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This paper describes an approach for combining Landsat and Radarsat satellite images to generate national statistics for urban ecosystem accounting. These accounts will inform policy related to the development of mitigation measures for climatic and hydrologic events in Canada. Milton, Ontario was used as a test case for the development of an approach identifying urban ecosystem types and assessing change from 2001 to 2019. Methods included decomposition of Radarsat images into polarimetric parameters to test their usefulness in characterizing urban areas. Geographic object-based image analysis (GEOBIA) was used to identify urban ecosystem types following an existing classification of local climate zones. Three supervised classifiers: decision tree, random forest and support vector machine, were compared for their accuracy in mapping urban ecosystems. Ancillary geospatial datasets on roads, buildings, and Landsat-based vegetation were used to better characterize individual ecosystem assets. Change detection focused on the occurrence of changes that can impact ecosystem service supply – i.e., conversions from less to more built-up urban types. Results demonstrate that combining Radarsat polarimetric parameters with the Landsat images improved urban characterization using the GEOBIA random forest classifier. This approach for mapping urban ecosystem types provides a practical method for measuring and monitoring changes in urban areas. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents some new concepts in the petroleum systems of the northern Labrador and southern Baffin Island offshore region of eastern Canada. The focus of this work is the region of the Hekja O-71 gas discovery of 1979 by Aquitaine, one of only five wells drilled between 1976 and 1980 within an area covering some 166,000 square kilometers within the Saglek Basin. This study emerged from a broad scale re-examination of the petroleum potential of this area “from the crust up” using regional reflection, refraction and potential field data. An opportunity to use SAR (synthetic aperture radar) data from the RADARSAT-1 Earth observation satellite was taken to incorporate alternative data sources to support this exploratory review and resource assessment. Examination of the final map of interpreted slick-like features on the sea surface, revealed a close correlation of some of these occurrences to several bathymetric features which have underlying seismic signatures similar to previously identified gas hydrate “pipes” or chimney anomalies as seen in data from offshore Nova Scotia and in the Irish Sea. Globally, many active marine hydrocarbon seeps appear on the seafloor as “pockmarks”; in this case no seafloor depressions were seen on conventional multi channel 2-D seismic data associated with active seepage. Instead, very distinct mound-like structures are seen associated with seeps at two locations east of Hudson Strait. The presence of significant cold water coral in close proximity to the active seepage sites may show a link between seafloor petroleum seepage and coral reef development similar to that observed offshore Norway. Close examination of the near surface seismic character led to the interpretation of what was originally seen as seismic noise in vintage data, as likely being fluid escape chimneys or gas pipes, along the eastern edge of the Hekja structural complex, where favourable hydrocarbon trapping conditions are present. No active seeps were seen there; this may be due to other factors, such as the nature of the fluids that are escaping or the possibility of self sealing activity by biological agents such as bacterial matting with associated carbonate hard-ground formation. One seep anomaly was noted relatively close to the major basaltic eruptive complex near the Gjoa G-37 well. This may be due to the presence of volcaniclastic- hosted hydrocarbons similar in style to those recently discovered at the Rosebank field in Paleocene volcanics in the Faroe-Shetland Basin. The occurrence of an active seep in a volcanically-dominated terrain raises the potential for a radical shift in accepted types of petroleum leads and where they may occur. The presence of apparent oil seepage versus the past history of finding only gas-prone accumulations is a strong indicator that a second, oil-prone petroleum system exists in the Saglek Basin. The signs of active petroleum systems as shown by oil seep anomalies with confirming seismic evidence of discrete sea floor structures in close proximity makes a compelling argument for re-examining these areas with an eye towards stratigraphic instead of structural plays. [Copyright &y& Elsevier]

The development of effective strategies to manage the river ice breakup process or the associated risks is hindered by a lack of understanding and information. Radar earth observation satellites offer excellent potential for collecting up-to-date information on the conditions of and changes in river ice cover during the breakup period. This text describes the development, performance and limitations of an automated procedure to map breaking river ice by means of C-band, HH-polarized Synthetic Aperture Radar (SAR) images. An original two-step supervised classification model (IceBC), which uses backscatter intensities, lies at the core of the procedure. First, IceBC identifies three primary classes: water, sheet ice and rubble ice. Next, each primary ice class is divided in three secondary classes that denote top surface roughness scale differences. Input images must have incidence angles from ~27° to ~60°. Below ~36°, IceBC may assign a class labelled "unclassified" to water or sheet ice pixels. The primary classification model yields overall accuracies of ~86% and ~93% for independent test pixels with incidence angles ≤ ~49° and ≥ ~29° or ≥ ~36°, respectively. The associated class accuracies for water, sheet ice and rubble ice are ~97% & 96%, ~69% & 85% and ~97% & 99%. Given its connection to ice jam flood events, the classification accuracy achieved for rubble ice is particularly important. Maps produced by means of IceBC comprise detailed spatial information regarding ice cover conditions and the development of the breakup process. Their quality may be affected by: freezing conditions, wet snow cover, meltwater pools, infrastructure, rapids or high winds. Monitoring is the key to managing the impacts of most of these challenges. An IceBC prototype has been used operationally since 2015. Unlabelled Image • One out of three floods in Canada results from the jamming of breaking river ice. • River ice breakup processes are difficult to document and thus poorly understood. • Radar satellites are very useful for collecting data on breaking river ice cover. • Radar images are used to map water and ice cover with different roughness levels. • Our supervised classifier performs better than popular unsupervised classifiers. [ABSTRACT FROM AUTHOR]

Mariners navigating within Canadian waters rely on Canadian Hydrographic Service (CHS) navigational charts to safely reach their destinations. To fulfil this need, CHS charts must accurately reflect the current state of Canadian coastal regions. While many coastal regions are stable, others are dynamic and require frequent updates. In order to ensure that important and potentially dangerous changes are reflected in CHS products, the organization, in partnership with the Canadian Space Agency, is exploring coastal change detection through satellite remote sensing (SRS). In this work, CHS examined a hybrid shoreline extraction approach which uses both Synthetic Aperture Radar (SAR) and optical data. The approach was applied for a section of the Mackenzie River, one of Canada's most dynamic river systems. The approach used RADARSAT-2 imagery as its primary information source, due to its high positioning accuracy (5 m horizontal accuracy) and ability to allow for low and high water line charting. Landsat represented the primary optical data source due to its long historical record of Earth observation data. Additional sensors, such as Sentinel-2 and WorldView, were also used where a higher resolution was required. The shoreline extraction process is based on an image segmentation approach that uses both the radar and optical data. Critical information was collected using the automated approach to support chart updates, resulting in reductions to the financial, human and time factors present within the ship-based hydrographic survey techniques traditionally used for chart improvements. The results demonstrate the potential benefit of wide area SRS change detection within dynamic waterways for navigational chart improvements. The work also demonstrates that the approach developed for RADARSAT-2 could be implemented with data from the forthcoming RADARSAT Constellation Mission (RCM), which is critical to ensure project continuity. [ABSTRACT FROM AUTHOR]