September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
SAR data for forestry and agriculture
Thuy Le Toan
September 5, 2007 Lecture D3L3
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Assets of radar data for vegetationmonitoring?
All weather capability to secure data acquisition during growing season
Information content on : - biomass- vegetation structure- soil moisture
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
• Forest biomass• Rice monitoring
Context
Use of SAR data in studies related to the Carbon cycle
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
The terrestrial carbon balanceMass balance equation (Inventory approach)
Δ C= Δ Above Ground Biomass + Δ Below Ground Biomass + Δ Litter + Δ Soil Carbon
Process equation (Dynamic Vegetation Model Approach, Productivity Efficiency Approach)
Δ C= Gross Primary Production- Autotrophic respiration-Heterotrophic respiration - Loss by disturbances
(GPP and Ra: depend on biomassRh and Loss by disturbances depend on past biomass)
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Austrian pine VHFλ > 3 m
P bandλ= 70 cm
L bandλ= 27 cm
X bandλ= 3 cm
Radar signal related to biomass of leaves, branches, trunk, depending on the SAR frequency band, polarisation and incidence
Why a SAR for forest biomass?
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Biomass vs Stem volume and height
Height (m)Stem volume (m3)
Bio
mas
s(to
ns/h
a)
Vol
ume
(m3/
ha)
( from Saatchi et al.)
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
-30
-25
-20
-15
-10
0 40 80 120 160
Above-ground biomass (tons/ha)
Sigm
a° (d
B)
L - HVP - HV
HF - VHF
Landes forestFrance
Sensitivity of SAR data to forest biomass
HV data
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Ecological studies
Landscape modelling(inventory)
Dynamic Vegetation modelling
Biomass0.1-1 ha
day-100s years
Biomass0.01-109ha1-100 years
BiomassGrid-109ha
day-100s years
Carbon Budget
Biomass informationin terrestrial carbon modelling
Light Use Efficiency modelling
BiomassGrid-109ha
day-10s years
Input
Input
Test
ForcingTest
Input
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
NBP
LEACHED
Litter Disturbance
ATMOSPHERICCO2
Biophysics
Soil
Photosynthesis
Growth
Biomass
GPP
NPPThinning
Mortality
Fire
The Dynamic Vegetation Model (CTCD)
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Map of biomass using L-band ESARComparison with output fromSheffield Dynamic Vegetation ModelC flux prediction using SDVM
Use of radar-retrieved biomass on temperate forests (localscale) for:. Local or regional carbon budget ( Kyoto protocol etc..). Forest management
Research results to illustrate:
Büdingen forest (Germany)
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
< 12 t/ha > 12 t/ha - 24 t/ha> 24 - 42 t/ha> 42 t/ha
Mapping of biomass using L-band data
Pixel-wise inversion
Stand-wise inversion
Büdingen forest, Land Hessen, Germany.
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
0102030405060708090
100
0 20 40 60 80 100
SDVGM estimated biomass (m3/ha)
Rad
ar re
triev
ed b
iom
ass
(m3/
ha)
SpruceDouglasOakBeech
Comparison biomass predicted by model and biomass by SAR
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Use of Dynamic Vegetation Model to predict Timber Volume for scenarios of climate (temperature, precipitation, CO2)
Timber volume up to 2020
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Use of Dynamic Vegetation Model to predict Carbon fluxesNet Primary Productivity (red) and soil respiration (blue)
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
BIOMASS
A P-band SAR for Carbon Assessment
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
The annual flux of C to the atmosphere 1850 -1990, in which the unidentified sink is assigned to uptake by the land (Houghton, 1999).
The The ‘‘missing carbon sinkmissing carbon sink’’
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Current status of global Current status of global biomassbiomass informationinformation
1. Biomass from inventory data2. Biomass from remote sensing
-->no biomass information suitable for carbon cycle and Earth system models
-> no consistent mapping of forest area, structure, and change
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Spatial distribution of biomassin the Amazon:
Comparison of current methods(Houghton et al., 2001)
Uncertainty in estimates of biomass at regional scale
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
LPJSDGVM
Carbon Carbon sources sources and sinks predicted and sinks predicted by modelsby models
( Hybrid, IBIS, LPJ, SDGVM, Triffid, Vecode)
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
90°E
Le Toan et al., 2004J. of Climatic Change
Sheffield Dynamic Vegetation Model
Biomass estimatesBiomass estimates:: ComparisonComparison ModelModel--EOEO
1
2
100°E
3
4 5
60° N
55° N
6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0
kg C m-2
Siberia-I radar forest map
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
2003 Burn 1988 Burn
Mapping Disturbance and Recovery
Yellowstone National Park
Pine Beatle Disease
( from Saatchi et al.)
