Deserts Less than 10 inches of precipitation per year Is San Diego considered to be in a desert area? San Diego Average Rainfall San Diego Rainfall Deserts of the World Low Latitude Deserts Low Latitude Deserts 30 degrees above and below equator Mid Latitude Deserts and Rainshadows Irregular, Large, Thunderstorms Flashfloods in Desert Wash Terms Coalescing Alluvial Fans Deflation and Blowouts Deflation Desert Pavement Formation of Sand Dunes Sand Dune Slip Face Navajo Sandstone Paleo Sand Dunes Largest Crossbeds Sand Dune Types Barchan Limited sand and flat with little vegetation Barchan Dune Features Barchan Dunes Transverse Steady wind lots of sand little vegetation Largest in size Transverse Dunes Longitudinal Moderate sand with variable wind Longitudinal Dunes Star Dunes Variable wind direction Star Dunes Badwater Fan Death Valley Black Mtns, Death Valley Southern Death Valley, California Panamint Range along top Black Mountains bottom of photo Badwater Fan is furthest left fan along the Black Mountains. Furnace Creek fan farthest right along the Black Mountains. Barchan Dune Tibet Sand Dunes-Mars