A scale invariant model for the expansion of agricultural land and government spending on the agricultural sector

• Published in: Land use policy Vol. 92; p. 104438
• Main Authors: Torres-Rojo, Juan Manuel, Francisco-Cruz, Carlos Alberto, Islas-Aguirre, Juan Francisco, Ramírez-Fuentes, Grodecz Alfredo, Pérez-Sosa, Leonardo
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-03-2020; Elsevier Science Ltd
• Subjects: Agricultural expansion; Agricultural industry; Agricultural land; Agricultural land expansion; Aquatic ecosystems; Centroids; Complexity; Density; Ecosystems; Expansion; Fractal dimension; Geographical distribution; Government spending; Independent variables; Invariants; Land use; Law; Population distribution; Power; Power law; Power-law models; River networks; Rural areas; Self-organized critically; Socioeconomic factors; Statistical analysis; Power-law models; Self-organized critically; Fractal dimension; Agricultural land expansion
• ISSN: 0264-8377; 1873-5754
• DOI: 10.1016/j.landusepol.2019.104438

•The paper shows that the expansion of agricultural land can be described by a power-law model.•Additionally, it shows that Government spending per unit of area to foster agriculture also follows a power-law model.•These results challenge common perceptions that these variables result from complex interactions.•Deviations from Power-law trajectories are due to the relative importance of centroid localities.•Some applications of the scale-invariant model for land use policy are discussed.
The expansion dynamics of the agricultural surface is a complex process, since it requires decisions among different actors under a multitude of socioeconomic and natural conditions, expectations, and risks. This paper shows that despite this complexity, and at odds with the intuition, the density of agricultural lands and the government spending to foster agriculture around a human settlement displays a simple power-law relationship regarding the distance to such a settlement. The theoretical proof of this relationship is based on theoretical and empirical findings made by several authors on the expansion of population centers, river networks, species and ecosystem’s distribution. The empirical proof is made by fitting a simple power-law model having as response variables: density of agricultural land; government spending coverage, and government spending per unit of agricultural surface, while the distance to the centroid settlement is used as independent variable. Results show that the scaling exponents of the power-law relationship estimated from those models, with data from rural settlements in Mexico, are similar statistically to the expected values from theoretical models for the three expansion processes tested. Three applications of the scale-invariant attribute characterizing the expansion process of agricultural lands are presented:
i)monitoring agricultural activities at the territories;ii)a proxy to estimate the expected growth of the agricultural surface; andiii)a typology to characterize government assistance at local level.