Flood watch: Lens Lookout for flooding

What is Lens Lookout?

Lens Lookout is your automated monitoring assistant, designed to sift through and analyze all the new data in Lens as soon as it becomes available. Harnessing state-of-the-art remote sensing technology and computing power, Lens Lookout is a revolutionary new way to continuously survey your land and identify changes based on your precise criteria.

You can create custom Lookout policies based on the data and thresholds relevant to your properties. Once set up, Lens will automatically analyze all incoming data and notify you as soon as a change is detected. This post will guide you through setting up a custom Lookout policy using flooding as an example.

Looking out for flooding

If you need to stay informed about flooding on your property, Lens Lookout is here to help you comb through data so you know when certain conditions are present.  Whether you're concerned about trail damage from past floods, planning a field visit and want to avoid muddy or flooded conditions, or monitoring beaver activity, Lookout can help you stay aware of what’s happening on your property.

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1. The first thing you’ll want to do before setting up a Lookout policy is ensure that the layer you’re interested in is active on your portfolio. In this case, we want to go to the Lens Library and make sure the Surface Water (S2) Layer is turned on for our portfolio. 

2. Next, we’ll want to get a baseline understanding of what normal water levels look like on our property. For this, let’s open up Analysis. Run analysis on your entire property selecting Surface Water (S2) as the dataset. For this example, we know there is a history of flooding and want to get a sense of historic trends. There are two thresholds we want to identify and calibrate to create our lookout policy: 1) the threshold for the value of Surface Water that will trigger a flood notification, and 2) the percentage of the property at risk of flooding. Our example property had a flood in 2018 that we can use to calibrate. We can see this flood caused a spike in our Analysis graph and our goal with Lookout is to essentially create a policy that will not be triggered by the low baseline data points, but will create a notification for a flood event like this one. 

Let’s now edit our chart and switch the Chart Type to Area by Category > Custom range. Adjust the slider to only catch areas of water, for this property 0.25 is a good cutoff. This value is the first threshold we’re interested in for creating our Lookout policy. Now click Analyze to see what percentage of the property typically falls within this range of values for Surface Water. 

We can see that in a non-flooded state, about 2% of this property tends to be covered in water. And during the flood event that increases to 12%. We want to set the percentage trigger for our lookout policy somewhere between 2% and 12% - the exact percentage depends on how sensitive of an alert you want. In this case, let’s say we’re interested in any flooding event so we’ll target 4%.

3. Now it’s time to create the Lookout policy! We’ve gathered all of the information we need and can now put it into action. Navigate to the Lookout pane and click ‘Create a policy.’ Then fill in the information using Surface Water as the dataset and the thresholds you picked for your property during step 2. For the Number of Scenes, let’s keep this at 1 since flooding is usually a flash event rather than a sustained one, so we want to be notified as soon as a single sensing meets our thresholds. Click ‘Next’ and select which properties in your portfolio you want enrolled in this Lookout policy. Once you hit Finish, Lens will begin monitoring for you - now just sit back and wait for any notifications.

4. If an event occurs that meets the requirements of your Lookout Policy, you will be notified by email and/or will see the new change under the ‘Recent Activity’ section of the homepage of Lens. You can review the change notifications by clicking on a specific notification in an email or on the homepage or you can navigate to the Lookout pane of the property of interest.

Click on the change notification card to review it and decide whether you want to save it as a note or dismiss the notification. For a more thorough review, you can click the Add layer button on the top bar of Lens to view the sensing prior to when the Lookout policy was triggered, or compare with truecolor S2 imagery for additional verification. You can also cursor over the location icon on the change notification to see the total size of the change area.

Thanks for setting up a Lookout policy with us! Lens Lookout can provide peace of mind by letting you know when conditions change. Whether you’re monitoring for floods, post-fire recovery, algal blooms, or other events, Lens Lookout has you covered. Enhance your monitoring with this feature, and let us know what you’re keeping an eye on!