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As reported in the recent image velocimetry literature, tracking the motion of sparse feature points floating on the river surface as done by the Optical Tracking Velocimetry (OTV) algorithm is a promising strategy to address surface flow monitoring. Moreover, the lightweight nature of OTV coupled with computational optimizations makes it suited even for its deployment in situ to perform measurements at the edge with cheap embedded devices without the need to perform offload processing. Despite these notable achievements, the actual practical deployment of OTV in remote environments would require cheap and self-powered systems enabling continuous measurements without the need for cumbersome and expensive infrastructures rarely found in situ. Purposely, in this paper, we propose an additional simplification to the OTV algorithm to reduce even further its computational requirements, and we analyze self-powered off-the-shelf setups for in situ deployment. We assess the performance of such set-ups from different perspectives to determine the optimal solution to design a cost-effective self-powered measurement node.
Arsal-Hanif Livoroi; Andrea Conti; Luca Foianesi; Fabio Tosi; Filippo Aleotti; Matteo Poggi; Flavia Tauro; Elena Toth; Salvatore Grimaldi; Stefano Mattoccia. On the Deployment of Out-of-the-Box Embedded Devices for Self-Powered River Surface Flow Velocity Monitoring at the Edge. Applied Sciences 2021, 11, 7027 .
AMA StyleArsal-Hanif Livoroi, Andrea Conti, Luca Foianesi, Fabio Tosi, Filippo Aleotti, Matteo Poggi, Flavia Tauro, Elena Toth, Salvatore Grimaldi, Stefano Mattoccia. On the Deployment of Out-of-the-Box Embedded Devices for Self-Powered River Surface Flow Velocity Monitoring at the Edge. Applied Sciences. 2021; 11 (15):7027.
Chicago/Turabian StyleArsal-Hanif Livoroi; Andrea Conti; Luca Foianesi; Fabio Tosi; Filippo Aleotti; Matteo Poggi; Flavia Tauro; Elena Toth; Salvatore Grimaldi; Stefano Mattoccia. 2021. "On the Deployment of Out-of-the-Box Embedded Devices for Self-Powered River Surface Flow Velocity Monitoring at the Edge." Applied Sciences 11, no. 15: 7027.
This work intends to lay the foundations for a theoretical framework of citizen science combining social and organizational implications with the support of information technologies. The proposed theoretical framework moves towards a shared and common research process between experts and citizens to deal with environmental and social challenges. The role and capacity of online communities is explored and their engagement capacity by means of web-based digital platforms supporting crowdsourcing activities. In this contribution, authors highlight the most common practices, methods and issues of citizen science approaches adopted from multidisciplinary application fields to obtain insights for designing a new participative approach for organizational studies. To reach this goal, authors illustrate the results of a systematic meta-review analysis, consisting of an accurate selection and revision of journal review articles in order to highlight concepts, methods, research design approaches and tools adopted in citizen science approaches.
Andrea Spasiano; Salvatore Grimaldi; Alessio Braccini; Fernando Nardi. Towards a Transdisciplinary Theoretical Framework of Citizen Science: Results from a Meta-Review Analysis. Sustainability 2021, 13, 7904 .
AMA StyleAndrea Spasiano, Salvatore Grimaldi, Alessio Braccini, Fernando Nardi. Towards a Transdisciplinary Theoretical Framework of Citizen Science: Results from a Meta-Review Analysis. Sustainability. 2021; 13 (14):7904.
Chicago/Turabian StyleAndrea Spasiano; Salvatore Grimaldi; Alessio Braccini; Fernando Nardi. 2021. "Towards a Transdisciplinary Theoretical Framework of Citizen Science: Results from a Meta-Review Analysis." Sustainability 13, no. 14: 7904.
Widely available digital technologies are empowering citizens who are increasingly well informed and involved in numerous water, climate, and environmental challenges. Citizen science can serve many different purposes, from the “pleasure of doing science” to complementing observations, increasing scientific literacy, and supporting collaborative behaviour to solve specific water management problems. Still, procedures on how to incorporate citizens’ knowledge effectively to inform policy and decision-making are lagging behind. Moreover, general conceptual frameworks are unavailable, preventing the widespread uptake of citizen science approaches for more participatory cross-sectorial water governance. In this work, we identify the shared constituents, interfaces and interlinkages between hydrological sciences and other academic and non-academic disciplines in addressing water issues. Our goal is to conceptualize a transdisciplinary framework for valuing citizen science and advancing the hydrological sciences. Joint efforts between hydrological, computer and social sciences are envisaged for integrating human sensing and behavioural mechanisms into the framework. Expanding opportunities of online communities complement the fundamental value of on-site surveying and indigenous knowledge. This work is promoted by the Citizens AND HYdrology (CANDHY) Working Group established by the International Association of Hydrological Sciences (IAHS).
Fernando Nardi; Christophe Cudennec; Tommaso Abrate; Candice Allouch; Antonio Annis; Thaine Herman Assumpção; Alice H. Aubert; Dominique Bérod; Alessio Maria Braccini; Wouter Buytaert; Antara Dasgupta; David M. Hannah; Maurizio Mazzoleni; Maria J. Polo; Øystein Sæbø; Jan Seibert; Flavia Tauro; Florian Teichert; Rita Teutonico; Stefan Uhlenbrook; Cristina Wahrmann Vargas; Salvatore Grimaldi. Citizens AND HYdrology (CANDHY): conceptualizing a transdisciplinary framework for citizen science addressing hydrological challenges. Hydrological Sciences Journal 2021, 1 -18.
