The Land Change Monitoring Assessment, and Projection
Initiative by the U.S. Geological Survey addresses the pressing need
to monitor and understand land change.
LCMAP is the foundation for an integrated USGS-wide land change
science framework, and supports the development of consistent data
and land cover products spanning large geographic extents
over extended periods and at a higher frequency than in the past.
LCMAP published 10 new science products.
All are developed from Landsat Analysis Ready Data
using a time series modeling approach.
The products include annual land cover using a classification
similar to Anderson level 1.
LCMAP provides users with both primary and secondary land cover,
and their associated model confidences.
The Annual Land Cover Change product is a derivative of
the Primary Land Cover.
When a change occurs between years, pixels are attributed with
the from-to classes.
The spectral products describe change as indicated by
the Landsat time series model, which is estimated
at a daily timestep.
The Spectral Model Quality product describes model details
for each pixel.
All LCMAP products are currently available for the contiguous
United States.
The Landsat ARD are modeled through time at a daily timestep.
Aspects of the resultant models are then described
in a suite of ten products.
The spectral change products are meant to inform one another,
as they are coincident in time and space.
The spectral change products include Time of Spectral Change
(this is when the spectral data no longer fit the model and cause
a break)
the Change in Magnitude, which is a measure of the spectral difference
before and after that break.
Other products include a count of days since the break,
and a count of days the current model was stable.
Again, the spectral model quality data are also provided.
These data and a boosted decision tree, specifically XGBoost,
were used to classify land cover.
LCMAP provides an annual product for the most likely land cover class
on July 1 of each year.
Also provided are the second most likely land cover classes
on July 1, and their associated confidences for each classification,
enabling users to determine if a secondary class assignment is useful
for their specific application.
LCMAP Collection 1 science products are useful for a variety of
science applications.
The products are appropriate for assessing land changes
at local to continental scales.
Land surface changes are important to the land science community.
These changes include single event types of change related to
natural hazards such as landslides, wildfire, damage from tornado
or hurricanes, and other gradual changes such as urban sprawl
and increasing surface water in response to shifts in climate.
In an animation of the annual land cover change product,
the dark green color represents pixels classified as tree cover.
In the tree covered area, purple pops up.
Purple represents class change.
The tree cover is replaced by grass/shrub after timber harvest.
Once the trees are replanted and the stand matures,
another land class change occurs: grass/shrub back to tree cover.
This pattern through time exemplifies the cylindrical nature
of forest harvest and regrowth.
A change in the year of 2014 of the animation was a devastating
land slide.
In the space of a minute, 19 million tons of debris traveled at
40 miles per hour.
The Oso Landslide in Washington involved a complex sequence
of geological and hydrological events that ultimately
resulted in a debris avalanche flow.
Zooming into the landslide area, the area is yellow in the
Time of Spectral Change product.
These changes were detected during the months of March and April.
The timing of the change aligns well with the March 22nd event.
The Magnitude product shows the difference in the spectral
properties before and after the landslide.
The magnitudes were greatest for the area where the initial instability
or slope failure occurred.
The other area with high magnitude is where the debris from
the landslide destroyed the tree cover.
The Santa Fe National Forest in New Mexico
has a history of wildfires.
Many of those are identified as land cover change
in the LCMAP Change product.
On the left, mapped fires from the Monitoring Trends in Burn Severity
(or MTBS) are shown.
The red perimeter is for the largest fire in
New Mexico's history.
The Las Conchas fire started on June 26, 2011,
in the Jemez Mountains.
When the fire was contained on August 3rd, it had burned
nearly 160,000 acres of mixed conifer, pinyon/juniper,
and Ponderosa forest.
The high severity of the fire was associated with forest health,
due to drought and bark beetle stress.
In the Time of Spectral Change product, changes were
estimated to occur in the July time frame.
Most of the change occurring in the 2011 annual products
correspond to the MTBS Fire perimeter shown in red.
Since the fire occurred towards the end of June and burned
until August, an estimate of timing of change during the month of July
is reasonable.
The Magnitude of Spectral Change, coincident in time,
shows the majority of the fire perimeter had moderate
spectral change.
The variance in magnitude suggests some areas may have more variation
and burn severity.
On April 27, 2011 a record number of tornados touched down
across the southern United States resulting in the loss of life
and property.
The tornados' paths appear as long purple stripes of change
in the Annual Land Cover Change products.
