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课件

1、区域可继续开展与人地关系行为机制模型研讨石 敏俊筑波大学.区域可继续开展与人地关系行为机制模型研讨 区域可继续开展与农业环境政策人地关系行为机制模型框架的建立：外部社会经济要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坚持影响的比较静态模拟自然科学与社会科学相交融的必要性.区域可继续开展与农业环境政策 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钱支持政策导致农产品过剩农业环境政策的中心是推行农业粗放化运营，减少化肥农药投入，减少农产品产量对于实行粗放运营的农户给予政策补贴.开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

2、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要素人口压力，农业技术程度依赖资源投入的静态增长导致农业粗放再消费和土地利用的平面扩张，土地利用超越环境容量时带来土地退化.开展中国家的农业可继续开展处理土地退化问题的出路在于开展可继续集约农业可继续集约农业：经过集约化到达可继续集约化：对少量土地实行集约运营，技术密集投入，提高单位土地面积消费力程度，为大面积退化土地休生育息恢复生态、实现区域可继续开展提供条件.维护环境与开展经济的关系.开展中国家的农业环境政策处理土地退化问题的农业环境政策该当结合开展可继续集约农业来展开开展可继续集约农业的关键是技术提高，开发适用适用技术适

3、用：实践农业活动中可运用的技术适用：适宜当地条件适宜当地农户采用的技术开展集约化技术提高和技术推行的政策补贴可作为环境维护投资进入环境经济核算.人地关系行为机制模型框架：社会经济要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要素人口增长市场和价钱变动技术提高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要素影响人地关系变化的机制.ResourceEnvironmentLand UseAgriculturalActivityInstitutionPolicyTechnologyMarketPriceResource ConstraintImpact onEnvi

4、ronmentPopulationgrowth外部社会经济环境与人地关系变化.Literature reviewFarm household decisions on land use activities and technological choice affect the soil quality and therefore play an important role in aggravating or reducing land degradation process. Farm household decisions are dependent on relative prices

5、 of output, input and production factors, and other socio-economic circumstances that are influenced by macroeconomic and agricultural policy. Agricultural policies affect soil degradation by influencing the level of output, input and factor prices (Heerink, 2001).社会经济要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

6、源环境变化反响：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，如今价值与未来价值的关系 外部社会经济环境变化：价钱变动，技术提高，资金和信誉约束政策和制度：经济政策和环境政策，资源分配和资源利用次序.Conceptual frameworkPolicy reformSocio-economic environmentHousehold decisionLand degradationMacro and Regional ModelsHousehold and Village ModelsBio-economic ModelsBio-economic household Model.Bi

7、o-economic village Model approachEconometric estimation approach:Lack of consistent data, especially long time series data about effect of soil degradation;Difficult to derive function form of the reduced-form equation. Meta modeling (Decision rule) approach: Estimate a statistical relationship betw

8、een exogenous and relevant endogenous variables; refer to a black-box representation of relationship between exogenous and endogenous variables;.Bio-economic village Model - continueMathematical programming approach:A major advantage of LP Model is that can combine economic behavior and biophysical

9、process in an integrated framework.Leontief input-output coefficients permits the combination of incompatible economic and biophysical production function.A disadvantage of LP Model is that may generate vast amount of what-if results if some of parameters of the model are not known with great accura

10、cy. .鄂尔多斯高原人地关系行为机制模型Bio-economic village LP ModelShort-term analysis: one year due to uncertaintyVillage model: appreciate level of analysisObjective function：maximizing benefit of householdsProduction function： Leontief input-output coefficients Consumption function：consumption choice based upon n

11、utrition and prices under constraints of basic nutrition intake demand and hobbySoil conservation process： converted land supplyFeedback of soil erosion to production：no feedback process.Bio-economic village LP Model (1)s.t. (2) (3) (4) (5) (6) .Variable definition: household discounted utility: per

