FLOOD FORECASTING

OVERVIEW

The forecasting functionality of waterRIDE™ FLOOD Manager facilitates real time mapping of flood forecasts.

The approach taken by waterRIDE™ in flood forecasting focuses on using readily available data (hydraulic modelling results, digital elevation models, property GIS datasets, critical infrastructure GIS datasets etc) to provide an indication of likely flood behaviour and, often more importantly, the consequences of such flooding on the community and emergency management efforts.

Generally, flood warnings are issued as a predicted height at a known location (or multiple locations, often gauges) along a river. waterRIDE™ FLOOD Manager can interpolate a flood surface for the predicted gauge level using a library of design flood events (ie pre-run model results from 1D or 2D models) as a means of describing the physics of flow across the floodplain. A brief explanation of the theory can be found in the brochures and a more detailed explanation in the waterRIDE™ FLOOD Manager manual.

The predicted (interpolated) flood surface is then mapped to the DEM (Digital Elevation Model) in waterRIDE™ FLOOD Manager, allowing the user to interrogate water levels, depths and flood extents throughout the catchment, as well as integrate the predicted water surface with various GIS datasets.

If the forecasting system uses predicted flood levels at a number of gauges (or locations), waterRIDE™ FLOOD Manager will instantly generate a water surface warped through all these predicted flood levels. This addresses the emergency managers need for the prediction of "real flood surfaces" in an actual event as distinct from static design flood surfaces. For example, one part of the catchment may be experiencing a 1 in 22 year flood whilst another may be experiencing a 1 in 117 year flood! In such a manner, waterRIDE™ accommodates the spatial variation in rainfall and resulting flooding across the catchment.

The forecasting functionality of waterRIDE™ FLOOD Manager is an invaluable tool for flood emergency management personnel, allowing them to readily visualise a predicted flood, and assess properties at risk using a clear, simple, and fast interface.

The forecasting functionality can also be used as a flood planning tool. Various flood levels ("what if" scenarios) can be readily assessed and utlilised in flood planning and evacuation response planning.

In conjunction with the unique time varying water surface and live GIS analysis capabilities of waterRIDE™ FLOOD, the floodplain and emergency manager is well equipped to handle and understand flooding emergencies!

KEY FEATURES

waterRIDE™ FLOOD Manager is flexible in the source of the forecast flood levels in the catchment. At present (although this list is constantly increasing), waterRIDE™ can deliver flood surfaces and flood intelligence for the following conditions:

• forecast peak flood levels are provided at a gauge (or number of gauges) in the catchment, or

• time varying forecast flood levels are provided at a gauge (or number of gauges) in the catchment, or

• peak levels at a time in the future are provided at a gauge (or number of gauges) in the catchment, or

• a hydrologic model is executed in real-time by waterRIDE™, converting live rainfall gauge readings and/or forecast rainfall into flows in the river, which are ultimately converted into levels at key locations (gauges) using rating curves*, or

• a hydraulic model is executed in real-time by waterRIDE™ using forecast flood hydrographs*, or

• multidimensional 'libraries' can be used for multiple input variables (eg ocean levels, rainfall, varying rates of rise etc)*.

* Note that any method denoted by an asterix involves customisation of the waterRIDE™ Forecasting engine. However, all forecast surfaces and derived flood intelligence will be available from a standard waterRIDE™ FLOOD Manager (or Viewer) application. The flexible nature of the waterRIDE™ environment allows customised systems to be developed efficiently.

(predicted flood surface for a gauge level of 8m)	Single Gauge Prediction A predicted gauge level(s) is provided to the forecast system and the resulting interpolated surface is mapped to a DEM in real time.

