Geography and Population
Turkey, with a total area of 77,945 km2, lies between Europe and Asia and is surrounded by the Black Sea, Bulgaria, and Greece in the north, the Aegean Sea in the west, the Mediterranean Sea, Syria, and Iraq in the south, Iran in the east and Armenia and Georgia in the north-east.
About 28 million hectares (ha), or 36% of the total area, are classified as cultivable. In 1991, the total cultivated area was estimated at 20.5 million ha, of which 17.5 million ha consisted of annual crops and 3.0 million ha consisted of permanent crops, mainly vineyards, fruit trees, and olives.
The total population is about 61.9 million (1995), of which 31% is rural, with an annual demographic growth estimated at 2%. Agriculture employed 44.5% of the total labor force in 1994 and accounted for nearly 16% of gross domestic product (GDP) in 1993. In 1992, agriculture provided 14.9% of the total export revenue.
Climate and Water Resources
Turkey has a subtropical, semi-arid climate with extremes in temperatures. In the east, summers are hot and dry, and winters are cold, rainy, and snowy. Along the coastal area, a Mediterranean climate is dominant with long, hot, dry summers and short, mild, rainy winters. Rainfall shows great differences from one region to another. Average annual rainfall is 643 millimeters (mm), ranging from 250 mm in the southeast to over 3,000 mm in the north-east Black Sea area. About 70% of the rain falls in the winter and spring seasons. Average runoff is about 37%.
Surface Water Resources
| Table 1. Major hydrological basins in Turkey.|
|Name of the basins||Total number of basins ||Total flow (km3/year) ||Draining to|
|Tigris, Euphrates*||2||52.94||Iraq/Syria/Iran (Persian Gulf)|
|Orontes, Ceyhan, Seyhan, Eastern Mediterranean, Antalya, Western Mediterranean||6||47.42||Mediterranean Sea|
|Greater Menderes, Smaller Menderes, Gediz, North Aegean, Meric||5||9.59||Aegean Sea|
|Marmara, Susurluk||2||13.76||Sea of Marmara|
|Sakarya, Western Black Sea, Kizilirmak, Yesilirmak, Eastern Black Sea, Coruh||6||49.81||Black Sea (Coruh first to Georgia with 6.30 km3/year)|
|Aras||1||4.63||Armenia/Azerbaijan/Iran (Caspian Sea)|
|Burdur Lakes Area, Akarcay, Konya Closed Basin, Van Lake||4||7.90||Interior|
|* Euphrates: figures of average runoff vary between 26.29 and 31.61 km3/year. The latter figure was used in this Table.|
Tigris: figures of average runoff vary between 18.00 and 21.33 km3/year. The latter figure was used in this Table. (Source: FAO)
The most important hydrological basins in Turkey are presented in Table 1.
Of the total surface runoff of the country, estimated at 192.8 cubic kilometers per year (km3/year), almost one-fourth comes from the Euphrates (Firat) and the Tigris (Dicle) rivers, which both have their sources in the eastern part of the country. Turkey contributes about 90% of the total annual flow of the Euphrates, while the remaining part originates in Syria and nothing is added further downstream in Iraq. Turkey contributes 38% directly to the main Tigris River and another 11% to its tributaries, which join the main stream of the Tigris further downstream in Iraq. In general, the streams vary greatly in their flow from season to season and year to year. For example, the Euphrates' annual flow at the border with Syria ranged from 15.3 km3 in 1961 to 42.7 km3 in 1963.
Average annual surface runoff entering Turkey from other countries is estimated at about 1.8 km3 (the Orontes, the Tunca). Another 5.8 km3/year comes from Bulgaria through the Meric River which forms the border between Turkey and Greece. Average annual surface runoff leaving the country is estimated at 60.4 km3, while almost 8 km3 flows in the interior basins.
A figure of 12.2 km3/year for groundwater is given for the year 1994. It probably represents identified development potential, and a figure of 20.0 km3/year for yearly groundwater recharge is probably a more realistic estimate. Groundwater flows to other countries are not known. However, the sources of the Khabour River, situated in Syria, with a runoff of 1.2 km3/year, have their origin in groundwater coming from Turkey.
By the end of 1991, the construction of 164 large dams, mostly rockfill or earthfill dams, and 765 small dams had been completed and put into service for water supply, irrigation, hydropower, and flood control. Total dam capacity is about 206 km3. In addition, in 1992, (in the Firat River) 78 large dams and 172 small dams were under construction. The Ataturk Dam on the Euphrates south-eastern part of the country, with a total storage capacity of 48.5 km3, is one of the 10 largest dams in the world. In the beginning of 1990, the filling of the reservoir behind the dam started and was completed in 1992. The surface area of the reservoir is about 817 km2.
