Fresh water resources Romania
Fresh water resources in numbers - Romania
The Danube is the second longest river in Europe (2,860 km), and flows along 1,075 km of Romania's territory and empties into the Black Sea through three arms (Chilia, Sulina, Sfantu Gheorghe) which form the Danube Delta. The other main rivers in Romania are: Mures (761 km on Romania's territory), Prut (742 km on Romania's territory), Olt (615 km), Siret (559 km on Romania's territory), Ialomita (417 km), Somes (376 km on Romania's territory), Arges (350 km) (1).
Romania has around 3,500 lakes, but only 1% of them have an area exceeding 1 km2. More important are the lagoons and the Black Sea coastal lakes (Razim 41,500 ha, Sinoie 17,150 ha) and the lakes along the Danube bank (Brates 2,111 ha, Bistret 1,867 ha). Glacial lakes are mostly spread in the Carpathian Mountains (Bucura is the largest of them, 10.5 ha) (1).
Out of the man-made lakes, the most important reservoir lakes for power generation are those on the Danube, at the Hydro-Power Plants of Iron Gates II (40,000 ha) and Iron Gates I (10,000 ha – with a water volume of 2,400 million cubic meters, which is three times as much as that of Iron Gates II), plus the reservoir lakes of Stânca-Costesti (5,900 ha) on the Prut and Izvorul Muntelui on the Bicaz (3,100 ha) (1).
Vulnerabilities - Romania
The possible consequences of a doubling of the CO2-concentration have been estimated. This may result in a decrease of river runoff; although the precipitation is higher in case of 2xCO2 scenario, due to the marked increase of the air temperature a significant increase of the evapotranspiration occurs, leading to the decrease in runoff. This scenario may also result in a redistribution of the monthly mean runoff, the most affected month being April, when the most pronounced decrease of maximum runoff occurs (1,2).
From the analysis of runoff distribution during the year in the case of the 2xCO2 climatic scenario the following conclusions may be drawn (1,2):
- the maximum monthly mean discharges shift from the spring - summer months to the winter ones, due to the temperature increase causing the snow cover melting at a different phase than precipitation (generally specific for April-July period);
- the minimum monthly mean discharges shift from the period October-January towards August-October, due to the temperature increase (leading to the evapo-transpiration increase and the soil moisture decrease) as well as the marked decrease of the precipitation in September.
In addition (5):
- the stress on water will increase as needs for irrigations in agriculture grow and the underground water supply and the water-bearing layers will be affected;
- the high temperatures may affect water quality in the rivers and storage lakes (increase of the pollution frequency; the decrease of the dissolved oxygen and algae flourishing, eutrophication may affect the fish populations);
- the decrease of the river outflows may bring problems on the provision of utilities, the selfcleaning capacity of the rivers, the aquatic ecology and recreation;
- diseases associated to water and damages produced by floods and droughts will increase.
Taking into account the existing water management works, the climate change impact is sensitive only for the Arges River Basin, one of the most important for the economic and social development and environmental issues. The capital of Romania Bucharest (about 2,000,000 inhabitants) is located within the Arges River Basin (1,2).
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 (3):
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 (3):
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.
Adaptation strategies - EU
EU policy orientations for future action
According to the EU, policy orientations for the way forward are (4):
- 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 (6), 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 (7,8). 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.
Adaptation strategies - Agriculture in Romania
The adaptation measures to mitigate the effects of climate changes on agriculture and water management in Romania can be roughly classified in two groups (1):
The first group is related to the national decision level and it refers to various governmental laws regarding the protection, conservation and improvement of soil and water resources and, therefore, indirectly refers to drought, desertification and soil degradation. One of the most important is related to the United Nations Convention to Combat Desertification, which was ratified by Romania through the Law no. 111/1998. A particular aspect of agriculture in drought affected areas is connected with the social security of the local people. Farmers cannot cover the losses by themselves in years of extreme drought, and especially since insurance companies do not cover the effects of drought, so there is a need for considering some kind of support actions in these situations.
The second group of strategies refers to those derived from research studies. In this way, in the agriculture field it was suggested that for unfavorable years the dominant strategy to minimize water stress during sensitive development phases has to be the use of irrigation while simultaneously increasing applied nitrogen levels up to 120-160 kg/ha. Irrigation has a maximum beneficial effect on yields when it is used during the development of the floral organs (in the late shooting, heading and flowering stage). Other measures are related to the using of some new more drought-tolerant hybrids with a high grain filling duration, and the sowing in the last 10 days of April using a density of 5 plants/m2 (for maize).
Adaptation strategies – Supply and demand in Romania
For the water supply the adaptation options refer to (1,5):
- new operational rules for the strategic reservoir Vidraru (live storage 420.106 m3) according to the time development of the user demands combined with a gradual reduction of the water losses in the water supply network;
- new infrastructures to turn the hydrological resources into socio-economic resources (new storage lakes, new inter-basin derivations, etc.);
- modification of the existing physical infrastructure in order to be able to regularize the liquid outflows whose distribution in time is being modified as a result of the climate change;
- design and implementation of solutions for the collection and use of rainwater;
- extension of the water recharge solutions of the phreatic layers;
- construction of water basins without dams (the water level is below the ground level);
- inter-basin water transfers;
- alternative management of the existing water supply systems;
- creation of safety sources for extreme cases (into the deep layers 150-300m);
- development of certain storage facilities for drinking water (the coverage of the
demand for 1-2 days);
- reduce losses in the distribution networks (from the current 50% to 20% in 2025);
- introduction of modern technologies into technologic processes in order to produce drinking water and to clean the waste water;
- recycling of the purified water and its further processing into an important source for the coverage of the industrial and public demand, having a non-drinking quality;
- introduction of risk management plans and inventive economic mechanisms for saving water.
Regarding the water demand the adaptation measures refer to (1,5):
- conservation and improving efficiency;
- technological change;
- adaptation of lifestyle (including raising awareness through education), crop variety, industrial recycling;
- elaboration and the implementation of certain price and tariff systems for water
according to the category of use, the season and the available resource.
The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Romania.
- Ministry of Environment and Watermanagement (2005)
- Cuculeanu and Balteanu (2004)
- Kuusisto (2004)
- Commission of the European Communities (2007)
- Ministry of Environment and Forests (2010)
- Faunt (2009), in: Taylor et al. (2012)
- Scanlon et al. (2012), in: Taylor et al. (2012)
- Sukhija (2008), in: Taylor et al. (2012)