12、iod: crop: land type: land endowment: the area of crop produced on land type in period : the per unit price of crop or livestock output: the yield function for production of crop c or livestock v: a vector of inputs used in production of crop c or livestock v: the per unit input price for input .Var

13、iable definition-continue: the crop or livestock output used for self-consumption: the crop or livestock output used for self-supply, such as fodder, draft animal: the production of units of livestock at period t: livestock: the wage level, such as seasonal off-farm wage , constant off-farm wage hir

14、ing labor wage : the off-farm labor supply of seasonal part-time labor or constant off-farm labor: the hiring labor supply: family labor: family labor input for farm activities: total labor input for farm activities: discount rate.Modules of LP ModelProcesses (73)Production (22): cropping correspond

15、ing to land typeCorn, 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,

16、 Fertilizers, Pesticide, seeds, Coal Self-supply (5):Seeds, Fodder, Manure, FirewoodResource supply(17): Land supply(6), Labor supply(11)Land degradation (1): Soil erosion.Modules of LP Model - continueConstraints (70)Products (12):Resources (30):land constraints (7); labor time constraints (13);lab

17、or allocation constraints (10): family labor (3), hiring labor (7)Balance (25):Nutrition and human demand (10);Farming input (11);Livestock input (4)Rotation (2)Soil erosion (1).Land use in Ge-zhen-yan Village, Zhunger, Inner Mongolia.The policy measure of converting slope field into forest and past

18、ure started Since 2000, with subsidy of 100kg grain and 20Yuan food-for work per 6.7a.Cropping system and land useTotalFlat fieldTerrace fieldSlope fieldSown areaYieldSown areaYieldSown areaYieldSown areaYieldhakg/hahakg/hahakg/hahakg/haCorn7.67 6,6604.27 9,2501.27 5,1002.13 3,750Millet6.87 1,8191.4

19、7 1,8505.41 1,808Rapeseed3.07 5802.00 6601.07 500Sunflower2.43 8850.73 1,0001.69 836Potato2.80 7,5001.07 7,1251.73 7,725Beans0.87 1,4000.47 1,5000.40 1,300Total23.70 4.27 7.00 12.43 .Agriculture and farm economyfarm typeunitTotalFarm householdPart-time householdhouseholdperson21129populationperson81

20、4932laborperson563422off-farm laborperson14410seasonal off-farm laborperson936constant off-farm laborperson514population per householdperson per household3.86 4.08 3.56 cultivated landha per household1.19 1.43 0.87 family incomeYuan per household8,9049,6457,998farm incomeYuan per household5,9459,018

21、2,188off-farm incomeYuan per household2,9606275,810ratio of off-farm income%33%7%73%ratio of livestock income within farm income%66%69%51%.Prices of agricultural productscommodityfarm gate pricesfarm purchase pricescommodityfarm purchase pricesCorn0.93 1.00 Wheat2.00 Millet0.82 1.60 Rice2.20 Potato0

22、.50 1.00 Beef15.00 Sunflower2.00 Fish14.00 Rapeseed2.00 Vegetable1.34 Mutton8.00 14.00 Compound fertilizer2.07 Pork8.00 10.00 Carbamide1.45 Wool200 Carbon ammonia0.72 Goat240 Corn seed4.86 Sheep140 Hog800 .Soil erosion: EPIC resultSoil erosion values derived from EPIC ModelField typeFlat fieldTerrac

23、eSlope fieldSlope0%5%10%Maize0.430 4.400 12.520 Millet0.550 5.620 15.770 Sunflower0.510 5.220 15.090 Rapeseed0.460 4.670 13.090 Potato0.200 2.070 5.880 Beans0.460 4.670 13.090 Note: 1)unit is ton ha-1.simulation results are means of ten years. 2)simulation results are means of ten years.Agriculture

24、and land use systemCrop-livestock system: corn-goat-sheep-hog.Corn mainly in flat field for feed and commercial use; millet in terrace and slope field for staple food; rapeseed, sunflower in terrace and slope field for commercial use; potato and beans for self-consumption.Field type is most importan

