How Technology and Big Data can Help Predict Impacts of Hurricanes

Guest Author: Steven Costa, Microsol Resources, an Autodesk Platinum Partner

For those of you who love experimenting with technology, Project Boulder for InfraWorks 360 is now available on Autodesk Labs. This technology gives you the ability to create two-dimensional (2D) flood simulations within InfraWorks 360 models. Being a New Yorker, I thought it would be interesting to see if I could model the flooding caused by Hurricane Sandy.

As you know, the effects of Hurricane Sandy on New York City’s infrastructure were considerable. Numbering among those was the East River overflowing its banks flooding large sections of Lower Manhattan, Battery Park enduring a water surge of 13.88’, the flooding of seven subway tunnels under the East River and the Ground Zero construction site. In addition, over 10 billion gallons of raw and partially treated sewage were released by the storm, 94% of which went into waters in and around New York and New Jersey. That being the case, consider waiting a couple of days after a big storm to use your Groupon to go kayaking on the Hudson!

To get started, I thought it would be easier to visualize what Manhattan looks like when impacted by a 14 foot surge so I generated a map using AutoCAD Civil 3D and Adobe Photoshop.

As you can see, a significant portion of Manhattan is affected. It’s scary to realize that according to research “had Sandy struck two weeks earlier or later, at the highest tides during the new moon, water levels could have been up to 17 inches higher than observed”!

To begin to model flooding impacts in InfraWorks 360, I scoured the web and came across the data I would need on NYC Open Data’s website. NYC Open Data is one of many online clearinghouses’ that provide GIS data free of charge. The use of that data is open to anyone looking to transform the data into something meaningful, informational and/or creative. The data I found was a digital elevation model (DEM) of New York City derived from a Light Detection and Ranging (LiDAR) scan enabling us to visualize New York City’s terrain up to a 1’ resolution. This file isn’t for the faint of heart as it weighed-in at an unzipped size of nearly 160GB (my poor SSD!). Fortunately, InfraWorks 360 allows you to set a project limit, so instead of loading the entire file I was able to just bring in the data for the area I wanted. Even this smaller segment of the file is no slouch, so make sure you have a robust CPU and GPU with plenty of RAM to tackle this beast of a file.

What I wanted to do was a full scale simulation of what happened when Hurricane Sandy’s storm surge struck lower Manhattan. The result looked something like this:

The solution, again provided by the InfraWorks 360 model and the Hydronia plug-in, allowed me to see results that I could quantify and use as a basis for a preliminary design that addresses a very real problem. Keep in mind that this was not a complete simulation, meaning that the tides, complex fluid mechanics, the geometry of the surrounding buildings, and other items were not considered. However, with this knowledge, could we as architects and engineers design something that would protect lower Manhattan from future storm surges?

To design something that could prevent the storm surge from inflicting the kinds of damage it did to New York City I started by examining the winning proposals for the Rebuild by Design design competition. One solution in particular I loved was the solution proposed by BIG (Bjarke Ingels Group) in a collaborative effort with a number of planners, architects and engineers known as the “Big U” or “Dryline”. If you haven’t seen this proposal yet, be sure to watch the Vimeo video that explains the design concept.

I reviewed some of the documentation outlining what BIG had made available to the public regarding their proposal and selected something that could be approximated in a short amount of time.  I was able to use Civil 3D and sketched out a rough shape that would be representative of the area I wanted to emulate based on BIG’s proposal.Once I did that, I wanted to produce that stepped effect but a simple offset wouldn’t do since there was a fair amount of variation among the tiers of the proposed berm. In order to make this step easier I exported my Civil 3D drawing as an EPS file that could be opened in Adobe Illustrator. Taking the original shape I drafted in Civil 3D, I created an interior boundary and used the Blend command to come up with a berm layout. Once I was happy with my results I re-imported the EPS file data back into Civil 3D and set the elevations for my proposed berm, and generated a Civil 3D surface. From here, I went to 3ds Max and added some very basic textures and imported my model into InfraWorks 360. In InfraWorks 360 I fleshed out the design with some of the built-in modeling tools to add some realism including the addition of light poles, trees, and cars.

For the true test, I ran a simulation using the existing conditions and a second simulation using the model containing my new proposed berm, providing evidence that the design could prevent a storm surge that would have otherwise completely flooded the selected area.

Of course, instinct might have told you that building a 10 or 15 foot wall would prevent the surge from flooding the Battery, but using the method outlined, you can specifically design something for yourself, test it out, and ultimately qualify what you’ve made!

To read more about the process I used to simulate the Hurricane Sandy impacts, read my two part blog post series here.

To access Project Boulder for InfraWorks 360 on Autodesk Labs go here.

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