Global%20land%20cover%20validation%20activities

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Global land cover validation activities

• Martin Herold (FSU Jena) Mark Friedl (UBoston)

With contributions from Curtis Woodcock
(UBoston), Olivier Arino (ESA), Steve Stehman
(SUNY)
CEOS WGCV LPV Focus Group Lead Meeting, Missoula,
Montana, June 15, 2009
www.fao.org/gtos/gofc-gold www.gofc-gold.uni-jena.
de
Global Observations of Forest Cover and Land
Dynamics
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Overview

• Political initiatives driving observation
  progress and needs for validation
• Observing land cover as ECV
• Global land cover observations and accuracy
  assessments
• MODIS and GLOBCOVER
• Best use of existing reference datasets
• Coordinated effort to develop LC validation
  database
• Accuracy assessment for fine-scale land cover
  change and area estimates
• Post-Kyoto agreement and best practices

3
International drivers

• United Framework Convention on Climate Change
• Reduce uncertainties in monitoring the global
  climate system through observing essential
  climate variables
• Capacity building needs to address stronger role
  of developing countries in post-2012 agreement
• Major REDD readiness funds are currently being
  allocated
• Group on Earth Observation (GEO) task DA-07-02
• Provide a suite of global land cover datasets,
  initially based on improved and validated
  moderate resolution land cover maps and
  eventually including land-cover change at high
  resolution (task co-lead by USGS and GOFC-GOLD)
• Global land cover monitoring and assessments
• GLOBCOVER, FAO-Forest Resources Assessm. 2010
• Operational validation / Efforts for deriving
  Best map

4
Observing land cover as ECV
www.fao.org/gtos/
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DA-07-02 key activities
2006 2007 2008 2009 2010 2011
Global level
Strategies (IGOS) Integrated Global
Observations for land (IGOL)
Integration of IGOL into GEO
Standards LCCS land cover classifiers and
validation procedures Harmonization best
available map
New global products GLOBCOVER (link to regional
level)
Continuity of observations Mid-decadal global
Landsat survey (MDGLS) Global Land Survey
2010
Specifications for fine-scale global land cover
change dataset (incl. validation framework)
Technical guidance for UNFCCCC/REDD (GOFC-GOLD
sourcebook)
Capacity building and support of global
assessments GLCN GOFC-GOLD networks / FAO-FRA
global remote sensing survey
National level
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GCOS implementation plan actions for land cover

• Establish international standards (T22)
• UN Land Cover Classification System (LCCS)
  classifiers
• Methods for map accuracy assessment (T23)
• CEOS WGCV/GOFC-GOLD best practices report
• Continuity for fine-scale satellite observations
  (T24)
• Commitments to operate Landsat 8 (US) and
  Sentinel 2 (EU)
• Develop an in situ reference network (T25)
• Global operational validation implementation plan
• Annual global land-cover products (T26)
• Release (and continuation) of GLOBCOVER
• High-resolution global land cover change (T27)
• FAO/FRA 2010 global sampling GEO definition of
  specifications

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International consensus on technical issues
Best Practices Document Strahler et al., 2006
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Integrated land cover observations
Completed and endorsed by IGOS partnership and
GEO in 2007
high
Spatial detail
Effort for frequent update
high
low
high
Thematic detail
From Herold et al 2008, IEEE Systems
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GLOBCOVER (2005/6)
Dataset release September 2008
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GLOBCOVER validation
More than 4300 validation points interpreted by
int. experts Blue points Globcover project (3835
points) Gonds set (n80) (including 225
double interpretation by 2 experts) Brown points
IMWI data (403 points) Global area weighted
accuracy 73 based on 3167 reference
points Validation report available 15. October
2008
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MODIS Collection 5 Land Cover (2001-present)
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MODIS Land Cover Validation1860 Training Sites
Cross Validation
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Probability
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Overview

1. Political initiatives driving observation
   progress and needs for validation
2. Global land cover observations and accuracy
   assessments
3. Coordinated effort to develop LC validation
   database (Curtis Woodcock)
4. Accuracy assessment for fine-scale land cover
   change and area estimates

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Overview

1. As the land cover community matures, an
   increasing emphasis on validation and accuracy
   assessment - a difficult, somewhat unpleasant and
   somewhat surprisingly expensive activity
2. The GOFC-GOLD LC IT has decided to try to support
   the broader community through validation
3. Idea is to collect ground reference data
   independent of any single land cover product to
   support validation of many land cover datasets
4. Intent is to supplement and complement ongoing
   validation activities associated with individual
   land cover datasets

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Operational lc validation framework
Existing global LC products
Time
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Operational lc validation framework

• Effort serves purpose for estimating
• Individual map accuracy / best available map
• Area of land-cover classes or land-cover change
• Sampling design
• 10 km by 10 km block (Landsat MODIS)
• Flexible to increase sample size to provide
  precise country or region specific estimates
• Stratification by geographic reporting regions,
  areas where maps differ, important rare
  land-cover classes
• Response design
• Reference data (i.e. SPOT) interpreted by
  regional experts (i.e. GOFC-GOLD networks) using
  LCCS classifiers
• Analysis design
• Error matrix for each map and region
• Estimates of class area
• Supplementary accuracy information on land-cover
  composition and landscape pattern

