SUBREGIONAL LINEAR-PROGRAMMING MODELS IN LAND-USE ANALYSIS - A CASE-STUDY OF THE NEGUEV SETTLEMENT, COSTA-RICA

The present paper deals with linear programming as a tool for land use analysis at the subregional level. A linear programming model of a ca se study area, the Neguev settlement in the Atlantic zone of Costa Ric a, is presented. The matrix of the model includes five submatrices eac h encompassing a different farm type. The farm types are distinguished on the basis of land-labour ratios, considering farm size and three d ifferent soil types, and assuming a fixed availability of household la bour. Land use activities are included in the form of Land Use Systems & Technologies. These represent land use systems with fixed input-out put coefficients. Two indicators for sustainability are taken into acc ount: soil nutrient depletion and biocide use. These are built into th e model via constraints, marking upper limits to the use of renewable resources and to the waste flow into the environment. The linear progr amming model forms part of the USTED (Use Sostenible de Tier ms En el Desarrollo) methodology for the analysis and planning of sustainable l and use. Several land use scenarios are analysed to assess whether the income of all farms in the Neguev can increase through an improved, a nd sustainable, land use. First, a base scenario is calculated to serv e as a reference for assessing the impact of policy measures or changi ng socio-economic conditions. A striking feature of the base scenario is the large area with palm heart in comparison to the actual area. Su stainability related policy measures studied are increasing biocide pr ices, and quantitative restrictions on biocide use and soil nutrient l osses. Doubling the biocide price hardly affects its use, while a quan titative restriction on the use of biocides per ha of 50% in compariso n to the base scenario use, reduces average incomes with less than 1%. A similar conclusion applies to soil nutrient depletion. Restricted t o 'critical nutrient losses' per year over a ten year period, specifie d per land unit per farm type, average incomes are reduced with hardly 3%. Other scenarios concern the impact of decreasing palm heart price s, as a consequence of increased supply, the influence of increasing w ages and the role of the discount rate.