An Integrated Modeling Framework to Understand Agricultural Land-Use Changes at a Global-scale

摘要

This paper presents an integrated agricultural land-use change model to simulate past and future dynamic changes in sown areas for four major crops at a global scale.This modeling approach,including four core models,was developed under the framework of Action-in-Context (AiC).The crop choice decision model,a Multinomial Logit model was used to model the crop choice decisions among a variety of available alternatives by using a crop utility function.A crop yield model,the GIS-based EPIC model was adopted to estimate the potential yields of different crop types under a given biophysical and agricultural management environment.A crop price model,the IFPSIM model was utilized to evaluate the price of the test crops in the international market.An urban expansion model was constructed to examine the characteristics of urban land expansion and the consequent cropland loss,and to dynamically update the total percentage of land available for agricultural land use.These models were seamlessly linked through data flow and exchange between them,and the dynamic feedback loop between agricultural land-use change and biophysical and socio-economic driving factors was studied.Empirical validation for the model conducted after model construction indicated the reliability of the model for addressing the complexity of current agricultural land-use change and its capacity for investigating long-term scenarios in the future.