ORCHIDEE Development Section

LCCCI

Tools : cross-walking tables and mapping algorithms

1. ESA CCI classes → Generic PFTs

The following cross-walking table (CWT) is used to distribute ESA CCI classes into generic plant-functional types (PFTs). Additionally, the external Köppen—Geiger (KG) climate map is used. Several values are shown:

  • red — new values (CWT v2.4, including blue values as well)
  • blue — values previously used in LSCE aggregation with the epoch maps (CWT v2.0)
  • black — default values coming with "lc-user-tools-3.13" (link : ftp://geo10.elie.ucl.ac.be/home/lc-user-tools-3.13.zip) (CWT v1.0)
CCI CLASS KG CLASS TREES SHRUBS GRASSES Bare Soil Water Snow and Ice Urban No Data
TrBrEv TrBrDe TrNeEv TrNeDe ShBrEv ShBrDe ShNeEv ShNeDe NatGr Crops
0
no data
100
10
cropland, rainfed
10
0
90
100
11
cropland, rainfed, herbaceous cover
10
0
90
100
12
cropland, rainfed, tree or shrub cover
70
50
30
50
20
cropland, irrigated or post-flooding
10
0
90
100
30
mosaic cropland (>50%) / natural vegetation (tree, shrub, herbaceous cover) (<50%)
5 5 5 5 5 15 60
40
mosaic natural vegetation (tree, shrub, herbaceous cover) (>50%) / cropland (<50%)
7.5
5
7.5
5
10
7.5
15
10
10
7.5
30
25
20
40
50
tree cover, broadleaved, evergreen, closed to open (>15%)
90 5 5
60
tree cover, broadleaved, deciduous, closed to open (>15%)
50
70
20
15
30
15
61
tree cover, broadleaved, deciduous, closed (>40%)
70 15 15
62
tree cover, broadleaved, deciduous, open (15-40%)
30 25 45
35
0
10
70
tree cover, needleleaved, evergreen, closed to open (>15%)
70 5 5 5 15
71
tree cover, needleleaved, evergreen, closed (>40%)
70 5 5 5 15
72
tree cover, needleleaved, evergreen, open (15-40%)
30 0
5
25
5
45
30
0
30
80
tree cover, needleleaved, deciduous, closed to open (>15%)
50
70
2.5
5
2.5
5
2.5
5
12.5
0
30
15
81
tree cover, needleleaved, deciduous, closed (>40%)
70 5 5 5 15
82
tree cover, needleleaved, deciduous, open (15-40%)
30 0
5
0
5
25
0
45
30
0
30
90
tree cover, mixed leaf type (broadleaved and needleleaved)
30 20 10 5 5 5 25
15
0
10
100
mosaic tree and shrub (>50%) / herbaceous cover (<50%)
10 20 5 5 5 10 5 40
110
mosaic herbaceous cover (>50%) / tree and shrub (<50%)
5 10 5 5 10 5 60
120
shrubland
def 20 20 20 20 20
1 15 30 15 40
21 15 30 15 40
22 15 30 15 40
31 20 40 20 20
32 20 40 20 20
121
shrubland, evergreen
def 30 30 20 20
1 30 30 40
21 30 30 40
22 30 30 40
31 40 40 20
32 40 40 20
122
shrubland, deciduous
def 60 20 20
1 60 40
21 60 40
22 60 40
31 80 20
32 80 20
130
grassland
100
60
0
40
140
lichens and mosses
100
60
0
40
150
sparse vegetation (tree, shrub, herbaceous cover) (<15%)
def 1 3 1 1 3 1 5 85
1 5 5 20 70
21 5 5 5 5 30 50
22 5 5 5 5 30 50
31 3 3 3 4 4 3 65 15
32 3 3 3 4 4 3 65 15
151
sparse trees (<15%)
def 2 6 2 5 85
1 10 20 70
21 10 10 30 50
22 10 10 30 50
31 7.5 7.5 5 65 15
32 7.5 7.5 5 65 15
152
sparse shrub (<15%)
def 2 6 2 5 85
1 10 20 70
21 10 10 30 50
22 10 10 30 50
31 7.5 7.5 5 65 15
32 7.5 7.5 5 65 15
153
sparse herbaceous cover (<15%)
def 15 85
1 30 70
21 50 50
22 50 50
31 85 15
32 85 15
160
tree cover, flooded, fresh or brakish water
37.5
30
37.5
30
25
20
0
20
170
tree cover, flooded, saline water
75
60
25
20
0
20
180
shrub or herbaceous cover, flooded, fresh/saline/brakish water
0
5
0
10
25
10
15
5
60
40
0
30
190
urban areas
0
2.5
0
2.5
0
15
0
75
0
5
100
0
200
bare areas
100
201
bare areas, consolidated
100
202
bare areas, unconsolidated
100
210
water bodies
100
220
permanent snow and ice
100

2. Köppen—Geiger climate map

The Köppen—Geiger climate map is used to refine above CWT for different climate zones (see the second column). Since the Köppen—Geiger map does not cover all land points from ESA dataset, it has been additionally expanded over the ocean filling with the dominant value for each latitude.