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
500 100 200150
Biomasse (T/ha)
• Image optiqueP-band SAR Image
Forêt de Nézer
CESBIO
Le Toan et al., 1992,Beaudoin et al.,1994
Biomass mapping: temperate conifer plantations
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Biomass map for BOREAS test sitefrom P-Band SAR
(Saatchi et Moghaddam, 2000)
0
50
100
150
200
0 50 100 150 2
Fiel
d S
tem
Bio
mas
s (to
ns/h
a)
SAR Predicted Stem Biomass
P-band AlgorithmR=0.954
Saatchi & Moghaddam 2000
Biomass mapping in boreal forest
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
P-band
Intensity
Coherence
Phase
Polarimetric interferometr
Garestier et al., 2006
Advanced techniques to measure tree height
BIOMASS proposal
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Rice monitoring using SAR data
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Methane global concentrations (SCIAMACHY):
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Rice field: a major source of methane
(Denier van der Gon, 1996)
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Role of rice fields in the terrestrial carbone cycle? (CH4 & CO2)
Changes in Green House Gases (GHG) due to changes in land use and farming practices ?
Projection in the future and solution for mitigation?
Questions
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Rice Monitoring in China
ESA-China Dragon Project
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
LPJmL grid cell- crops- managed grasses- land use change
Crop specificparameterisation:
- Phenology: sowingdates, maturity, determination of somevarietal parameters
- Carbon allocation to the yield-storage organ.
The LPJ Dynamic Global Vegetation Modeladapted to managed land (Bondeau et al., GCB, 2007)
C budget, H20 & CO2 Fluxes,Vegetation CompositionCrop production
Modelling approach
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
GISGIS
CH4MODCH4MODCropCrop--CC
Field measurements & literature reports
Model validation
Process levelUnderstanding
C model from Institute of Atmospheric Physics, CAS, Beijing
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
LPJ Model inputs
Farming practices:• Cropping system (single-crop rice, double-crop rice, rice-wheat, rice-maize,etc)• Crop calendar: sowing date, harvest dates for each crop variety• Flooding and drainage calendar• Which variety class (e.g. high-yield variety: harvest index)• Sowing density (plant density)• Fertilizer inputs calendar • Residues management (straw taken out, burned, left over the field and flooded, ploughted into the soil ?)• TillageLand use / land cover• % crops cover (rice and other crops) within the grid cell• History (land use change, needed for soil carbon building)
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Ear
th O
bser
vatio
n
Ric
e ca
rbon
Mod
elsRice mapping
Rice varieties
Crop calendarWatermanagement
LAI/FAPAR
Biomass.
Initiation
Assimilation
Run time control
Testing
Approach: use of remote sensing & models
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Rice MappingLocal & regional
Rice Parameters
Yieldestimation
ENVISATASAR & MERIS,
VGT
Rice and BiochemistryModels
Methane & CO2 Fluxes
Ancillary& ground data
RiceProduction
Rice in Carboncycle
Methane Measurement
ENVISATSCIAMACHY
Meteorological data
Remote Sensing Methods
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Remote Sensing results
Development and validation of methods for mapping of paddy fields at local and regional scales using ASAR data
Retrieval of rice biomass using ASAR
Mapping of rice varieties using ASAR
Determination of rice and other crop calendar using SPOT VGT
Detection of mid season drainage using ASAR
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Water
ASAR for rice monitoringAt C band, HH and VV: the dominant scattering mechanism is thedouble bounce vegetation-waterHH>VV because of the stronger attenuation of VV by verticalstems
HH and VV increases with the plantbiomass.The increase is very important (up to 10 dB during the growth season) (Le Toan et al., 1997).
HH/VV is related to biomass
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
-30-28-26-24-22-20-18-16-14-12-10-8-6-4
0 10 20 30 40 50 60 70 80 90 100Days (days after sowing)
Bac
ksca
tteri
ng co
effic
ient
(dB
)
Scatterring mechanisms
ERS Model
-20-18-16-14-12-10-8-6-4-20
0 500 1000 1500 2000 2500 3000 3500 4000Moist Biomass (g/m²)
Bac
ksca
tteri
ng co
effic
ient
(dB
)
Volume-Surface
Volume Scattering
Basic principle of using C-band SAR for rice monitoring
Strong increase (>10 dB)during the growth cycle
Main scattering mechanism is volume-surface interaction
Le Toan et al., 1997, Wang et al., 2004
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Bac
ksca
tter
ing
Coe
ffic
ient
(dB
)
-20-18-16-14-12-10-8-6-4-20
0 500 1000 1500 2000 2500 3000 3500 4000Moist Biomass (g/m²)
Effect of Polarisation
ERS (VV)
RADARSAT (HH)
Solid line: modelling result
• Strong increase as a function of biomass, from transplanting to maturity• HH>VV• Smaller increase at higher incidence
Effet of Incidence angle
-16-15-14-13-12-11-10-9-8-7-6-5-4
0 20 40 60 80 100 120Age (# days after sowing)B
acks
catt
erin
gC
oeff
icie
nt (d
B)
C-HH-23°
C-HH-43°
Solid line: modelling result
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Example of Chaindeveloped using:
•Gamma ASAR (Gamma RS)
•Multi-image filtering(Quegan et al., 2000)
• Temporal change (Le Toan et al., 1997)
Mapping algorithmInitial images
Calibrated coregistered
Filtered
Filteredgeocoded
1 2 M…………….
