When sun and warmth attract people: Escalating pressure on Spain's drylands

Abstract

In recent decades, Spain has experienced an expansion of drylands, with an increase of approximately 4% of its surface area, alongside processes of demographic transformation that altered the spatial distribution of the population. The aim of this study is to quantify the population residing in Spain's drylands and to analyse its evolution between 1960 and 2020, as well as the territorial and environmental implications of these changes. To this end, municipal-scale demographic data are combined with climatic aridity maps based on 30-year averages. Three time points are analysed: 1960, prior to the rural exodus; 1991, following its culmination; and 2020, representing the current scenario, applying the corresponding aridity classification to each period. The results show that the population living in drylands has increased by more than 8% over the study period and currently accounts for nearly 80% of the country's total population. This growth has occurred mainly in semi-arid and arid areas, while non-drylands regions have experienced a sustained demographic decline. This imbalance, combined with the concentration of water-intensive economic activities such as agriculture and tourism in regions characterised by structural water deficits, increases pressure on natural resources and contributes to the intensification of soil degradation and desertification processes.