7th Annual E-GOV AfricaKampala, Uganda

7th Annual E-GOV AfricaKampala, 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 MensahCentre for Remote Sensing and Geographic Information Services

University of GhanaLegon-Accra

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OutlineOutline

• Introduction• Introduction

• GIS

GIS C St di• GIS Case Studies

• GPS

• Remote Sensing

• SLM

• A Panacea for Drylands – 15min Video

About CERSGISAbout CERSGIS

• Established by EPA and University of Ghana

• Geographic Information Services and ResearchSupport CentreSupport Centre

• It is a non-profit, self sustaining organization

• Provide Remote Sensing and Geographic InformationSystems (GIS) services in the application of GIS andRemote Sensing.

• Provides services to government agencies, non-governmental organizations, research institutions

d th i t tand the private sector

IntroductionIntroduction

• We live in an information age

• Geospatial information is one of the most criticalelements underpinning decision-making for manyp g g ydisciplines

• Geospatial information is an essential building blockp gfor sustainable development.

• Increasing the availability, access and interoperabilityIncreasing the availability, access and interoperabilityof Geospatial information will stimulate innovation,contribute to economic transformation and facilitatenational developmentnational development

Geographic Information System (GIS) Geographic Information System (GIS)

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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

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RasterRaster--Vector Data ModelVector Data Model

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Applications of spatial dataApplications of spatial data::

• Modelingf– Developing “where is” and “what if” scenarios

• Decision making support– communicating processes and information that help

solve or avoid problems.

• Monitoringrelating to environmental management and support– relating to environmental management and support

for programme management services.

M P d ti• Map Production

Applications of spatial dataApplications of spatial data::

Spatial data analysis1. 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

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thanksthanks toto geospatialgeospatial technology!technology!

LandLand suitabilitysuitability analysisanalysis

Land suitability analysis involves the application of

criteria to the landscape to assess where land is mostp

and least suitableLand use

Rainfall

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Site suitability analysis Site suitability analysis

Why do site suitability assessment?– It greatly reduces the time and effort which might otherwise g 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.

suitability modeling suitability modeling

R litReality Spatial data layers Suitable areas

Model criteria:- Land use- Elevation- Climate

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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

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ProcessProcess flowflow (Modeling)(Modeling)

Land use

Rainfall

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Sample suitability and weighting

Criteria:landscape restoration will benecessary in certain areas

Weighting:

Open access areas more importantthan reserved areas

Bare areas more important thancloseness to towns

Annual rainfall greater than 1200mmAnnual rainfall greater than 1200mmis highly suitable

Slopes less than 10% is highlysuitable

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suitable

Case Study:Case Study:Case Study: Case Study:

Suitability Modeling Suitability Modeling for for Landscape Landscape

Restoration Restoration

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MethodologyMethodology

Landuse Mapping

Terrain Analysis

Climatic Analysis

Landuse &Accessibility Rainfall

Suitable Slopeand Elevation

GIS Analysis to GenerateOverall Suitability

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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

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Criteria ScoringCriteria Scoring

Input Layer

Criteria Potential ScoreLow (0) High (1)

Terrain Elevation <500m asl >500m asl

Slope >10 degree <10 degreeSlope >10 degree <10 degree

Low (0) Moderate (2) High (3)

ClimaticRainfall 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 UseLand Use Types Reserved

Long Fallow Short Fallow Grassland

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Elevation Criterion2 Classes :Altitude 0 - 500 msl = 0 (Low Suitability)Altitude >500 msl = 1 (High Suitability)

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Slope CriterionSlope Criterion

2 Classes:Slope >10 degrees = 0 (Low Suitability)Slope <10 degrees = 1 (High Suitability)

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Annual Rainfall Criterion

3 Classes:1000 0 (L S it bilit )<1000mm = 0 (Low Suitability)

1001 – 1200mm = 2 (Moderate Suitability)>1200mm = 3 (High Suitability)

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Land Use CriterionLand Use Criterion

4 Classes:Reserved Area = 0Closed Forest = 1Closed Forest = 1Long Fallow = 2Short Fallow = 3Grassland = 4

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ResultsResultsResultsResults

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Slope & Elevation

Elevation layer is overlaid with Slope layer:Suitability score ranges from 0, for areas thatmeet no criteria to 2, for areas that meet bothcriteria

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Slope, Elevation & RainfallSlope layer is overlaid with the rainfalland elevation layerand elevation layer

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AreasAreas suitablesuitable forfor landscapelandscape restorationrestoration

Ranking Suitability Area % Area (ha) Class Total(ha)

0Low

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

7High

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

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Case Study:Case Study:Case Study: Case Study:

Desertification Hazard Mapping Desertification Hazard Mapping

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Desertification Hazard Desertification Hazard

It is a process that can be as much man-caused asnatural and therefore is one of the natural hazards bestsuited for mitigation by those who plan, implement, andmanage 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

