Table Of ContentEnvironmental Science and Engineering
Subseries: Environmental Science
Series Editors: R. Allan • U. Förstner • W. Salomons
TanzaniaMeteorologicalAgency(TMA)
UnitedNationsConventiontoCombatDesertification(UNCCD)
WorldMeteorologicalOrganization(WMO)
Mannava V.K. Sivakumar · Ndegwa Ndiang’ui (Eds.)
Climate and
Land Degradation
With192Figuresand61Tables
123
Mannava V.K. Sivakumar
AgriculturalMeteorologyDivision
WorldMeteorologicalOrganization
7bisAvenuedelaPaix
P.O.Box2300
1211Geneva2,Switzerland
E-mail: [email protected]
Ndegwa Ndiang‘ui
CommitteeonScienceandTechnology(CST)
UnitedNationsConventiontoCombatDesertification
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D-53113Bonn
Germany
e-mail:[email protected]
ISSN 1863-5520
ISBN10 3-540-72437-0 SpringerBerlinHeidelbergNewYork
ISBN13 978-3-540-72437-7 SpringerBerlinHeidelbergNewYork
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Foreword
Desertificationisoneofthemostalarmingprocessesofenvironmentaldegrada-
tion. It is about land degradation: the loss of the land‘s biological productivity,
caused by human-induced factors and climate change, affecting one-third of the
Earth‘ssurfaceandoverabillionpeople.Moreover,itcanhavedevastatingconse-
quencesintermsofsocialandeconomiccosts.
Theimpactsoflanddegradationonglobalfoodsecurityandthequalityofthe
environmentareofmajorsignificanceandconcernwhenoneconsidersthatonly
about11%ofthegloballandsurfacecanbeconsideredasprimeland,yetthismust
feedthe6billionpeopleinhabitingtheWorldtodayandthe8.2billionexpected
bytheyear2020.Long-termfoodproductivityisthreatenedbysoildegradation,
whichisnowsevereenoughtoreducecropyieldsonapproximately16%oftheag-
ricultural land, especially in Africa and Central America, as well as the African
pastures.TherateoflanddegradationishighestinSub-SaharanAfrica,whereit
isestimatedthatlossesinproductivityofcroppinglandareintheorderof0.5-1%
annually,suggestingacumulativelossofatleast20%overthelast40years.
Sustainable development of countries affected by drought and desertification
canonlycomeaboutthroughconcertedeffortsbasedonasoundunderstanding
ofthedifferentfactorsthatcontributetolanddegradationaroundtheWorld.Cli-
maticvariationsarerecognizedamongthemajorfactorscontributingtolanddeg-
radation,asdefinedintheUnitedNationsConventiontoCombatDesertification
(UNCCD),anditisimportanttounderstandtherespectiverolesofthedifferent
climatic factors in land degradation. For example, development and adoption of
sustainablelandmanagementpracticesareamongthemajorsolutionsadoptedto
combatlanddegradationoverdrylands,buttoaccuratelyassesssustainableland
managementpractices,theclimateresourcesandtheriskofclimate-relatedorcli-
mate-inducednaturaldisastersmustbewellknownforagivenregion.
Only when climate resources are paired with potential management or devel-
opmentpracticescanthelanddegradationpotentialbeassessedandappropriate
mitigationtechnologiesbedeveloped.Theuseofclimateinformationmustbeap-
pliedeffectivelyindevelopingsustainablepractices,sinceclimaticvariationisone
ofthemajorfactorscontributingtoorevenactingasatriggertolanddegradation.
Thereisthereforeaclearneedtoconsidercarefullyhowclimatecaninduceandin-
fluencelanddegradation.
TheWorldMeteorologicalOrganization(WMO)contributestotheunderstand-
ing of the interactions between climate and land degradation through dedicated
observationsoftheclimatesystem;improvementsintheapplicationofagrometeo-
rologicalmethodsandtheproperassessmentandmanagementofwaterresourc-
es;advancesinclimatescienceandprediction;andpromotionofcapacitybuild-
ingintheapplicationofmeteorologicalandhydrologicaldataandinformationin
VI
Foreword
droughtpreparednessandmanagement.However,muchmoreneedstodone,such
asthepromotionoffurtherinterestandresearchinthistopic.
