DYNAMICS of LAND COVER/LAND USE in the SEDHIOU REGION Dynamiques De L’Occupation/Utilisation Des Sols Dans La Région De Sédhiou
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DYNAMICS OF LAND COVER/LAND USE IN THE SEDHIOU REGION Dynamiques de l’Occupation/Utilisation des sols dans la Région de Sédhiou Report n° 1 Edoardo Fiorillo September Maurizio Bacci Séraphin Dorégo 2013 Vieri Tarchiani This study has been realised within the framework of the “Programme d’Appui au Programme National d’Investissement de l'Agriculture du Sénégal” (PAPSEN) by a team composed of researchersThis study has of been the realisedNational in Researc the frameworkh Council of (CNR)the Programme of Italy and d’Appui the Senegaleseau Programme Institute National of Agriculturald’Investissement Research de (ISRA):l'Agriculture du Sénégal (PAPSEN) by a team of the National Research Council of Italy, composed by: Edoardo Fiorillo (IBIMET-CNR) MaurizioEdoardo FiorilloBacci (IBIMET (IBIMET-CNR)-CNR) et Vieri Tarchiani (IBIMET-CNR) and The study Séraphin has been Dorégo co- funded(ISRA) by the General Direction for Development Cooperation of the TheItalian study Ministry has beenof Foreign co-funded Affairs by and the the General National Direction Research for Council Development of Italy through Cooperation the PAPSEN of the- ItalianCNR project. Ministry of Foreign Affairs and the National Research Council of Italy through the PAPSEN- TheCNR Authorsproject andacknowledge by the Senegalese the contribution Institute ofof Mr.Agricult Babacarural ResearchFall (Inspectorat. Régional des Eaux et TheForêts authors de Sédhiou) want to in thankthe comprehension Babacar Fall and of local all the changes staff of and "Eaux dynamics. et Forêts" Regional Service for support in field campaign and regional dynamics comprehension. Table of Contents 1. Introduction ................................................................................................................................................... 6 2. Methodological approach ............................................................................................................................. 7 2.1 Land cover / land use............................................................................................................................... 7 2.2 1990-2005 land cover change detection ................................................................................................. 9 2.3 Land cover and population dynamics comparative analysis ................................................................. 10 2.4 2013 field campaign .............................................................................................................................. 10 3. Sédhiou Region ............................................................................................................................................ 11 4. 2005 Sédhiou Region land cover ................................................................................................................. 14 4.1 Natural vegetation (NV)......................................................................................................................... 15 4.2 - Rainfed herbaceous crops (RHC) ......................................................................................................... 16 4.3 - Irrigated herbaceous crops (IHC) ......................................................................................................... 18 4.4 - Tree plantations and orchards (TP) ..................................................................................................... 19 4.5 - Urban areas and rural settlements (U) ................................................................................................ 20 4.6 – Rivers (R) ............................................................................................................................................. 20 4.7 - Humid and natural areas (HA) ............................................................................................................. 21 5. Land cover changes during 1990-2005 period ............................................................................................ 22 6. Sédhiou Region population dynamics ......................................................................................................... 29 7. Conclusions .................................................................................................................................................. 33 8. Comments and recommendations .............................................................................................................. 35 List of figures Fig. 1 – IBIMET mission treks carried out during July 2013 field campaign. .................................................. 11 Fig. 2 – Administrative boundaries of Sédhiou Region, main road network, rivers and Forêts Classées (forest reserves). Background: False color Landsat Image (Red=Vegetation). ........................................................... 12 Fig. 3 – 2005 Land cover map for Sédhiou Region according to 7 classes reclassification (1=first class; 2=second class; HA= humid and natural areas; IHC= irrigated herbaceous crops; NV= natural vegetation; RHC= rainfed herbaceous crops; TP= tree plantations; U= urban; W= water. ................................................ 14 Fig. 4 – “Natural vegetation” (NV) class coverage percentages for each Communauté rurale of Sédhiou Region in 2005. Background: False color Landsat Image (Red=Vegetation). .................................................. 16 Fig. 5 – “Rainfed herbaceous crops” (RHC) class coverage percentages for each Communauté rurale of Sédhiou Region in 2005. Background: False color Landsat Image (Red=Vegetation). .................................... 17 Fig. 6 – Example of accuracy assessment for “rainfed herbaceous crops” (RHC) class performed on Google Earth (2005 image). Control point (green icon) is located inside an actually not cultivated area; the polygon effectively covers an agricultural area. ........................................................................................................... 18 Fig. 7 – Example of accuracy assessment for “irrigated herbaceous crops” (IHC) class (red boundaries polygon) performed on Google Earth (2005 image). Control point (green icon) is located inside an area covered by natural vegetation; rice crops can be recognized in the central area. ......................................... 18 Fig. 8 – “Irrigated herbaceous crops” (RHC)class coverage percentages for each Communauté rurale of Sédhiou Region in 2005. Background: False color Landsat Image (Red=Vegetation). .................................... 19 Fig. 9 – “Tree plantations and orchards” (TP) class coverage percentages for each Communauté rurale of Sédhiou Region in 2005. Background: False color Landsat Image (Red=Vegetation). .................................... 20 Fig. 10.– LC change percentages for each Communauté rurale of Sédhiou Region (period 1990-2005). Background: False color Landsat Image (Red=Vegetation). ............................................................................ 23 Fig. 11 − “Natural vegetation” (NV) class changes (%) for each Communauté rurale of Sédhiou Region (period 1990-2005). Background: False color Landsat Image (Red=Vegetation). ........................................... 24 Fig. 12 – “Rainfed herbaceous crops” (RHC) class changes (%) for each Communautés rurales of Sédhiou Region (period 1990-2005). Background: False color Landsat Image (Red=Vegetation). ............................... 25 Fig. 13 – Main LC changes (period 1990-2005) occurred in northeastern Communautés rurales (Tankon, Faoune, Boghal and Ndiamacouta). (NV= natural vegetation; RHC= rainfed herbaceous crops). 432 LANDSAT image acquired in November 2005. Background: False color Landsat Image (Red=Vegetation). ................. 26 Fig. 14 - Main LC changes (period 1990-2005) occurred in northwestern Communautés rurales (Inor and Bona). (NV= natural vegetation; RHC= rainfed herbaceous crops). 432 LANDSAT image acquired in november 2005. Background: False color Landsat Image (Red=Vegetation). ................................................ 27 Fig. 15 – Main LC changes (period 1990-2005) occurred in southwestern Communautés rurales (Kaour and Djibanar). (NV= natural vegetation; RHC= rainfed herbaceous crops). 432 LANDSAT image acquired in November 2005. Background: False color Landsat Image (Red=Vegetation). ............................................... 28 Fig. 16– 1988 Population densities (ab/Km2) per Communauté rurale of Sédhiou Region. Background: False color Landsat Image (Red=Vegetation). .......................................................................................................... 30 Fig. 17– 2008 Population densities (ab/Km2) per Communauté rurale of Sédhiou Region. Background: False color Landsat Image (Red=Vegetation ............................................................................................................ 31 Fig. 18 Communauté rurale population grow rates (PGRc) during 1988-2008 period. Background: False color Landsat Image (Red=Vegetation). ................................................................................................................... 32 Fig. 19 Comparison between “rainfed herbaceous crops” class percentage changes (V.RHC) and Communauté rurale growth rates normalized to Sédhiou Region growth rate (PGRc/PGRr). Background: False color Landsat Image (Red=Vegetation). ................................................................................................. 34 List of tables Tab. 1 – Reclassification classes for the purposes of