Geospatial PortalGeospatial Portal

demand for geospatial data

access to quality geospatial dataMetadata serviceMetadata service

minimize duplication

efficient data maintenance Map serviceMap service

platform for partnerships

efficient data maintenance Map serviceMap service

DD--support servicesupport service

ONLINE GIS PLATFORMONLINE GIS PLATFORMONLINE GIS PLATFORM FOR

AGRICULTURAL DEVELOPMENT IN GHANA

ONLINE GIS PLATFORM FOR

AGRICULTURAL DEVELOPMENT IN GHANA

http://www.gis4ghagric.nethttp://www.gis4ghagric.net

Land coverLand cover MetadataMetadata

ElevationElevation

CropsCrops

SoilsSoils

ClimateClimate

MEAN ANNUAL RAINFALL

EVAPOTRANSPIRATION

Land SuitabilityLand Suitability

Cowpea

Millet

Sample MapSample Map

Global Positioning System (GPS)Global Positioning System (GPS)

GPS Requires 4 Satellites To Obtain A “Position”

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)

Getting your location/position on the earth’s surfacethe earth s surface

+

FarmerFarmer--level GPS Mappinglevel GPS Mapping

1

2

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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

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4 05.44572 001.59902

5 05.68331 001.62045

1 05.52341 001.60019

GPSGPS DataData CollectionCollection

This is becoming extremely important collecting data on locations ofi t tinterest.

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Remote SensingRemote Sensing

Why remote sensing?Why remote sensing?y gy g

• Access large areas

• Map inaccessible areas

• Timely repeats for monitoring• Timely repeats for monitoring

Types of remote sensing dataTypes of remote sensing data

Optical Lidar

Radar

Optical dataOptical dataOptical dataOptical data

SpaceSpace--basedbased applicationsapplications

Optical Optical –– high resolutionhigh resolution

e.g. Worldview, Aerial photographs

1961 2007 Change

Optical Optical –– medium resolutionmedium resolutione g Landsat ASTER SPOT DMC (incl NigeriaSAT) CBERSe.g. Landsat, ASTER, SPOT, DMC (incl. NigeriaSAT), CBERS…

10 km

Optical Optical –– coarse resolutioncoarse resolutione g MODIS SPOT-VGT AVHRR MERISe.g. MODIS, SPOT VGT, AVHRR, MERIS…

MODIS (500 m)

ASTER (15 m)

QuickBird (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 ProhibitivelyProhibitivelyExpensiveExpensiveExpensiveExpensive

Vegetation Index Vegetation Index –– ‘greenness’‘greenness’

• Reflection: leaves ≠ soil

• Normalised Difference V t ti I d (NDVI) e 

(%)

Vegetation Index (NDVI)

lectan

ceRe

fl

Wave Length (nm)

High NDVIHigh NDVI

Satellite Scenes – same season

0 k

ASTER 27th Nov

Landsat ETM+ 12th

Landsat TM 30th Dec

10 km

27th Nov 2006

ETM+ 12th

Dec 200030th Dec 1986

> 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

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

Dense forest

Mosaic forest

GLC 2000 Africa mapMosaic forest

Woodlands

ShrublandsShrublands

Grasslands

AgricultureAgriculture

Bare soil

WaterbodiesWaterbodies

Land Land cover map cover map -- GhanaGhana

Problem 1: Cloud

Problem 2: These look the same in optical

1. Pristine

2. DegradedBudongo Forest, Uganda

RadarRadarRadarRadar

RadarRadarRadarRadar

• Side-looking

Active radar  Return 

signalpulse signal (backscatter)

Optical vs. Radar

Radar satellitesRadar satellitesBand Wavelength

Typical maximum resolution Satellitesgfrom 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)

Conclusions Conclusions -- RadarRadar

• Sees through clouds• Sees through clouds

• Penetrates vegetation

• Data not free

LidarLidar –– light detection and ranginglight detection and ranging

L• Laser

• Vertical looking

• Detects returns with high accuracy

33--D D LidarLidar Imagery Imagery

ConclusionsConclusions -- LiDARLiDARConclusions Conclusions 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

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

Disaster monitoringDisaster monitoring

When you are on the ground, it is hard to grasp the size of these

events.

Land cover mappingLand cover mapping

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.

Change DetectionChange Detection

Useful websitesUseful websites

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Famine Early Warning Systems Network (FEWS NET)

http://www.fews.net82

http://www.fews.net

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85http://www.foodsecurityportal.org/africa-food-security-vulnerability-indices

86http://www.fao.org/docrep/008/J6398e/maps/afr.htm

Land Use Planning :Land Use Planning :Sustainable Sustainable 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.

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

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VIDEOVIDEO

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THANKTHANK YOUYOU !!fmensah@ug.edu.gh