25、t factor affecting yield.Level of input and technological choice of various crops correspond to field types.Soil erosion modulus differ between field types and various crops.Farm economy Smallholders: farm households(12) and part-time households(9).Farm households earn income from crop-livestock act

26、ivity (livestock income:70%).Part-time households earn most income from off-farm activity(73%). Off-farm job opportunity is limited.Only members of the village can gain right of land management. There is few mobility of land management right.退耕还林还草政策对水土坚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钱变动对土地利用变化影响的比较静态模拟

27、结果退耕还林还草政策对土地利用变化和水土坚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坚持影响的比较静态模拟结果非农就业时机对土地利用变化和水土坚持影响的比较静态模拟结果.Comparison between actual situation and base run resultsunitActual situation in 2002Base runTotal family incomeYuan139,141194,403 Crop productionCorn flatmu64.00.0 Corn terracemu19.07.4 Corn slopemu32.00.0

28、Feed corn flatmun.a66.0 Feed corn terracemun.a53.1 Feed corn slopemun.a34.9 Millet Terracemu22.00.0 Millet Slopemu81.146.6 Potato terracemu16.06.8 Potato slopemu26.00.0 Sunflower terracemu11.00.0 Sunflower slopemu25.460.7 Rapeseed terracemu30.053.7 Rapeseed slopemu16.00.0 Beanmu13.020.7 LivestockGoa

29、t family laborhead377.0348.4 Shed sheephead123.0734.9 Hoghead39.00.0 Grazing cattlehead4.04.0 .The base runHouseholds may realize a significant increase in income without increase in soil erosion if they put a much great weight on sedentary livestock by using maize and straws as fodder instead of se

30、lling maize to earn cash income, and change to grow much more cash crops such as sunflower and rapeseeds in stead of millet. One of probable reason of farmers self-sufficient choice is from constraint of investment. Another probable reason is from farmers risk aversion. .Price change and land degrad

31、ationChanges in prices of livestock will affect livestock choice, but have no significant effects on land use choice as well as soil erosion.Changes in price ratios of commercial crops affect land use choice, especially land use choice of slope fields, and then have significant impacts on soil erosi

32、on. The effects of price change on soil erosion depend on ratio of erosion modulus between concerning crops. .Off-farm job opportunity and soil erosionIncrease in off-farm job opportunities for seasonal part-time labors have few effects on land use activities. Increase in off-farm job opportunities

33、for constant off-farm labors will influence land use choice and then land degradation. While the number of constant off-farm labors continues to increase and exceeds over 25 persons, cultivation of millet in slope fields will tend to decrease. As the result, soil erosion will tend to decrease due to

34、 withdrawal of cultivation in slope fields along with an increase in off-farm job opportunities. .Land conversion policy and soil erosionIntroducing land conversion policy will affect land use choice of slope fields as well as terrace fields, and concomitant livestock choice, then have significant e

35、ffects on reducing soil erosion.Subsidy towards converted slope fields will encourage conversion of slope fields and have significant effects on land use choice, livestock choice as well as soil erosion.Subsidy and soil erosionWhen introducing land conversion policy without subsidy, farm income tend

36、s to decrease as a cost for combating soil erosion. While allowance of more than 160 Yuan per 6.67a was paid for farmers, soil erosion will be relieved significantly with an increase in farm income. The subsidy for converted slope fields in loess plateau includes 100kg grain with a price of 1.4Yuan

37、per kg and 20Yuan of food-for work aid per 6.7a, which is equal to 160Yuan per 6.7a. .Conclusion and implicationAn integrated bio-economic household model may simulate the effects of change in socio-economic factors on land degradation by involving farm economic behavior within an integrated framework.Mathematical programming approach is useful to develop a bio-economic household model because it can combine farm economic behavior and bi