Using Precipitation Using Precipitation and Temperature to and Temperature to Model Agriculture Model Agriculture Conditions in Africa Conditions in Africa Eric Wolvovsky Eric Wolvovsky NOAA/FEWS-NET NOAA/FEWS-NET July 1, 2008 July 1, 2008
Dec 17, 2015
Using Precipitation and Using Precipitation and Temperature to Model Temperature to Model
Agriculture Conditions in Agriculture Conditions in AfricaAfrica
Eric WolvovskyEric WolvovskyNOAA/FEWS-NETNOAA/FEWS-NET
July 1, 2008July 1, 2008
OverviewOverview
Introduction to FEWS-NETIntroduction to FEWS-NET MethodologyMethodology OutputOutput ApplicationsApplications Potential Future WorkPotential Future Work ConclusionConclusion
IntroductionIntroduction
Famine Early Warning System NetworkFamine Early Warning System Network Early warning on food security concernsEarly warning on food security concerns US Agencies involvedUS Agencies involved
• USAID (Lead)USAID (Lead)• USDAUSDA• USGSUSGS• NASANASA• NOAANOAA• ChemonicsChemonics
USGS and Chemonics have staff in countryUSGS and Chemonics have staff in country
IntroductionIntroduction
IntroductionIntroduction
NOAAs role in FEWS-NETNOAAs role in FEWS-NET Analyze and track meteorological Analyze and track meteorological
phenomenon as it relates to food securityphenomenon as it relates to food security• Tropical cyclonesTropical cyclones• Large scale severe weatherLarge scale severe weather• Extreme heatExtreme heat• FreezesFreezes• Rainfall for crops, pastures and drinking waterRainfall for crops, pastures and drinking water
IntroductionIntroduction
Goals for model:Goals for model: Analyze individual cropsAnalyze individual crops Analyze regionallyAnalyze regionally High resolutionHigh resolution Simple metricSimple metric Light weightLight weight Relates temperature and rainfallRelates temperature and rainfall
MethodologyMethodology
Blaney-Criddle FormulaBlaney-Criddle Formula
E is seasonal moisture requiredK is crop coefficientTai is mean monthly temperaturedi is monthly fraction of annual daylight hoursn is number of months
MethodologyMethodology
Data ChallengesData Challenges Of the 1000 weather Of the 1000 weather
stations in Africa ~500 stations in Africa ~500 report dailyreport daily
Data is not filteredData is not filtered• May have bad dataMay have bad data• May have reported May have reported
-999.0-999.0
MethodologyMethodology
CPC RFE 2.0CPC RFE 2.0 Uses 3 satellite inputs and Uses 3 satellite inputs and
daily station datadaily station data Daily temporal resolutionDaily temporal resolution 0.1 degree spatial 0.1 degree spatial
resolutionresolution StrugglesStruggles
• CoastsCoasts• MountainsMountains• Areas with few station reportsAreas with few station reports
MethodologyMethodology
NCEP/NCAR ReanalysisNCEP/NCAR Reanalysis Uses:Uses:
• StationStation• ShipShip• AircraftAircraft• SatelliteSatellite
Monthly Temporal ResolutionMonthly Temporal Resolution 2.5 degree spatial resolution2.5 degree spatial resolution Temperatures have a warm Temperatures have a warm
bias at higher elevationsbias at higher elevations
MethodologyMethodology
Monthly Fractional Hours Monthly Fractional Hours of Annual Daylightof Annual Daylight Developed as a function Developed as a function
of latitude based on fixed of latitude based on fixed valuesvalues
Monthly temporal Monthly temporal resolution resolution
0.1 degrees resolution0.1 degrees resolution Hours of daylight varies Hours of daylight varies
only with latitudeonly with latitude
MethodologyMethodology
FAO Crop shapefilesFAO Crop shapefiles Monthly temporal resolutionMonthly temporal resolution
Crop CoefficientCrop Coefficient Determined by US Soil Determined by US Soil
Conservation Service field Conservation Service field teststests
Values usedValues used• Maize 2.2Maize 2.2• Sorghum 2Sorghum 2• Wheat 1.8Wheat 1.8• Millet 1.4Millet 1.4
MethodologyMethodology
Blaney-Criddle FormulaBlaney-Criddle Formula
*Crop Coefficient *
MethodologyMethodology
MethodologyMethodology
Conditions are determined by comparing Conditions are determined by comparing required rainfall with received rainfallrequired rainfall with received rainfall
Percent of RequiredPercent of Required RainfallRainfall ClassificationClassification
Less than 50%Less than 50% FailureFailure
Between 50% and 75%Between 50% and 75% PoorPoor
Between 75% and 125%Between 75% and 125% Below AverageBelow Average
Between 125% and 175%Between 125% and 175% AverageAverage
Between 175% and 225%Between 175% and 225% GoodGood
Greater than 225%Greater than 225% ExcellentExcellent
Required Rainfall
CPC RFE 2.0* 100 = Percent of Required Rainfall Received
MethodologyMethodology
OutputOutput
OutputOutput
OutputOutput
OutputOutput
OutputOutput
OutputOutput
ApplicationsApplications
Hazards assessmentsHazards assessments
Weekly weather briefingsWeekly weather briefings
Use by decision makersUse by decision makers
Potential Future WorkPotential Future Work
Beyond AfricaBeyond Africa
Beyond GrainsBeyond Grains
Increase temporal resolutionIncrease temporal resolution
Better method of validationBetter method of validation
ConclusionConclusion
Light weight agriculture modelLight weight agriculture model
Method uses inputs that are knownMethod uses inputs that are known
Method is expandableMethod is expandable
Will support FEWS-NETWill support FEWS-NET
Thank YouThank You
[email protected]@noaa.gov