It is estimated that 95 km3 of the total surface runoff of 192.8 km3/year could be technically developed for economic use. In 1992, total annual water withdrawal was 31.6 km3, of which agricultural use accounted for 72.5% (16.4% is withdrawn for domestic use and 11.1% for industrial use). About 24% of total water withdrawal, or 7.6 km3, was estimated to be groundwater, of which 3.7 km3 was for agricultural purposes. Almost 98% of the urban and 85% of the rural populations have access to safe drinking water. The treatment of domestic wastewater is estimated at 0.1 km3/year.
International Rivers and Agreements
The total length of the boundary between Turkey and its surrounding countries is 2,753 km, of which 615 km is formed by rivers: 238 km with Bulgaria and Greece; 76 km with Syria; 58 km with Iraq and Iran; and 243 km with Armenia and Georgia. In 1927, Turkey and the USSR signed a 'Treaty on the Beneficial Uses of Boundary Waters', in which they agreed to share water on a fifty-fifty basis. A Joint Boundary Water Commission was established (although without legal identity) to control the use of the frontier water. In 1973 the two governments signed an additional 'Treaty on the Joint Construction of the Arpacay or Ahuryan Storage Dam'. In a similar vein, Turkey and Greece after the Treaty of Lausanne (1923) signed several protocols regarding the control and management of the Meric River which forms the border between Greece and Turkey.
The protocol concerning the Euphrates and the Tigris rivers dates back to 1946 when Turkey and Iraq agreed that the rivers' control and management depended to a large extent on the regulations of flow in Turkish source areas. Turkey, at that time, agreed to begin monitoring the two rivers and to share related data with Iraq. In 1980 Turkey and Iraq further specified the nature of the earlier protocol by establishing a Joint Technical Committee on Regional Waters. After a bilateral agreement in 1982, Syria joined the committee. Turkey has unilaterally guaranteed to allow 15.75 km3/year (500 m3/s) of water across the border to Syria, but no formal agreement has been obtained so far on the sharing of the Euphrates water.
Irrigation and Drainage Development
Out of the cultivable area of 28 million ha, almost 26 million ha are classified as suitable for irrigation. Considering the water resources this area is reduced to 12.5 million ha. When other economic considerations are brought in, the official estimated irrigation potential of Turkey is 8.5 million ha, of which 93% would be from surface water resources and 7% from groundwater.
|Table 2. Irrigation management (1994)|
|Water management area (ha)||As % of total||Equipped by||Operated by |
|1,080,000||26||Private farmers||Private (groups of) farmers|
|* Other agencies: irrigation cooperatives, heads of villages, municipalities, some state organizations. (Source: FAO)|
Irrigation development in Turkey is carried out by the public sector, represented by DSI (State Hydraulic Works) and GDRS (General Directorate of Rural Services), and by the private sector (farmers and groups of farmers). As of January 1994, the total water managed area was estimated at almost 4.2 million ha, or 49% of the irrigation potential, of which 115,164 ha was equipped wetland. Over 3.1 million ha have so far been developed by the public sector, compared with less than 0.5 million ha in 1965. The total water managed area can be classified in four categories as shown in Table 2.
On public schemes, the national average of the irrigation ratio (the part of the equipped area actually irrigated) varies between 64 and 72% with wide regional and annual fluctuations (28-82% and 34-76% respectively).
Of the total area developed by the public sector for full and partial control irrigation 20% is irrigated from groundwater, while for the area developed by the farmers the figure is only 7%.
Almost 94% of the total area is irrigated using surface irrigation methods (furrow, basin, border, wild flooding). The remaining part is under sprinkler irrigation (mainly hand-move) and some micro-irrigation, mainly in the Aegean and Mediterranean regions. The conventional (hand-move) sprinkler irrigation is common all over Turkey among the farmers and an estimated 200,000 ha are irrigated using this method. On DSI schemes, 63,849 ha are irrigated by sprinklers, mainly for sugar beet, cereals, beans, alfalfa, cotton, sunflowers, watermelons, and vegetables. Micro-irrigation is practiced on 386 ha of DSI schemes, mainly for citrus fruits, vineyards, vegetables, strawberries, and watermelons.