AMA StyleFernando Nardi, Christophe Cudennec, Tommaso Abrate, Candice Allouch, Antonio Annis, Thaine Herman Assumpção, Alice H. Aubert, Dominique Bérod, Alessio Maria Braccini, Wouter Buytaert, Antara Dasgupta, David M. Hannah, Maurizio Mazzoleni, Maria J. Polo, Øystein Sæbø, Jan Seibert, Flavia Tauro, Florian Teichert, Rita Teutonico, Stefan Uhlenbrook, Cristina Wahrmann Vargas, Salvatore Grimaldi. Citizens AND HYdrology (CANDHY): conceptualizing a transdisciplinary framework for citizen science addressing hydrological challenges. Hydrological Sciences Journal. 2021; ():1-18.
Chicago/Turabian StyleFernando Nardi; Christophe Cudennec; Tommaso Abrate; Candice Allouch; Antonio Annis; Thaine Herman Assumpção; Alice H. Aubert; Dominique Bérod; Alessio Maria Braccini; Wouter Buytaert; Antara Dasgupta; David M. Hannah; Maurizio Mazzoleni; Maria J. Polo; Øystein Sæbø; Jan Seibert; Flavia Tauro; Florian Teichert; Rita Teutonico; Stefan Uhlenbrook; Cristina Wahrmann Vargas; Salvatore Grimaldi. 2021. "Citizens AND HYdrology (CANDHY): conceptualizing a transdisciplinary framework for citizen science addressing hydrological challenges." Hydrological Sciences Journal , no. : 1-18.
Soil erosion during rainfall events is affected by several factors, such as topography, soil type, land management, and vegetation cover. In this study, a series of tests investigates the influence of selected perennial herbaceous plants with a deep and strong rooting system, called MC1, on runoff generation and soil erosion. The tests on the investigated nature-based solution have been performed in the Cape Fear experimental hillslope with natural and artificial rainfall and for different vegetation heights. For all the experiments, runoff, soil moisture, and erosion data were observed and collected. The results obtained in this study suggest the following conclusions: (1) MC1 is effective in terms of soil erosion reduction already with a minimum vegetation height equal to 30 cm; (2) MC1 maximum efficiency, in terms of soil loss reduction, has been reached for a vegetation height equal to 70 cm; (3) In terms of the eroded material, the use of MC1 allows for a reduction of soil loss up to 300 times higher than the bare soil condition; (4) The use of MC1 allows for a reduction in the runoff coefficient up to 1/3 of the corresponding value in the bare soil condition.
Ciro Apollonio; Andrea Petroselli; Flavia Tauro; Manuela Cecconi; Chiara Biscarini; Claudio Zarotti; Salvatore Grimaldi. Hillslope Erosion Mitigation: An Experimental Proof of a Nature-Based Solution. Sustainability 2021, 13, 6058 .
AMA StyleCiro Apollonio, Andrea Petroselli, Flavia Tauro, Manuela Cecconi, Chiara Biscarini, Claudio Zarotti, Salvatore Grimaldi. Hillslope Erosion Mitigation: An Experimental Proof of a Nature-Based Solution. Sustainability. 2021; 13 (11):6058.
Chicago/Turabian StyleCiro Apollonio; Andrea Petroselli; Flavia Tauro; Manuela Cecconi; Chiara Biscarini; Claudio Zarotti; Salvatore Grimaldi. 2021. "Hillslope Erosion Mitigation: An Experimental Proof of a Nature-Based Solution." Sustainability 13, no. 11: 6058.
Monitoring ephemeral and intermittent streams is a major challenge in hydrology. While direct field observations are best to detect spatial patterns of flow persistence, on site inspections are time and labor intensive and may be impractical in difficult-to-access environments. Motivated by latest advancements of 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. 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. Time-lapse imagery is processed through a computationally inexpensive algorithm featuring image quantization and binarization, and water level time series are filtered through a simple statistical scheme. The feasibility of the approach is demonstrated through a set of benchmark experiments performed in controlled and natural settings, characterized by an increased level of complexity. Maximum mean absolute errors between stage-camera and reference data are approximately equal to 2 cm in the worst scenario that corresponds to severe hydrometeorological conditions. Our preliminary results are encouraging and support the scalability of the stage camera in future implementations in a wide range of natural settings.
Simone Noto; Flavia Tauro; Andrea Petroselli; Ciro Apollonio; Gianluca Botter; Salvatore Grimaldi. Continuous water level monitoring using time-lapse imagery. 2021, 1 .
AMA StyleSimone Noto, Flavia Tauro, Andrea Petroselli, Ciro Apollonio, Gianluca Botter, Salvatore Grimaldi. Continuous water level monitoring using time-lapse imagery. . 2021; ():1.
Chicago/Turabian StyleSimone Noto; Flavia Tauro; Andrea Petroselli; Ciro Apollonio; Gianluca Botter; Salvatore Grimaldi. 2021. "Continuous water level monitoring using time-lapse imagery." , no. : 1.
