Deserts are defined scientifically as areas that experience an annual moisture deficit. Paradoxically, water plays a vital role in shaping dryland landscapes. It acts as a solvent, slowly dissolving minerals and transporting them to sites where they may be deposited as near-surface crusts that bind soils and sediments together.
On a larger scale, periods of above-normal rainfall may stimulate vegetation growth and limit the effects of the wind. Water is also vital for maintaining life, so much so that the historical writings of desert dwellers can be used to reconstruct past climate variations.
Drawing upon 20 years of research in the drylands of southern Africa, South America and southern Europe, this lecture explores some of these themes and considers the future for the world's drylands.