Based on climatic zoning, Iran is one of the arid and semi-arid climates. The average rainfall in large parts of the east and southeast of the country is between 50 to 150 mm. To overcome the country's arid climate, Iranians have a strong history in managing water resources and have managed variable water conditions and arid lands well throughout history.
2500 years ago, Iranians invented the aqueducts and built waterways (Pasargad water transfer canal and Daryoun creek), dams and flood dams (Mizan dam) and storage structures (Yazd reservoir); and they have been pioneer in this regard, having strong system and regulations (Sheikh Baha'i petition) and monitoring methods. Rivers and surface waters in the country originate from permanent glaciers in high mountains such as Dena, Zardkooh Oshtorankooh, Alvand and Sabalan.
With climate change and declining rainfall, river flows and surface water have often become seasonal and accidental, and groundwater is now the most important and only way to supply water for all uses in most provinces. The result of excess water withdrawal is the deficit of annual groundwater storage that affects the quality of water. On the other hand, climate change and the reduction of rainfall have affected the inflow of water.
The study of water balance in Iran shows that 3.72% of rainfall is spent on evapotranspiration and this country is facing a negative balance of about 6 billion cubic meters, so that the possibility of developing and exploiting groundwater resources is banned in large parts of the country. One of the solutions to face water shortage is the construction of dams and water transmission lines and canals.
In addition, the potential of stored water volume behind dams and the length of network lines and water transfer are the most important indicators of optimal consumption and prevention of water loss in the country. Clean Electricity Generation is another benefit of building dams. The most important way to deal with the water crisis in the country is optimal management and consumption in all sectors, including household, industrial and agricultural.
The National Water Atlas will play an effective role in appropriate decision-making in terms of policy-making, management and evaluation of success by showing the distribution and trend of indicators affecting the current situation and how they work on water resources management.
It is worth mentioning that on April 30 of this year coincided with the commemoration of Persian Gulf National Day, the National Water Atlas was unveiled in the National Cartographic Center of Iran in the presence of Dr. Mirkazemi, Vice President and Head of Plan and Budget Organization.