Fresh water resources Turkey
Present situation in Turkey
Turkey is one of the most water rich countries of the Mediterranean, but due to an enormous population increase from 28 million in the 1960’s to 68 million in 2000 the availability of water resources has already decreased from around 4000 m3 to 1500 m3 per capita/year today. Water demand in Turkey approximately has doubled in the second half of the last century. The overall water demand in Turkey continues to increase, even more in the light of the effects of drought (or climate change). Turkey will suffer from water scarcity in the next years (8).
73.2% of the total water supply of Turkey is used for agricultural irrigation, remaining 15.5% and 11.3% are used for drinking-domestic and industrial purposes, respectively (9).
Abstraction non-renewable groundwater reserves
‘‘Non-renewable groundwater’’ denotes groundwater gained by abstraction in excess of recharge. The amount of non-renewable groundwater abstraction that contributes to gross irrigation water demand has been calculated for a large number of countries, allowing for a global overview. The results of this study show that non-renewable groundwater abstraction globally contributes nearly 20%, or 234 km3 annually, to the gross irrigation water demand (for the reference year 2000) and has more than tripled in size since the year 1960. From 1960 to 2000 an increased dependency was shown of irrigation on non-sustainable groundwater with time. Thus, irrigation is more and more sustained by an unsustainable water source (12).
Country assessments reveal that non-renewable or non-sustainable groundwater supplies large shares of current irrigation water, particularly for semi-arid regions where surface freshwater and rainfall are very scarce: Pakistan, Iran, Saudi Arabia, Libya, UAE and Qatar. Much of current irrigation in these regions is sustained by non-sustainable groundwater (12).
For Europe, the contribution (%) of non-renewable groundwater abstraction to gross irrigation water demand was calculated for Italy (15%), Spain (7%), Turkey (7%) and Greece (2%) (12). Projected increases in irrigation demand in southern Europe will serve to stress limited groundwater resources further (21).
Vulnerabilities Turkey - Future projection
Studies indicate that Turkey has some of the highest levels of water security threat of the countries in Europe. It is densely populated and most areas of the country face high or very high levels of water stress. This problem is likely to increase with the rapidly rising population and the potential drying associated with rising temperatures (13,17). Estimates of changes in runoff of between -52% and -61% (14), and reductions of surface waters in the Turkish basins of 20%, 35% and 50% for 2030, 2050 and 2100 have been reported (15). By 2100 Turkey could experience an expansion of arid areas that could lead to increased water stress around the southern Mediterranean areas (16).
The likely effects of climate change on the water resources of the eastern Mediterranean and Middle East region have been investigated using a high-resolution regional climate model (PRECIS) by comparing precipitation simulations of 2040–2069 and 2070–2099 with 1961–1990 (18). The projected change in internal water resources is assumed to be the same as the projected change in precipitation. Turkey has a large rural population, with 43% of its economically active population, nearly 15 million people, working in agriculture. Its precipitation and water resources were projected to suffer a modest decline of 11% by midcentury and 12% by the end of the century. While water resources as a whole for the country remain relatively plentiful, Turkey is still facing having its per capita water resources decrease by nearly one third by midcentury. Turkey’s agricultural sector will therefore be forced to become more water efficient and will, despite this increased efficiency, probably still decline as a source of employment. In spite of this decline, Turkey is likely to remain a major net agricultural exporter as its large land area, large rural population, and relatively large water resources will allow it to export virtual water to its water-scarce regional environment.
Substantial reductions in potential groundwater recharge are projected for the 21st century in southern Europe (Spain and northern Italy) whereas increases are consistently projected in northern Europe (Denmark, southern England, northern France) (19). Along the southern rim of the Mediterranean Sea decreases in potential groundwater recharge of more than 70% by the 2050s have been simulated using output from two climate models (ECHAM4, HadCM3) under two emissions scenarios (A2, B2) (20).