.
.
1 2 M…………….date 1 date Mdate 2
1 2 M…………….
1 2 M…………….
Analysis , RetrievalClassification
Spatial filteringGeocoding
Multi image filtering
CalibrationRegistration
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Jiangsu Province
Rice monitoring using ENVISAT
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Small field: powerful filtering
Filtering using 20 images (2 polarisations, 10 dates)
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
HH VVHongze (Jiangsu) 2004 09 06
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Magenta=HH, Green=VV 34km*38km
September 6th, 2004 , Hongze area
yellow=rice, red=urban, black=other
Rice mapping at a single date using HH/VV
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
In situ mapping of 1km x 1km samples with DGPS
Ground campaign for validation
Overall accuracy: 80-88%
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
pixel size : 75 m210 km * 127.5 km
magenta : August 18green : October 27
Funing
HuaiAn
Chuzhou
Suqian
Shuyang
Yancheng
ASAR WSM region North of Qingjiang, Jiangsu province
Rice mapping using WS ASAR data
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
XinqiRiver
Guboshanhou River
JieyuRiver
Guangriver
QiangweiRiverHuaimu
xinRiver
Lianyungang
Guannian
Guanyun
Regional rice mapping
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Mapping of rice varieties
Hybrid rice
Japonica rice
Dragon projectCAAS, Nanjing
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Continuous flooding
Mid-season drainage
Wuxian, Jiangsu province
Mid-season drainage reduces methane emissions
Li et al.,JGR,2001
30 to 60%
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Magenta: 20060705 Green: 20060809Magenta: 20060702 Green: 20060806
WSM VVMapping of mid season drainage in rice fields
Fields in magenta are flooded rice fields and fields in green are rice fields with temporary drainage that occurs approximately 3 weeks after transplantation (in July)
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Dates 2004
28-june
20-july
2-august
18-august
8-sept.
24-sept.
11-oct.
HH/VV vs Wet biomass of a test field in Gaoyou, 2004
0
1
2
3
4
5
0 1 2 3 4 5 6
Wet biomass (kg/m²)
HH/V
V (d
B)
flowering
tillering
jointing
heading
ripening
ready for harvest
Retrieving of biomass
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Hongze and Gaoyou - Beginning of Tillering to Flowering2004 (Blue), 2005 (Magenta)
y = 1,0266x - 0,1058R2 = 0,7968
-1
0
1
2
3
4
5
6
0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5
Wet Biomass
HH
/VV
Relation HH/VV and rice wet biomass
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Determining rice and other crop cycle and calendar using SPOT VGT (1 km, 10 days)
Wheat Rice
RiceRice
SPOT VGT-NDVI
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
triple-cropping farmland
double-cropping farmland
forest
urban
water
2005
Landuse/cover and number of crop/year using VGT
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Transplanting date (min NDVI) 2005
Light green: 1-10 June
Green: 11-20 June
Dark green: 21-30 June
TransplantingTransplanting datedate
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Ricepercentage
2004
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
Jun
80 90 100 110 120 130
2025
3035
4045
50
0
2
4
6
8
10
Jul
80 90 100 110 120 130
2025
3035
4045
50
0
2
4
6
8
10
Aug
80 90 100 110 120 130
2025
3035
4045
50
0
2
4
6
8
10
GgCH4
Rice monthly CH4 1991−2000
Total annualCH4 emissionfrom Rice fieldsin China:
4.9 Tg CH4
Initial modelling result using LPJmL
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
In June and August, the extreme high tropospheric CH4 enrichment appeared over central China with the values of 9.2 ppb and 11.5 ppb.
IAP-CAS
Modelling results by IAP
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
A peak increment of 11.9 ppb in July occurred in Sichuan
IAP-CAS
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
In June and August, the extreme high tropospheric CH4enrichment appeared over central China
IAP-CAS
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan
September 5,2007 Lecture D3L3 SAR data for agriculture and forestry Thuy Le Toan