Diversification of Agricultural Crops to Adapt to Climate Change in the Guadiana River Basin

Adaptation is gaining attention as an inevitable answer to the challenges posed by climate change. The increasingly uncertain climatic conditions to which actors are exposed are becoming a constraint for their well-being. This paper looks at diversification as a key factor in reducing risk and means of coping with an uncertain climate. The aim of this work is to identify combinations of agricultural crops that reduce current and future climate related risks in the Guadiana River Basin. The Guadiana is a transboundary river between Spain and Portugal. The paper uses the variance of the revenue of agricultural crops as a proxy for climate risk, associating minimum variance with a region that is well adapted to the climatic conditions. The paper assesses risks as a function of the key agricultural crops and the climatic conditions that the Guadiana is subjected to. Crop yields under different climatic conditions are simulated by linking climate scenarios from General Circulation Models to the regional crop simulation model CropSyst. Borrowing from economic theory, the paper shows what cropping patterns reduce climate related risk. Crops with yields that have a low correlation provide the highest potential to reduce climate risks. Comparing model simulations of the scenario period 1961-1990 to the period 2071-2100, results suggest that the climate will have modest effects on the average crop yield, but will significantly reduce the variance of crop yields and change crop yield correlation. This changes the cropping pattern that provides the highest risk security.