The highlands of Iran are in the shadow of the Alborz and Zagros mountains. Therefore, about 73% of the area of Iran in arid or semi-arid zones with low humidity, and large fluctuations in annual rainfall is. The country is divided into six main areas, depending on the water resources: the Caspian Sea to the north, the Persian Gulf and the Gulf of Oman to the south, the Urmia Lake to the north-west, the Markazi High Plains to the center, Hirmand and Maschkel to the east and Sarach in the northeast (National Geographical Organization of Iran, 2003-2005). Within this project the focus is mainly on the Karun river catchment area in the main Persian Gulf and the Urmia Lake.
The catchment area of Karun, Khuzestan, Iran
The catchment area of the Karun River is one of the largest river catchment areas in Iran. In the middle and lower reaches, the Iranian province of Khuzestan is located almost entirely dependent regarding water and power supply of this river. The province is surrounded on the north and east by Zagrus- or Bakhtiyari Mountains, in the south it borders on the Persian Gulf and to the west by Iraq. The climate in the area is arid and semi-arid marked. The area is typically hot, but also partly wet, especially in the south, while the winters are much drier and cooler. Khuzestan is one of the most developed industrial zones of Iran with almost 90% of Iranian oil production and approximately 25% of the Iranian heavy industry. 4, 5 million people live in the region. The center of the province is the city of Ahvaz, which lies on the banks of the Karun River and about 1, has 1 million inhabitants. The Karun area is the main entrance area of the Karuna and Karun catchment areas, which originate in the Zagros Mountains. In the Karun, Haffar and Bahmanshir first unite before they merge with the Arvandroud River to later land in the Persian Gulf. The total catchment area is 67.257km 2 large, of which 67% in the mountains and 33% is in the foothills and on the plains. The annual rainfall in the Karun basin varies between 153mm in the southern lowland areas up to 2000mm in the mountains. The long-term mean annual runoff for the catchment area to the level Gotvand is given as 410m3/s. In the underlying catchment area of Dec. River is the only major tributary, contributing with 230m 3 / sec for total runoff. Currently there are a total of six hydroelectric power stations with a total of 16.8 MW in the investigation area with the Dec-, Karun 4-, Karun 3- (Fig. 5), Karun 1- (Shahid Abaspour Dam), Godarlandar and Gotvand dams Billion liters of storage capacity, 9,470 MW of total output and 20,614 GWh of annual electricity production. In this regard, the Karun is the most important Iranian river catchment area for generating electricity from hydropower. At the same time the increasing sedimentation in the reservoirs is a serious problem for all dams. It is currently regarded as the most important challenge for the long-term security of the hydroelectric power plant performance. It is assumed that approximately 1,134,702 ha of agricultural area are suitable for irrigation in the study area. Already, about 325,560 hectares are 25 modern irrigation networks irrigated, 24 other networks with a worse standard modernization irrigate additional 15,750 hectares of land, and three other networks older type irrigate 40,000 hectares. This makes the Karungebiet is also the main center for agriculture and food production in Iran. The increasingly heavy use of water resources of the Karun River has meant that the area of wetlands in the lower reaches of the river, about 50 - 100 km before it flows into the Persian Gulf (Horolazim and Shadegan wetlands), has declined sharply, with significant ecological problems, but also consequences for the population, such as an increasing salinisation of the water resources. Recently, several projects have been initiated to build additional hydropower plants and / or water passages, to plan or to study their feasibility and efficiency. These projects include further dams and tunnels designed to divert water from the Karun Basin into other adjacent areas to meet today's and future water requirements. It should be pointed out that the new water transfer projects are politically motivated. The project will affect both the water runoff of the rivers, and the water quality.
This project was financed by the German Federal Ministry of Education and Research under the financial assistance agreement No 02WGR1421.