Transcript Developing historic land cover databases The BIOME 300

Developing historic land
cover databases
The BIOME 300-experience
Prof. Dr. Rik Leemans
[[email protected]]
Dutch Institute of Public Health and the Environment
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Land and land use
The traditional use of land in
most global carbon-cycle models
• Often initialized by modeled potential vegetation,
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not actual vegetation
tropical deforestation is the only land-use change
considered
Land conversions included but generally no land
modifications
Still a missing sink (i.e. the different approaches
do not agree on the current global budget)
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Improving the carbon cycle
• Inter-annual variability is added to the models:
the biosphere reacts rapidly
• Include realistic patterns of deforestation and
reforestation
• Add realistic management for forests, pastures
and agriculture
• Develop a good high-resolution initialization
database for the recent past: BIOME 300
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Using the current
understanding for
explaining past and
projecting future
climate
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Why historic land-cover databases?
• Testing against historical data is an
important step for validating
integrated environmental models of
global change
• The description of historic carbon
budgets and land-climate interactions
require good initialisation data
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An example: HYDE (hundred
year database on the environment)
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Basic Driving Forces
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Energy & Industry data
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Terrestrial data
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Oceanic & Atmospheric data
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Population, GDP, value added,
private consumption,
climate data
Energy consumption, GHG
emissions, industrial
production
Land use, crop production
(area and yield), animal
production, food and fertilizer
consumption livestock
numbers, etc.
Concentration of GHGs
The total population numbers per country are scaled down by a factor derived from the
historical statistics, and then allocated according the 1994 NCGIA population density map.
1994
World Population Prospects 1950 2050, United Nations Population
Division, the 1996 Revision.
0.5 degree lat/lon population density map, NCGIA (1995)
1950
International Historical Statistics,
B.R. Mitchell (1975 - 1995)
&
Country Census data
&
e.g.
1800
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Logistic curves for countries with ‘no
data’ or ‘filling the gaps’
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The total land use estimates per country are derived from historical statistics, and then
allocated according to HYDE 2.0 population density maps (proxy for arable area)
and a methane emission density map (proxy for pasture)
Excel spreadsheets arable area, pasture
country1
year 1700
.…. ..…
.…. ..…
.…. ..…
.…. ..…
year 1995
.…. ..…
country 204
…..
…...
…..
…...
…..
…...
…..
…...
…..
…...
Export to csv format
Fortran routines,
allocating areas to
IMAGE grid cells
Export to ascii matrix,
and import in Arc/Info as
grid
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Arable land and pastures in HYDE
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Arable land and pastures in HYDE
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Disadvantages of the global
backcasting approaches
• Coarse scale patterns are captured but
locally many discrepancies remain
• Non-linearities neglected through the
scaling
Major challenges:
How to improve the regional historic land
use and land-cover patterns?
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Regional historic
reconstructions
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Land used in Harvard Forest
The mixed natural forest before the settlement of Europeans
in 1700
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Landuse in Harvard Forest
Deforestation of small farms by earlier settlers in 1740
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Land use in Harvard Forest
Maximum of agraricultural land use in 1830
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Land use in Harvard Forest
Most farms abandonned in 1850. The new forests are
composed of pine
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Land use in Harvard Forest
Pine forests for wood production on abandonned land in
1910
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Land use in Harvard Forest
Natural regeneration of mixed broadleafed forests replace
the cut pine forests in 1930
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Land use in Harvard Forest
The currentsituation of Harvard Forest, one of the most
researched, relatively young broadleafed forests
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Remote sensing approaches
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Deforestation in Rondônia in 1970
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Deforestation in Rondônia in 1973
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Ontbossing in Rondônia in 1976
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Deforestation in Rondônia in 1978
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Deforestation in Rondônia in 1985
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Deforestation in Rondônia in 1988
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Deforestation in Rondônia in 1991
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Deforestation in Rondônia in 1996
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Emperical models of the
dynamics of deforestation
Period 1988 to 1989
degradation 5294 ha/year
Closed forests
deforestation 8634 ha/year
Agriculture
Regrowth forest
Degradation: 1543 ha/year
abandonment:
7203 ha/year
Closed bos
deforested again 6210 ha/year
deforestation: 4112 ha/year
Agriculture
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Period 1986 to 1987
Regowth forests
abandonned: 2902 ha/year
deforested again 1973 ha/year
Farms along the TransAmazon
Highway in Altamira, Brazil
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Deforestation
Different drivers in
different regions:
include the humans
dimenison
An example of extreme events
Arable land
Grasslands
woodland
Soil erosion
An extreme rain event
Source: Bork et al., 1998
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Conclusions
• Natural and socio-economic extreme events are
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important in defining historical trends
Top-down and bottom-up approaches must be
linked to improve the resolution of the global data
The scientific communities on past (PAGES),
present (LUCC, BAHC & GCTE) must work
together with help of historians
The PAGES HITE initiative is a good start to
continue with a BIOME 300 activity
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