CoastalDEM®: Accurate elevation data for accurate flood risk assessment

Request Dataset+1.609.986.1990

The leading global DEM averages more than 2 meters (6 feet) too high. That's taller than most coastal floods. Use CoastalDEM instead.

Available for non-commercial and commercial purposes.

CoastalDEM®

CoastalDEM is Climate Central's proprietary, high-accuracy Digital Elevation Model for coastal areas. It reduces median errors in NASA's widely-used SRTM DEM to near zero, and reveals flood threats more than three times larger. Top-accuracy DEMs from airborne lidar are unavailable for most of Asia, Africa and Latin America. CoastalDEM can help you understand coastal risk in these areas and globally.

Or inquire about our Portfolio Analysis Tool, and let us quantify coastal flood risk for you.

Billions in real estate investments
near the coast are going to reprice.

Coastal flooding is accelerating and coming to new locations. Some may be in your portfolio. Real estate values are already taking a hit – directly by flood damage and indirectly when insurance, roads and services are impacted. 

Are you underestimating your coastal flood risk?

CoastalDEM® is a digital terrain model providing bare earth elevations for low-lying coastal areas between latitudes 60N and 56S. It has continuous vertical resolution and 1 arc second (~100 foot) horizontal resolution. By contrast, NASA's SRTM DEM provides elevation in 1-meter (3.3-ft) vertical increments instead of continuous values. Because SRTM is a digital surface model that fails to exclude treetops and rooftops, SRTM overestimates ground elevations by more than 2 meters (6 feet) on average and, in dense cities, more than twice that. As a result, SRTM severely underestimates coastal threats. SRTM’s average error exceeds the height of most coastal floods today and most 21st century sea level rise projections – meaning that many areas face much greater flood risk than SRTM-based analyses suggest.  Assessments based on CoastalDEM find more than 3X the number of people on land potentially exposed to these coastal threats, compared to SRTM.

Climate Central scientists created CoastalDEM using sophisticated machine-learning techniques to improve on the SRTM dataset. Validation tests indicate CoastalDEM has almost no vertical bias (under four inches in the most reliable tests) and cuts SRTM's error scatter nearly in half.

CoastalDEM also outperforms other recent global DEMs: AW3D30 and MERITDEM produce coastal exposure estimates similar to SRTM.

CoastalDEM is based on rigorous peer-reviewed science – and costs pennies on the dollar versus commercial products that may have vertical accuracy comparable to CoastalDEM.

View the CoastalDEM flier to see sample images and comparison statistics.

Request Dataset+1.609.986.1990

Climate Central is a non-profit
research organization providing authoritative,  science-based information products to help public and corporate stakeholders make sound decisions about climate and energy. Hundreds of thousands have used our tools, including professionals in real estate, insurance, banking and government.

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Our analysts bring you top research and datasets to help you manage risk in a changing climate. We provide practical information you can use in your business, organization or community.

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CoastalDEM®: Accurate elevation data for accurate flood risk assessment

The leading global DEM averages more than 2 meters (6 feet) too high. That's taller than most coastal floods. Use CoastalDEM instead.

Available for non-commercial and commercial purposes.

CoastalDEM is Climate Central's proprietary, high-accuracy Digital Elevation Model for coastal areas. It reduces median errors in NASA's widely-used SRTM DEM to near zero, and reveals flood threats more than three times larger. Top-accuracy DEMs from airborne lidar are unavailable for most of Asia, Africa and Latin America. CoastalDEM can help you understand coastal risk in these areas and globally.

Or inquire about our Portfolio Analysis Tool, and let us quantify coastal flood risk for you.

CoastalDEM®

Coastal flooding is accelerating and coming to new locations. Some may be in your portfolio. Real estate values are already taking a hit – directly by flood damage and indirectly when insurance, roads and services are impacted. 

Billions in real estate investments
near the coast are going to reprice.

CoastalDEM® is a digital terrain model providing bare earth elevations for low-lying coastal areas between latitudes 60N and 56S. It has continuous vertical resolution and 1 arc second (~100 foot) horizontal resolution. By contrast, NASA's SRTM DEM provides elevation in 1-meter (3.3-ft) vertical increments instead of continuous values. Because SRTM is a digital surface model that fails to exclude treetops and rooftops, SRTM overestimates ground elevations by more than 2 meters (6 feet) on average and, in dense cities, more than twice that. As a result, SRTM severely underestimates coastal threats. SRTM’s average error exceeds the height of most coastal floods today and most 21st century sea level rise projections – meaning that many areas face much greater flood risk than SRTM-based analyses suggest.  Assessments based on CoastalDEM find more than 3X the number of people on land potentially exposed to these coastal threats, compared to SRTM.

Climate Central scientists created CoastalDEM using sophisticated machine-learning techniques to improve on the SRTM dataset. Validation tests indicate CoastalDEM has almost no vertical bias (under four inches in the most reliable tests) and cuts SRTM's error scatter nearly in half.

CoastalDEM also outperforms other recent global DEMs: AW3D30 and MERITDEM produce coastal exposure estimates similar to SRTM.

CoastalDEM is based on rigorous peer-reviewed science – and costs pennies on the dollar versus commercial products that may have vertical accuracy comparable to CoastalDEM.

View the CoastalDEM flier to see sample images and comparison statistics.

Climate Central is a non-profit
research organization

providing authoritative,  science-based information products to help public and corporate stakeholders make sound decisions about climate and energy. Hundreds of thousands have used our tools, including professionals in real estate, insurance, banking and government.

Our analysts bring you top research and datasets to help you manage risk in a changing climate. We provide practical information you can use in your business, organization or community.

2050 flood exposure* - SRTM

2050 flood exposure* - CoastalDEM

CoastalDEM offers important improvements over the most common alternative.

CoastalDEM reveals significant increases in projected flood exposure in coastal areas as sea levels rise. Here is an example for average annual flood height near Bangkok, Thailand in 2050.

* Maps reflect inland elevations relative to the extreme coastal water levels and do not incorporate potential defenses, such as seawalls and levees. Greenhouse gas emissions pathway: moderate emissions cuts (RCP 4.5) roughly consistent with the Paris climate agreement's two-degree target. Sea level rise model: Kopp et al. 2014, median climate sensitivity.

CoastalDEM offers important improvements over the most common alternative.

CoastalDEM reveals significant increases in projected flood exposure in coastal areas as sea levels rise. Here is an example for average annual flood height near Bangkok, Thailand in 2050.

For information about CoastalDEM® datasets and licensing, please select a dataset.

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2050 flood exposure* - CoastalDEM

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