Geographic Information Systems for Food Security and Land Management in Africa - Foster Mensah

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A flagship CTO event, this has grown into a platform for knowledge-sharing among peer groups steering ICT projects in e-delivery of health care, education and governance. This Forum echoes the …

A flagship CTO event, this has grown into a platform for knowledge-sharing among peer groups steering ICT projects in e-delivery of health care, education and governance. This Forum echoes the Commonwealth's 2013 theme: The Road Ahead for Africa.

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  • 1. 7th Annual E-GOV Africa Kampala, Uganda 7th Annual E-GOV Africa Kampala, Uganda GEOGRAPHIC INFORMATION SYSTEMS FOR FOOD SECURITY AND LAND MANAGEMENT IN AFRICA GEOGRAPHIC INFORMATION SYSTEMS FOR FOOD SECURITY AND LAND MANAGEMENT IN AFRICAFOOD SECURITY AND LAND MANAGEMENT IN AFRICAFOOD SECURITY AND LAND MANAGEMENT IN AFRICA Foster Mensah Centre for Remote Sensing and Geographic Information Services University of Ghana Legon-Accra 1
  • 2. OutlineOutline • Introduction• Introduction • GIS GIS C St di• GIS Case Studies • GPS • Remote Sensing • SLM • A Panacea for Drylands – 15min Video
  • 3. About CERSGISAbout CERSGIS • Established by EPA and University of Ghana • Geographic Information Services and Research Support CentreSupport Centre • It is a non-profit, self sustaining organization • Provide Remote Sensing and Geographic Information Systems (GIS) services in the application of GIS and Remote Sensing. • Provides services to government agencies, non- governmental organizations, research institutions d th i t tand the private sector
  • 4. IntroductionIntroduction • We live in an information age • Geospatial information is one of the most critical elements underpinning decision-making for manyp g g y disciplines • Geospatial information is an essential building blockp g for sustainable development. • Increasing the availability, access and interoperabilityIncreasing the availability, access and interoperability of Geospatial information will stimulate innovation, contribute to economic transformation and facilitate national developmentnational development
  • 5. Geographic Information System (GIS)Geographic Information System (GIS) 5
  • 6. What is GIS ?What is GIS ? Reality • Geographical Information System (GIS) • Software and hardware that allows creation, visualization, query and analysis of spatial data.q y y p • Spatial data refers to information about the geographic location of an entityy 6
  • 7. 7
  • 8. RasterRaster--Vector Data ModelVector Data Model 8
  • 9. Applications of spatial dataApplications of spatial data:: • Modeling f– Developing “where is” and “what if” scenarios • Decision making support – communicating processes and information that help solve or avoid problems. • Monitoring relating to environmental management and support– relating to environmental management and support for programme management services. M P d ti• Map Production
  • 10. Applications of spatial dataApplications of spatial data:: Spatial data analysis 1. distances between geographic locations 2. The amount of area within a certain geographic region 3. What geographic features overlap other features 4. The amount of overlap between features 5. The number of locations within a certain distance of another 10
  • 11. thanksthanks toto geospatialgeospatial technology!technology!
  • 12. LandLand suitabilitysuitability analysisanalysis Land suitability analysis involves the application of criteria to the landscape to assess where land is mostp and least suitable Land use Rainfall 12
  • 13. Site suitability analysisSite suitability analysis Why do site suitability assessment? – It greatly reduces the time and effort which might otherwiseg y g be spent manually searching records – It is a key factor and critical initial step in the design of many projects – It produces a detailed display of the most-suitable to least- suitable areas for consideration, while filtering out unusable or less desirable sites.