Atits58thordinarysession,theUNGeneralAssemblydeclared2006tobethe
International Year of Deserts and Desertification (IYDD). In doing so, the Gen-
eralAssemblyunderlineditsdeepconcernfortheexacerbationofdesertification,
particularly in Africa,and noted its far-reaching implicationsfor the implemen-
tationoftheMillenniumDevelopmentGoals(MDGs),whichmustbemetbythe
year2015.Accordingly,theIYDDpresentsagoldenopportunitytogetthemessage
across,stronglyandeffectively,thatDesertificationisaglobalproblemthatwecan
onlyignoreatourownperil.Italsooffersanimpulsetostrengthenthevisibility
andimportanceofthedrylandsissueontheinternationalenvironmentalagenda,
whileprovidingatimelyremindertotheinternationalcommunityoftheimmense
challengesthatstilllieahead.
In recognition of the importance of climatic factors in land degradation, the
SeventhSessionoftheConferenceofParties(COP-7)totheUNCCDaccordedpri-
oritytoclimateissuesinlanddegradationinthefutureworkoftheCommitteeon
ScienceandTechnology(CST)oftheConvention,invitingWMOtoorganizeand
find the necessary funding for an International Workshop on Climate and Land
Degradationin2006,inthespiritofimplementationoftheInternationalYearof
DesertsandDesertification(IYDD)andalsoaskingCSTtoassistWMOinfinding
expertsforthisworkshop.
ItiswiththisbackgroundthatWMO,theUNCCDSecretariatandtheTanza-
niaMeteorologicalAgencyjointlyorganizedinArusha(Tanzania),from11to15
December2006,theInternationalWorkshoponClimateandLandDegradation.
Theworkshop,whichwascosponsoredbytheOrganizationofthePetroleumEx-
portingCountries(OPEC)FundforInternationalDevelopment(OFID),theUnit-
edNationsDevelopmentProgramme(UNDP)andtheUnitedNationsEducation-
al,ScientificandCulturalOrganization(UNESCO),focusedthewaythatclimate
induces andinfluences land degradation and what measures need to be taken in
order to enhancethe applicationsofweather andclimateinformationtocombat
landdegradation.
Wehopethatthepaperspresentedinthisbookwillserveasasignificantsource
ofinformationtotheCSTaswellastoallagenciesandorganizationsinvolvedin
designing and implementing appropriate strategies for sustainable land manage-
menttoarrestlanddegradation.
M. Jarraud Hama Arba Diallo
Secretay-General ExecutiveSecretary
WorldMeteorologicalOrganization SecretariatoftheConvention
toCombatDesertification
Preface
Landdegradationisathreattonaturalresourceswithconsequencesonfoodsecu-
rity,poverty,andenvironmentalandpoliticalstability. Theincreasingoccurrence
ofclimateextremes(forexampleheatwaves,droughts,heavyprecipitation)ishav-
inganimpactonlanddegradationprocesses,includingfloods,massmovements,
soilerosionbywaterandwindandsalinizationinallpartsoftheglobe. Climate
variability,climatechangeandlanddegradationareintimatelylinkedandaregen-
eratingunexpectedeffects,forexample,anincreasedoccurrenceofweathercon-
ditionsthataresuitableforafiretostart,ortopropagateinthewild,inlargeparts
of the globe. Sustainable development of countries affected by drought and de-
sertificationcanonlycomeaboutthroughconcertedeffortsbasedonasoundun-
derstandingofthedifferentfactorsincludingclimaticvariationsthatcontributeto
landdegradationaroundtheworld.
Toaddressthesekeyissues,expertsfromaroundtheworldwerebroughttogeth-
eratanInternationalWorkshoponClimateandLandDegradationwhichwasheld
inArusha,UnitedRepublicofTanzaniafrom11to15December2006.Thework-
shop focused on how climate induces and influences land degradation and what
measuresneedtobetakentoenhancetheapplicationofweatherandclimatein-
formationtocombatlanddegradation. TheworkshopwasorganizedbytheWorld
MeteorologicalOrganization,theUnitedNationsConventiontoCombatDesert-
ification (UNCCD) and the Tanzania Meteorological Agency and was co-spon-
sored by the OPEC Fund for International Development (OFID), the United Na-
tionsDevelopmentProgramme(UNDP)andtheUnitedNationsEducational,Sci-
entificandCulturalOrganization(UNESCO).
