OGC blogs

  • Geomatics Web Services Used in Recent Quebec Floods
    Contributed by: 
    Nicolas Gignac and Serge Legaré

    Editor’s note: This article has been jointly written by Nicolas Gignac and Serge Legaré from the Ministry of Public Safety in Quebec. It was originally published on GoGeomatics.ca.

    During Spring 2017, a major flood occurred in Eastern Canada, centered around south west Quebec. This flood was created by abundant rainfall lasting two months during the melting season. It was among the most severe floods since 1974. It impacted heavily populated areas of southern Quebec near Montreal and Gatineau. Hundreds of square kilometers of flooded areas exceeded the 100-year record.

    Pic 1. 2017-04-01 Abundant rainfall warnings and precipitation in real time (GeoMet Web Service Weather Radar) issued by Environment Canada.

    Rainfall tends to last for weeks in Eastern Canada, as snow melts in the northern area as early as the beginning of April. Public Safety Quebec Emergency Operational Center (PSQ-EOC) monitors the situation 24/7 by coordinating assistance with its partners in all regions of Quebec. As flows started rising at the end of April, the Quebec government decided to move its PSQ-EOC from Quebec City to Montreal to be closer to the affected area. The flow peaked on May 8. The situation needed good coordination and planning, as experts, emergency teams, and army were mobilized on the ground to assist citizens and the municipal manager.

    Pic 2. © [2017] Airbus Defense and Space, License by Planet Labs Geomatics Corp., www.blackbridge.com/geomatics

    Here is a summary of statistics for this unusual flood in southern Quebec:

    • Active operations of PSQ-EOC lasted from 5 April to 5 June
    • 23 conference calls were held between May 5 and 19
    • 78 reports were published by PSQ-EOC to follow up and inform partners during operations
    • 1,500+ employees were mobilized in various Government of Quebec departments and agencies
    • 261 municipalities were affected; State of Emergency was declared in 22; 170+ used the provincial financial assistance program
    • 5,371 residences were flooded
    • 4,066 people were evacuated
    • ~550 roads were damaged
    • 3 deaths took place
    • 2,600 Canadian military personnel were engaged in operations
    • As at June 2, $13,581,663 was paid through the Quebec's Specific Financial Assistance Program for Floods

    It was important to closely monitor the situation, especially: meteorological events; hydrological impacts; past, present and future flood areas; affected municipalities; status of the road network; and the level of flows. Related information was requested to assist emergency managers working in this wide and densely populated region. Consequently, PSQ-EOC and its partners had to request, access, purchase, integrate, and publish various geomatics products to support decision making. During this event, one of the mandates of PSQ-EOC operations was to coordinate all those geomatics operations. In such a major disaster, organisations, journalists, and citizens typically look for near real-time information. They usually search web maps to provide a quick overview as 'a picture worth a thousand words'!

    To reuse web mapping products and minimize administrative barriers in this time-critical situation, the decision was made to openly offer all products through public URLs as standard Web OGC services. They included:

    1. Web Map Service (WMS): for overlays with a clear symbology
    2. Web Map Service Time (WMS-Time): for historical analysis for near real-time data
    3. Web Feature Services (WFS): for raw open data to process and mapping
    4. Web Map Tile Service (WMTS): for base maps

    All these services were hosted in a solid Open GIS Infrastructure, called IGO (Open Geomatics Infrastructure: www.igouverte.org/english/). IGO was developed by the Quebec government and hosted by Public Safety Quebec. Adding to this, there was also an easy-to-use interactive web mapping application adapted to mobile devices that universally depicted the evolution of the event using these web services.

    Here are the main facts related to the high demand of these geomatics services during this period:

    • 45 million web requests occurred just in May on geomatics Public Safety Quebec Web GIS servers
    • A maximum of 100 queries per second and 6-7 million queries per day occurred on May 7-8, 2017 on these same servers
    • 30+ satellite images products were shared and published (Radarsat-2, SPOT, Pleiades)
    • 50+ map layers in OGC Web services (WMS, WFS) and in a web map application through regular browsers and mobile devices
    • Activation of the International Charter "Space and Major Disasters" in Eastern Canada on May 6th, 2017
    • Several requests were made for thematic mapping products and spatial analysis on flooded areas for different operational and administrative needs

    Usually, Public Safety Quebec requests radar imageries to monitor ice river conditions and mapped ice jamming with certain known high risk flood areas during the spring season, under its Radarsat-2 agreement with Public Safety Canada. However, in April and May of this year, emergency events were more related to flood in open water situation, not the usual ice jam situation. Quebec Public Safety therefore had to adapt its processes and ask Natural Resources Canada (NRCan) Emergency Geomatics Services group (EGS) to test a new NRCAN image processing algorithm for the first time. This emergency service was developed in a near real-time event to map the extent of floods in an open water situation. This new algorithm for open water situation was recently developed by using high-resolution radar satellite images (e.g. 9m resolution). This was like the ones that were already ordered by Public Safety Quebec.