  • 14. suitability modelingsuitability modeling R litReality Spatial data layers Suitable areas Model criteria: - Land use - Elevation - Climate 14
  • 15. LandLand suitabilitysuitability modelingmodeling processprocess 1. Determine the question to be studied 2. Define the criteria for the analysis 3. Determine the data needed to answer the question 4. Determine the GIS procedures needed 5. Create the model 6. Analyze the results and improve the model 7. Make a decision 15
  • 16. ProcessProcess flowflow (Modeling)(Modeling) Land use Rainfall 16
  • 17. Sample suitability and weighting Criteria: landscape restoration will be necessary in certain areas Weighting: Open access areas more important than reserved areas Bare areas more important than closeness to towns Annual rainfall greater than 1200mmAnnual rainfall greater than 1200mm is highly suitable Slopes less than 10% is highly suitable 17 suitable
  • 18. Case Study:Case Study:Case Study:Case Study: Suitability ModelingSuitability Modeling forfor LandscapeLandscape RestorationRestoration 18
  • 19. MethodologyMethodology Landuse Mapping Terrain Analysis Climatic Analysis Landuse & Accessibility Rainfall Suitable Slope and Elevation GIS Analysis to Generate Overall Suitability 19
  • 20. Inputs and CriteriaInputs and Criteria 1. Preliminary criteria categories were decided and weights assigned based on the level of importance 2. Less suitable sites were given low values/weights (0 been the lowest) and the most suitable areas assigned a higher weight (4 been the highest) 3 Layers added to each other and values for each data layer carried through and3. Layers added to each other and values for each data layer carried through and applied to output 4. Rank as suitable the closer an area matches the optimum 5. The result is a suitability map which shows a range of values that reflect a area’s suitability based on the user define criteria 20
  • 21. Criteria ScoringCriteria Scoring Input Layer Criteria Potential Score Low (0) High (1) Terrain Elevation <500m asl >500m asl Slope >10 degree <10 degreeSlope >10 degree <10 degree Low (0) Moderate (2) High (3) Climatic Rainfall Distribution <1000mm 1000-1200mm >1200mm Low (0) Moderate Low (1) Moderate (2) Moderate High (3) High (4)Low (0) Moderate Low (1) Moderate (2) Moderate High (3) High (4) Land Use Land Use Types Reserved Long Fallow Short Fallow Grassland 21
  • 22. Elevation Criterion 2 Classes : Altitude 0 - 500 msl = 0 (Low Suitability) Altitude >500 msl = 1 (High Suitability) 22
  • 23. Slope CriterionSlope Criterion 2 Classes: Slope >10 degrees = 0 (Low Suitability) Slope <10 degrees = 1 (High Suitability) 23
  • 24. Annual Rainfall Criterion 3 Classes: 1000 0 (L S it bilit )<1000mm = 0 (Low Suitability) 1001 – 1200mm = 2 (Moderate Suitability) >1200mm = 3 (High Suitability) 24
  • 25. Land Use CriterionLand Use Criterion 4 Classes: Reserved Area = 0 Closed Forest = 1Closed Forest = 1 Long Fallow = 2 Short Fallow = 3 Grassland = 4 25
  • 26. ResultsResultsResultsResults 26
  • 27. Slope & Elevation Elevation layer is overlaid with Slope layer: Suitability score ranges from 0, for areas that meet no criteria to 2, for areas that meet both criteria 27
  • 28. Slope, Elevation & Rainfall Slope layer is overlaid with the rainfall and elevation layerand elevation layer 28
  • 29. AreasAreas suitablesuitable forfor landscapelandscape restorationrestoration
  • 30. Ranking Suitability Area % Area (ha) Class Total(ha) 0 Low 0.0 629 103,617 1 1.0 100,664 2 0.0 2,324 3 Medium 2 190,190 4 8 836,712 5 20 1,975,211 5,788,8896 28 2,786,776 7 High 30 3,030,098 4 050 585 8 8 762,548 9 3 257 939 4,050,5859 3 257,939 Total 100 9,943,091 9,943,091 30
  • 31. Case Study:Case Study:Case Study:Case Study: Desertification Hazard MappingDesertification Hazard Mapping 31