Monitoring ephemeral and intermittent streams is a major challenge in hydrology. While direct field observations are best to detect spatial patterns of flow persistence, on site inspections are time and labor intensive and may be impractical in difficult-to-access environments. Motivated by latest advancements of 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. 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. Time-lapse imagery is processed through a computationally inexpensive algorithm featuring image quantization and binarization, and water level time series are filtered through a simple statistical scheme. The feasibility of the approach is demonstrated through a set of benchmark experiments performed in controlled and natural settings, characterized by an increased level of complexity. Maximum mean absolute errors between stage-camera and reference data are approximately equal to 2 cm in the worst scenario that corresponds to severe hydrometeorological conditions. Our preliminary results are encouraging and support the scalability of the stage-camera in future implementations in a wide range of natural settings.
Simone Noto; Flavia Tauro; Andrea Petroselli; Ciro Apollonio; Gianluca Botter; Salvatore Grimaldi. Technical Note: Low cost stage-camera system for continuous water level monitoring in ephemeral streams. 2021, 2021, 1 -17.
AMA StyleSimone Noto, Flavia Tauro, Andrea Petroselli, Ciro Apollonio, Gianluca Botter, Salvatore Grimaldi. Technical Note: Low cost stage-camera system for continuous water level monitoring in ephemeral streams. . 2021; 2021 ():1-17.
Chicago/Turabian StyleSimone Noto; Flavia Tauro; Andrea Petroselli; Ciro Apollonio; Gianluca Botter; Salvatore Grimaldi. 2021. "Technical Note: Low cost stage-camera system for continuous water level monitoring in ephemeral streams." 2021, no. : 1-17.
Hydroclimatic time series analysis focuses on a few feature types (e.g., autocorrelations, trends, extremes), which describe a small portion of the entire information content of the observations. Aiming to exploit a larger part of the available information and, thus, to deliver more reliable results (e.g., in hydroclimatic time series clustering contexts), here we approach hydroclimatic time series analysis differently, i.e., by performing massive feature extraction. In this respect, we develop a big data framework for hydroclimatic variable behaviour characterization. This framework relies on approximately 60 diverse features and is completely automatic (in the sense that it does not depend on the hydroclimatic process at hand). We apply the new framework to characterize mean monthly temperature, total monthly precipitation and mean monthly river flow. The applications are conducted at the global scale by exploiting 40-year-long time series originating from over 13 000 stations. We extract interpretable knowledge on seasonality, trends, autocorrelation, long-range dependence and entropy, and on feature types that are met less frequently. We further compare the examined hydroclimatic variable types in terms of this knowledge and, identify patterns related to the spatial variability of the features. For this latter purpose, we also propose and exploit a hydroclimatic time series clustering methodology. This new methodology is based on Breiman's random forests. The descriptive and exploratory insights gained by the global-scale applications prove the usefulness of the adopted feature compilation in hydroclimatic contexts. Moreover, the spatially coherent patterns characterizing the clusters delivered by the new methodology build confidence in its future exploitation. Given this spatial coherence and the scale-independent nature of the delivered feature values (which makes them particularly useful in forecasting and simulation contexts), we believe that this methodology could also be beneficial within regionalization frameworks, in which knowledge on hydrological similarity is exploited in technical and operative terms.
Georgia Papacharalampous; Hristos Tyralis; Simon Michael Papalexiou; Andreas Langousis; Sina Khatami; Elena Volpi; Salvatore Grimaldi. Global-scale massive feature extraction from monthly hydroclimatic time series: Statistical characterizations, spatial patterns and hydrological similarity. Science of The Total Environment 2020, 767, 144612 .
AMA StyleGeorgia Papacharalampous, Hristos Tyralis, Simon Michael Papalexiou, Andreas Langousis, Sina Khatami, Elena Volpi, Salvatore Grimaldi. Global-scale massive feature extraction from monthly hydroclimatic time series: Statistical characterizations, spatial patterns and hydrological similarity. Science of The Total Environment. 2020; 767 ():144612.
Chicago/Turabian StyleGeorgia Papacharalampous; Hristos Tyralis; Simon Michael Papalexiou; Andreas Langousis; Sina Khatami; Elena Volpi; Salvatore Grimaldi. 2020. "Global-scale massive feature extraction from monthly hydroclimatic time series: Statistical characterizations, spatial patterns and hydrological similarity." Science of The Total Environment 767, no. : 144612.
The design hydrograph estimation in small and ungauged basins represents one of the most common practices and, yet, a challenging open research topic for hydrologists. When discharge observations are not available, the practitioner is compelled to apply empirical approaches. The rational formula is slowly disappearing, while event-based approaches are more and more widespread. A step forward is represented by continuous models that have the potential to address the major drawbacks of event-based approaches. In this work we applied a continuous model specifically designed for ungauged basins (COSMO4SUB) and tested its use in conditions where typically the rational formula and the event-based approaches are applied. Results confirm that the continuous modelling is suitable for rapid and effective design simulations supporting flood hazard modelling and mapping studies.
Salvatore Grimaldi; Fernando Nardi; Rodolfo Piscopia; Andrea Petroselli; Ciro Apollonio. Continuous hydrologic modelling for design simulation in small and ungauged basins: A step forward and some tests for its practical use. Journal of Hydrology 2020, 595, 125664 .
AMA StyleSalvatore Grimaldi, Fernando Nardi, Rodolfo Piscopia, Andrea Petroselli, Ciro Apollonio. Continuous hydrologic modelling for design simulation in small and ungauged basins: A step forward and some tests for its practical use. Journal of Hydrology. 2020; 595 ():125664.
