in direct contact with the water column. The ability to constantly measure stream velocity allows for a more robust data set that can improve gage records, provide calibration data for velocity mapping techniques, and provide calibration data for streamflow modeling. A velocity radar typically measures a relatively small area of the channel surface and is installed over an area of the river channel where the highest velocities are expected. The ability to constantly measure stream velocity ensures a more robust dataset that can improve streamgage records and provides calibration data for velocity mapping techniques and streamflow modeling.
Video Camera and Particle Tracking Data Collection
Video cameras were installed at the Laguna Creek streamgage to record video of the streamflow directly downstream of the bridge and along the right bank directly upstream of the bridge. The video cameras are activated by the streamgage’s electronic data logger when the water level sensed by the streamgage exceeds a predefined threshold. The recorded videos provide documentation of streamflow and erosion events; and are also used to calculate water-surface velocity using Large-Scale Particle Image Velocimetry (LSPIV) techniques, which are then used to compute streamflow at the streamgage.
Video for Surface Velocity Measurements
Image velocimetry through videography and large-scale particle image velocimetry (LSPIV) techniques can be used to calculate surface velocity and therefore streamflow. LSPIV software splits streamflow video into its component still frames and compares the individual images, identifying surface features moving through the images of streamflow, such as waves and debris. Unaided, the software can only detect the presence of movement; it cannot directly quantify the absolute distance a particle has moved. However, combined with predetermined, measured, channel geometry, the software can orthorectify the video to determine how far the particle has traveled between images and thus more accurately estimate surface velocity.
3D Land Surface Models
Ground based LiDAR (LIght Detection And Ranging) scanning equipment was used to scan the river channel around the bridge at Laguna Creek. The scanning equipment provides high resolution point cloud data that is used to generate land surface and vegetation models. The baseline scan data of the river channel can be compared with future scans to accurately measure changes in the river banks after a flow has occurred. Land surface models can also be used within 2D hydraulic software to model streamflow (discharge, stream depth, stream velocity, shear stress, etc.) and further calibrate the streamgage to a wider range of flows. These ground based LiDAR models can be combined with stereophotogrammetric (overlapping photography) models created using data collected from small unmanned aerial vehicles (sUAS). These combined data sets can be used to evaluate channel changes following streamflow events. The sUAS captured data can be collected relatively quickly and processed within a few days to generate new land-surface models after each flight. Air based data collection provides the ability to collect land surface data on a much larger scale and at a much lower cost compared to collecting large data sets using traditional surveying methods. One example is the ability to produce erosion change mapping where several ground or air based scans can be overlayed to detect erosion activity.
Scour chains were installed in the channel underneath the bridge structure on Laguna Creek. The scour chains were driven vertically into the bed to depths of 3 to 6 feet. Acceleration data loggers (tilt sensors) were attached to the upper end of each chain to document the timing and duration of scour during a flow event. After an event, maximum scour depth at the chain locations can be determined by measuring the length of chain exposed during the event, which should be evident because the chain will be in an orientation other than vertical at this depth.
Indirect Measurement of Discharge
Indirect measurements of peak discharge are conducted at rivers where direct measurements were not possible to obtain. Indirect measurements are conducted by surveying the stream channel at multiple cross-sections in the river reach, surveying the peak water-surface elevation as evidenced by high water marks left during the event, and estimating channel roughness present within each cross section. These data are used to calculate the peak discharge of the flood using the slope-area method. The estimates of peak flows can then be used to further calibrate the streamgage and also can be used in statistical watershed analyses.
Streamstats 4.0 for calculation of peak-flow statistics at ungaged stream locations
The USGS Streamstats 4.0 tool is available online for Arizona and now supports calculation of flood frequency statistics at ungaged locations on streams using the regression equations updated as described in Methods for Estimating Magnitude and Frequency of Floods in Arizona. The Streamstats tool also facilitates the calculation of a variety of basin and climate characteristics.
The 4.0 interface contains a number of improvements including multiple map layers. If you haven't already been using it, be sure to follow the steps on the left of the program window as those guide through how to delineate a basin and calculate flow statistics and basin characteristics.
New beta version of USGS real-time water data pages
One of the key science products of the AzWSC and USGS nationally is publically-available streamflow, groundwater, and water-quality data served through our Water Data webpages and available in real time. The current web interface has been serving these data since the mid-1990s but much has changed in the meantime, most notably through the proliferation of mobile computing devices and cellular data availability.
Accordingly, the USGS has released a beta version of the next generation USGS Water Data for the Nation website. The "classic" pages will remain available until all concerns and needs of users are addressed but the new pages are available now and are both modern in approach and mobile device friendly. Please use these pages as is beneficial to you and if you'd like to provide feedback, it can be sent to me or submitted using the form linked at the top of the data pages.
The new pages can be most easily accessed through a link at the top of current "classic" gage data pages that states "Important: next Generation Station Page".