Erg (landform) Erg (landform) An erg (also sand sea or dune sea, or sand sheet if it lacks dunes) is a broad, flat area of desert covered with wind-swept sand with little or no vegetative cover. The term takes its name from the Arabic word "ʿarq" (), meaning "dune field". Strictly speaking, an erg is defined as a desert area that contains more than of aeolian or wind-blown sand and where sand covers more than 20% of the surface. Smaller areas are known as "dune fields". The largest hot desert in the world, the Sahara, covers and contains several ergs, such as
Human geography human geography. Well-known geographers from this period are Fred K. Schaefer, Waldo Tobler, William Garrison, Peter Haggett, Richard J. Chorley, William Bunge, and Torsten Hägerstrand. From the 1970s, a number of critiques of the positivism now associated with geography emerged. Known under the term 'critical geography,' these critiques signaled another turning point in the discipline. Behavioral geography emerged for some time as a means to understand how people made perceived spaces and places, and made locational decisions. The more influential 'radical geography' emerged in the 1970s and 1980s. It draws heavily on Marxist's theory and techniques, and is associated with