  • 32. Desertification HazardDesertification Hazard It is a process that can be as much man-caused as natural and therefore is one of the natural hazards best suited for mitigation by those who plan, implement, and manage national development efforts. Why create Hazard maps?Why create Hazard maps? – Visual information better than tables of numbers – Easier to convince peopleEasier to convince people – Can be updated and disseminated easily – Useful for mitigation planning
  • 33. Geospatial PortalGeospatial Portal demand for geospatial data access to quality geospatial data Metadata serviceMetadata service minimize duplication efficient data maintenance Map serviceMap service platform for partnerships efficient data maintenance Map serviceMap service DD--support servicesupport service
  • 34. ONLINE GIS PLATFORMONLINE GIS PLATFORMONLINE GIS PLATFORM FOR AGRICULTURAL DEVELOPMENT IN GHANA ONLINE GIS PLATFORM FOR AGRICULTURAL DEVELOPMENT IN GHANA
  • 35. http://www.gis4ghagric.nethttp://www.gis4ghagric.net
  • 36. Land coverLand cover MetadataMetadata ElevationElevation
  • 37. CropsCrops
  • 38. SoilsSoils
  • 39. ClimateClimate MEAN ANNUAL RAINFALL EVAPOTRANSPIRATION
  • 40. Land SuitabilityLand Suitability Cowpea Millet
  • 41. Sample MapSample Map
  • 42. Global Positioning System (GPS)Global Positioning System (GPS)
  • 43. GPS Requires 4 Satellites To Obtain A “Position”
  • 44. Longitude / LatitudeLongitude / Latitude (North / West)(North / West) (North / East)(North / East) 9O9Ooo OOoo 3O3Ooo 6O6Ooo Equator ( 0 NS) OOoo6O6Ooo18O18Ooo 120120oo Equator ( 0 NS) (South / West)(South / West) (South / East)(South / East) Prime Meridian (0 )(0 EW)
  • 45. Getting your location/position on the earth’s surfacethe earth s surface +
  • 46. FarmerFarmer--level GPS Mappinglevel GPS Mapping 1 2 5 1 2 5 2 3 4 3 4 HandHand--held GPS Receiverheld GPS Receiver PT. NO LATITUDE LONGITUDE 1 05.68771 001.62076 2 05.52341 001.60019 3 05.33322 001.59332 49 4 05.44572 001.59902 5 05.68331 001.62045 1 05.52341 001.60019
  • 47. GPSGPS DataData CollectionCollection This is becoming extremely important collecting data on locations of i t tinterest. 50
  • 48. Remote SensingRemote Sensing
  • 49. Why remote sensing?Why remote sensing?y gy g • Access large areas • Map inaccessible areas • Timely repeats for monitoring• Timely repeats for monitoring
  • 50. Types of remote sensing dataTypes of remote sensing data Optical Lidar Radar
  • 51. Optical dataOptical dataOptical dataOptical data
  • 52. SpaceSpace--basedbased applicationsapplications
  • 53. OpticalOptical –– high resolutionhigh resolution e.g. Worldview, Aerial photographs 1961 2007 Change
  • 54. OpticalOptical –– medium resolutionmedium resolution e g Landsat ASTER SPOT DMC (incl NigeriaSAT) CBERSe.g. Landsat, ASTER, SPOT, DMC (incl. NigeriaSAT), CBERS… 10 km
  • 55. OpticalOptical –– coarse resolutioncoarse resolution e g MODIS SPOT-VGT AVHRR MERISe.g. MODIS, SPOT VGT, AVHRR, MERIS… MODIS (500 m) ASTER (15 m) QuickBir d (1 m) Landsat (30 m)(500 m) (15 m) d (1 m)(30 m) Daily ~40 days ~60 days on demandDaily ~40 days ~60 days on demand FreeFree FreeFree Low costLow cost ProhibitivelyProhibitively ExpensiveExpensiveExpensiveExpensive
  • 56. Vegetation IndexVegetation Index –– ‘greenness’‘greenness’ • Reflection: leaves ≠ soil • Normalised Difference V t ti I d (NDVI) e (%) Vegetation Index (NDVI) lectanceRefl Wave Length (nm) High NDVIHigh NDVI
  • 57. Satellite Scenes – same season 0 k ASTER 27th Nov Landsat ETM+ 12th Landsat TM 30th Dec 10 km 27th Nov 2006 ETM+ 12th Dec 2000 30th Dec 1986
  • 58. > 4 S D ChangeChange--detectiondetection +1 to +2 S.D.s +2 to +3 S.D.s > +4 S.D.s No Change (± 1 S.D) Water / no data < -3 S.D.s -2 to -3 S.D.s -1 to -2 S.D.s ∆ NDVI 1986 ∆ NDVI 2000ETM+ ∆ NDVI 1986 2000 ∆ NDVI 2000 2006 ETM   2000
  • 59. Example use of optical dataExample use of optical data Land cover mapping • Global Land cover Mapping Project 2000 • Classification based on SPOT VGT data and• Classification based on SPOT VGT data and expert opinion/fieldwork - 1 km resolution Mayaux, P., et al. 2004. A new land-cover map of Africa for the year 2000. Journal of Biogeography, 31, 861-877
