区域可持续发展与人地关系行为机制模型研究(发展经济学.ppt

区域可持续发展与人地关系行为机制模型研究,石敏俊筑波大学,区域可持续发展与人地关系行为机制模型研究,区域可持续发展与农业环境政策人地关系行为机制模型框架的建立：外部社会经济因素影响人地关系变化的机制鄂尔多斯高原：人地关系行为机制模型与退耕还林对水土保持影响的比较静态模拟自然科学与社会科学相融合的必要性,区域可持续发展与农业环境政策,欧美国家的农业环境政策石油农业的化肥农药高投入导致水质污染等环境问题价格支持政策导致农产品过剩农业环境政策的核心是推行农业粗放化经营，减少化肥农药投入，减少农产品产量对于实行粗放经营的农户给予政策补贴,发展中国家的农业环境问题,土地退化引起的农业环境问题沙漠化，水土流失，盐碱化环境负荷引起的农业环境问题水质污染，土壤污染土地退化的人为因素人口压力，农业技术水平依赖资源投入的静态增长导致农业粗放再生产和土地利用的平面扩张，土地利用超过环境容量时带来土地退化,发展中国家的农业可持续发展,解决土地退化问题的出路在于发展可持续集约农业可持续集约农业：通过集约化达到可持续集约化：对少量土地实行集约经营，技术密集投入，提高单位土地面积生产力水平，为大面积退化土地休生养息恢复生态、实现区域可持续发展提供条件,保护环境与发展经济的关系,发展中国家的农业环境政策,解决土地退化问题的农业环境政策应当结合发展可持续集约农业来展开发展可持续集约农业的关键是技术进步，开发实用适用技术实用：实际农业活动中可应用的技术适用：适合当地条件适合当地农户采用的技术发展集约化（技术进步和技术推广）的政策补贴可作为环境保护投资进入环境经济核算,人地关系行为机制模型框架：社会经济因素影响人地关系变化的机制,影响人地关系和环境生态变化的社会经济因素人口增长市场和价格变动技术进步制度和政策收入和消费期望单一或综合的因果关系分析不能阐明社会经济因素影响人地关系变化的机制,ResourceEnvironment,LandUseAgriculturalActivity,InstitutionPolicy,Technology,MarketPrice,ResourceConstraint,ImpactonEnvironment,Populationgrowth,外部社会经济环境与人地关系变化,Literaturereview,Farmhouseholddecisionsonlanduseactivitiesandtechnologicalchoiceaffectthesoilqualityandthereforeplayanimportantroleinaggravatingorreducinglanddegradationprocess.Farmhouseholddecisionsaredependentonrelativepricesofoutput,inputandproductionfactors,andothersocio-economiccircumstancesthatareinfluencedbymacroeconomicandagriculturalpolicy.Agriculturalpoliciesaffectsoildegradationbyinfluencingthelevelofoutput,inputandfactorprices(Heerink,2001).,社会经济因素影响环境变化的机制,政策和制度外部社会经济环境农户经济行为资源环境变化反馈：资源环境变化农户经济行为（资源环境退化对经济福利的影响，现在价值与将来价值的关系）外部社会经济环境变化：价格变动，技术进步，资金和信用约束政策和制度：经济政策和环境政策，资源分配和资源利用秩序,Conceptualframework,Policyreform,Socio-economicenvironment,Householddecision,Landdegradation,MacroandRegionalModels,HouseholdandVillageModels,Bio-economicModels,Bio-economichouseholdModel,Bio-economicvillageModelapproach,Econometricestimationapproach:Lackofconsistentdata,especiallylongtimeseriesdataabouteffectofsoildegradation;Difficulttoderivefunctionformofthereduced-formequation.Metamodeling(Decisionrule)approach:Estimateastatisticalrelationshipbetweenexogenousandrelevantendogenousvariables;refertoablack-boxrepresentationofrelationshipbetweenexogenousandendogenousvariables;,Bio-economicvillageModel-continue,Mathematicalprogrammingapproach:AmajoradvantageofLPModelisthatcancombineeconomicbehaviorandbiophysicalprocessinanintegratedframework.Leontiefinput-outputcoefficientspermitsthecombinationofincompatibleeconomicandbiophysicalproductionfunction.AdisadvantageofLPModelisthatmaygeneratevastamountofwhat-ifresultsifsomeofparametersofthemodelarenotknownwithgreataccuracy.,鄂尔多斯高原人地关系行为机制模型,Bio-economicvillageLPModelShort-termanalysis:oneyearduetouncertaintyVillagemodel:appreciatelevelofanalysisObjectivefunction：maximizingbenefitofhouseholdsProductionfunction：Leontiefinput