Land-use and land-cover assessment for the study of lifestyle change in a rural Mexican community: The Maycoba Project

BACKGROUND In 1995, a study was conducted to identify the effects of traditional and westernized environments on the prevalence of type 2 diabetes in Pima Indians (Pimas) in Mexico and the United States. The study concluded that the more traditional lifestyle in Mexico had a protective effect against this metabolic disorder. In the ensuing 15 years, the environmental circumstances of the Mexican Pimas changed, and a follow-up study was conducted to determine the role environmental change plays in the development of diabetes in this genetically susceptible population. A major element of environmental transition relates to land-use and land-cover (LULC) changes that could affect physical activity and promote an obesogenic environment. This study examined changes in the region's LULC to determine whether there have been transitions in agricultural land use and urbanization that would be consistent with a more sedentary lifestyle. Changes were assessed from 1994 aerial photographs and 2007 satellite images. RESULTS The land-cover analysis showed that mixed vegetation and dense trees cover most of the study area. It suggested a rural environment that includes a low percentage of impermeable areas, and it indicated that the area experiencing human intervention covers 7% of the total area. The land-use-change findings showed a decrease or no change in agricultural or ranching areas and a decrease in farmland due to reforestation or revegetation. Three variables from the land-use-change analysis were examined as proxies for lifestyle change: urban development, dwelling-unit density, and variation in the road network. Two of the measures -the amount of urbanization and the number and density of dwelling units-showed increases, most notably in the town of Maycoba. There were only minor changes in the road network: most of the road segments are short and concentrated in Maycoba where most of the buildings, points of interest (e.g., church, stores), and cars are located. CONCLUSIONS The LULC in Maycoba and surrounding settlements had changed during the study period. LULC change was used as a proxy to examine lifestyle changes that can affect levels of physical activity.