    Pic 3. Map of polygon extent

    Maximum extent polygons were then generated derived from a system operated by NRCan's Strategic Policy and Results Sector (SPSR) using radar satellite imagery products (ex. Radarsat-2, TerraSar -X, Sentinel) from PSQ-EOC. These mapping products were then shared with partners and processed by SPSR for quick validation by PSQ-EOC. During the event, these products were distributed in near real-time, depending on imaging availability (approximately every three days for Radarsat-2). These polygons products represented the extent of water in urban and vegetated environment. It should be noted that the product was a near real-time interpretation of satellite data and was not fully validated during the emergency phase.

    Pic 4. Second map of polygon extent

    In order to monitor the evolution of the water level on the infrastructure more effectively, and to map historical maximum of the flood, other satellite imageries in the visible and infrared spectrum (SPOT 1.5 m resolution and Pleiades resolution 50 cm) were also purchased and processed. These images were acquired in particular through PSQ-EOC with Ministry of Energy and Resource of Quebec in order to ensure coherence between public safety needs and various sensors available on the market. To facilitate the exchange of information between government and agencies, discussions were held real-time through an online collaborative platform. The acquired images were made available by the Government of Quebec a few hours after data capture to RNCAN for validation. Moreover, these images in the visible and infrared spectrum were made available later in the summer to the general public with the agreement made with the private operators of the satellites (Distribution Astrium Services, Airbus Defense and Space) a few weeks later by Web service and in the Open Data portal: Données Québec (www.donneesquebec.ca).

    Pic 5. Includes equipment © CNES (2017), Distribution Astrium Services / Spot Image Corporation, USA, all rights reserved

    PSQ-EOC also received the support from Transport Canada through its National Aerial Surveillance Program (NASP) to acquire oblique images for the impacted areas. Two aircrafts from Transport Canada, the Moncton-based Dash-8 and the Ottawa-based Dash-7, flew over flooded areas from May 7th to 16th and acquired more than 14,000 oblique images. NRCan's developed a standardised web-based service (WMS) shared with Public Safety Quebec to get an overview of these 14,000 oblique images acquired and integrated into their Web mapping applications. These oblique images were also used by NRCan to validate their polygons for the extent of open water in their process.

    Pic 6. PNSA 2017-05-15 Lake Saint-Pierre at Highway 40

    Here is a summary of the geomatics data used and made available to the general public:

    Geomatics work will continue during the current recovery phase to more accurately determine the historical maximum flood by reusing NRCan's polygons maximum extent and validating them with field operations to be made in the upcoming months. Discussions with OpenStreetMap community of mappers about their involvement will also take place.

    Recently, Public Safety Quebec was also able to test a new web mapping application adapted for mobile devices and developed by the government (https://geoegl.msp.gouv.qc.ca/igo2/apercu-qc/?context=inondation). This solution called Open Geomatics Infrastructure version 2.0 (IGO2: https://github.com/infra-geo-ouverte/igo2) was offered from a mobile device to easily track floods. IGO 2.0 is an open source GIS development project carried out in partnership with many organisations in Quebec. This solution follows the latest web trends (mobility, API searching tool, simplicity, offline tool) and geomatics (OGC web service, time analysis). It will be enhanced in the coming months with new features. This solution is based on other open source projects, such OpenLayers 4, Google Angular 4, and Google Material. For now, it has been made available to the public in the application gallery of Quebec's Open Data Portal: Données Québec (www.donneesquebec.ca/fr/applications/). At the same time, another internal secure version of IGO2 for Public Safety organisations was successfully tested on mobile devices at the PSQ-EOC.

    Pic 7. Web mapping application – IGO2.

