Applications of Image-Based Computer Vision for Remote Surveillance of Slope Instability

Landslides and slope failures represent critical hazards for both the safety of local communities and the potential damage to economically relevant infrastructure such as roads, hydroelectric plants, pipelines, etc. Numerous surveillance methods, including ground-based radar, InSAR, Lidar, seismometers, and more recently computer vision, are available to monitor landslides and slope instability. However, the high cost, complexity, and intrinsic technical limitations of these methods frequently require the design of alternative and complementary techniques. Here, we provide an improved methodology for the application of image-based computer vision in landslide and rockfall monitoring. The newly developed open access Python-based software, Akh-Defo, uses optical flow velocity, image differencing and similarity index map techniques to calculate land deformation including landslides and rockfall. Akh-Defo is applied to two different datasets, notably ground- and satellite-based optical imagery for the Plinth Peak slope in British Columbia, Canada, and satellite optical imagery for the Mud Creek landslide in California, USA. Ground-based optical images were processed to evaluate the capability of Akh-Defo to identify rockfalls and measure land displacement in steep-slope terrains to complement LOS limitations of radar satellite images. Similarly, satellite optical images were processed to evaluate the capability of Akh-Defo to identify ground displacement in active landslide regions a few weeks to months prior to initiation of landslides. The Akh-Defo results were validated from two independent datasets including radar-imagery, processed using state of the art SqueeSAR algorithm for the Plinth Peak case study and very high-resolution temporal Lidar and photogrammetry digital surface elevation datasets for the Mud Creek case study. Our study shows that the Akh-Defo software complements InSAR by mitigating LOS limitations via processing ground-based optical imagery. Additionally, if applied to satellite optical imagery, it can be used as a first stage preliminary warning system (particularly when run on the cloud allowing near real-time processing) prior to processing more expensive but more accurate InSAR products such as SqueeSAR

COVID-19 Outbreak and Cancer Radiotherapy Disruption in Lombardy, Northern Italy

none37nononeJereczek-Fossa B.A.; Palazzi M.F.; Soatti C.P.; Cazzaniga L.F.; Ivaldi G.B.; Pepa M.; Amadori M.; Antognoni P.; Arcangeli S.; Buffoli A.; Beltramo G.; Berlinghieri S.; Bignardi M.; Bracelli S.; Bruschieri L.; Castiglioni S.; Catalano G.; Di Muzio N.; Fallai C.; Fariselli L.; Filippi A.R.; Gramaglia A.; Italia C.; Lombardi F.; Magrini S.M.; Nava S.; Orlandi E.; Pasinetti N.; Sbicego E.L.; Scandolaro L.; Scorsetti M.; Stiglich F.; Tonoli S.; Tortini R.; Valdagni R.; Vavassori V.; Marvaso G.Jereczek-Fossa, B. A.; Palazzi, M. F.; Soatti, C. P.; Cazzaniga, L. F.; Ivaldi, G. B.; Pepa, M.; Amadori, M.; Antognoni, P.; Arcangeli, S.; Buffoli, A.; Beltramo, G.; Berlinghieri, S.; Bignardi, M.; Bracelli, S.; Bruschieri, L.; Castiglioni, S.; Catalano, G.; Di Muzio, N.; Fallai, C.; Fariselli, L.; Filippi, A. R.; Gramaglia, A.; Italia, C.; Lombardi, F.; Magrini, S. M.; Nava, S.; Orlandi, E.; Pasinetti, N.; Sbicego, E. L.; Scandolaro, L.; Scorsetti, M.; Stiglich, F.; Tonoli, S.; Tortini, R.; Valdagni, R.; Vavassori, V.; Marvaso, G

Using annual Landsat imagery to identify harvesting over a range of intensities for non-industrial family forests

The monitoring of forested landscapes dominated by many small private forest owners is difficult or not possible without spatially explicit and up-to-date information on land cover change. Analysis of time series multispectral data from the Landsat series of satellites have the spatial and temporal characteristics required to detect sub-hectare and non-stand replacing harvest events over large areas. We identified harvests that occurred in six western upper Michigan counties from 1985 to 2011 using Landsat best available pixel (BAP) image composites and the Composite2Change (C2C) approach. We detected a total of 7071 harvesting events with size ranging from 0.5 to 171.36 ha and average size of 6.42 ha, and analyzed their temporal trajectory. To gain confidence in our harvest mapping, we compared our findings to the overlapping decade of Global Forest Watch (GFW) data. Agreement between the datasets was high, with 94.24% of the C2C and GFW harvest pixels identified with the same change year and improving to 98.74% within ±1 year. This automated harvest detection system, which can capture small and otherwise missed harvests, is valuable to natural resource agencies responsible for monitoring and compliance with regulations over large areas, and researchers requiring estimates of harvest levels and the nature of forest cover status and trends on family forests

The impact of persistent volcanic degassing on vegetation: A case study at Turrialba volcano, Costa Rica

