Discharge Estimation with the Use of Unmanned Aerial Vehicles (UAVs) and Hydraulic Methods in Shallow Rivers

Although river discharge is essential hydrologic information, it is often absent, especially for small rivers and remote catchment areas. Practical difficulties frequently impede the installation and operation of gauging stations, while satellite-sensed data have proved to be relatively useful only...

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Main Authors: Sergios Lagogiannis, Elias Dimitriou
Format: Article
Language:English
Published: MDPI AG 2021-10-01
Series:Water
Subjects:
Online Access:https://www.mdpi.com/2073-4441/13/20/2808
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author Sergios Lagogiannis
Elias Dimitriou
author_facet Sergios Lagogiannis
Elias Dimitriou
author_sort Sergios Lagogiannis
collection DOAJ
description Although river discharge is essential hydrologic information, it is often absent, especially for small rivers and remote catchment areas. Practical difficulties frequently impede the installation and operation of gauging stations, while satellite-sensed data have proved to be relatively useful only for discharge estimation of large-scale rivers. In this study, we propose a new methodology based on UAV-sensed data and photogrammetry techniques combined with empirical hydraulic equations for discharge estimation. In addition, two different riverbed particle size distributions were incorporated, to study the effect of fine sediment inclusion (or exclusion) in the estimation process. Accordingly, 17 study sites were selected and six different approaches were applied in each. Results show that at 75% of sites at least one approach produced an accurate discharge estimation, while in 10 out the 17 sites (58.8%) all six approaches produced accurate estimations. A strong correlation between a threshold value for the hydraulic radius (<i>Rh</i> = 0.3 m) of cross-sections and high estimation errors for sites exceeding it was also observed. The fine sediment inclusion improved only the performance of certain approaches and did not have a consistently positive effect. Overall, the relatively high percentage of sites with satisfactory discharge estimates indicates that using UAV-derived data and simple hydraulic equations can be used for this purpose, with an acceptable level of accuracy.
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spelling doaj.art-9c72ab6759724d72b8cc2fb839a64da92023-11-22T20:21:02ZengMDPI AGWater2073-44412021-10-011320280810.3390/w13202808Discharge Estimation with the Use of Unmanned Aerial Vehicles (UAVs) and Hydraulic Methods in Shallow RiversSergios Lagogiannis0Elias Dimitriou1Department of Water Resources and Environmental Engineering, National Technical University of Athens, 15780 Athens, GreeceHellenic Centre for Marine Research, Institute of Marine Biological Resources and Inland Waters, 19013 Anavyssos, GreeceAlthough river discharge is essential hydrologic information, it is often absent, especially for small rivers and remote catchment areas. Practical difficulties frequently impede the installation and operation of gauging stations, while satellite-sensed data have proved to be relatively useful only for discharge estimation of large-scale rivers. In this study, we propose a new methodology based on UAV-sensed data and photogrammetry techniques combined with empirical hydraulic equations for discharge estimation. In addition, two different riverbed particle size distributions were incorporated, to study the effect of fine sediment inclusion (or exclusion) in the estimation process. Accordingly, 17 study sites were selected and six different approaches were applied in each. Results show that at 75% of sites at least one approach produced an accurate discharge estimation, while in 10 out the 17 sites (58.8%) all six approaches produced accurate estimations. A strong correlation between a threshold value for the hydraulic radius (<i>Rh</i> = 0.3 m) of cross-sections and high estimation errors for sites exceeding it was also observed. The fine sediment inclusion improved only the performance of certain approaches and did not have a consistently positive effect. Overall, the relatively high percentage of sites with satisfactory discharge estimates indicates that using UAV-derived data and simple hydraulic equations can be used for this purpose, with an acceptable level of accuracy.https://www.mdpi.com/2073-4441/13/20/2808unmanned aerial vehiclesremote sensingdischarge estimationshallow riversfine sedimentparticle size distribution
spellingShingle Sergios Lagogiannis
Elias Dimitriou
Discharge Estimation with the Use of Unmanned Aerial Vehicles (UAVs) and Hydraulic Methods in Shallow Rivers
Water
unmanned aerial vehicles
remote sensing
discharge estimation
shallow rivers
fine sediment
particle size distribution
title Discharge Estimation with the Use of Unmanned Aerial Vehicles (UAVs) and Hydraulic Methods in Shallow Rivers
title_full Discharge Estimation with the Use of Unmanned Aerial Vehicles (UAVs) and Hydraulic Methods in Shallow Rivers
title_fullStr Discharge Estimation with the Use of Unmanned Aerial Vehicles (UAVs) and Hydraulic Methods in Shallow Rivers
title_full_unstemmed Discharge Estimation with the Use of Unmanned Aerial Vehicles (UAVs) and Hydraulic Methods in Shallow Rivers
title_short Discharge Estimation with the Use of Unmanned Aerial Vehicles (UAVs) and Hydraulic Methods in Shallow Rivers
title_sort discharge estimation with the use of unmanned aerial vehicles uavs and hydraulic methods in shallow rivers
topic unmanned aerial vehicles
remote sensing
discharge estimation
shallow rivers
fine sediment
particle size distribution
url https://www.mdpi.com/2073-4441/13/20/2808
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AT eliasdimitriou dischargeestimationwiththeuseofunmannedaerialvehiclesuavsandhydraulicmethodsinshallowrivers