No abstract

Remote surface flow observations are crucial for improving the comprehension of hydrological phenomena. A recent advancement in remote hydrological measurements involves the use of drones for generating surface flow-velocity field maps through large-scale particle image velocimetry (LSPIV). In this work, we perform a comparative analysis of drone-based LSPIV with fixed implementations. Quantitative indices are introduced to test the efficiency of the techniques with regards to measurement accuracy, sensitivity to the transit of tracers, and platform mobility. Experimental findings support drone-based observations in outdoor settings. Specifically, measurements from the aerial platform are more sensitive to the transit of tracers and closer to benchmark values than traditional LSPIV implementations. Future work should aim at improving the stability of the aerial platform and mitigating the effects of tracer scarcity.Image resolution and frequency are opportunely adjusted for LSPIV analyses. Average observation times (Obs. time) and interrogation window sizes (Int. window) are reported for each set of experiments. LSPIV, large-scale particle image velocimetry; HD, high-definition.

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.

Since 2004, increasing attention has been focused on improving UAV applications in forestry. The technology related to the drones also allowed to prefigure new applications related to forest monitoring in real-time and timely, such as the monitoring of fire fronts during forest fires. Accurate information about forest composition, structure, volume, growth, and extent is essential for sustainable forest management. The aim of this paper is to compare the results obtained from Web of Science and Scopus databases in order to have a wide framework of the bibliography to explore between 2004 to date. The number of found publications in Scopus and Web of Science databases, underline that there is an increasing interesting on the investigated thematic; the comparison between the two databases show that WoS is more complete than Scopus. In conclusion, the results comparison, for each keywords combination in both databases, show that Web of Science is the best bibliographic database research for the explored thematic.

The water conservation topic is likely to become increasingly important and alternative water resources employment should be considered as one possible response to the challenges of fresh water demand and environmental protection; among alternative water sources, municipal wastewaters represent one of the most profitable source but in order to reuse them they need adequate and advanced depuration techniques, such as the use of Integrated System of Phytodepuration (ISP). Across a 3-year sampling period, the performances of an ISP within the Natural Park of the Sile River in the Northern Italy were evaluated, analyzing raw wastewater and final effluent characteristics according to the recommendations of European and Italian legislation. The investigated ISP represents one of the first attempts designed in Italy to improve the efficiency of an existing wastewater treatment plant, able to serve 8000 equivalent inhabitants. The results obtained during the 3 years of analysis show that the designed ISP is characterized by a general efficiency value higher than 87% for TSS removal, 79% for TN, 91% for BOD5 and 86% for COD; moreover the ISP final effluent is characterized by a quality not only suited for release into surface waters but also for irrigation.