A climatic delineation of the ‘real’ Chihuahuan Desert

Abstract

The Chihuahuan Desert is one of the least-known regions in North America. The lack of scientific investigation by any discipline is reflected by the vague and inconsistent boundaries assigned to this arid zone. Placing the Chihuahuan Desert into a regional framework is further complicated by the lack of studies which extend across the international boundary between the United States and Mexico. This investigation was undertaken to provide a more detailed and definitive map of the Chihuahuan Desert. Mean annual temperatures and precipitation values, obtained for nearly 800 weather stations, were utilized to delineate the Chihuahuan Desert based upon the de Martonne aridity index. Using an aridity index ≤ 10, it was found that the Chihuahuan Desert occupies approximately 350,000 km2, and includes 115 weather stations. As large areas exist where climatic data are not available, or where long-term climatic records are non-existent, twelve other delineations of this arid zone were mapped at the same scale to make possible a comparison, and provide additional basis for establishing relatively firm boundaries for North America’s least known desert.