The Physiography of the Mediterranean Lands with Special Emphasis on California and Chile

Abstract

On the basis of climatic similarity a few small areas on the surface of the earth are classified as mediterranean lands. Elsewhere in this volume the climate of these areas is discussed (see H. Aschmann and F. Di Castri). Therefore it is only necessary for us here to refer to those aspects of climate which affect other physical phenomena with which we are particularly concerned. In brief these climatic characteristics include a warm to hot and emphatically dry, high sun season with high evaporation rates. Contrasting with this is a mild and wet low sun period when the precipitation is more effective. Areas with these moisture and temperature characteristics are found in a number of separated, but expected locations on the globe. Mediterranean core areas are typically centered at about 35° north and south of the equator on the west sides of continents. On a hypothetical continent they would extend through about 10° of latitude being bounded on their equatorward margins by drylands, on their polar margins by cool humid areas and on the east by humid or subhumid lands with greater seasonal temperature contrasts (Fig. 1). In the real world, because of different coastal configurations and other factors, the extent of mediterranean lands varies widely (see H. Aschmann).