-outputcoefficientsConsumptionfunction：consumptionchoicebaseduponnutritionandpricesunderconstraintsofbasicnutritionintakedemandandhobbySoilconservationprocess：convertedlandsupplyFeedbackofsoilerosiontoproduction：nofeedbackprocess,Bio-economicvillageLPModel,(1),s.t.,(2),(3),(4),(5),(6),Variabledefinition,:householddiscountedutility,:period,:crop,:landtype,:landendowment,:theareaofcrop,producedonlandtype,inperiod,:theperunitpriceofcroporlivestockoutput,:theyieldfunctionforproductionofcropcorlivestockv,:avectorofinputsusedinproductionofcropcorlivestockv,:theperunitinputpriceforinput,Variabledefinition-continue,:thecroporlivestockoutput,usedforself-consumption,:thecroporlivestockoutput,usedforself-supply,suchasfodder,draftanimal,:theproductionofunitsoflivestock,atperiodt,:livestock,:thewagelevel,suchasseasonaloff-farmwage,constantoff-farmwage,hiringlaborwage,:theoff-farmlaborsupplyofseasonalpart-timelabororconstantoff-farmlabor,:thehiringlaborsupply,:familylabor,:familylaborinputforfarmactivities,:totallaborinputforfarmactivities,:discountrate,ModulesofLPModel,Processes(73)Production(22):croppingcorrespondingtolandtypeCorn,Millet,Potato,Sunflower,Rapeseed,Beans,Goat,Sheep,Hog,CattleSale(11):Corn,Millet,Potato,Sunflower,Rapeseed,Goat,Sheep,Hog,Mutton,Pork,WoolSelf-consumption(6):Corn,Millet,Potato,Beans,Mutton,PorkPurchase(11):Wheat,Rice,Pork,Mutton,Beef,Vegetable,Fertilizers,Pesticide,seeds,CoalSelf-supply(5):Seeds,Fodder,Manure,FirewoodResourcesupply(17):Landsupply(6),Laborsupply(11)Landdegradation(1):Soilerosion,ModulesofLPModel-continue,Constraints(70)Products(12):Resources(30):landconstraints(7);labortimeconstraints(13);laborallocationconstraints(10):familylabor(3),hiringlabor(7)Balance(25):Nutritionandhumandemand(10);Farminginput(11);Livestockinput(4)Rotation(2)Soilerosion(1),LanduseinGe-zhen-yanVillage,Zhunger,InnerMongolia,ThepolicymeasureofconvertingslopefieldintoforestandpasturestartedSince2000,withsubsidyof100kggrainand20Yuanfood-forworkper6.7a,Croppingsystemandlanduse,Agricultureandfarmeconomy,Pricesofagriculturalproducts,Soilerosion:EPICresult,Agricultureandlandusesystem,Crop-livestocksystem:corn-goat-sheep-hog.Cornmainlyinflatfieldforfeedandcommercialuse;milletinterraceandslopefieldforstaplefood;rapeseed,sunflowerinterraceandslopefieldforcommercialuse;potatoandbeansforself-consumption.Fieldtypeismostimportantfactoraffectingyield.Levelofinputandtechnologicalchoiceofvariouscropscorrespondtofieldtypes.Soilerosionmodulusdifferbetweenfieldtypesandvariouscrops.,Farmeconomy,Smallholders:farmhouseholds(12)andpart-timehouseholds(9).Farmhouseholdsearnincomefromcrop-livestockactivity(livestockincome:70%).Part-timehouseholdsearnmostincomefromoff-farmactivity(73%).Off-farmjobopportunityislimited.Onlymembersofthevillagecangainrightoflandmanagement.Thereisfewmobilityoflandmanagementright.,退耕还林还草政策对水土保持影响的比较静态模拟,模拟结果与现状的拟合比较农产品价格变动对土地利用变化影响的比较静态模拟结果退耕还林还草政策对土地利用变化和水土保持影响的比较静态模拟结果退耕还林还草补贴对土地利用变化和水土保持影响的比较静态模拟结果非农就业机会对土地利用变化和水土保持影响的比较静态模拟结果,Thebaserun,Householdsmayrealizeasignificantincreaseinincomewithoutincreaseinsoilerosioniftheyputamuchgreatweightonsedentarylivestockbyusingmaizeandstrawsasfodderinsteadofsellingmaizetoearncashincome,andchangetogrowmuchmorecashcropssuchassunflowerandrapeseedsinsteadofmillet.Oneofprobablereasonoffarmersself-sufficientchoiceisfromconstraintofinvestment.Anotherprobablereasonisfromfarmersriskaversion.,Pricechangeandlanddegradation,Changesinpricesoflivestockwillaffectlivestockchoice,buthavenosignificanteffectsonlandusechoiceaswellassoilerosion.Changesinpriceratiosofcommercialcropsaffectlandusechoice,especiallylandusechoiceofslopefields,andthenhavesignificantimpactsonsoilerosion.Theeffectsofpricechangeonsoilerosiondependonratiooferosionmodulusbetweenconcerningcrops.,Off-farmjobopportunityandsoilerosion,Increaseinoff-farmjobopportunitiesforseasonalpart-timelaborshavefeweffectsonlanduseactivities.Increaseinoff-farmjobopportunitiesforconstantoff-farmlaborswillinfluencelandusechoiceandthenlanddegradation.Whilethenumberofconstantoff-farmlaborscontinuestoincreaseandexceedsover25persons,cultivationofmilletinslopefieldswilltendtodecrease.Astheresult,soilerosionwilltendtodecreaseduetowithdrawalofcultivationinslopefieldsalongwithanincreaseinoff-farmjobopportunities.,Landconversionpolicyandsoilerosion,Introducinglandconversionpolicywillaffectlandusechoiceofslopefieldsaswellasterracefields,andconcomitantlivestockchoice,thenhavesignificanteffectsonreducingsoilerosion.Subsidytowardsconvertedslopefieldswillencourageconversionofslopefieldsandhavesignificanteffectsonlandusechoice,livestockchoiceaswellassoilerosion.,Subsidyandsoilerosion,Whenintroducinglandconversionpolicywithoutsubsidy,farmincometendstodecreaseasacostforcombatingsoilerosion.Whileallowanceofmorethan160Yuanper6.67awaspaidforfarmers,soilerosionwillberelievedsignificantlywithanincreaseinfarmincome.Thesubsidyforconvertedslopefieldsinloessplateauincludes100kggrainwithapriceof1.4Yuanperkgand20Yuanoffood-forworkaidper6.7a,whichisequalto160Yuanper6.7a.,Conclusionandimplication,Anintegratedbio-economichouseholdmodelmaysimulatetheeffectsofchangeinsocio-economicfactorsonlanddegradationbyinvolvingfarmeconomicbehaviorwithinanintegratedframework.Mathematicalprogrammingapproachisusefultodevelopabio-economichouseholdmodelbecauseitcancombinefarmeconomicbehaviorandbiophysicalprocess.,Conclusionandimplication-continue,Thesoilconservationprogramtoconvertslopefieldsintoforestorpastureisaneffectivewayforcombatingsoilerosion.Areasonablesubsidyascompensationthatishigherthan