Chicago/Turabian StyleSalvatore Grimaldi; Fernando Nardi; Rodolfo Piscopia; Andrea Petroselli; Ciro Apollonio. 2020. "Continuous hydrologic modelling for design simulation in small and ungauged basins: A step forward and some tests for its practical use." Journal of Hydrology 595, no. : 125664.
Since the turn of the 21st century, image-based velocimetry techniques have become an increasingly popular approach for determining open-channel flow in a range of hydrological settings across Europe and beyond. Simultaneously, a range of large-scale image velocimetry algorithms have been developed that are equipped with differing image pre-processing and analytical capabilities. Yet in operational hydrometry, these techniques are utilised by few competent authorities. Therefore, imagery collected for image velocimetry analysis (along with reference data) is required both to enable inter-comparisons between these differing approaches and to test their overall efficacy. Through benchmarking exercises, it will be possible to assess which approaches are best suited for a range of fluvial settings, and to focus future software developments. Here we collate and describe datasets acquired from seven countries across Europe and North America, consisting of videos that have been subjected to a range of pre-processing and image velocimetry analyses (Perks et al., 2020, https://doi.org/10.4121/uuid:014d56f7-06dd-49ad-a48c-2282ab10428e). Reference data are available for 12 of the 13 case studies presented, enabling these data to be used for reference and accuracy assessment.
Matthew T. Perks; Silvano Fortunato Dal Sasso; Alexandre Hauet; Elizabeth Jamieson; Jérôme Le Coz; Sophie Pearce; Salvador Peña-Haro; Alonso Pizarro; Dariia Strelnikova; Flavia Tauro; James Bomhof; Salvatore Grimaldi; Alain Goulet; Borbála Hortobágyi; Magali Jodeau; Sabine Käfer; Robert Ljubičić; Ian Maddock; Peter Mayr; Gernot Paulus; Lionel Pénard; Leigh Sinclair; Salvatore Manfreda. Towards harmonisation of image velocimetry techniques for river surface velocity observations. Earth System Science Data 2020, 12, 1545 -1559.
AMA StyleMatthew T. Perks, Silvano Fortunato Dal Sasso, Alexandre Hauet, Elizabeth Jamieson, Jérôme Le Coz, Sophie Pearce, Salvador Peña-Haro, Alonso Pizarro, Dariia Strelnikova, Flavia Tauro, James Bomhof, Salvatore Grimaldi, Alain Goulet, Borbála Hortobágyi, Magali Jodeau, Sabine Käfer, Robert Ljubičić, Ian Maddock, Peter Mayr, Gernot Paulus, Lionel Pénard, Leigh Sinclair, Salvatore Manfreda. Towards harmonisation of image velocimetry techniques for river surface velocity observations. Earth System Science Data. 2020; 12 (3):1545-1559.
Chicago/Turabian StyleMatthew T. Perks; Silvano Fortunato Dal Sasso; Alexandre Hauet; Elizabeth Jamieson; Jérôme Le Coz; Sophie Pearce; Salvador Peña-Haro; Alonso Pizarro; Dariia Strelnikova; Flavia Tauro; James Bomhof; Salvatore Grimaldi; Alain Goulet; Borbála Hortobágyi; Magali Jodeau; Sabine Käfer; Robert Ljubičić; Ian Maddock; Peter Mayr; Gernot Paulus; Lionel Pénard; Leigh Sinclair; Salvatore Manfreda. 2020. "Towards harmonisation of image velocimetry techniques for river surface velocity observations." Earth System Science Data 12, no. 3: 1545-1559.
Monitoring streamflow velocity is of paramount importance for water resources management and in engineering practice. To this aim, image-based approaches have proved to be reliable systems to non-intrusively monitor water bodies in remote places at variable flow regimes. Nonetheless, to tackle their computational and energy requirements, offload processing and high-speed internet connections in the monitored environments, which are often difficult to access, is mandatory hence limiting the effective deployment of such techniques in several relevant circumstances. In this paper, we advance and simplify streamflow velocity monitoring by directly processing the image stream in situ with a low-power embedded system. By leveraging its standard parallel processing capability and exploiting functional simplifications, we achieve an accuracy comparable to state-of-the-art algorithms that typically require expensive computing devices and infrastructures. The advantage of monitoring streamflow velocity in situ with a lightweight and cost-effective embedded processing device is threefold. First, it circumvents the need for wideband internet connections, which are expensive and impractical in remote environments. Second, it massively reduces the overall energy consumption, bandwidth and deployment cost. Third, when monitoring more than one river section, processing “at the very edge” of the system efficiency improves scalability by a large margin, compared to offload solutions based on remote or cloud processing. Therefore, enabling streamflow velocity monitoring in situ with low-cost embedded devices would foster the widespread diffusion of gauge cameras even in developing countries where appropriate infrastructure might be not available or too expensive.
Fabio Tosi; Matteo Rocca; Filippo Aleotti; Matteo Poggi; Stefano Mattoccia; Flavia Tauro; Elena Toth; Salvatore Grimaldi. Enabling Image-Based Streamflow Monitoring at the Edge. Remote Sensing 2020, 12, 2047 .
AMA StyleFabio Tosi, Matteo Rocca, Filippo Aleotti, Matteo Poggi, Stefano Mattoccia, Flavia Tauro, Elena Toth, Salvatore Grimaldi. Enabling Image-Based Streamflow Monitoring at the Edge. Remote Sensing. 2020; 12 (12):2047.
