RISK INDEXES FOR FORAGE CROP AREA LOSS
Juan Manuel Torres-Rojo1*, y Roberto Isaac Bahena-González1
Information and understanding of climate dynamics and its effect on agricultural crops have improved in recent years. This progress is the result of the development of more complex predictive and structural models. The objective of the study was to empirically test the existence of a “Power Law” relationship of the frequency distribution of annual forage crop area losses. The scale invariability of the tested relationship is used to build two risk indexes. The first index is an indicator of crop area losses, while the second one is an indicator of the maximum crop area at risk of loss given a likelihood of occurrence. The analysis is performed at regional and national levels for the different production systems (spring-summer rainfed, spring-summer irrigation, autumn-winter rainfed and autumn-winter irrigation). The proof of the “Power Law” relationship was done with the Pareto model, while a method of non-linear least squares was used to fit the empirical distribution. The results show that the scale parameter estimates range between -1.42 and -1.70 for different systems in different territorial units. Estimates are statistically similar to the expected values and also comply with the principle of universality and the finite-size scaling hypothesis. Thus, it can be concluded that the affected area of forage crops follows a self-organized critical behavior. Therefore, the risk indexes derived from this relationship can be considered long-term risk indexes.
Key words: Damaged area, self-organized critical behavior, power law, risk index, crop area at risk.
1 Centro de Investigación y Docencia Económicas, Carretera México Toluca 3655 CP. 01210 México, D.F. México
*Autor para correspondencia E-mail: [email protected]