On this blog most of the discussion relating to underground infrastructure has been focused on construction focussing on the risks to workers and the public and the drag on the economics of construction. There are other important impacts to not knowing where underground utilities and telecommunications infrastructure are. During natural and man-made emergencies, there are two problems relating to underground infrastructure that emergency managers have to face. The first is that, as Scott Sternfeld emphasized at the December Open Geospatial Consortium (OGC) Energy Summit at EPRI in Charlotte, there is no public regional, state or national outage map in the U.S. Emergency management personnel have to go to each utility one by one. Utilities may not have an online outage map, which means calling them. This problem is exacerbated by a lack of shared, reliable information about the location of infrastructure. Together these problems severely hamper first responders. At the Energy Summit Tatjana Kutzner, working with Thomas Kolbe, presented on a utility extension to the OGC standard for city modeling, CityGML, that allows modeling of multi-utility networks in an urban environment including interdependencies between them.
Disaster management use case
I remember being impressed by the UK Environment Agency's flood modeling simulations after the 2007 floods in the UK. And also by Ergon Energy's flood assessment during the Queensland floods in 2011. In both these examples a digital terrain model and information about building footprints and elevations were used to determine if a substation or a pumping station were likely affected. It seemed to me at the time that using that information plus network connectivity from utilities would make it possible to determine customers who likely were without power or water. From a utility GIS perspective this is not a difficult calculation. Many utilities know for about 85% of their customers which feeder they are attached to and a simple network trace would enable them to determine who will likely be affected by a transformer or substation outage. Thomas Kolbe and co-workers having been working for some time on a standards-based model for interdependent utility networks to provide a foundation for this type of modeling.
The next step is determining interdependencies. If a feeder providing power to a pumping station has lost power, then using the water utility's network connectivity it is possible to determine which customers are likely without water. If all interdependencies are considered including electric power, communications, water, district heating, and others it is possible to determine all the customers who are affected by a storm or other disaster, how they are affected and to prioritize restoration efforts.
Integrated modeling of multi-utility networks
Standards exist for modeling specific types of utility networks, for example, for electric power the CIM and Multispeak standards are widely used. However, there is currently no standard for representing all utilities in an urban environment including interdependencies. At the Energy Summit Tatjana Kutzner presented on the work that she and others are doing to address this serious lack of sharable information for emergency managers.
To provide emergency managers access to the utility information they need to put together a composite assessment of the impact of a storm, flood or other disaster requires a model that can model network 3D geometry (location), topology and function, can represent all utility networks simultaneously, can represent the interdependencies between them, is hierachical - able to represent high, medium and low voltage electric or transmission and distribution water networks, and is able to interact with a city model to ultimately determine who is affected by a disaster and how. Such a model makes enables analysis and visualization during a disaster and to simulate different different disaster scenarios.
Utility application domain extension (ADE)
Thomas Kolbe and co-workers are the developers of the CityGML standard that has been adopted by the Open Geospatial Consortium. There are several Application Domain Extensions (ADEs) that have been developed to extend CityGML to other domains. In 2010 a basic extension Utility Networks ADE was proposed for city utility networks. The intention is to model infrastructure networks both as a 3D topographic, topological and and functional network. In other words, this is not simply a compilation of network as-builts, but includes the function of each component and its relationships to other components. It knows the difference between different network topologies; water, electric power, steam, wastewater, and communications. It also knows the interdependencies between different networks.
Tatjana explained how the Utility Network ADE extends CityGML to utilities with a common network core, different network components including functional components and materials classes and packages for specific utilities: electricity, district heating, water and so on. She also discussed how the Utility ADE relates to existing network standards. For example, the electric network package is based on CIM and allows interoperability with CIM. It doesn't include all of CIM, but only those elements that are important for the use cases that the Utility ADE is intended to address.
Applications
She described a several projects that have used the utility ADE to model different disaster scenarios.
- Simulating cascading failures in Berlin (SIMCAS 3D)
- Risk analysis of supply infrastructure for the German Armed Forces. Simulation of the propagation of an explosion at a substation to determine how many people would be affected in order to estimate the number of water trucks that would be required to provide water.
- Linking below ground and above ground infrastructure (Xander den Dujin Masters Thesis TU Delft). Simulation of damage to the below ground electric power network and using pgRoute to determine which street lights would be out.
- Modelling, simulation and visualization of dependencies between drinking water and electrical networks at a combined drinking water facility hydroelectric power station in Nanaimo, British Columbia (Isaac Boates Masters Thesis University of Applied Sciences Karlsruhe).
I should add parenthetically that although there is no public regional, state or national outage map in the U.S. there are ways of mapping outages using social networks. DataCapable's Global Power Outage Tracker mines social media and then generates map visualizations using a GIS. The data is presented on a mapping dashboard, showing the time and location of each tweet found.
Conclusion
The Utility Network ADE Core extension supports geospatial, topographic and functional modeling of multi-utility networks. It supports modeling of different types of networks including electric power, water, and gas networks. Because it is an extension to the CityGML urban model the ADE supports linking utility networks with city structures including residential, commercial and industrial. It is designed to build on existing utility network models such as CIM for electric power networks. It provides a data model for modeling multi-utility scenarios including interdependencies and can be applied for analyzing, visualizing and simulating the disaster scenarios mentioned at the beginning of this blog which involve cascading network failures. In addition it probably contains all of the data elements required for including distribution analytics for electric power and water networks which would enable this to provide the basis for dynamic modeling of multi-utility networks.
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