Eastern Guiana shield land cover classification using SPOT-4 / VEGETATION instrument Gond Valéry CIRAD, Natural forest department Route de Montabo BP 165 F-97323 Cayenne French Guiana GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18-22 March 2002 Centre International De Recherche en Agronomie Pour le Développement

CONTEXT An almost unknown area generally considered as a big green leaf An heterogeneous continuum of forest (180 tree species by ha) - A hot-spot of Biodiversity (1200 tree species in French Guiana) An inaccessible fragile ecosystem (except by rivers) A high cloud cover rate perturbing image analysis

General documentation of the area Eva, 1999 Lowland dense moist forest Coverted forest cover Mangrove Seasonally flooded grassland Scolar book, 1999 Forest Cerrado Coastal forest Siebert, 1996 Humid tropical forest, plaine Open woodland, cerrado Inunded tropical forest Mangrove

First approach : angular study* From -45° to -30° West Nadir From +30° to +45° East Cloud mask inspired by Cherlet, et al., (2000) using B0 and SWIR Empirical estimation of the cloud shadow (dilate filter around cloud) Take into account of view angle using VZA loss of information (eastern coast) because of the shadow mask Mis-classification of pioneer front and forest class (confusion) Patch effect over several places (mis-classification) * In cooperation with Jousseaume, K.

Second approach : temporal classification Basic cloud detection (BO > 50) Ten-day composite based on maximum NDVI Monthly composite based on minimum SWIR ISODATA classification using B2, B3 and SWIR on 12 composites Mis-classification of particular features (Brazilian fish-bone) Mis-classification of inner savannas (South Surinam) Cloud patterns in many places

Third approach : annual compositing 1 2 3 4 Third approach : annual compositing Forest Savannas Swamp Belem Agriculture - Basic cloud detection (BO > 50) Ten-day composite based on maximum NDVI Monthly composite based on minimum SWIR Annual composite based on minimum SWIR ISODATA classification using B2, B3 and SWIR on the annual composite Good elimination of clouds and partial elimination of shadows Accuracy of features (fish-bones, savannas, agriculture) Identification of specific area (inner forest gradient)

Validation : macro-analysis Topography Geology Guiana shield coherence (topography and geology) Relationship with rainfall Botanical coherence Rainfall Rain gradient Botanical knowledge

Validation : high resolution images-analysis Guyana-Suriname border Rio Tocantins Landsat +ETM Forest limits Agriculture polygons Tumuc Humac Devide and savanna Belém Forest – savanna limit Fragmented cover Santarém transamazonian Rio Paru and Rio Jari Forest mixing Hydrographic features

Validation : Counami forest 1 4 2 5°21’58 N 53°12’52W Wetland 5°24’6 N / 53°6’25 W Savanna Palm trees? 5°15’0 North / 53°8’2 West 5°8’34 North / 53°9’6 West Illegal gold mining 5°17’40 North / 53° 17’8 West Legal logging

Eastern Guyana shield land cover 5°South 46° West 7° N 59° West 0° 4°N 4° S 50° W 54° W 58° W Forest (type1) Forest (type 2) Forest (type 3) Inundated vegetation Wetland, swamp Converted forest Savanna Water, not classified N 100 200 300 km

Legend LCCS Inundated forest Broadleaf evergreen forest on Permanently flooded land Plain : Flat to almost flat Sedimentary rock, sand Podzols Tropics – perhumid Altitude <50m LCCS code: 40499-4795 Legend LCCS Forest (type 1) Multi-layered broadleaf Evergreen forest Plain gently undulating Metamorphic rock, shale Ferrasols Tropics – Perhumid Altitude 100-300 No visible erosion LCCS code: 20636-15058 Wetland Broadleaf evergreen open woody veg On permanently flooded land Plain, Flat to almost flat Sedimentary rock, clay Gleysols Tropics – perhumid Altitude <50m LCCS code: 40559-81 Forest (type 2) Multi-layered Semi-evergreen Plateau gently undulating Plutonic rock, granite Ferrasols Tropics – perhumid Altitude 300-600 No visible erosion LCCS code: 20636-15050 Converted forest Scattered clustered fields of rainfed Graminoids crops with isolated fields Of broadleaf evergreen tree crops Plain : flat to almost flat Sedimentary rock, sand Podzols Tropics – perhumid Altitude <50ml Food crops LCCS code: 10877 Forest (type 3) Multi-layered semi-deciduous Plateau gently undulating Plutonic rock, granite Ferrasols Tropics – humid Altitude 600-1000 No visible erosion LCCS code: 20643-15050 Savanna Open medium tall grassland with Medium shrubs Plain : gently undulating Plutonic rock, granite Ferralsols Tropics – humid Altitude 300-1500m LCCS code: 21353-218

Neccessary improvments - Bad restitution of a pattern in North Para. Is it a Forest type 3 or a Savanna? Bad delineation Bad restitution of two types of forest Forest type 1 and 2 difficult to separate Bad classification along Oyapock river. There is only forest there, no lake. Confusion coming from cloud shadow - taking into account the shadow in the process