    An indication that GIS Web services or products were needed by citizen and the media was that much data and web GIS application were intensely used to inform the public. These geospatial data and maps available on the Web have been widely publicized by various media during this major events. These include (some only in French):

    GIS Web services has proven to be very useful by the media and popular to follow other disaster events this year, such as Forest Fire in British Columbia and Hurricane Harvey in Texas.

  • Advancing standards for marine data
    Contributed by: 
    Scott Simmons

     

    The OGC has long maintained standards that are used in the marine domain. These standards have been applied to studies of bathymetry, ocean science, navigation, logistics, and more. Long-standing Domain Working Groups (DWGs) in the OGC provide expertise in ocean science (Meteorology and Oceanography DWG) and safety of navigation (Defense and Intelligence DWG). However, only a small subset of the diverse disciplines that work in the marine environment have representatives in OGC’s membership. Thus, in 2016 theMarine DWG was established to provide a forum for discussion across marine topics and to link the OGC with other organizations in the field.

     

    As the Marine DWG was being established, the OGC also formed an alliance with the International Hydrographic Organization (IHO -www.iho.int), a body dedicated to ensuring that the world’s navigable waterways are surveyed and charted, and that the data are accessible to all stakeholders through the use of international standards. The OGC and IHO now regularly support each other through attendance at each others’ events, and together they jointly chair the OGC Marine DWG. The Marine DWG is already promoting a future Concept Development Study for a Marine Spatial Data Infrastructure (MSDI) and is considering various whitepaper topics to illustrate the advantages of standards and data accessibility to the marine community.

     

    The OGC and the IHO are also key participants in the United Nations Committee of Experts on Global Geospatial Information Management (UN-GGIM -ggim.un.org). The UN-GGIM has a broad mission to develop global geospatial data and associated infrastructure, primarily in support of the UN Sustainable Development goals. Now, with the support of IHO and OGC, the UN-GGIM has established a Working Group on Marine Geospatial Information (MGIWG) in recognition that marine data are a critical part of a global geospatial data infrastructure. For an excellent summary of the UN-GGIM work in this area, please seeIHO Circular Letter 47/2017.

     

    So, how can you get involved? TheMarine DWG is open to all. Subscribe to themailing list and visit the publicwiki. Considerjoining the OGC or working with your national representatives to the IHO to have your opinion heard. And finally, take advantage of the output of these efforts: discoverable and interoperable data are of benefit to all of us.

     

    Image courtesy of NRCan: http://www.bedfordbasin.ca/halifaxharbour/DVD/fig7-eng.php

  • OGC, INSPIRE, and Metadata
    Contributed by: 
    Carl Reed

    Metadata is critical for geospatial resource discovery, determination of fitness for purpose, and more. The value of metadata lies in the structure and meaning that it provides. Metadata serves asset discovery by identifying assets and allowing them to be found by relevant criteria. Metadata also brings similar assets together and distinguishes dissimilar assets. Value is added to data and service holdings. Standards for the creation and use of metadata have a long history in the OGC, as well as many ongoing SDI activities such as INSPIRE and the US Geoplatform Activity.

    This is why a key OGC CDB Standards Working Group (SWG) activity is enhancing the OGC CDB standard to define requirements and practices for metadata. CDB version 1.0 does not provide any guidance on the use of metadata as used in the geospatial community. These metadata enhancements are planned for CDB version 1.1. As part of this activity, the SWG investigated a number of metadata standards used in the geospatial community. Major metadata activities such as those in INSPIRE were also evaluated. The review of the INSPIRE Metadata Technical Guidance and related documents led me to write this blog.

    The investigation of INSPIRE metadata requirements and related technical guidance was very educational but not easy. A fairly large number of documents need to be read and understood in order to implement metadata that’s compliant with the INSPIRE technical guidance.

    Article 5 sub-clause 1 of the INSPIRE Directive states, “Member States shall ensure that metadata are created for the spatial data sets and services corresponding to the themes listed in Annexes I, II and III, and that those metadata are kept up to date.” The directive does not define what metadata standard or related technologies to use. The Directive states basic requirements. The implementing guidance is provided in a separate, very detailed document INSPIRE Metadata Implementing Rules: Technical Guidelines based on EN ISO 19115 and EN ISO 19119. This document specifies the requirements for implementing INSPIRE compliant metadata based on various ISO standards, specifically 19115:2005 and 19119:2005. This guidance defines which elements are mandatory and which are conditional or optional. Other documents provide additional technical guidance. There are also metadata validation and compliance policies and related tools.