Chicago/Turabian StyleFabio Tosi; Matteo Rocca; Filippo Aleotti; Matteo Poggi; Stefano Mattoccia; Flavia Tauro; Elena Toth; Salvatore Grimaldi. 2020. "Enabling Image-Based Streamflow Monitoring at the Edge." Remote Sensing 12, no. 12: 2047.
Devastating floods are observed every year globally from upstream mountainous to coastal regions. Increasing flood frequency and impacts affect both major rivers and their tributaries. Nonetheless, at the small-scale, the lack of distributed topographic and hydrologic data determines tributaries to be often missing in inundation modeling and mapping studies. Advances in Unmanned Aerial Vehicle (UAV) technologies and Digital Elevation Models (DEM)-based hydrologic modeling can address this crucial knowledge gap. UAVs provide very high resolution and accurate DEMs with low surveying cost and time, as compared to DEMs obtained by Light Detection and Ranging (LiDAR), satellite, or GPS field campaigns. In this work, we selected a LiDAR DEM as a benchmark for comparing the performances of a UAV and a nation-scale high-resolution DEM (TINITALY) in representing floodplain topography for flood simulations. The different DEMs were processed to provide inputs to a hydrologic-hydraulic modeling chain, including the DEM-based EBA4SUB (Event-Based Approach for Small and Ungauged Basins) hydrologic modeling framework for design hydrograph estimation in ungauged basins; the 2D hydraulic model FLO-2D for flood wave routing and hazard mapping. The results of this research provided quantitative analyses, demonstrating the consistent performances of the UAV-derived DEM in supporting affordable distributed flood extension and depth simulations.
Antonio Annis; Fernando Nardi; Andrea Petroselli; Ciro Apollonio; Ettore Arcangeletti; Flavia Tauro; Claudio Belli; Roberto Bianconi; Salvatore Grimaldi. UAV-DEMs for Small-Scale Flood Hazard Mapping. Water 2020, 12, 1717 .
AMA StyleAntonio Annis, Fernando Nardi, Andrea Petroselli, Ciro Apollonio, Ettore Arcangeletti, Flavia Tauro, Claudio Belli, Roberto Bianconi, Salvatore Grimaldi. UAV-DEMs for Small-Scale Flood Hazard Mapping. Water. 2020; 12 (6):1717.
Chicago/Turabian StyleAntonio Annis; Fernando Nardi; Andrea Petroselli; Ciro Apollonio; Ettore Arcangeletti; Flavia Tauro; Claudio Belli; Roberto Bianconi; Salvatore Grimaldi. 2020. "UAV-DEMs for Small-Scale Flood Hazard Mapping." Water 12, no. 6: 1717.
Global floodplain mapping has rapidly progressed over the past few years. Different methods have been proposed to identify areas prone to river flooding, resulting in a plethora of available products. Here we assess the potential and limitations of two main paradigms and provide guidance on the use of these global products in assessing flood risk in data-poor regions.
Giuliano Di Baldassarre; Fernando Nardi; Antonio Annis; Vincent Odongo; Maria Rusca; Salvatore Grimaldi. Brief communication: Comparing hydrological and hydrogeomorphic paradigms for global flood hazard mapping. Natural Hazards and Earth System Sciences 2020, 20, 1415 -1419.
AMA StyleGiuliano Di Baldassarre, Fernando Nardi, Antonio Annis, Vincent Odongo, Maria Rusca, Salvatore Grimaldi. Brief communication: Comparing hydrological and hydrogeomorphic paradigms for global flood hazard mapping. Natural Hazards and Earth System Sciences. 2020; 20 (5):1415-1419.
Chicago/Turabian StyleGiuliano Di Baldassarre; Fernando Nardi; Antonio Annis; Vincent Odongo; Maria Rusca; Salvatore Grimaldi. 2020. "Brief communication: Comparing hydrological and hydrogeomorphic paradigms for global flood hazard mapping." Natural Hazards and Earth System Sciences 20, no. 5: 1415-1419.
Image velocimetry (IV) is a remote technique which calculates surface flow velocities of rivers (or fluids) via a range of cross-correlation and tracking algorithms. IV can be implemented via a range of camera sensors which can be mounted on tri-pods, or Unmanned Aerial Systems (UAS). IV has proven a powerful technique for monitoring river flows during flood conditions, whereby traditional in-situ techniques would be unsafe to deploy. However, little research has focussed upon the application of such techniques during low flow conditions. The applicability of IV to low flow studies could aid data collection at a higher spatial and temporal resolution than is currently available. Many IV techniques are under-development, that utilise different cross-correlation and tracking algorithms, including, Large Scale Particle Image Velocimetry (LSPIV), Large Scale Particle Tracking Velocimetry (LSPTV), Optical Tracking Velocimetry (OTV), Kanade Lucas Tomasi Image Velocimetry (KLT-IV) and Surface Structure Image Velocimetry (SSIV). Nevertheless, the true applications and limitations of such algorithms have yet to be extensively tested. Therefore, this study aimed to conduct a sensitivity analysis on the commonly relatable parameters between the different algorithms, including the particle identification area parameters (such as Interrogation Area (LSPIV, LSPTV and SSIV), Block Size (KLT-IV) and Trajectory Length (OTV)) and the feature extraction rate (or sub sampled frame rate).
