photo: doug parker use of formosat images over the gourma site (mali) e. mougin, v. demarez, p....
TRANSCRIPT
![Page 1: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/1.jpg)
Ph
oto
: D
ou
g
Pa
rke
r
Use of FORMOSAT images
over the Gourma site (Mali)
E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat,V. Le Dantec, M. Grippa, Y. Auda, F. Timouk
![Page 2: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/2.jpg)
• The study site
• FORMOSAT data
• Field data
• Applications
Content
![Page 3: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/3.jpg)
The AMMA Gourma site
Anomalies of annual rainfall, Hombori, 1920-2009
-300
-200
-100
0
100
200
300
400
500
19
20
19
25
19
30
19
35
19
40
19
45
19
50
19
55
19
60
19
65
19
70
19
75
19
80
19
85
19
90
19
95
20
00
20
05
mean = 373 mm
Short rainy season : JJASHigh rainfall variabilityHigh aerosol loading
A Sahelian climate
. Characterized by large homogeneous surfaces
. Dedicated to satellite product validation Soil moisture- albedo, Radiation, Ts- LAI, FAPAR, NPP
A pastoral Sahelian site
![Page 4: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/4.jpg)
The Hombori site(15.3°N, 1.6°W)
AERONET photometer
Radiometer / PAR sensor
![Page 5: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/5.jpg)
The Gourma land units
Shrub Savannah
Open forestFlooded plains
LAI : 2 - 4
LAI : 0.5 - 2
LAI : 2 - 4
![Page 6: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/6.jpg)
The Gourma land units
PondErosion surface
Tiger bushMillet field
LAI : < 0.1
LAI : 0.5 - 2
![Page 7: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/7.jpg)
Sand dunes
Open forest
Erosion surface
60 kmTiger bush
Ponds
SPOT-HRV image
Monitoring site
Agoufou
![Page 8: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/8.jpg)
July 15
May 29June 06
July 17
2005
August 20August 19
A strong seasonal dynamics and a high inter annual variability of vegetation cover
2006 2007
July 16
June 08
August 23
![Page 9: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/9.jpg)
July 05 August 26July 28
July 02 August 27 September 16
Seasonal dynamics of acacia forests and millet fields
![Page 10: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/10.jpg)
Field data : LAI, FCover, FAPAR
Use of hemispherical photographs
![Page 11: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/11.jpg)
Field data : LAI, FCover, FAPAR (trees)
Isolated trees
Open Acacia forest : 500 m transect
WinScanopysoftware
![Page 12: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/12.jpg)
Field data : LAI, FCover, FAPAR (grass)
Derivation of LAI/FCover and LAI/FAPAR relationships at quadrat, ESU and km scale
Evaluation of Can-Eye derived LAI (destructive measurements) and FAPAR (SunScan)
![Page 13: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/13.jpg)
Seasonal variation of LAI (grass)
Monitoring of 8 sites every 10 days during the rainy season
![Page 14: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/14.jpg)
FORMOSAT-2 data (2007)
Period: June -November
Number: 29 images
View angle: 53°
Size: 58 x 24 km
AOT images
No SPOT data during the rainy season in 2007! (15 images in 2006)
Landsat
Aerial photos
SPOT
![Page 15: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/15.jpg)
Agoufou pondfireBare sand dune
Clay-silt plain
Rocky outcrops
(2007_06_09)Dry season AOT image
Bare sand dune
Agoufou
![Page 16: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/16.jpg)
2007_08_04
Wet season AOT image
- Begining of herbaceous vegetation growth
- High spatial variability
Agoufou
![Page 17: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/17.jpg)
2007_08_24
Wet season AOT image
Maximum of herbaceous vegetation LAI
![Page 18: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/18.jpg)
08_20
08_12
29 images
24 with clear sky among which 15 were acquired during the rainy season :
June : 4July : 4August : 5September 6
DoY
Example of atmospheric contamination
![Page 19: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/19.jpg)
What do you mean by aerosols?