Headwaters of Euphrates and Tigris
The Euphrates–Tigris Basin hosts the two important snow-fed rivers of the Middle East, and its water resources are critical for the hydroelectric power generation, irrigation and domestic use in the basin countries, namely Turkey, Syria, Iraq and Iran (27). Approximately 90% of the Euphrates flow and 46% of the Tigris flow originate in Turkey (28). Based on different model and scenario simulations, projections were made of future changes in temperature, precipitation, snow cover and river discharge in the Euphrates–Tigris basin countries. From these projections the following was concluded (27):
- Temperature: All scenario simulations indicate surface temperature increases across the entire Euphrates–Tigris basin. The increase is comparatively greater in the highlands in winter. Increase in annual surface temperature in the highlands ranges between 2.1°C (lower emissions scenario, B1) and 4.1°C (higher emissions scenario, A1FI) for 2041–2070, whereas it ranges between 2.6°C and 6.1°C for 2071–2099. Cold season temperature increase has the potential to greatly impact the regional hydrological cycle by reducing the snow cover and changing the seasonality of surface runoff.
- Precipitation: Precipitation is projected to decrease in the highlands and northern parts of the basin and increase in the southern parts, as was shown before (e.g., Evans, 2008; Onol and Semazzi, 2009; Chenoweth et al., 2011). The changes in precipitation are statistically significant in the large areas of the basin in most of the simulations. Projected precipitation decrease in the highlands by the end of the present century is 33% under the higher emissions scenario (A1FI) and 6 - 24% under the A2 scenario. Snow water equivalent precipitation in the highlands is projected to decrease by 55% for B1 scenario, 77–85% for A2 scenario and 87% for A1FI scenario.
- River discharge: The territory of Turkey will likely experience more adverse direct effects of the climate change compared to the territories of the other countries in the basin. The annual surface runoff is projected to decrease by 26 - 57% in the territory of Turkey by the end of the present century. Because much of the headwaters are located in this territory, all other countries in the basin are expected to feel the stress for the diminishing waters during the twenty first century.
These results are substantiated by other model studies that show a 12% decrease of the average annual Euphrates–Tigris river discharge in Turkey by 2040–2069 (IPCC A1B scenario (29)), and a 29–73% decrease of the Euphrates River discharge by the end of the present century (a number of models and emissions scenarios (30)).
Regional climate model results for the period of 2071–2100 under SRES A2 emission scenario, compared with 1961–1990, indicate that a significant increase (48 %) in the autumn season precipitation is simulated over south-eastern Turkey, which may help to offset the winter deficit and therefore reduce the net change during the annual cycle (25). However, in this area societal risks are high and adaptive capacity is low, which enhances potential conflicts and stress on water resources (25,26).
Europe: five lake categories
There are almost one and a half million lakes in Europe, if small water bodies with an area down to 0.001 km2 are included. The total area of lakes is over 200,000 km2; in addition the manmade reservoirs cover almost 100,000 km2. The response of European lakes to climate change can be discussed by dividing the lakes into five categories (10):
Deep, temperate lakes
Typical representatives of this class are e.g. Lakes Maggiore, Ohrid, Geneva and Constance with mean depths of 177, 164, 153 and 90 meters, respectively. Due to the great depth and relatively mild winters, there is usually no ice cover. The future climate change in Europe may suppress the turnover in deep lakes. This implies the enhancement of anoxic bottom conditions and an increased risk of eutrophication. The oxygen conditions can also be anticipated to deteriorate due to increased bacterial activity in deep waters and surficial bottom sediment.
Shallow, temperate lakes
Balaton (600 km2, 3 m) in Hungary and Müritz (114 km2, 8 m) in Germany belong to this class. Increasing water temperatures may result in intensified primary production and bacterial composition. The probability of harmful extreme events, e.g. mass production of blue-green algae, will increase. The impacts may extend to fish life; changes in species composition and reduced fish catches will be anticipated. The use of the expression 'thermal pollution' is well justified for these lakes.
Ladoga (17 670 km2, 51 m), Onega (9670 km2, 30 m) and Vänern (5670 km2, 27 m) are the largest in this class, being also the three largest lakes in Europe. This group includes about 120 lakes with an area exceeding 100 km2. Most lakes of the boreal zone mix from top to bottom during two mixing periods each year. Shortening of the ice cover period will be the most obvious consequence of climate change in these lakes. This could improve the oxygen conditions in winter and spring.
These are mainly small water bodies in northern Scandinavian mountains and in the tundra region. Arctic lakes are generally considered to be particularly sensitive to environmental changes. Melting permafrost may seriously threaten the ecosystems of arctic lakes. In some cases the whole lake may disappear as a consequence of ground thaw and enhanced evaporation.