Fieldwork was carried out on Kolubara River near the city of Obrenovac in Central Serbia. Cross-sectional surface width was relatively constant, varying between 23.30 and 23.45m. During the experiment, low flow conditions were present with a discharge of approx. 3.4m3 s-1 (estimated using a Sontek M9 ADCP), and depths of up to 1.9m. A DJI Phantom 4 Pro UAS was used to collect video data of the surface flow. Artificial seeding material (wood-mulch) was distributed homogenously across the rivers’ surface, in order to improve the conditions for IV techniques during slow flows. Two 30-second videos were utilised for surface velocity analysis.
This study highlighted that KLT, SSIV, OTV and LSPIV are the least sensitive algorithms to changing parameters when no pre- or post-processing of results are conducted. On the other hand, LSPTV must undergo post-processing procedures in order to avoid spurious results and only then, results may be reliable. Furthermore, KLT and SSIV highlighted a slight sensitivity to changing the feature extraction rate, however changing the particle identification area did not affect significantly the outputted surface velocity results. OTV and LSPTV, on the other hand, highlighted that changing the particle identification area provided a higher variability in the results, whilst changing the feature extraction rate did not affect the surface velocity outputs. LSPIV proved to be sensitive to changing both the feature extraction rate and the particle identification area.
This analysis has led to the conclusions that during the conditions of sampling with surface velocities of approximately 0.12ms-1, and homogeneous seeding on the rivers surface, IV techniques can provide results comparable to traditional techniques such as ADCPs during low flow conditions. All IV algorithms provided results that were, on average, within 0.05ms-1 of the ADCP measurements.
Sophie Pearce; Robert Ljubicic; Salvador Pena-Haro; Matthew Perks; Flavia Tauro; Alonso Pizarro; Silvano Fortunato Dal Sasso; Dariia Strelnikova; Salvatore Grimaldi; Ian Maddock; Gernot Paulus; Jasna Plavsic; Dusan Prodanovic; Salvatore Manfreda; Mark Corbett; Nick Everard. An evaluation of image velocimetry techniques under low flow conditions and high seeding densities using Unmanned Aerial Systems. 2020, 1 .
AMA StyleSophie Pearce, Robert Ljubicic, Salvador Pena-Haro, Matthew Perks, Flavia Tauro, Alonso Pizarro, Silvano Fortunato Dal Sasso, Dariia Strelnikova, Salvatore Grimaldi, Ian Maddock, Gernot Paulus, Jasna Plavsic, Dusan Prodanovic, Salvatore Manfreda, Mark Corbett, Nick Everard. An evaluation of image velocimetry techniques under low flow conditions and high seeding densities using Unmanned Aerial Systems. . 2020; ():1.
Chicago/Turabian StyleSophie Pearce; Robert Ljubicic; Salvador Pena-Haro; Matthew Perks; Flavia Tauro; Alonso Pizarro; Silvano Fortunato Dal Sasso; Dariia Strelnikova; Salvatore Grimaldi; Ian Maddock; Gernot Paulus; Jasna Plavsic; Dusan Prodanovic; Salvatore Manfreda; Mark Corbett; Nick Everard. 2020. "An evaluation of image velocimetry techniques under low flow conditions and high seeding densities using Unmanned Aerial Systems." , no. : 1.
Estimating the design hydrograph (DH) is a crucial problem in practical hydrology and hydraulics. The development of reliable DHs is particularly challenging in small and ungauged basins due to the lack of observed discharge data that are needed for calibrating advanced models. For such basins, the modeler is often forced to adopt simple and conceptual modelling like the so called event-based approach. It consists in selecting a design rainfall event, which is related to an assigned return period, estimating the rainfall excess and then transforming it into the DH. In recent years, the continuous modelling approach was introduced. This relies on generating a long synthetic rainfall time series at sub-daily resolution that feeds a continuous rainfall–runoff model. Then, a discharge time series is produced that allows for estimating the DH. In this work, we would like to emphasize the added value of the continuous modelling approach in providing a more reliable estimation of the DH.
S. Grimaldi; A. Petroselli; R. Piscopia; F. Tauro. The Benefit of Continuous Modelling for Design Hydrograph Estimation in Small and Ungauged Basins. Lecture Notes in Civil Engineering 2020, 133 -139.
AMA StyleS. Grimaldi, A. Petroselli, R. Piscopia, F. Tauro. The Benefit of Continuous Modelling for Design Hydrograph Estimation in Small and Ungauged Basins. Lecture Notes in Civil Engineering. 2020; ():133-139.
Chicago/Turabian StyleS. Grimaldi; A. Petroselli; R. Piscopia; F. Tauro. 2020. "The Benefit of Continuous Modelling for Design Hydrograph Estimation in Small and Ungauged Basins." Lecture Notes in Civil Engineering , no. : 133-139.
Salvatore Grimaldi. Editor Comment: the manuscript will be withdrawn as requested by the authors. 2020, 1 .
AMA StyleSalvatore Grimaldi. Editor Comment: the manuscript will be withdrawn as requested by the authors. . 2020; ():1.
Chicago/Turabian StyleSalvatore Grimaldi. 2020. "Editor Comment: the manuscript will be withdrawn as requested by the authors." , no. : 1.