![Page 20: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/20.jpg)
Land Cover
![Page 21: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/21.jpg)
July 27
Temporary ponds
Millet fields
Road Field with high organic content
Isolated Trees
Acacia forest
Formosat view of an agro-pastoral area (wet season)
Sand dune covered by a grass layer
Bare loamy soils
![Page 22: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/22.jpg)
Comparison of HR images
September, 2007
Formosat (8m)Landsat (30m) SPOT-5 (10m)
FORMOSAT offer a better discrimination of cultivated areas
![Page 23: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/23.jpg)
June 1 July 27 September 29 November 04
Time series of Formosat images over an agro-pastoral area
Dry season Wet season Wet season Dry season
A large contrast between fields and grasslands during the rainy season (phenological differences)
Burnt area
![Page 24: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/24.jpg)
Land cover classification (work in progress)
Hiernaux, Auda,…
July 27
Sep
tem
ber
29
NDVI
NIR
Green
Red
6 identified classes:
LF, LJ, LN SF, SJ, SNJ: fallowF: manured fieldsN: non manured fields
L: loamy – sandsS: Sand dune
Only multi-date images enable LC to be discriminated
![Page 25: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/25.jpg)
Vegetation monitoring and
LAI mapping
![Page 26: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/26.jpg)
Period of water stress well detected on NDVI images as well as regrowth of green vegetation
Effect of straw/litter on NDVI
NDVI seasonal variation over the Agoufou site
June July August Sept.
![Page 27: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/27.jpg)
NDVI en fonction des LAI vrais
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0 1 2 3 4
LAI
ND
VI
Site17_3107
Site17_1508
Site18_0108
Site18_1608
Site19_0108
Site21b_0308
Site31_3107
Site31_1608
Site21b_1608
Site19_1608
Site17_2708
Série12
Site41_1708
site41_0208
sol nu
Lacombe, 2008; Larouziere, 2009
NDVI – LAI relationships :
r² = 0.83
n = 115
VALERI methodology
ESU scale : 10m x 10m
![Page 28: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/28.jpg)
y = 1.4446x + 0.0788
R2 = 0.9207
y = 1.1309x + 0.0574
R2 = 0.9575
0.00
0.10
0.20
0.30
0.40
0.50
0.60
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
LAI
ND
VI
Photo H
planimètre
NDVI – LAI relationships (Field)°
2009_08_03
Le Dantec, 2009
![Page 29: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/29.jpg)
August 4 August 8 August 20
Demarez, Mougin, in preparation
Spatialization of LAI
![Page 30: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/30.jpg)
Spatialization of LAI / Comparison with MODIS product
2 approaches are compared
![Page 31: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/31.jpg)
Comparison with MODIS LAI Products
200 400 600 800 1000 1200 14000
0.5
1
1.5
2
DAY of YEAR (Since 2005/01/01)
LA
I (m
2 m-2)
Site 17 (2005 - 2008)
2005 2006 2007 2008
MODIS LAILAI in situ
0 0.5 1 1.5 2 2.50
0.5
1
1.5
2
2.5
in situ LAI
MO
DIS
LA
I
0 0.5 1 1.5 2 2.50
0.5
1
1.5
2
2.5
in situ LAI
MO
DIS
LA
I
All MODIS data Principal algorithm
N = 29 N = 14
R² = 0.82 R² = 0.94
Mougin, Demarez, in preparation
![Page 32: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/32.jpg)
(Gardelle et al., in revision)
Monitoring of Sahelian ponds : Ex of the Agoufou pond
![Page 33: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/33.jpg)
Comparison FORMOSAT/MODIS/SPOT
MODIS-2007 SPOT-2005/06
Evaluation of a MODIS based methodology for surface water mapping
![Page 34: Photo: Doug Parker Use of FORMOSAT images over the Gourma site (Mali) E. Mougin, V. Demarez, P. Hiernaux, L. Kergoat, V. Le Dantec, M. Grippa, Y. Auda,](https://reader035.vdocument.in/reader035/viewer/2022070306/5519436955034688738b4606/html5/thumbnails/34.jpg)
Concluding remarks
High spatial and temporal resolution of Formosat data are found useful for :
- Land cover mapping (change) of cultivated surfaces (small size)
- Vegetation monitoring : detection of period of water stress
- Mapping and monitoring of small ponds
However, over sahel, data acquisition are hampered by aerosol and cloud contamination.
As a consequence, no data was acquired during 2 weeks within the core of the growing season