the land cover of africa for the year 2000 p. mayaux, e. bartholomé, m. massart, c. van cutsem, a....
TRANSCRIPT
The Land cover of Africa for the year 2000
The Land cover of Africa for the year 2000
P. Mayaux, E. Bartholomé, M. Massart, C. Van Cutsem, A. Cabral,
A. Nonguierma, O. Diallo, C. Pretorius, M. Thompson, M. Cherlet,
J-F. Pekel, P. Defourny, M. Vasconcelos, A. Di Gregorio, S.Fritz,
G. De Grandi , C.Elvidge, P.Vogt, A. Belward
The overall contextThe overall context
• 30,000,000 km2
• From dry deserts to tropical rain forests
• Evergreen (forests, deserts) and seasonal (savannahs, grasslands) ecosystems
• Isolated continent no overlap with other windows
• 1 continental window (baseline map) + regional windows (improvements)
Characteristics of the productCharacteristics of the product
• Collaboration between many institutions: FAO, Instituto Investigação Cientifica Tropical (Lisbon), Université Catholique de Louvain (Louvain-la-Neuve), Agrhymet (Niamey), CSIR (Pretoria)…
• Various techniques: statistical averaging and clustering (Louvain-la-Neuve), composition on albedo and tree classifiers (Lisbon), clean NDVI & NDWI profiles and clustering (CCR)
• Data used: SPOT VEGETATION, ERS & JERS SAR (flooded forests), DMSP (cities)
• Legend has put the accent on the savanna and the forests• The current product is still in improvement
Cleaning up of the NDVI profilesCleaning up of the NDVI profiles
• Elimination of low values• Interpolation over long periods
Monthly max NDVI and min NDWIMonthly max NDVI and min NDWI
August – April - January
Forests Forêts Closed evergreen lowland forest Degraded evergreen lowland forest Montane evergreen forest (> 1000 m) Swamp forest Mangrove Mosaic Forest / Croplands Mosaic Forest / Savanna Closed decidous forest (Miombo)
Forêt dense humide Forêt dense dégradée Forêt de montagne Forêt marécageuse Mangrove Mosaïque agriculture / forêt humide Mosaïque forêt / savane Forêt décidue dense(Miombo)
Woodlands, shrublands and grasslands Savanes Deciduous woodland Deciduous shrubland with sparse trees Open deciduous shrubland Closed grassland Open grassland with sparse shrubs Open grassland Sparse grassland Swamp bushland and grassland
Savane boisée décidue Savane arborée à arbustive décidue Savane arbustive décidue Savane herbacée dense décidue Savane herbacée ouverte à faible strate arbustive Savane herbacée ouverte Pseudo-steppe Savane herbacée et arbustive inondée
Agriculture Agriculture Croplands (>50%) Croplands with open woody vegetation Irrigated croplands Tree crops
Agriculture (>50 %) Mosaïque agriculture / végétation sèche Agriculture irriguée Vergers
Other land-cover classes Autres occupations du sol
Bare soil Salt hardpans Waterbodies Cities
Sol nu Dépôts salins Eau Villes
MarocMaroc
• Urge agricultural areas
• Urban settlements
• Meditteranean vegetation
• Inversed vegetation cycle
Irrigation in the Lybia desertIrrigation in the Lybia desert
• Urge irrigation areas
• Urban settlements
• Desert
• Salt hardpans
Nile DeltaNile Delta
• Urge cities (Cairo, Alexandria)
• Free water and swamp grasslands, and irrigated agriculture
• Desert
SenegalSenegal
• Urge agricultural areas (“Bassin Arachidier”
• Mangroves (Saloum, Casamance)
• Urban settlements
• From sparse grasslands to woodlands
• Remnants of tropical forests (Basse Casamance)
Chad LakeChad Lake
• Chad lake
• Free water and swamp grasslands (“prairie flottante)
• Agriculture
• From desert to closed shrublands
Internal delta of Nile Internal delta of Nile
• Urge areas of swamp grasslands, water
• From shrublands to dense woodlands
MalawiMalawi
• Agriculture
• Miombo woodlands
• Large lake
South D.R. CongoSouth D.R. Congo
• Wet miombo woodlands
• Swamp grasslands
• Shrublands and grasslands
• Woodlands mixed with agriculture
Wet miombo woodlandsWet miombo woodlands
Delta of the OkavangoDelta of the Okavango
• Swamp grasslands and shrublands
• From grasslands to woodlands
• Salt hardpans
Cape TownCape Town
• Intensive agriculture (wheat, vineyards)
• Vegetation related to topography
• Large urban settlements
• High botanical biodiversity
Forest blocks in GhanaForest blocks in Ghana
• Volta Lake
• Lagoons
• Urban settlements
• Forest reserves
• Forest / croplands / savanna mosaic
Central “Cuvette” of Congo RiverCentral “Cuvette” of Congo River
• Swamp forests
• Swamp grasslands (“prairie flottante)
• Agriculture mixed with fallows and forest
• Enclosed savannas
Congo Basin forestsCongo Basin forests
• Agriculture mixed with fallows and forest along the former “paysannats”
• Penetration by the logging tracks
Niger deltaNiger delta
• Mangroves
• Lowland and montane forests
• Urban settlements
• Forest / croplands / savanna mosaic
• Woodlands mixed with agriculture
Montane forestsMontane forests
• Kilimanjaro, Mehru…
• Montane forests
• Closed grasslands
• Agriculture
MadagascarMadagascar
• Montane and lowland rain forests
• Dry deciduous forests
• Secondary forests & rural complex
• Mangroves
• Grasslands and shrublands
• Thicket
Global land-cover mapsGlobal land-cover maps
IGBP DIS-Cover University of Maryland
GLC 2000VGT colour composite
The locust windowThe locust window
FAO / JRC
Qualitative validationQualitative validation
Agricultural areasAgricultural areas
LimitationsLimitations
• Confusion in the agricultural areas (mixed with natural vegetation)
• Seasonal cycle of the vegetation could be more exploited (number and period of vegetation cycles)
• Local legends do not fit with the continental one
Necessity of regional products