Global floodplain mapping has rapidly progressed over the past few years. Different methods have been proposed to identify areas prone to flooding, resulting into a plethora of freely available products. Here we assess the potential and limitations of two main paradigms, and provide guidance on the use of these global products in assessing flood risk in data-poor regions.
Giuliano Di Baldassarre; Fernando Nardi; Antonio Annis; Vincent Odongo; Maria Rusca; Salvatore Grimaldi. Brief communication: Comparing top-down and bottom-up paradigms for global flood hazard mapping. 2020, 1 -6.
AMA StyleGiuliano Di Baldassarre, Fernando Nardi, Antonio Annis, Vincent Odongo, Maria Rusca, Salvatore Grimaldi. Brief communication: Comparing top-down and bottom-up paradigms for global flood hazard mapping. . 2020; ():1-6.
Chicago/Turabian StyleGiuliano Di Baldassarre; Fernando Nardi; Antonio Annis; Vincent Odongo; Maria Rusca; Salvatore Grimaldi. 2020. "Brief communication: Comparing top-down and bottom-up paradigms for global flood hazard mapping." , no. : 1-6.
Image velocimetry has proven to be a promising technique for monitoring river flows using remotely operated platforms such as Unmanned Aerial Systems (UAS). However, the application of various image velocimetry algorithms has not been extensively assessed. Therefore, a sensitivity analysis has been conducted on five different image velocimetry algorithms including Large Scale Particle Image Velocimetry (LSPIV), Large-Scale Particle Tracking Velocimetry (LSPTV), Kanade–Lucas Tomasi Image Velocimetry (KLT-IV or KLT), Optical Tracking Velocimetry (OTV) and Surface Structure Image Velocimetry (SSIV), during low river flow conditions (average surface velocities of 0.12–0.14 m s − 1 , Q60) on the River Kolubara, Central Serbia. A DJI Phantom 4 Pro UAS was used to collect two 30-second videos of the surface flow. Artificial seeding material was distributed homogeneously across the rivers surface, to enhance the conditions for image velocimetry techniques. The sensitivity analysis was performed on comparable parameters between the different algorithms, including the particle identification area parameters (such as Interrogation Area (LSPIV, LSPTV and SSIV), Block Size (KLT-IV) and Trajectory Length (OTV)) and the feature extraction rate. Results highlighted that KLT and SSIV were sensitive to changing the feature extraction rate; however, changing the particle identification area did not affect the surface velocity results significantly. OTV and LSPTV, on the other hand, highlighted that changing the particle identification area presented higher variability in the results, while changing the feature extraction rate did not affect the surface velocity outputs. LSPIV proved to be sensitive to changing both the feature extraction rate and the particle identification area. This analysis has led to the conclusions that for surface velocities of approximately 0.12 m s − 1 image velocimetry techniques can provide results comparable to traditional techniques such as ADCPs. However, LSPIV, LSPTV and OTV require additional effort for calibration and selecting the appropriate parameters when compared to KLT-IV and SSIV. Despite the varying levels of sensitivity of each algorithm to changing parameters, all configuration image velocimetry algorithms provided results that were within 0.05 m s − 1 of the ADCP measurements, on average.
Sophie Pearce; Robert Ljubičić; Salvador Peña-Haro; Matthew Perks; Flavia Tauro; Alonso Pizarro; Silvano Fortunato Dal Sasso; Dariia Strelnikova; Salvatore Grimaldi; Ian Maddock; Gernot Paulus; Jasna Plavšić; Dušan Prodanović; Salvatore Manfreda. An Evaluation of Image Velocimetry Techniques under Low Flow Conditions and High Seeding Densities Using Unmanned Aerial Systems. Remote Sensing 2020, 12, 232 .
AMA StyleSophie Pearce, Robert Ljubičić, Salvador Peña-Haro, Matthew Perks, Flavia Tauro, Alonso Pizarro, Silvano Fortunato Dal Sasso, Dariia Strelnikova, Salvatore Grimaldi, Ian Maddock, Gernot Paulus, Jasna Plavšić, Dušan Prodanović, Salvatore Manfreda. An Evaluation of Image Velocimetry Techniques under Low Flow Conditions and High Seeding Densities Using Unmanned Aerial Systems. Remote Sensing. 2020; 12 (2):232.
Chicago/Turabian StyleSophie Pearce; Robert Ljubičić; Salvador Peña-Haro; Matthew Perks; Flavia Tauro; Alonso Pizarro; Silvano Fortunato Dal Sasso; Dariia Strelnikova; Salvatore Grimaldi; Ian Maddock; Gernot Paulus; Jasna Plavšić; Dušan Prodanović; Salvatore Manfreda. 2020. "An Evaluation of Image Velocimetry Techniques under Low Flow Conditions and High Seeding Densities Using Unmanned Aerial Systems." Remote Sensing 12, no. 2: 232.
Aim of the study: Aim of the study is to provide a comparative assessment of event based (EBA4SUB) and continuous (COSMO4SUB) modelling approaches for rainfall-runoff modeling for small and ungauged basins, focusing on the influence of the Antecedent Moisture Condition (AMC) of the soil on the...
Andrea Petroselli; Salvatore Grimaldi; Rodolfo Piscopia; Flavia Tauro; Rome Freelance. DESIGN HYDROGRAPH ESTIMATION IN SMALL AND UNGAUGED BASINS: A COMPARATIVE ASSESSMENT OF EVENT BASED (EBA4SUB) AND CONTINUOUS (COSMO4SUB) MODELING APPROACHES. Acta Scientiarum Polonorum Formatio Circumiectus 2019, 18, 113 -124.