In the Time of Spectral Change products,
the estimate of timing of change or model break was early May, 2011
just after the deadly storm.
The Change Magnitude product captures surface changes
and indicates moderate spectral response for pixels in the
tornados' paths.
Hurricane Andrew, its path shown as a green line, formed over
the Atlantic Ocean and made landfall in south Florida in August of 1992.
The hurricane was a category 5 storm causing significant damage
to wetlands in Everglades National Park.
Perhaps the most dramatic effect of its passage through the park
was the major structure damage to trees and mangroves caused by
strong winds and storm surge.
The Time of Spectral Change product indicates changes were detected
along the coast in September and October, shown in purple,
while the Magnitude product indicates moderate change
corresponding to a September- October time frame.
In August of 2005, Hurricane Katrina (its path shown in green)
made landfall on the Atlantic side of Florida as a category 1
and weakened only slightly before moving into the Gulf of Mexico.
Later that same year in October, Hurricane Wilma, its path shown in
purple, made landfall in southwest Florida and tracked towards the
northeast.
Most of the damage from the hurricane is on the Gulf coast
of the state, and once again the spectral magnitude indicates
moderate change.
Unlike Hurricane Andrew on the previous slide,
these hurricanes had a more northerly path,
and change isn't prevalent on the eastern or Atlantic coasts.
If we look at the primary land cover product, we see that the Atlantic
coast is developed land cover.
The southwestern part of the state is home to the Everglades
National Park, which contains 1.5 million acres of wetlands.
The vegetation is likely more susceptible to spectral change
before and after storm events.
Since 1990, Meridian has experienced exponential growth,
becoming the second largest city in Idaho, and one of the
top 10 fastest growing cities in the nation, coming in at number 3
in 2020.
The recent trends in urban development, especially zoning
changes to allow for construction of high-density housing,
have current residents concerned about how that will affect
the remaining mostly rural community.
In the 1990s to 2000, there were only one neighborhood in Meridian
with more than 12 people per acre.
The LCMAP Primary Land Cover product shows an ongoing conversion from
cropland to developed through this time period.
The late 1980s were dry in the upper plain states.
Prior to the mid 1990s, the region saw an uptick in precipitation
and that continued during most of the subsequent years.
This change in moisture, along with higher commodity prices,
led many to convert grasslands into cropland.
In the animation, patches of cropland increase through time.
Also the number of wetlands and lakes increases.
The expansion of central pivot irrigation are visible as round
circles of cropland.
These land cover changes indicate a decrease in grassland connectivity
and an increase in wetland connectivity.
The Spectral Stability Product shows the number of days that have
passed since a spectral change, whether due to a land cover
class change, or only a change in condition.
As the animation shows each year through time pixels without change
will continue up the color ramp from orange, or zero,
at the beginning of the time series, through the yellows,
and then blue-green.
Pixels with change due to a model break will be recoded
to zero days and start the count of days of stability over.
With this long record of big data provided by the Landsat ARD,
we now know that about 12% of the U.S. has experienced a land cover
change through this period, and less than 1% changes annually.
But in certain regions, take the southeast for example,
it's dominated by intense commercial timber management.
This land use lends to changes in thematic land cover more often
as tree cover changes to grass/shrub and back to tree cover through time.
In contrast, the western U.S.'s change is driven by
ecosystems that are severely impacted by drought conditions.
The data from 33 years of LCMAP products contribute to a better
understanding of land change in the United States.
Moving forward, LCMAP will be releasing products for
the years 2018 and 2019 in the coming months.
We are also working on Hawaii and the Alaska collection.
Collection 2.0 LCMAP science products will be developed
and available in a cloud environment.
LCMAP is establishing a land cover Science working group
and we are looking to expand collaborations and partnerships.
To receive our latest news, please subscribe at the link provided.
LCMAP provides solutions to the science and management communities'
growing needs for an improved understanding of fundamental drivers
of land change, the consequences of change in human and natural
systems, and feedbacks associated with land change processes.
For access to data, LCMAP Collection 1 science products
can be downloaded by Landsat ARD tile on EarthExplorer, or
by area of interest using the LCMAP Viewer.
More information as well as supporting documentation
can be found at USGS.gov/lcmap
For those interested in joining our team, LCMAP has
2 Mendenhall positions available.
If you have questions, please feel free to contact
Doctor Heather Tollerud.
Thank you for your interest in LCMAP.