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Project Overview (Woodcock Lead)

• Randomized stratified sampling
• Primary sampling units by blocks of 10 10 km
• World divided into seven continents
• Strata based on Köppens climate zones together
  with population density
• Strata independant of the land cover products
• Currently about 70 samples per continent planned
• Validation workshops planned VHR satellite data
  (source not determined) interpreted by local
  experts
• Landsat data will be used to monitor change at
  sample sites
• First workshop will be held in Almaty, Kazakhstan
  in September 2009

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Stratification and Sample Design Seven
Continents North Am./South Am./Europe/Africa/ For
mer USSR/South Asia/Oceania
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Current Status Early Stages of Stratification
and Sample Design Workshop tentatively planned
for late July in Boston
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Observing land cover as ECV

• Towards standardization of satellite derived
  products
• Coordinated observations
• Integrated and standardized mapping and
  monitoring
• Independent quality assessment

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Overview

1. Political initiatives driving observation
   progress and needs for validation
2. Global land cover observations and accuracy
   assessments
3. Coordinated effort to develop LC validation
   database
4. Accuracy assessment for fine-scale land cover
   change and area estimates

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Fine-scale land cover change

• Suite of national / regional experiences
• National/regional monitoring programs
• UNFCCC Kyoto reporting on LULUCF/AFOLU
• UNFCCC process on reducing emissions from
  deforestation in developing countries
• case studies, readiness activities, post 2012
• Projects with global/large scale focus
• EU/JRC TREES 3 (sampling approach)
• UMD/SDSU combined MODIS/Landsat approach
• FAO-Forest Resources Assessment 2010
• Accuracy assessment of area changes?

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Current availability of fine-scale satellite data
sources and capacities for global land cover
change observations
Satellite observation system/program Technical observation challenges solved Access to information on quality of archived data worldwide Continuous observation program for global coverage Pre-processed global image datasets generated accessible Image data available in mapping agencies for land change analysis Capacities to sustainably produce/use map products in developing countries
O P T I C A L LANDSAT TM/ETM
O P T I C A L ASTER On demand
O P T I C A L SPOT HRV (1-5) Commercially
O P T I C A L CBERS 1-3 Regionally
O P T I C A L IRS / Indian program Regionally
O P T I C A L DMC program Probably Commercially
S A R ALOS/PALSAR JERS Regionally
S A R ENVISAT ASAR, ERS 1/2 Regionally
S A R TERRARSAR-X Commercially
IKONOS, GEOEye Probably Commercially
ICESAT/GLAS (LIDAR)
(Note dark graycommon or fully applicable,
light graypartially applicable/several examples,
whiterare or no applications or examples)
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FAO FRA 2010 remote sensing survey
13,500 monitoring sites
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Building national capabilities for IPCC reporting
Important components Practical considerations
FOREST AREA CHANGE Primary source Landsat-type satellite data
Deforestation Starting point for historical assessment 1990-2005 (3 time steps minimum) Build basic satellite data proc. capabilities
Monitoring of forest degradation Forest fire and burned area Relevance and characteristics for human-induced carbon emissions Definition of suitable monitoring system
Accuracy assessment Using best/transparent methods and efforts for continuous improvement Prepare for statistically robust approach
CHANGE in CARBON STOCKS Primary source ground/inventory data
Existing stratifications and forest carbon estimates Inventory of available data Decide on carbon pool/TIER level to report
Towards improved carbon stock change estimations New inventory including other carbon pools Stratification in relevant areas/forest types
ACCOUNTING REPORTING Provide conservative estimates
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Accuracy assessment of area change estimates

• Uncertainties should be quantified and reduced as
  far as practicable (IPCC reporting guidelines,
  LULUCF)
• Need for standard/best practice methods
  (CEOS/GOFC-GOLD)
• Capacity development in developing countries
• Robust validation may not be achievable or
  practicable i.e. monitoring historical land
  changes in developing countries
• Good practice recommendation if no thorough
  accuracy assessment is possible or practicable
• apply the best suitable mapping method in a
  transparent manner
• consistency assessment allow some estimation of
  the quality
• Principle of conservativeness
• estimates (i.e. C-emissions) should not be
  overestimated
• assumes reward for more robust and accurate
  monitoring system
• GOFC-GOLD REDD sourcebook
• www.gofc-gold.uni-jena.de/redd/

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Final remarks

• Deforestation and land change prominent on the
  political agenda and driving observation
  progress
• Reducing uncertainties in observing the global
  climate system
• National capacity development (i.e. climate
  change mitigation)
• Key issues for land cover validation
• Need for continuous and consistent baseline
  observations
• Move towards operational global system (framework
  exists)
• Efforts for best available land cover map
• Best practices and good practices for accuracy
  assessment of land cover change and area
  estimates
• Communication with political/policy level (GEO,
  UNFCCC)
• Key role for CEOS WGCV for evolving ECV
  monitoring
• Sustained support for validation activities