To this class belong all high altitude lakes in central Europe and also those located in southern Scandinavia. Even if mountain lakes were connected by channels, physical and ecological constraints limit species migration between them. In a warming climate, there is no escape route; the only possibility for survival is adaptation.
South-eastern Europe: four types of lakes
In order to discuss the effect of climate change to lakes in south-eastern Europe, the region is divided into three climatic sub regions. The main characteristic in this subdivision is the mean temperature in January, because the severity of winter has an essential influence to the lakes. The sub regions and the anticipated influences of climate change, around the year 2050, are as follows (10):
The Mediterranean sub region
In today's climate the mean temperature varies in January between +10 and -2°C, in July it is generally 20 - 25°C. This sub region covers the narrow coastal area on the Adriatic Sea, most of the Greek territory and the lowlands on the southwest side of the Black Sea.
Only the smallest lakes have short ice cover season every winter in today's climate, in the future climate ice will be almost non-existent. Summertime water temperatures will get very high, leading to algal and water quality problems. Water balance will be negatively affected by climate change; evaporation will increase and inflows tend to decrease. The use of lakes as water sources, e.g. for rising needs of irrigation, will be limited.
In today's climate, the runoff in the Adriatic part of this sub region is generally over 1000 mm, while it ranges between 30 and 200 mm in the vicinity of the Black Sea. The difference of lake precipitation and lake evaporation is 200 - 600 mm in the former area, whereas it is between -200 and -400 mm in the latter. In the climate of 2050, shallow lakes in the latter area will become intermittent and reservoirs will have considerably high water losses.
Mean temperature in January is between -5 and -2°C, in July around 20°C. This sub region covers large parts of Hungary, eastern Croatia, central parts of Serbia, southern and eastern Romania, and Moldova. As to the runoff, this is the driest area in south-eastern Europe; in Hungary and on the Black Sea coast annual runoff is locally less than 20 mm. The difference of lake precipitation and lake evaporation is between 0 and -300 mm.
In today's climate most lakes in this sub region mix from top to bottom during two mixing periods each year and have an ice cover for 1-3 months. They may still freeze in 2050, but the possibility of ice-free winters will increase. Adverse water balance changes may affect many lakes; intermittency and increased salinity can be anticipated.
South-eastern Europe is topographically one of the most diverse regions in the world. In addition to two main mountain ranges, Carpathians and Dinaric Alps, there are numerous other ridges and plateaus. At highest elevations, mean temperature in January can be as low as -10°C and extremes below -30°C have been recorded. In July typical mean temperatures are between 10 and 20°C. Precipitation is generally abundant but very variable even at small scale.
Most lakes are located in river valleys, but smaller ones occur also at high plateaus and depressions. Ice cover season may be as long as 5-6 months, snow on lakes further reduces the penetration of radiation into the water mass. Some of the highest lakes mix once a year but mixing twice a yearis much more common.
Climate change may not cause very harmful changes in water balance of these lakes. Increased erosion by intense precipitation may lead to sedimentation and degradation of water quality. At lower elevations, the occurrence of ice cover may become uncertain. For water supply, the mountain lakes and river basins will probably be very important in south-eastern Europe in the future, because run-off may considerably decrease at lower altitudes.
Underground (karstic) lakes
This is a special type of lakes. Due to the karstic geology, there are underground lakes in the Balkan region. They are not immune to the impacts of climate change; in fact their water balance and ecology may be sensitive to changes of the quantity and quality of inflowing waters.
Present situation in Europe
In the EU as a whole, energy production accounts for 44% of total water abstraction, primarily serving as cooling water. 24% of abstracted water is used in agriculture, 21% for public water supply and 11% for industrial purposes (3).
These EU-wide figures for sectoral water use mask strong regional differences, however. In southern Europe, for example, agriculture accounts for more than half of total national abstraction, rising to more than 80 % in some regions, while in western Europe more than half of water abstracted goes to energy production as cooling water. In northern EU Member States, agriculture's contribution to total water use varies from almost zero in a few countries, to over 30% in others (7). Almost 100% of cooling water used in energy production is restored to a water body. In contrast, the consumption of water through crop growth and evaporation typically means that only about 30% of water abstracted for agriculture is returned (3).
