Author(s)

H. Moghimi

Abstract

As Iran has a semi-arid to arid climate, ground water resource application is of significant importance. The Kordan Basin is also one of the areas that due to excessive application has faced a sharp fall of 2-4m in the ground water level in the last 30 years. Thus, in order to determine the parameters affecting the water level fall and to study the Plain aquifer situation, it is necessary to prepare a water balance. Hashtgerd Plain is located in 36º-05´ to 36º-45´ latitude and 50º- 30´ to 50º-55´ longitude. The budget area is 468.45 km² and located in the north west of Tehran. The balance (budget) elements were examined one by one by applying different methods and the present equations for the ground water, then having applied the general budget equation, the reservoir volume changes for the water year 1996-97 were studied and calculated. In the calculations, two items were considered: first, it was confirmed that there has been a fall in ground water level and a decrease in aquifer reservoir volume of the Kordan Basin, secondly, the reasons for the fall and reduction were studied and clarified. Based on the present situation of the Plain it is necessary for the relevant organizations, especially the Ministry of Power and Agriculture, to have a joint project with joint planning. There should be some short, mid and long-term projects and in the mid and short term there must be strategic management to keep the water level stable. For the long-term projects, the objective should be focused on both water and agricultural. Keywords: water balance, budget elements, water year, budget area, Kordan Basin, Hashtgerd Plain. 1 Introduction As Iran has an arid and semi-arid climate, water is an invaluable asset and its use needs proper programming and sometimes critical management. In order to

Keywords

water balance, budget elements, water year, budget area, Kordan Basin, Hashtgerd Plain.