The release of a change dataset for North America’s three largest countries will enable GIS researchers to more easily study continent-scale land use patterns that cross international borders.
The release of the 2010-2015 change product from the North American Land Change Monitoring System (NALCMS) was timed to coincide with International GIS Day, November 18, 2020.
NALCMS datasets are produced through the trinational Commission for Environmental Cooperation (CEC), which plans to roll out a series of GIS Story Maps in the coming weeks to highlight changes caused by wildfire in Canada’s Northwest Territories, urban sprawl in Dallas, Texas, USA, and aquaculture in Sinaloa, Mexico.
The stories of land change enabled by the datasets are emblematic of the importance of the CEC’s work, according to Jon Dewitz, who serves as the NALCMS project manager for the U.S. Geological Survey.
Dewitz works at the USGS Earth Resources Observation and Science Center (EROS), which produces a U.S. version of NALCMS called the National Land Cover Database (NLCD). Aligning NLCD’s land cover classes with the 19 classes used in the continental product enables broad-scale scientific research, he said.
“We are not a nation among ourselves. We’re part of a continent. When you have a product that shows change across the continent, you get that more complete picture,” Dewitz said. “What this does is provide that continuous North American look at change.”
The change data is an add-on derived from the third edition of NALCMS, which was released in early 2020 and depicts conditions on the ground as of 2015 at 30-meter spatial resolution. Earlier land cover products plotted land cover for 2005 and 2010.
The change products are a deeper dive into that data that pinpoints pixels that transitioned from one class to another between 2010 and 2015. Land cover and land change datasets are useful in a wide variety of applications, including carbon sequestration analysis, wildlife habitat mapping, ecosystem monitoring, environmental planning, water quality assessments, and evaluation of biofuels production potential.
The change dataset shows, for example, the addition of more than 10,000 square kilometers of urban land across the U.S., Mexico, and Canada between 2010 and 2015, while just 1,845 square kilometers were lost. More than 252,000 square kilometers of forest were lost, with 74,497 square kilometer gained.
The newly-released products offer a simplified way for users to scan the continent by isolating particular change transitions across the landscape, Dewitz said.
“This makes it easier for everybody. Having the change products listed as they are helps you to find the type of change you’re looking for. Especially for non-GIS types, it becomes a lot more useful,” he said.
The satellite-derived datasets are available for download and use at no cost to the public through the CEC’s website, but are also accessible through ArcGis software and through the NALCMS map viewer.
North American Land Change Monitoring System
NALCMS is a joint initiative among Natural Resources Canada (NRCan)’s Canada Centre for Mapping and Earth Observation (CCMEO), the United States Geological Survey (USGS), and three Mexican organizations: the National Institute of Statistics and Geography (Instituto Nacional de Estadística y Geografía—INEGI), the National Commission for the Knowledge and Use of Biodiversity (Comisión Nacional para el Conocimiento y Uso de la Biodiversidad—Conabio), and the National Forestry Commission (Comisión Nacional Forestal—Conafor), and supported by the Commission for Environmental Cooperation (CEC). http://www.cec.org/nalcms.
The North American Environmental Atlas
The NALCMS is part of the CEC’s North American Environmental Atlas, bringing together maps, data and interactive map layers to allow for continental and regional perspectives on environmental issues that cross boundaries.