Automation in GIS Data Processing helps identify flood hazards and determine possible responses

Climate change is affecting people, infrastructure, and ecosystems across Canada. Although the impacts are currently most pronounced in coastal regions, people and infrastructure everywhere are at risk. Many communities and infrastructure built in floodplains are at increased risk of flooding due to the projected effects of climate change and other non-stationary factors such as wildfires, dams, and other anthropogenic changes. In response to these risks, both the Canadian federal and provincial governments are mobilizing to identify and respond to flood hazards.

The goal of flood hazard mapping is to provide the first step towards tangible improvements to public safety. Real improvement comes from planning, analyzing, and developing adaptation and mitigation projects that are successfully implemented in communities.

Once a hazard has been identified, we often conduct flood risk assessments that evaluate the path of a potential flood and quantify the damages expected to people, infrastructure, and assets (such as houses, parks, or culturally significant places). This information helps secure funding for adaptation and mitigation projects by providing a quantifiable return on investment, and helps decision-makers prioritize adaptation or mitigation projects or areas.

Custom-built GIS tools are a key part of identifying flood hazards and determining adaptation and mitigation strategies

To facilitate flood hazard and flood risk assessments, Associated Engineering uses custom-built GIS tools to identify flood hazards. With the development of new, custom-built processes, work that was previously labour and time intensive can now be completed more efficiently. This allows our team to focus on collaborating with our clients to discuss risks and mitigation strategies, and design solutions that provide tangible improvements to public safety and flood risk reduction.

These tools have been used successfully on projects, and more are in active development to expand our suite of modelling and mapping tools. Additionally, our team is working on a research assignment to further optimize flood hazard mapping and make analysis more efficient and effective.

Automation in GIS data processing, including the tools discussed below, allows our team to more efficiently identify flood hazards so that we can focus on implementing solutions.

The Tools

Our team developed these automated, GIS data-processing tools to support flood mapping for 165 kilometres of rivers in BC, as part of the Flood Hazard Identification and Mapping Program. The visuals shown are not final; final mapping will be available online within one year of project completion. The tools address the challenges of providing large-scale, high-detail flood mapping. Some of these tools include:

Survey Processing and DEM Development: Linearizing, interpolating, and overlaying bathymetric survey with LiDAR to create a representative surface for use in hydraulic modelling. These automated methods help preserve data and expedite the processing time.

Model Results Extraction and Processing: Automated comparison and combination of result surfaces allows for robust analysis of multi-hazard scenarios.

Automated Generation and Review of Legal Flood Maps: Application of required freeboard and preparation of flood construction levels using a data-driven methodology.

About the Authors:

Andromeda MacIsaac, P.Eng. is Water Resources Engineer in our Vancouver office. She has 11 years of experience in hydrology, hydraulics, hydrologic/hydraulic modelling, and integrated water resources management. Her expertise includes modelling, analysis, and design of minor and major surface water systems and related hydraulic structures, including flood-plain mapping, existing system capacity analysis, fish passage structures, bridge sizing, stormwater best management practices, inflow/infiltration, and scour protection.

Chloe Sirges, E.I.T. is a Water Resources Engineer in our Vancouver office. Her water resources experience includes hydraulic modelling, flood-risk assessment and mitigation, site inspection, bridge scour condition assessments, and coastal work. Chloe is proficient in GIS data processing and flood-plain mapping