Abstract
This paper explores the potential of the joint application of unmanned aerial vehicle (UAV)-based photogrammetry and an automated sensor network for building a hydrodynamic flood model of a montane stream. UAV-based imagery was used for three-dimensional (3D) photogrammetric reconstruction of the stream channel, achieving a resolution of 1.5 cm/pixel. Automated ultrasonic water level gauges, operating with a 10 min interval, were used as a source of hydrological data for the model calibration, and the MIKE 21 hydrodynamic model was used for building the flood model. Three different horizontal schematizations of the channel—an orthogonal grid, curvilinear grid, and flexible mesh—were used to evaluate the effect of spatial discretization on the results. The research was performed on Javori Brook, a montane stream in the Sumava (Bohemian Forest) Mountains, Czech Republic, Central Europe, featuring a fast runoff response to precipitation events and that is located in a core zone of frequent flooding. The studied catchments have been, since 2007, equipped with automated water level gauges and, since 2013, under repeated UAV monitoring. The study revealed the high potential of these data sources for applications in hydrodynamic modeling. In addition to the ultra-high levels of spatial and temporal resolution, the major contribution is in the method’s high operability, enabling the building of highly detailed flood models even in remote areas lacking conventional monitoring. The testing of the data sources and model setup indicated the limitations of the UAV reconstruction of the stream bathymetry, which was completed by the geodetic-grade global navigation satellite system (GNSS) measurements. The testing of the different model domain schematizations did not indicate the substantial differences that are typical for conventional low-resolution data, proving the high reliability of the tested modeling workflow.
Highlights
The rapidly evolving techniques for the precise surveying and monitoring of dynamic processes are providing new types of data for hydrological research with the potential for obtaining a better explanation of the dynamics of hydrological and fluvial processes [1]
Such an ultra-high resolution of the topography can be achieved at the complex segments, which allows for the development of channel models covering the processes for functional stream and floodplain segments, which allows for the development of channel models covering the units of the riverscape
Despite the high accuracy of the data derived from aerial Light Detection And Ranging (LiDAR) scanning [37,38] and their satisfactory resolution for general morphometric analyses, the qualitative leap in the data density satisfactory resolution for general morphometric analyses, the qualitative leap in the data density in in the DEM derived from the unmanned aerial systems (UASs) is substantial (Figure 15)
Summary
The rapidly evolving techniques for the precise surveying and monitoring of dynamic processes are providing new types of data for hydrological research with the potential for obtaining a better explanation of the dynamics of hydrological and fluvial processes [1]. In hydrological research, these are applied mainly to the acquisition of accurate and up-to-date spatial information on the riverscape and to the automated monitoring of hydroclimatic processes with high precision and a high sampling frequency [2]. The appropriate spatial and temporal discretization and model conceptualization could significantly reduce the uncertainties in the description and in modeling runoff and fluvial processes [3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
