Examples of Formosat-2 data use:

Nezer-Arcachon datasets

Framework:

Vegetation and environnement monitoring of agriculture and forest landscapes in Aquitaine under global change (climate, anthropogenic activities)

Dominique Guyon, INRA Bordeaux, Unité EPHYSE

Formosat2/VENµS Users meeting

CESBIO, Toulouse, January 12th 2010

Venµs, Formosat-2 : high spatial resolution + high repetitivity

-> separate immediate changes due to agricultural practices operating at field level from those due to natural environment (soil, climate).

-> complementary approaches:

- monitoring the seasonal/interannual changes of the remote sensing signal (e.g. NDVI, red-edge bands reflectance):

dating phenological stages,

dating and detecting agricultural activities (sowing, thinning out of leaves, harvest, felling…),

detecting events of climate accidents (storm), stress or early senescence

- mapping of vegetation based on seasonal changes during the whole year

- retrieval of the annual course of biophysical variables at plot scale : LAI, Fcover, faPAR

- assessing the information loss due to a scaling from local measurements to low resolution remote sensing time-series (e.g. VEGETATION or MODIS).

- coupling to process-based models: biomass production, crop yield, productivity, C and water fluxes

VENµS: Propositions de sites

UR EPHYSE (terrestrial ecosystems)

UMR EPOC (maritime ecosystems)

FORMOSAT2: Database KALIDEoS-Littoral / CNES

KALIDEOS-Littoral

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2

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Some INRA’s sites:1: NEZER (forest landscape) and BILOS (fluxes meas.)2, 3: Watersheds of Bouron, Tagon

► forest structure changes monitoring with VHR imagery

Programm ORFEO/Cnes, PhD 2010-2013?

Collaboration EGID-Univ. Bordeaux3

• Nezer

•Climate events and sylvicultural changes (thinning, felling)

•application to map the 24th January 2009 windfall damages

► Phenology monitoring

tree layer and understory vegetation

•Bilos ; 2008-2009

•Ground-based measurements of LAI and fAPAR,

•Seasonal change of vegetation indices from Spot/VEGETATION

•Formosat/VEGETATION: to be done

FORMOSAT2:

- time-series 2008-2009

NEZER + Bilos

14/03/200821/08/200822/12/2008 Storm on January 2904/02/200929/05/200924/06/200916/06/200913/08/200907/09/2009

- after 2009?

Other landscape site?

Estimation of C and water fluxes

Forest structure changes monitoring with VHR imagery

Programm ORFEO/CNES

► mapping the 24th January 2009 windfall damages: First results

C.ORNY12, N.CHEHATA1, S.BOUKIR2, D.GUYON1, 2009

1 EGID-Université Bordeaux3, 2 INRA

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Before the storm: 22/12/2008 After the storm: 04/02/2009

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Radiometric features extraction :- Textural- Temporal change- Vegetation indices.

Segmentation -> areas with same changes

unsupervised classificationautomatical binary

classification

before and after storm

Methodology – overall framefrom algorithms in Orfeo Tool Box (CNES) / mean shift algorithm

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Satisfactory results: Unsupervised classification concentrated damages (MMU)

Errors :

No detection of damages in young stands

Difficult for plot edge (shadows and class limits)

false détection due to shadows moving To be estimated for diffuse damages

intact

damaged

1 km

Confusion matrix :

Results: binary map of damages and validation

Ground level

sate

llit

e le

vel

MMU = 5 pixels = 300m² ->5 to 45 trees according to density