AMA StyleAndrea Petroselli, Salvatore Grimaldi, Rodolfo Piscopia, Flavia Tauro, Rome Freelance. DESIGN HYDROGRAPH ESTIMATION IN SMALL AND UNGAUGED BASINS: A COMPARATIVE ASSESSMENT OF EVENT BASED (EBA4SUB) AND CONTINUOUS (COSMO4SUB) MODELING APPROACHES. Acta Scientiarum Polonorum Formatio Circumiectus. 2019; 18 (4):113-124.
Chicago/Turabian StyleAndrea Petroselli; Salvatore Grimaldi; Rodolfo Piscopia; Flavia Tauro; Rome Freelance. 2019. "DESIGN HYDROGRAPH ESTIMATION IN SMALL AND UNGAUGED BASINS: A COMPARATIVE ASSESSMENT OF EVENT BASED (EBA4SUB) AND CONTINUOUS (COSMO4SUB) MODELING APPROACHES." Acta Scientiarum Polonorum Formatio Circumiectus 18, no. 4: 113-124.
In this paper, we explore the dynamics of surface runoff formation in an outdoor experimental plot, Cape Fear, by reporting the relationships among rainfall, runoff, and soil moisture for 101 rainfall-runoff events observed in the time span of more than five years (January 2014–March 2019). Cape Fear is a recently developed 7 × 7 m2 experimental plot that combines features from both small scale facilities and catchment-scale experimental hillslopes, thus leveraging observation of major hydrological variables at high temporal and spatial resolution. Despite the small dimension and simplicity of the plot, the relations among hydrological variables are unexpectedly quite spread. Experimental results seem to suggest that Cape Fear runoff response presents an increasing and non-linear relationship with rainfall, with a surface runoff coefficient increasing for higher rainfall. Direct runoff apparently increases with soil moisture, while initial abstraction seems not to be influenced by rainfall and is found to decrease with increasing soil moisture. Observations suggest that complex interactions between soil moisture conditions and rainfall pattern properties modulate the plot response.
Andrea Petroselli; Flavia Tauro; Salvatore Grimaldi. Investigating runoff formation dynamics: field observations at Cape Fear experimental plot. Environmental Monitoring and Assessment 2019, 191, 642 .
AMA StyleAndrea Petroselli, Flavia Tauro, Salvatore Grimaldi. Investigating runoff formation dynamics: field observations at Cape Fear experimental plot. Environmental Monitoring and Assessment. 2019; 191 (11):642.
Chicago/Turabian StyleAndrea Petroselli; Flavia Tauro; Salvatore Grimaldi. 2019. "Investigating runoff formation dynamics: field observations at Cape Fear experimental plot." Environmental Monitoring and Assessment 191, no. 11: 642.
Since the turn of the 21st Century, image based velocimetry techniques have become an increasingly popular approach for determining open-channel flow in a range of hydrological settings across Europe, and beyond. Simultaneously, a range of large-scale image velocimetry algorithms have been developed, equipped with differing image pre-processing, and analytical capabilities. Yet in operational hydrometry, these techniques are utilised by few competent authorities. Therefore, imagery collected for image velocimetry analysis, along with validation data is required both to enable inter-comparisons between these differing approaches and to test their overall efficacy. Through benchmarking exercises, it will be possible to assess which approaches are best suited for a range of fluvial settings, and to focus future software developments. Here we collate, and describe datasets acquired from six countries across Europe and Asia, consisting of videos that have been subjected to a range of pre-processing, and image velocimetry analysis (Perks et al., 2019, https://doi.org/10.4121/uuid:34764be1-31f9-4626-8b11-705b4f66b95a). Validation data is available for 12 of the 13 case studies presented enabling these data to be used for validation and accuracy assessment.
Matthew T. Perks; Silvano Fortunato Dal Sasso; Alexandre Hauet; Jérôme Le Coz; Sophie Pearce; Salvador Peña-Haro; Flavia Tauro; Salvatore Grimaldi; Borbála Hortobágyi; Magali Jodeau; Ian Maddock; Lionel Pénard; Salvatore Manfreda. Towards harmonization of image velocimetry techniques for river surface velocity observations. 2019, 2019, 1 -20.
AMA StyleMatthew T. Perks, Silvano Fortunato Dal Sasso, Alexandre Hauet, Jérôme Le Coz, Sophie Pearce, Salvador Peña-Haro, Flavia Tauro, Salvatore Grimaldi, Borbála Hortobágyi, Magali Jodeau, Ian Maddock, Lionel Pénard, Salvatore Manfreda. Towards harmonization of image velocimetry techniques for river surface velocity observations. . 2019; 2019 ():1-20.
Chicago/Turabian StyleMatthew T. Perks; Silvano Fortunato Dal Sasso; Alexandre Hauet; Jérôme Le Coz; Sophie Pearce; Salvador Peña-Haro; Flavia Tauro; Salvatore Grimaldi; Borbála Hortobágyi; Magali Jodeau; Ian Maddock; Lionel Pénard; Salvatore Manfreda. 2019. "Towards harmonization of image velocimetry techniques for river surface velocity observations." 2019, no. : 1-20.