HISTORY OF WATER MANAGEMENT IN ANCIENT IRAN

The Iranian plateau is made up of elevations, valleys and low lands. There are two mountain ranges stretching in north and west of Iran. These mountains have turned the central plateau of Iran into a confined basin with no connection to free seas, causing this area to be arid. The genesis of the arid deserts dates back to the early fourth geological era, between ten and fifteen thousand years ago (Ghobadian, 1361, pp 15 & 16). So the central plateau is not watered by such rivers as Tigris, Euphrates or Nile whose annual overflow make the lands fertile. Also, this area does not enjoy regular favourable rainfalls. Therefore, since earliest days, water has been at issue, and irrigation has been a common technique in Iran (Ghirshman, 1364, p119) The existence of the mountain ranges in north and west has led to a climatic diversity resulting in the formation of some human communities with different types of livelihood. We examine two main factors in the formation of human settlements: A- the rivers running in the boundary areas of Iran B- the springs and lakes in the central plateau of Iran In the course of time, the climatic changes led to the drying of internal lakes, changing the environmental conditions in the region.