© 2017 Elsevier B.V. Although the impacts of large volcanic eruptions on the global environment have been frequently studied, the impacts of lower tropospheric emissions from persistently degassing volcanoes remain poorly understood. Gas emissions from persistent degassing exceed those from sporadic eruptive activity, and can have significant long-term (years to decades) effects on local and regional scales, both on humans and the environment. Here, we exploit a variety of high temporal and high spatial resolution satellite-based time series and complementary ground-based measurements of element deposition and surveys of species richness, to enable a comprehensive spatio-temporal assessment of sulfur dioxide (SO2) emissions and their associated impacts on vegetation at Turrialba volcano (Costa Rica) from 2000 to 2013. We observe increased emissions of SO2 coincident with a decline in vegetation health downwind of the vents, in accordance with the prevalent wind direction at Turrialba. We also find that satellite-derived vegetation indices at various spatial resolutions are able to accurately define the vegetation kill zone, the extent of which is independently confirmed by ground-based sampling, and monitor its expansion over time. In addition, ecological impacts in terms of vegetation composition and diversity and physiological damage to vegetation, all spatially correspond to fumigation by Turrialba\u27s plume. This study shows that analyzing and relating satellite observations to conditions and impacts on the ground can provide an increased understanding of volcanic degassing, its impacts in terms of the long-term vegetation response and the potential of satellite-based monitoring to inform hazard management strategies related to land use

Multispectral technology for mining exploration in arid lands: a short review (tecnologia multispettrale per l’esplorazione d’idrocarburi in ambienti aridi: una breve review)

A oggi non esistono stime attendibili sull’effettiva consistenza delle risorse d’idrocarburi e solamente poco più di un quarto dei bacini potenzialmente interessanti ai fini dell’esplorazione sono stati adeguatamente studiati. Anche le tecniche d’indagine più sofisticate spesso si rivelano inadeguate o contraddittorie e per questo motivo numerose compagnie petrolifere stanno valutando le potenzialità offerte da altre nuove tecnologie, come ad esempio il Telerilevamento multispettrale. Questa breve review descrive lo stato dell’arte nella ricerca di microseep d’idrocarburi in ambienti aridi mediante l’utilizzo di tecniche di Telerilevamento ottico multispettrale

Monitoring large oil slick dynamics with moderate resolution multispectral satellite data

Accidental release of crude oil into the sea due to human activity causes water pollution and heavy damages to natural ecosystems killing birds, fish, mammals and other organisms. A number of monitoring systems are used for tracking the spills and their effects on the marine environment, as well as for collecting data for feeding models. Among them, Earth observation technologies play a crucial role and moderate spatial resolution satellite systems are able to collect images with a very short revisit time or even daily. This paper describes the use of MODIS (Moderate Resolution Imaging Spectroradiometer) data for monitoring large oil slicks with the Fluorescence/Emissivity Index (FEI) and Object Based Image Analysis (OBIA). Two case studies are presented: the Deepwater Horizon (2010) and the Campos Basin (2011) oil spill accidents. Results show that is possible to track the dynamics of the slick both for massive and long-lasting accidents and for smaller and very quick accidents. The main advantages of the method proposed are a straightforward implementation, a fast and semi-automated data processing and the capability of integration of daytime and nighttime acquisitions, as well as its adaptability to different sensors

Equipment, staffing, and provision of radiotherapy in Lombardy, Italy: Results of three surveys performed between 2012 and 2016

Introduction: Several efforts are being implemented at the European level to measure provision of up-to-date radiation treatments across the continent. Methods: A snapshot survey involving all radiation oncology centers within Lombardy, Italy, was performed in 2012 and repeated in 2014 and 2016, in cooperation with regional governmental officers. Centers were asked to provide detailed information concerning all individual patients being treated on the index day, and to report data on available local resources. Results: We observed an increase in the number of centers and of megavoltage units (MVU) (from 76 to 87, i.e., 8.7 MVU per million inhabitants in 2016). Mean number of MVU per center was 2.5. Average age of MVU increased from 5.3 to 7.5 years and patients on the waiting list also increased. Conformal 3D radiotherapy (RT) treatments decreased from 56% to 42% and were progressively replaced by intensity-modulated RT treatments (from 39% to 49%). Waiting times were overall satisfactory. Radiation oncologists treated on average 152 and radiation therapists 100 RT courses per year. Average reimbursement per course was €4,879 (range €2,476-€8,014). Conclusions: The methodology of snapshot survey proved feasible and provided valuable information about radiation oncology provision and accessibility in Lombardy

Back to (new) normality—A CODRAL/AIRO-L survey on cancer radiotherapy in Lombardy during Italian COVID-19 phase 2

Background: Italy experienced one of the world’s severest COVID-19 outbreak, with Lombardy being the most afflicted region. However, the imposed safety measures allowed to flatten the epidemic curve and hence to ease the restrictions and inaugurate, on the 4th of May 2020, the Italian phase (P) 2 of the pandemic. The present survey study, endorsed by CODRAL and AIRO-L, aimed to assess how radiotherapy (RT) departments in Lombardy have dealt with the recovery. Materials and methods: A questionnaire dealing with the management of pandemic was developed online and sent to all CODRAL Directors on the 10th of June 2020. Answers were collected in full anonymity one week after. Results: All the 33 contacted RT facilities (100%) responded to the survey. Despite the scale of the pandemic, during P1 14 (42.4%) centres managed to safely continue the activity (≤ 10% reduction). During P2, 10 (30.3%) centres fully recovered and 14 (42.4%) reported an increase. Nonetheless, 6 (18.2%) declared no changes and, interestingly, 3 (9.1%) reduced activities. Overall, 21 centres (63.6%) reported suspected or positive cases within healthcare workforce since the beginning of the pandemic. Staff units were quarantined in 19 (57.6%) and 6 (18.2%) centres throughout P1 and P2, respectively. In the two phases, about two thirds centres registered positive or suspected cases amongst patients. Conclusion: The study revealed a particular attention to anti-contagion measures and a return to normal or even higher clinical workload in most RT centres in Lombardy, necessary to carry out current and previously deferred treatments