Currently, just two countries, Germany and France, account for more than 40% of European water abstraction by manufacturing industry (3).
In general, water is relatively abundant with a total freshwater resource across Europe of around 2270 km3/year. Moreover, only 13% of this resource is abstracted, suggesting that there is sufficient water available to meet demand. In many locations, however, overexploitation by a range of economic sectors poses a threat to Europe's water resources and demand often exceeds availability. As a consequence, problems of water scarcity are widely reported, with reduced river flows, lowered lake and groundwater levels and the drying up of wetlands becoming increasingly commonplace. This general reduction of the water resource also has a detrimental impact upon aquatic habitats and freshwater ecosystems. Furthermore, saline intrusion of over-pumped coastal aquifers is occurring increasingly throughout Europe, diminishing their quality and preventing subsequent use of the groundwater (3).
Virtually all abstraction for energy production and more than 75% of that abstracted for industry and agriculture comes from surface sources. For agriculture, however, groundwater's role as a source is probably underestimated due to illegal abstraction from wells. Groundwater is the predominant source (about 55%) for public water supply due to its generally higher quality than surface water. In addition, in some locations it provides a more reliable supply than surface water in the summer months (3).
Fresh water reservoirs
Currently about 7000 large dams are to be found across Europe, with a total capacity representing about 20% of the total freshwater resource (3). The number of large reservoirs is highest in Spain (ca 1200), Turkey (ca 610), Norway (ca 360) Italy (ca 570), France (ca 550), the United Kingdom (ca 500) and Sweden (ca 190). Europe's reservoirs have a total capacity of about 1400 km3or 20% of the overall available freshwater resource (6).
Three countries with relatively limited water resources, Romania, Spain and Turkey, are able to store more than 40% of their renewable resource. Another five countries, Bulgaria, Cyprus, Czech Republic, Sweden and Ukraine, have smaller but significant storage capacities (20–40%). The number and volume of reservoirs across Europe grew rapidly over the twentieth century. This rate has slowed considerably in recent years, primarily because most of the suitable river sites for damming have been used but also due to growing concerns over the environmental impacts of reservoirs (3).
Projected future situation in Europe
Appliance ownership data is not currently readily available for the new Member States but it is believed that rates are currently relatively low and likely to rise in the future. Higher income can also result in increased use and possession of luxury household water appliances such as power showers, jacuzzis and swimming pools. Changes in lifestyle, such as longer and more frequent baths and showers, more frequent use of washing machines and the desire for a green lawn during summer, can have a marked effect on household water use. The growth in supply within southern Europe has been driven, in part, by increasing demand from tourism. In Turkey, abstraction for public water supply has increased rapidly since the early 1990s, reflecting population growth and a rise in tourism (3).
Water stress over central and southern Europe is projected to increase. In the EU, the percentage of land area under high water stress is likely to increase from 19% today to 35% by the 2070s, by when the number of additional people affected is expected to be between 16 and 44 million. Furthermore, in southern Europe and some parts of central and eastern Europe, summer water flows may be reduced by up to 80% (4).
Runoff is estimated to increase north of 47°N by approximately 5-15% by the 2020s and 9-22% by the 2070s. North of 60°N, these ranges would be considerably higher, particularly in Finland and northern Russia (1). Average annual runoff in Europe varies widely, from less than 25 mm in southeast Spain to more than 3000 mm on the west coast of Norway. Climate change is thus going to make the distribution of water resources in Europe much more uneven than it is today. And even today's distribution is highly uneven, particularly considering the distribution of population density. Almost 20% of water resources are north of 60°N, while only 2% of people live there (2).
Not only will climate change affect the spatial distribution of water resources, but also their distribution in time. In northern Europe, the flows in winter (December to February) will increase two- to three-fold, while in spring they will attenuate considerably, in summer increase slightly and in autumn almost double by the period 2071-2100 (2).
EU policy orientations for future action
According to the EU, policy orientations for the way forward are (11):
- Putting the right price tag on water;
- Allocating water and water-related funding more efficiently: Improving land-use planning, and Financing water efficiency;
- Improving drought risk management: Developing drought risk management plans, Developing an observatory and an early warning system on droughts, and Further optimising the use of the EU Solidarity Fund and European Mechanism for Civil Protection;
- Considering additional water supply infrastructures;
- Fostering water efficient technologies and practices;
- Fostering the emergence of a water-saving culture in Europe;
- Improve knowledge and data collection: A water scarcity and drought information system throughout Europe, and Research and technological development opportunities.
