Overview and general geography

Strictly speaking, the Mediterranean lands are those bordering the Mediterranean Sea separating Africa and Europe (Fig. 17.1). This includes southern Europe, the Middle East, and Africa north of the Sahara. The essence of a “Mediterranean-type climate” is one with mild, wet winters and warm, dry summers. This description best fits regions near the Mediterranean Sea, semi-arid steppes with mean annual rainfall on the order of 100–350 mm. Further south and east are true deserts, where only slight to moderate rains occur during the cool season. The demarcation between desert and semi-arid steppe is roughly 70–100 mm, the lower threshold for rainfed vegetation. The largest are the Saharan, Arabian and the Negev deserts. In these deserts winters can become quite cold and summers are dry but can be unbearably hot.

This chapter considers all of the arid and semi-arid portions of the Mediterranean countries, as far south as the southern limit of the winter rainfall regime. For the sake of convenience, the summer rainfall region of the southern Arabian Peninsula is also included here. The Mediterranean of southern Europe is predominantly subhumid and is hence omitted. The information and data in this chapter come primarily from the Meteorological Office (1962), Dubief (1963), LeHouerou (1986), Orshan (1986), and Takahashi and Arakawa (1981). Littman and Berkowicz (2008) also provide an excellent review.