    In addition to the INSPIRE metadata mandate and guidance, governments in the EU also need to comply with the requirement to achieve cross portal metadata interoperability. This requirement states that metadata provided and/or used in an INSPIRE compliant geoportal must interoperate with metadata from other eGovernment portals. The eGovernment portals use a European Union de-facto standard called DCAT-AP. DCAT-AP was developed as part of the EU Programme Interoperability solutions for public administrations, businesses and citizens (ISA²) “with the purpose of defining a cross-domain metadata interchange format that can be used to share dataset metadata across data catalogues operated across the EU.”

    Within this context, under the EU ISA Program, and taking into account the INSPIRE metadata profile and relevant ISO standards on which it is based, the community developed a geospatial profile of DCAT-AP: GeoDCAT-AP. The work was coordinated by a Working Group with representatives from the EU Member States led by JRC. The profile has been endorsed by the Member States through the ISA SIS Group / Coordination Group / TIE Cluster where Member States ‘adopt’ e-Government solutions. There is no legislation as is the case for INSPIRE.

    GeoDCAT-AP is specifically designed to enable the sharing of geospatial metadata, in particular those available via the INSPIRE infrastructure. GeoDCAT-AP defines mappings from ISO 19115 (the ISO standard for geospatial metadata) to DCAT-AP and other general-purpose RDF vocabularies. The GeoDCAT-AP work included the development of an API. This API provides the ability able to transform on the fly ISO 19139 records into DCAT-AP or GeoDCAT-AP. ISO 19139 defines an XML-based implementation of ISO 19115. Please note that the GeoDCAT-AP specification does not replace the INSPIRE Metadata Regulation nor the INSPIRE Metadata technical guidelines based on ISO 19115 and ISO19119. The purpose of GeoDCAT-AP is to give owners of geospatial metadata the possibility to achieve more visibility by providing an additional RDF syntax binding. Of course, at least to me, this raises the question of whether the current INSPIRE Metadata guidance and related policy directives need to evolve to meet market and user needs.

    What does all this mean?

    The INSPIRE metadata requirements were originally specified in the mid-2000s and the technical guidance originally published in 2007 and the implementing rules published in 2008. Ten years is an eternity in IT. Since then, there has been a tremendous move to using web technologies for discovery, linking, and access to information resources. Issues, such as the metadata technical guidance being XML based, need to be addressed. The Web world is moving away from XML to other technologies such as JSON and RDF. Today’s users want to use search engines to express queries and discover ‘fit for purpose’ spatial data. More and more users want applications that easily link data resources and enable rapid discovery traversal of these resources. At the end of the day, users are recognizing the need for a web of spatial resources. However, as stated in the W3C Data on the Web Best Practices Recommendation: “The openness and flexibility of the Web creates new challenges for data publishers and data consumers, such as how to represent, describe and make data available in a way that it will be easy to find and to understand.”

    There is a tension within the INSPIRE community. Much of the tension is a response to the market and user forcing functions. Another factor is a desire for more simple approaches that reduce the complexity and costs of the current in force technical guidance and related compliance requirements. In some ways, INSPIRE is facing the same technology life cycle and evolution challenges that any software company has to deal with: how does one move forward to capitalize on better technologies and user experience without destroying investments in existing infrastructure and knowledge base?

    This is not just an INSPIRE issue. This is a geospatial industry wide issue (although INSPIRE has the additional challenge of EU legislation and compliance requirements). As an industry wide issue, we need to work collaboratively to make sure that current and future requirements for metadata and spatial resource discovery are addressed. In recognition of this need, over the last few years the synergies between the INSPIRE community, the OGC, and the W3C have increased. Evidence of this collaboration is the joint W3C/OGC Spatial Data on the Web Working Group, increasing DCAT and DCAT-AP discussions in the OGC, and the INSPIRE ‘What If’ sessions at the 2017 Delft OGC meeting and this September’s INSPIRE Conference. These collaborative efforts need to not just continue but to expand. The long-term success of INSPIRE and other SDI activities rest on our ability to identify and document standards and best practices that enable the agility and flexibility to meet the ever-changing landscape of policy, user needs, and technology.


Markus Schneider blog

Simple Features

On INSPIRE, rich application schemas, GML and deegree in general
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