  • 60. Dense forest Mosaic forest GLC 2000 Africa map Mosaic forest Woodlands ShrublandsShrublands Grasslands AgricultureAgriculture Bare soil WaterbodiesWaterbodies
  • 61. LandLand cover mapcover map -- GhanaGhana
  • 62. Problem 1: Cloud
  • 63. Problem 2: These look the same in optical 1. Pristine 2. Degraded Budongo Forest, Uganda
  • 64. RadarRadarRadarRadar
  • 65. RadarRadarRadarRadar • Side-looking Active  radar  Return  signalpulse signal  (backscatter)
  • 66. Optical vs. Radar
  • 67. Radar satellitesRadar satellites Band Wavelength Typical maximum resolution Satellitesg from orbit X-band 2.5-3.75 cm ~1 m TerraSAR-X (2007-) TanDEM-X (2010-) COSMO-SkyMed (2007-COSMO-SkyMed (2007- ) C-band 3 75 7 5 cm ~3 m ERS-1 (1991-2000) ERS-2 (1995-2011) ASAR (2002 2012)C-band 3.75-7.5 cm ~3 m ASAR (2002-2012) RADARSAT 1 (1995-) RADARSAT 2 (2007-) S b d 1 6 N SAR (201 )S-band 7.5-15 cm ~6 m NovaSAR (2015-) JERS-1 (1992-1998) ALOS PALSAR (2007- L-band 15-30 cm ~20 m ( 2011) ALOS-2 PALSAR-2 (2013-) SAOCOM (2015)( ) ?DESDynI (2019) P-band 70-130 cm ~50 m ?BIOMASS (2019)
  • 68. ConclusionsConclusions -- RadarRadar • Sees through clouds• Sees through clouds • Penetrates vegetation • Data not free
  • 69. LidarLidar –– light detection and ranginglight detection and ranging L• Laser • Vertical looking • Detects returns with high accuracy
  • 70. 33--DD LidarLidar ImageryImagery
  • 71. ConclusionsConclusions -- LiDARLiDARConclusionsConclusions LiDARLiDAR Gi t i & t ti h i ht• Gives terrain & vegetation height • Potential for very high resolution • Sampling tool • Cloud problems • 1 satellite ever (ICESat GLAS) • Mostly aircrafty
  • 72. Risk and damage assessment – with climate change it is likely that Earth observation and weather monitoring satellites will become increasingly i t t t i i ti i k timportant to improve existing risk assessment processes, especially for damage evaluation. Land cover monitoringLand cover monitoring – given the effect agricultural expansion have on biodiversity and climate change assessing the condition of land coverand climate change, assessing the condition of land cover can be achieved by EO
  • 73. Disaster monitoringDisaster monitoring When you are on the ground, it is hard to grasp the size of these events.
  • 74. Land cover mappingLand cover mapping
  • 75. Rural development – Earth observation satellites allow objective assessments of remote rural areas to help design, plan and monitor the i t f l d d i lt l j timpact of land use and agricultural projects Change DetectionChange Detection – An important concept in monitoring is change... B t llit j t k i d th l b th– Because satellites just keep on going round the globe, they take repeat images which can be very helpful in explaining change over timechange over time.
  • 76. Change DetectionChange Detection
  • 77. Useful websitesUseful websites 81
  • 78. Famine Early Warning Systems Network (FEWS NET) http://www.fews.net 82 http://www.fews.net
  • 79. 83
  • 80. 84
  • 81. 85 http://www.foodsecurityportal.org/africa-food-security-vulnerability-indices
  • 82. 86 http://www.fao.org/docrep/008/J6398e/maps/afr.htm
  • 83. Land Use Planning :Land Use Planning :SustainableSustainable Land ManagementLand Management • An iterative process • Based on the dialogue amongst all stakeholders • Negotiation and decision for sustainable land use • Monitoring implementation. Provides the prerequisites for achieving a sustainable form of land use which is acceptable as far as the social and environmental contexts are concerned andsocial and environmental contexts are concerned and is desired by the society while making sound economic sense.
  • 84. MAIN PRINCIPLES:MAIN PRINCIPLES: • Active community participation • Consistent with national/local planning schemes • Environmentally friendlyEnvironmentally friendly • Community validation and approval Approval by local authority• Approval by local authority • Implementation and monitoring 88
  • 85. VIDEOVIDEO 89
  • 86. THANKTHANK YOUYOU !! fmensah@ug.edu.gh