3. C4 vegetation map (C. Still et al.)

The use of the Köppen—Geiger climate map results in the sharp transition between C3 and C4 vegetation. For this reason, a different map from Still et al. (2009) has been used to distribute grasses and crops into different PFTs.



4. Generic PFTs → ORCHIDEE PFTs

The following cross-walking table is used to combine generic PFTs into 13 standard ORCHIDEE PFTs.

KG CLASS TrBrEv TrBrDe TrNeEv TrNeDe ShBrEv ShBrDe ShNeEv ShNeDe NatGr Crops BS Water SnowIce Urban NoData
1 (tropical) PFT2 PFT3 PFT4 PFT3 PFT2 PFT3 PFT4 PFT3 PFT10
PFT11

using
C4veg
(Still)
PFT12
PFT13

using
C4veg
(Still)
PFT1 PFT1 at land

dillute between PFT2-13 at coast
PFT1 80% → BS 20% → NatGr PFT1
21 (temp warm) PFT5 PFT6 PFT6 PFT5 PFT6 PFT6
22 (temp cool) PFT9 PFT9
31 (boreal warm)
32 (boreal cool) PFT8 PFT7 PFT8 PFT7

List of ORCHIDEE PFTs:
PFT1 : Bare Soil
PFT2 : Tropical Evergreen
PFT3 : Tropical Raingreen
PFT4 : Temperate Needleleaf Evergreen
PFT5 : Temperate Broadleaf Evergreen
PFT6 : Temperate Broadleaf Summergreen
PFT7 : Boreal Needleleaf Evergreen
PFT8 : Boreal Broadleaf Summergreen
PFT9 : Boreal Needleleaf Deciduous
PFT10 : Temperate Natural Grassland (C3)
PFT11 : Natural Grassland (C4)
PFT12 : Crops (C3)
PFT13 : Crops (C4)
PFT14 : Tropical Natural Grassland (C3)
PFT15 : Boreal Natural Grassland (C3)

5. Merge with LUH2

The LUH2 dataset has the following structure:

LUH CLASS Description   Transition to primf to primn to secdf to secdn to urban to c3ann to c4ann to c3per to c4per to c3nfx to pastr to range
primf forested primary land   primf                        
primn non-forested primary land   primn                        
secdf potentially forested secondary land   secdf                        
secdn potentially non-forested secondary land   secdn                        
urban urban land   urban                        
c3ann C3 annual crops   c3ann                        
c4ann C4 annual crops   c4ann                        
c3per C3 perennial crops   c3per                        
c4per C4 perennial crops   c4per                        
c3nfx C3 nitrogen-fixing crops   c3nfx                        
pastr managed pasture   pastr                        
range rangeland   range                        

For the merge with the LUH2 dataset the ORCHIDEE PFT map for 2010 is used. From this "present-day" map the fractioning of the natural vegetation between PFTs is calculated in the following way:

LUHNAT = LUHPRIMF + LUHPRIMN + LUHSECDF + LUHSECDN + LUHRANGE + LUHURBAN

LUHC3 = LUHC3ANN + LUHC3PER + LUHC3NFX

LUHC4 = LUHC4ANN + LUHC4PER

ANTH = LUHC3 + LUHC4 + LUHPASTR

GRASSANTH = max(0, ANTH – ORC12 – ORC13)

GRASSNAT = max(0, ORC10 + ORC11 – GRASSANTH)

GRASSNAT_C3 = GRASSNAT · ORC10 / (ORC10 + ORC11)

GRASSNAT_C4 = GRASSNAT · ORC11 / (ORC10 + ORC11)

TOTALNAT = ORC1 + ... + ORC9 + GRASSNAT_C3 + GRASSNAT_C4

f1 = ORC1 / TOTALNAT

...

f9 = ORC9 / TOTALNAT

f10 = GRASSNAT_C3 / TOTALNAT

f11 = GRASSNAT_C4 / TOTALNAT

Then for each particular year of backward/forward reconstruction the crops data are directly imposed from LUH2, other LUH2 classes are distributed to the ORCHIDEE PFTs using the present-day fractioning:

PFT1 = f1 · LUHNAT

...

PFT9 = f9 · LUHNAT

PFT10 = f10 · LUHNAT + StillC3 · LUHPASTR

PFT11 = f11 · LUHNAT + StillC4 · LUHPASTR

PFT12 = LUHC3

PFT13 = LUHC4