Drought Impacts in Mexico: Climate, Agriculture, Technology, and Land Tenure in Sonora and Puebla

This paper shows how vulnerability to natural hazards can be measured and analyzed and how drought vulnerability might relate to new agricultural technologies and land tenure in Mexico. Several authors have suggested that the impacts of drought on agricultural systems are determined as much by the technological, economic, and political characteristics of a region as by the severity of meteorological events. But the literature on natural hazards and cultural ecology lacks both detailed quantitative assessments of drought impacts at the regional scale and empirical measures of vulnerability to drought and climate change. In Mexico, agricultural losses from natural hazards are severe, varying widely between regions and between different farm sectors. This study analyzes the pattern and severity of drought losses in municipios in the states of Sonora and Puebla, using data from the 1970 Mexican agricultural census. These states represent a range of physical conditions, technological and economic resources, and landownership structures, and thus permit an examination of how the Green Revolution and land reform affect the relationships between climatic variation and agricultural production. Reported drought losses were severe in many parts of Sonora and Puebla in 1969; some losses can be explained by rainfall deficits, especially in Puebla. Low drought losses in dry regions of Sonora often can be explained by the widespread use of irrigation. In general, technologies like irrigation, fertilizer, and improved seeds are associated with lower rather than higher drought losses in both states. Drought losses also are higher on the communally held ejido lands than on large private farms, supporting previous research documenting the economic and environmental vulnerability of ejido farmers.