Trade-offs between the Economic,Social and Environmental Objectives in Optimal Resource Management in the Fang Watershed, Chiang Mai Province, Thailand

The objective of this study was to find the relationships and trade-offs between the citrus farms and the natural resource management at the watershed level. Data collection were done among 149 households in Chai Prakan, Fang and Mae Ai districts, Chiang Mai, Thailand. A weighted multi-goal programming was employed with eight model objectives/goals covering economic, social and environmental aspects. These were maximization of annual equivalent value (AEV) of cropping systems, employment and revenue from non-timber forest products and minimization of revenue variance, dependence from external inputs, expenditure on pesticides, nitrogen use, soil erosion. This study looked at trade-offs between decisions at the farm and watershed level, economic and environmental objectives, economic and social objectives, and social and environmental objectives. If decisions on optimal land use were done at the farm level, farm land in the watershed would be allocated to mixed fruit trees and annual crops while if they were done at the watershed level, land would be planted to fruit trees and some forests and not so much annual crops. Trade-off analysis between different objectives revealed that expenditure on pesticides or nitrogen use as well as soil erosion could be substantially reduced for only a relatively small decrease in the annual equivalent value and employment. On the other hand, employment could not be much reduced without scarifying farmers' income. Nevertheless, further reductions in the environmental goals would lead to rapid rates of reduction in employment and the annual equivalent value. (C) 2015 Published by Elsevier B.V.