Controls on patterns of soil moisture in arid and semi-arid systems

Abstract

Soil moisture is a major control on ecohydrological processes at both the storm event and seasonal scales. It influences the partitioning of precipitation into infiltration and runoff (Chapter 3), is a control on biogeochemical processes (Chapter 11) and is a control on evapotranspiration by limiting water availability to plants (Chapter 3), and so also affecting the partitioning of energy into latent and sensible heat (Chapter 5). In this way soil moisture is a link between the surface energy, water and biogeochemical cycles. In water limited systems such as the arid and semi-arid zones, soil moisture plays a major role in vegetation patterns and type of vegetation cover, and is consequently of primary importance to the ecosystems of these areas (Chapters 1, 15; Hupet and Vanclooster, 2002; Kim and Eltahir, 2004).