Tools

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
CCI CLASS	KG CLASS	TrBrEv	TrBrDe	TrNeEv	TrNeDe	ShBrEv	ShBrDe	ShNeEv	ShNeDe	NatGr	Crops	Bare Soil	Water	Snow and Ice	Urban	No Data
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.

2b. Updated Köppen—Geiger climate map

The data are taken from http://koeppen-geiger.vu-wien.ac.at/present.htm
The original grid of 1/36=0.0277° is resampled to 0.25° by calculating the class fractions
Classes are joined into 7 groups following the table shown below
Points without data are filled by the dominant class of each latitude

KG31 to KG7	Af	Am	As	Aw	BSh	BSk	BWh	BWk	Cfa	Cfb	Cfc	Csa	Csb	Csc	Cwa	Cwb	Cwc	Dfa	Dfb	Dfc	Dfd	Dsa	Dsb	Dsc	Dsd	Dwa	Dwb	Dwc	Dwd	EF	ET
tropical	1	1	1	1
arid_warm					1		1
arid_cool						1		1
temp_warm									1			1			1
temp_cool										1	1		1	1		1	1	1
boreal_warm																			1			1	1			1	1
boreal_cool																				1	1			1	1			1	1	1	1

3. C4 vegetation map (C. Still et al. 2009)

The use of the Köppen—Geiger climate map results in the sharp transition between C3 and C4 vegetation. For this reason, a different map (at 0.5° resolution) from Still et al. (2009) has been used to distribute grasses and crops into different PFTs.

3b. Updated C4 vegetation map (C. Still et al. 2018)

An updated C3/C4 distribution product (at 1/6° resolution) from C. Still (2018) has been received.

4. Generic PFTs → ORCHIDEE PFTs

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

1 (tropical)

PFT10
PFT11

using
C4veg
(Still)

PFT12
PFT13

using
C4veg
(Still)

PFT1

PFT1 at land

dillute between PFT2-13 at coast

80% → BS 20% → NatGr

21 (temp warm)

22 (temp cool)

31 (boreal warm)

32 (boreal cool)

4b. Updated Generic PFTs → ORCHIDEE PFTs

The same cross-walking table as in section 4, but with slight attunements and established for 15 PFTs.

TrBrEv

TrBrDe

TrNeEv

TrNeDe

ShBrEv

ShBrDe

ShNeEv

ShNeDe

NatGr

Crops

Water

SnowIce

Urban

NoData

Still-C3

Still-C4

LUH-C3

LUH-C4

Inland

Coast

KG Tropical

PFT2

PFT3

PFT4

PFT3

PFT2

PFT3

PFT4

PFT3

PFT14

PFT11

PFT12

PFT13

PFT1

Dillute between existing PFTs

PFT1

80% → BS 20% → NatGr

PFT1

KG Arid Warm

KG Arid Cool

PFT5

PFT6

PFT5

PFT6

PFT10

KG Temperate Warm

KG Temperate Cool

PFT9

KG Boreal Warm

PFT7

PFT15

KG Boreal Cool

PFT8

PFT7

PFT8

PFT7

4c. Adapted Generic PFTs → ORCHIDEE PFTs

The new ESACCI land cover dataset (since v2.0.8) is represented directly in Generic PFTs. So the first transformation step (ESA CCI classes → Generic PFTs) is not needed anymore. However, as we were distributing the shrub content between trees and grass, the same fractioning is needed to be done for the new data at this step (Generic PFTs → ORCHIDEE PFTs). Moreover, the split between C3/C4 for natural and managed grass is also directly embedded in the new dataset. The adapated cross-walking table for v2.0.8+ is shown below.

TrBrEv

TrBrDe

TrNeEv

TrNeDe

ShBrEv

ShBrDe

ShNeEv

ShNeDe

NatC3

NatC4

ManC3+ManC4

Water

SnowIce

Urban

NoData

LUH-C3

LUH-C4

Inland

Coast

KG Tropical

PFT2

PFT3

PFT4

PFT3

PFT2(60%)
PFT14(40%)

PFT3(60%)
PFT14(40%)

PFT4(60%)
PFT14(40%)

PFT3(60%)
PFT14(40%)

PFT14

PFT11

PFT12

PFT13

PFT1

Dillute between existing PFTs

PFT1

80% → BS 20% → NatGr

PFT1

KG Arid Warm

KG Arid Cool

PFT5

PFT6

PFT5(60%)
PFT10(40%)

PFT6(60%)
PFT10(40%)

PFT4(60%)
PFT10(40%)

PFT6(60%)
PFT10(40%)

PFT10

KG Temperate Warm

KG Temperate Cool

PFT9

PFT9(60%)
PFT10(40%)

KG Boreal Warm

PFT7

PFT7(80%)
PFT15(20%)

PFT6(80%)
PFT10(20%)

PFT4(80%)
PFT15(20%)

PFT9(80%)
PFT15(20%)

PFT15

KG Boreal Cool

PFT8

PFT7

PFT8(80%)
PFT15(20%)

