Hydraulic Property Determination of Vesiculated Soil Peds in Desert Pavement Environments

Desert pavements are prominent features in arid and semi-arid environments, and can be found on a variety of landforms of significantly diverse ages ranging from Holocene to Tertiary. Desert pavements consist of a surface layer of closely packed gravel, typically one stone thick, that overlies a silt-rich vesicular A (Av) soil horizon. The vesicular horizon is composed of highly structured, prismatic soil peds, typically about 10 cm in diameter and less than 10 cm thick. Highly structured soils can greatly affect desert ecosystem development due to the impacts on local water balances. The concentration of silt and clay significantly reduces the infiltration rate and increases the water holding capacity, thereby reducing the penetration of wetting fronts. Field and laboratory studies were conducted to quantify the hydraulic properties of individual peds and pavement surfaces, and to ultimately use the information in a process-based evaluation of the soil moisture balance in arid environments. Field sites