SpecificobjectivesoftheWorkshopwere:
(cid:122) Tosurveythestatusof,andsummarizetheinformationon,trendsinlanddeg-
radationatnationalandregionallevels;
(cid:122) Toreviewandassesstheextenttowhichweatherandclimatedataandinforma-
tionarecurrentlyusedatthenationalandregionallevelsinordertoadequately
monitorandassesslanddegradationandtodevelopsustainablelandmanage-
mentpracticestocombatlanddegradation;
(cid:122) Toproviderecommendationsonappropriatestrategiesforreducinglanddegra-
dationthroughmoreeffectiveuseofweatherandclimateinformationandap-
plications;
(cid:122) To assess the historic loss of terrestrial carbon pool due to land degradation,
andestimatethepotentialofcarbonsequestrationinsoil/terrestrialecosystems
throughsoilrestorationanddesertificationcontrol;
VIII
Preface
(cid:122) To assess the feasibility of restoring degraded/desertified lands with a view to
achievingfoodsecurityintheaffecteddevelopingcountries;
(cid:122) To document case studies of successful measures to manage land use, protect
landandmitigatelanddegradation;
(cid:122) To suggest ways and means of improving the implementation of the National
Action Programmes(NAPs)throughtheeffectiveuseofearlywarning.
Sixty four participants from 30 countries and 5 UN agencies (WMO, UNCCD,
FAO,UNDP,UNEP)presentedstate-of-the-artpapers,realworldapplicationsand
innovativetechniquesforcombatinglanddegradation,andofferedrecommenda-
tions for effectively using weather and climate information for sustainable land
managementpractices.
Altogethertherewere9sessions(includingtheopeningandclosingsession)in
theworkshopduringwhich34invitedpaperswerepresentedaddressingthediffer-
entspecificobjectivesoftheworkshop.Alltheparticipantsintheworkshopwere
engagedindiscussionsonthesepapersanddevelopedseveralusefulrecommenda-
tionsforallorganizationsinvolvedinpromotingclimatepredictionandapplica-
tionsinagriculture,andincombatinglanddegradationparticularlyinthedevel-
opingcountries.
Thisvolumeincludes33invitedpaperspresentedattheworkshop,theconclu-
sions and recommendations that emerged out of the working group discussions
and the final workshop statement. As editors of this volume, we would like to
thankalltheauthorsfortheireffortsandfortheircooperationinbringingoutthis
volumeintime.WearemostgratefultoMr.M.Jarraud,theSecretary-Generalof
WMOandMrArbaDiallo,ExecutiveSecretaryoftheUNCCDfortheircontinu-
oussupportandencouragement.
Mannava V. K. Sivakumar
Ndegwa Ndiang’ui
Editors
Contents
1 The Assessment of Global Trends in Land Degradation
Uriel N. Safriel
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1.1 Landdegradation–whatisitandhowisitassessed . . . . . . . . 2
1.1.2 Theneedforassessmentataglobalscale . . . . . . . . . . . . . . . 3
1.1.3 Assessmentoflanddegradationattheglobalscale . . . . . . . . . 4
1.2 Assessmentofcurrentdegradation. . . . . . . . . . . . . . . . . . . . . . . 5
1.2.1 Globallanddegradationanddrylanddesertification . . . . . . . . 5
1.2.2 Islanddegradationindrylandsdifferentthanthat
inthenon-drylands? . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.2.3 Degradationdegreeanddegradationseverity . . . . . . . . . . . . 11
1.2.4 TheSpatialextentofgloballanddegradation . . . . . . . . . . . . 18
1.2.5 Thespatialextentofdrylanddegradation . . . . . . . . . . . . . . 18
1.2.6 Degradationanddegradationvulnerability . . . . . . . . . . . . . 19
1.2.7 Degradationvulnerabilityanddegradationrisk . . . . . . . . . . 20
1.3 Remote-sensingofproductivityforassessingglobaldegradation . . . . . 23
1.3.1 Soilorvegetationassessment? . . . . . . . . . . . . . . . . . . . . . 23
1.3.2 Degradationasapersistentreductioninlandproductivity . . . . 26
1.3.3 Assessingdegradationasdeviationofproductivity
fromitspotential . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1.4 Assessmentofdegradationtrends . . . . . . . . . . . . . . . . . . . . . . . 30
1.4.1 RainUseEfficiencymethodology . . . . . . . . . . . . . . . . . . . 31
1.4.2 TheResidualTrendsmethodology . . . . . . . . . . . . . . . . . . 34
1.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
2 Status and Trends in Land Degradation in Africa
Lamourdia Thiombiano and Ignacio Tourino-Soto
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
2.2 EvaluatingthetrendsinlanddegradationinAfrica . . . . . . . . . . . . . 40
2.2.1 DiversityofAgro-ecologicalzones,soilsandlandusesystems . . 40
2.2.2 Methodologicalapproachtoestimatelanddegradationextent
inAfrica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