What Do The Predicted Levels Mean? Use the standard tools in waterRIDE™ FLOOD Manager to interrogate the forecasted flood surface: - What is the likely flood depth and extent? - What properties are affected? - Calculation of flood damages - What and when inundation occurs (property, evacuation routes, entire regions) - What and when critical infrastructure is inoperable (eg loss of power, loss of communications, inundation of emergency services etc) - Timing of flood peaks - Duration of inundation - Flood impacts associated with key gauge levels	(predicted flood surface for a gauge level of 12m)

	"On the Fly" Mapping to Digital Elevation Models Predicted flood depths are created by automatically mapping the interpolated flood surface to a DEM "on the fly".

"On the Fly" Integration with Property Datasets Integrate the predicted flood level with cadastral (or any other GIS) information to determine predicted levels at specific locations. Process the predicted levels with data from the GIS table to derive information such as "depth of overfloor flooding" and "freeboard to floor level"

	"On the Fly" Integration with Property Datasets Predicted flood levels can be displayed on registered photos.
"On the Fly" Integration with GIS Datasets Combine emergency management GIS layers with predicted flood levels to show: - depth above evacuation routes - depth above critical infrastructure layer - when evacuation routes are closed
	Convert Forecast Levels Into Useful Flood Intelligence Access the forecast flood surface in waterRIDE™ FLOOD Manager and utilise any of the sophisticated tools to derive flood intelligence (the forecast surface is treated as a standard model surface by waterRIDE™) For example, the image to the left shows the "time to inundation" using a parameter query.
Forward Looking Surface If time varying water level information is available, time varying snapshot surfaces can be prepared, such as the "forward looking surface" The figure to the right shows the current flood extent in blue, the flood extent in 2 hours time in yellow, and the flood extent at the forecast peak in red.
	Sensitivity Analysis Readily compare changes in forecast levels or input parameters as different flood extents superimposed on the one view.
Wide Distribution Options Delivery of forecast flood surfaces and flood intelligence is completely flexible. Example delivery methods include (but are not limited to): " Fully interactive waterRIDE™ datasets, " LAN and WAN based, " Web-based graphics and information, " SMS and email alerts, and " Hard copy reports. The system can be configured to operate the way you want it to, rather than making your operations fit the system!

BENEFITS

Aside from access to the forecast flood surface using waterRIDE™'s array of sophisticated tools, there are a number of specific benefits to the waterRIDE™ forecasting engine, including:

" Uses readily available data - a forecasting system can be setup very quickly.

" Robust/Stable - as the engine uses predetermined datasets, there is no chance of model crashes rendering the system unusable. It can even be run a laptop in the field!

" Fast - likely flood surfaces can be calculated in as little as a few seconds!

" Powerful visualisation and interrogation - all waterRIDE™ FLOOD Manager interrogation and visualisation tools are available to analyse the forecast surface, just as if it was one of your design flood model surfaces.

" Simple to use - the waterRIDE™ interface is simple and intuitive to use, with unnecessary complexity hidden from the user unless desired. The user does not need to have hydraulic/hydrologic modelling experience to run the tool.

" Flexibility - you can use the flood forecasting capabilities of waterRIDE™ FLOOD Manager "off the shelf", or a customised system can be developed that matches your requirements and the way you wish to operate.

DATA REQUIREMENTS

At the most basic level, hydraulic modelling results from a range of flood events are required.

As more data is available, the capability of the system is enhanced. Recommended minimum additional datasets include:

" Aerial photography, and

" Digital Elevation Model

The highest level of flood intelligence can be determined with more detailed datasets such as:

" Property datasets including floor levels

" Critical Infrastructure with key levels

" Evacuation route low points

More sophisticated systems can utilise real-time gauge readings/telemetry.

LICENSING OPTIONS

The general forecasting features are part of waterRIDE™ FLOOD Manager. The more sophisticated systems require the development of a forecasting server application to manage data collection, model execution and surface preparation. However, the waterRIDE™ engine is very flexible and such applications can be readily created.

DOWNLOADS

Click here to view the Technical Specifications for waterRIDE™ FLOOD Manager

Click here to download a demonstration version of waterRIDE™ FLOOD Manager and manual

Click here to download waterRIDE™ Brochures

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