PFT7(80%)
PFT15(20%)

List of ORCHIDEE PFTs:

PFT1 : Bare Soil
PFT2 : Tropical Evergreen Forest
PFT3 : Tropical Raingreen Forest
PFT4 : Temperate Needleleaf Evergreen Forest
PFT5 : Temperate Broadleaf Evergreen Forest
PFT6 : Temperate Broadleaf Summergreen Forest
PFT7 : Boreal Needleleaf Evergreen Forest
PFT8 : Boreal Broadleaf Summergreen Forest
PFT9 : Boreal Needleleaf Deciduous Forest
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)

ORCHIDEE PFTs	Forest				Grass		Crop
	Broadleaf		Needleleaf		C3	C4	C3	C4
	Deciduous	Evergreen	Deciduous	Evergreen
Tropical	PFT3	PFT2	PFT3	PFT4	PFT14	PFT11	PFT12	PFT13
Temperate	PFT6	PFT5	PFT6	PFT4	PFT10
Boreal	PFT8	PFT7	PFT9	PFT7	PFT15

5. Merge with LUH2

The LUH 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 LUH dataset covering 850-2100 the single ORCHIDEE PFT map for 2010 is used. LUH data are joined into 4 groups:

LUH_NAT = LUH_PRIMF + LUH_PRIMN + LUH_SECDF + LUH_SECDN + LUH_RANGE + LUH_URBAN

LUH_C3 = LUH_C3ANN + LUH_C3PER + LUH_C3NFX

LUH_C4 = LUH_C4ANN + LUH_C4PER

LUH_PASTR

The C3/C4 crops and pasture data are directly imposed from LUH (LUH crops are put to ORC crops, LUH pasture is put to ORC grasses), other LUH classes are distributed to ORCHIDEE PFTs using the present-day fractioning calculated from 2010. As grasses are only partly represented by pasture, for the residual grasses part we calculate the difference ORC_grass+ORC_crop-LUH_C3-LUH_C4-Pastr, and this portion is used to define the residual present-day fraction of grasses. This residual is calculated in two steps. First, we caclulate anthropogenic part as ANT=LUH_C3+LUH_C4+Pastr-ORC_crop and limit it to zero if ORCHIDEE crops amount is larger than total anthropogenic part of LUH. Second, we calculate natural part as NAT=ORC_grass-ANT and limit it to zero if resulting ANT is larger than grass amount of ORCHIDEE. Overall, the calculation of present-day fractioning of natural vegetation (i.e. sum of LUH classes excluding crops and pasture) between ORCHIDEE PFTs is done in the following way:

LUH_ANT = LUH_C3 + LUH_C4 + LUH_PASTR

GRASS_ANT = max(0, LUH_ANT – ORC₁₂ – ORC₁₃)

GRASS_NAT = max(0, ORC₁₀ + ORC₁₁ – GRASS_ANT)

GRASS_{NAT_C3} = GRASS_NAT · ORC₁₀ / (ORC₁₀ + ORC₁₁)

GRASS_{NAT_C4} = GRASS_NAT · ORC₁₁ / (ORC₁₀ + ORC₁₁)

TOTAL_NAT = ORC₁ + ... + ORC₉ + GRASS_{NAT_C3} + GRASS_{NAT_C4}

f₁ = ORC₁ / TOTAL_NAT

...

f₉ = ORC₉ / TOTAL_NAT

f₁₀ = GRASS_{NAT_C3} / TOTAL_NAT

f₁₁ = GRASS_{NAT_C4} / TOTAL_NAT

Then for each particular year of backward/forward reconstruction the ORCHIDEE PFTs are obtained by splitting the LUH data with respect to the pre-calculated fractions:

PFT₁ = f₁ · LUH_NAT

...

PFT₉ = f₉ · LUH_NAT

PFT₁₀ = f₁₀ · LUH_NAT + Still_C3 · LUH_PASTR

PFT₁₁ = f₁₁ · LUH_NAT + Still_C4 · LUH_PASTR

PFT₁₂ = LUH_C3

PFT₁₃ = LUH_C4

6. Merge with LUH3

The merge of ORCHIDEE PFT map data with LUH3 dataset is done following the same equations as outlined above for LUH2, but with some differences:

for the historical reconstruction (years 850-1991) the present-day fractioning is calculated from the average ORCHIDEE PFT map dervied from ESACCI land cover across the first available five years of data (1992-1996), LUH3 data are taken from the same averaging period;
for the recent present-day maps (years 2021-2024) and future projection (years 2025-2100) the present-day fractioning is calculated from the average ORCHIDEE PFT map dervied from ESACCI land cover across the last available five years of data (2016-2020), LUH3 data are taken from the same averaging period;
for the ESACCI land cover period (1992-2020) the merge with LUH3 is performed following the same methodology, but all calculations are done using the corresponding one-year data (for both ORCHIDEE PFT map derived from ESACCI land cover and LUH3 data)