Managed aquifer recharge
Comprehensive management approaches to water resources that integrate ground water and surface water may greatly reduce human vulnerability to climate extremes and change, and promote global water and food security. Conjunctive uses of ground water and surface water that use surface water for irrigation and water supply during wet periods, and ground water during drought (22), are likely to prove essential. Managed aquifer recharge wherein excess surface water, desalinated water and treated waste water are stored in depleted aquifers could also supplement groundwater storage for use during droughts (23,24). Indeed, the use of aquifers as natural storage reservoirs avoids many of the problems of evaporative losses and ecosystem impacts associated with large, constructed surface-water reservoirs.
A number of measures exist that may potentially reduce the use of publicly supplied water. These can be broadly grouped into the categories of water saving devices; greywater re-use; rainwater harvesting and the efficient use of water in gardens and parks; leakage reduction; behavioural change through raising awareness; water pricing; and metering. Since treating, pumping and heating water consumes significant amounts of energy, using less publicly supplied water also reduces energy consumption (3).
In Denmark and Estonia, for example, a steady rise in the price of water since the early 1990s has resulted in a significant decline in household water use. Metering leads to reduced water use; in England and Wales, for example, people living in metered properties use, on average, 13% less water than those in unmetered homes (5).
Desalination increases the total available freshwater resource and, in this respect, may be preferable to further depletion of the surface and groundwater stocks. Detrimental environmental impacts are associated with desalination plants, however, in particular their energy consumption and the production of highly concentrated brine that may be released into sensitive marine waters. Furthermore, expanding supply from desalination plants does not provide any incentive to either reduce water use or improve the efficiency of use. Decisions on the suitability of future desalination plants need to be addressed on a case-by-case basis, accounting for all environmental and economic issues (3).
Headwaters of Euphrates and Tigris
There are still plans and investments to construct more dams on the Euphrates and Tigris rivers. On one hand, decreased water availability and reduced hydropower potential in the future make it questionable to build more dams on these rivers for power generation. On the other hand, the temporal change in the peak flows may make it necessary to build more dams to compensate the diminishing reservoir attribute of the snow cover to be able to save water for the spring and summer when dry conditions prevail in the basin. Construction of more dams in the basin, however, causes, in addition to environmental problems, irreversible damages to the rich historical and cultural heritage of the region (27).
The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Turkey.
- Alcamo et al. (2007)
- Eisenreich (2005)
- EEA (2009)
- EEA, JRC and WHO (2008)
- Environment Agency (2008a), in: EEA (2009)
- EEA (2007), in: EEA (2009)
- IEEP (2000), in: EEA (2009)
- Dogdu and Sagnak (2008)
- DSI (2005); MGR (2007); Margat (2004), all in: Dogdu and Sagnak (2008)
- Kuusisto (2004)
- Commission of the European Communities (2007)
- Wada et al. (2012)
- Vörösmarty et al. (2010), in: MET Office (2011)
- Fujihara et al. (2008b), in: MET Office (2011)
- Ozkul (2009), in: MET Office (2011)
- Gao and Giorgi (2008), in: MET Office (2011)
- MET Office (2011)
- Chenoweth et al. (2011)
- Hiscock et al. (2011), in: Taylor et al. (2012)
- Döll (2009), in: Taylor et al. (2012)
- Falloon and Betts (2010), in: Taylor et al. (2012)
- Faunt (2009), in: Taylor et al. (2012)
- Scanlon et al. (2012), in: Taylor et al. (2012)
- Sukhija (2008), in: Taylor et al. (2012)
- Önol and Unal (2012)
- Scheffran and Battaglini (2011), in: Önol and Unal (2012)
- Bozkurt and Sen (2012)
- FAO (2009), in: Bozkurt and Sen (2012)
- Chenoweth et al. (2011), in: Bozkurt and Sen (2012)
- Kitoh et al. (2008); Nohara et al. (2006), both in: Bozkurt and Sen (2012)