Caspian Sea State of the Environment 2019
4.4. External inputs: discharge and run-off Pollutants enter the Caspian Sea from various sources, including river run-off, precipitation, sewage, discharge from ships and oil and gas facil- ities, and gas and liquid releases from the seabed. For geographic and historical reasons, pollution sources are unevenly distributed along the coast- line and in the sea. River run-off predominantly affects the Northern Caspian (Figure 4.2), with most of the pollutants discharged into the sea along with river water in the area. The amount of precipitation falling on the southern coast is five times greater than that which falls on the north- ern coast, so atmospheric pollutants primarily affect the southern coast. Wastewater discharge is mainly concentrated on the western and southern
coasts, where there are large urban settlements and well-developed industrial and agricultur- al sectors. Gaseous and liquid releases from the seabed (streams, springs and mud volcanoes) are associated with geologically active regions, which are heavily concentrated around the Absheron Peninsula. As shown by observations from space, discharge from ships is mainly localized along navigable routes connecting large seaports. Pol- lution from oil and gas facilities depends on the condition of the facility – modern facilities with a zero-discharge policy do not pollute the marine environment when operating normally, but dis- charges are possible in the event of an accident, something which often occurs at older facilities. River run-off, sewage and atmospheric transport are land-based sources of Caspian Sea pollution. Pollution of the Caspian Sea from land- based sources in Azerbaijan Pollution of the Caspian Sea from the territory of Azerbaijan comes mainly from the discharge of pol- luted wastewater. The Kura River, which is heavily polluted by domestic and industrial wastewater from Armenia and Georgia, plays a significant role here. To prevent the discharge of untreated sewage into the sea, Azerbaijan is undertaking a huge amount of investment, carrying out large-scale projects, rebuild- ing and modernizing major sewage treatment plants and constructing modern new treatment plants and sewage systems. Recently built or modernized wastewater treatment facilities alone have a capacity of up to one million cubic metres of water per day. The main sources of polluted water discharged into Baku Bay have been eliminated. In addition, to pre- vent the sea frombeing polluted by small local sourc- es that are not connected to the central sewer system, modular treatment plants have been installed along the Caspian coast on the Absheron Peninsula Pollution of the Caspian Sea from land- based sources in Kazakhstan Water quality in the north-eastern sector of the sea is affected by run-off from the Ural River and the Volga River. During the period of 2012 to 2017 the waters of the Ural River on the territory of Atyrau Region were rated as “normatively clean”
RUSSIA
Volga Basin
256 km³
Share of basins discharge
10.1 km³ Ural Basin
Volga Basin 80%
Others 20%
AZOV SEA
KAZAKHSTAN
Terek
Samur, Sulak and West Coast small rivers Basin
Basin
11 km³
ARAL SEA
Basin with dry rivers
8.5 km³
BLACK SEA
CASPIAN SEA
UZBEKISTAN
GEORGIA
ARMENIA
TURKEY
AZERBAljAN
Kura-Araks Basin
TURKMENISTAN
18.6 km³
Iranian rives Basin
Border
16.1 km³
Basin
IRAN
Country
Canal Annual discharge 8.5 km³
Source: Roshydromet, 2016. Map by Manana Kurtubadze, GRID-Arendal, April 2018.
200 km
0
Figure 4.2: River basin discharge into the Caspi- an Sea
44
Made with FlippingBook - professional solution for displaying marketing and sales documents online