During the last three decades GDRS has carried out considerable on-farm water development works, for example the reclamation of saline and alkaline soils on 803,000 ha and open drains on 3,143,000 ha. In 1992, about 223,000 ha were estimated to be power-drained. The flood protected area amounted to almost 800,000 ha in 1994. It was estimated in 1992, that of the total area operated by DSI, about 41,000 ha was salinized by irrigation.
The cost of irrigation development varies between US$1,750/ha for small schemes (<1,000 ha) and US$3,000/ha for large schemes (>1,000 ha, with 70% being >10,000 ha). The average cost of operation and maintenance varies between US$50/ha for small schemes and US$70/ha for large schemes (excluding dams). The cost of drainage development (the average for sub-surface and open drains) was estimated at US$274/ha in 1994. Water rates are charged on a cropped area basis, with different rates for each crop. During 1990-1992 the average water charges for large schemes were estimated at US$35/ha.
Data for major crops and their production are not available for the whole country. In 1991 60% of the total area equipped and operated by DSI (over 1.34 million ha), or 810,000 ha, was cropped.
The average yield for irrigated cereals (wheat and barley) was 4.1 tonnes per hectare (t/ha) as against 2.1 t/ha for rainfed crops. For irrigated pulses (chick peas and lentils) the average yield was 2.5 t/ha; for cotton 2.9; for sunflowers 2.3; for maize 7.9; for sugar beet 55.2; and for tobacco 1.1 t/ha.
There are two governmental organizations involved in major irrigation and drainage development:
- The State Hydraulic Works (DSI) was established in 1954 as a legal entity and brought under the aegis of the Ministry of Public Works and Settlement and is responsible for the planning, design, construction, and operation of water resources development for various purposes like irrigation, flood control, wetland reclamation, hydropower development, navigation, and water supply to cities with over 100,000 inhabitants.
- The General Directorate of Rural Services (GDRS) was established in 1984 by incorporating the soil conservation and irrigation organization, the rural settlement organization and the rural roads, water, and electricity organization into one organization. It is responsible for the development of small-scale irrigation schemes and small reservoirs, rural roads, and water supply to rural areas. It is also responsible for land consolidation and the on-farm development of all irrigation projects, including the projects developed by DSI. It was formerly under the Ministry of Agriculture and Rural Affairs, but now falls under the Prime Minister's Office.
Trends in Water Resources Management
In several areas, problems are emerging as urban activities encroach onto agricultural lands. There is an increasing interest in using the land as a vehicle for the treatment and disposal of the wastewater from agri-business and urban activities. In particular there is current concern about the use of polluted water resources to irrigate agricultural lands, especially in western Turkey, which has been experiencing water shortages on a regular basis in recent years.
A regional agricultural development project, the South East Anatolian Project (GAP), is planned for the lower Euphrates River and the Tigris River basin within the boundaries of Turkey. The project involves the integrated development of irrigated agriculture and agroindustry, and supporting services, including communications, health, and education. It includes 13 major projects of which 7 are in the Euphrates basin and 6 in the Tigris basin. After full development it will include 22 dams, 19 hydroelectric power plants and the irrigation of almost 1.7 million hectares. The water obtained from the Ataturk dam on the Euphrates is carried to the Harran Plain by the Sanli Urfa tunnel system, which is the largest tunnel system in the world in view of its length and flow rate. The waters of the river pass through banners which are 26.4 kilometers in length and 7.62 meters in diameter with an estimated flow of about 328 cubic meters per second (m3/s), which is one-third of the total flow of the Euphrates.
However, the downstream riparian states, Syria and Iraq, do not agree with water abstraction for irrigation. Especially as far as the Euphrates River is concerned, problems regarding sharing water might arise between these countries. Turkey has unilaterally guaranteed to allow 15.75 km3/year of water from the Euphrates River across the border to Syria, but no formal agreement has been obtained thus far. Although fewer water problems exist on the Tigris River, mainly because more than 50% of the water originates downstream of Turkey (relative to less than 10% of the Euphrates water), here also the use of the water resources has to be carefully planned.
According to the different scenarios established, full irrigation development by the countries in the Euphrates-Tigris river basin would lead to water shortages and solutions will have to be found at basin level through regional cooperation.
- New Criteria for Resettlements in Regional Development: Turkey's Water and Land - Based on Regional Development Experience in Southeastern Anatolia Region and Project. World Commission on Dams.
- Water in Turkey. UNESCO.
- Water Resources and Freshwater Ecosystems: Turkey. Earthtrends.
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