International Journal of Marine Science, 2017, Vol.7, No.3, 19-30
21
angle and big seabed roughness. For drawing the schematic figures different methods were applied for various
marine parameters which have been separately explained in the related sections. It should be previously
mentioned that various statistical methods were applied for data processing including: averaging, interpolation,
extrapolation, regression, etc. Also, the Surfer 8 software program was applied for presentation of data analysis
results. This software was also used for drawing the schematic figures of Caspian Sea Hydromorphology. In truth,
the study of data presented in the maps of this paper will help us know more about the abiotic features of the
Caspian Sea, and the processing results can be exploited in the Caspian Sea applied sciences.
2 Results
2.1 Caspian Sea general hydromorphology
The Caspian Sea which is the largest enclosed body of water in world is situated in an important geopolitical area
named Eurasia. This body of water is surrounded by five littoral states of Azerbaijan, Iran, Kazakhstan, Russia,
Turkmenistan; each one has respectively the shoreline of 850 km, 865 km, 1800 km, 695 km, and 560 km in the
margin of Caspian Sea (Figure 3). The Caspian Sea shape is like a Latin Letter S and is stretched along the
meridian ward. It is also situated between the latitudes 47.57 N and 36.33 N and longitudes 45.43 E and 54.30 E.
The length of the Caspian Sea is 1200 km and its average width is 310 km. Its most and least breadth are 435km
and 196 km. The Caspian Sea water level is 27 meters lower than Baltic Sea water level and in this situation its
surface area and water volume are 392600 km
2
and 78648 km
3
(Kosarev and Yablonskaya, 1994). Caspian Sea is
a deep lake with an extensive shelf and its depth is only lower than Baikal (1620 m) and Tanzania (1435 m) lakes
which are the world’s largest lakes. The Caspian Sea average depth is 208 meters and the depth curve of its water
volume distribution shows that major part of its water volume (62%) is distributed within the depth limit of 100 to
600 meters, 25.7% is distributed within the depth limit of 1-100 meters, and the other 16 percent is distributed
within the depth limit of more than 800 meters. The Caspian Sea watershed area, with the surface area of 3.5
million km
2
. More than 130 rivers flow into this sea, among them Volga River is the first and the most important
because of its discharging regime, and Kura River is in the second place (Kostianoy et al., 2005). In terms of the
structural geomorphological, physiographical and meteorological features, the Caspian Sea can be divided into
three parts of north, south and middle Caspian (Figure 3) (Kostianoy et al., 2005). The line connecting Chechnya
islands and Cape Tiob-Karagan is chosen as the contractual border between north and middle Caspian, and the
connecting line of Zhiloy and Cape Kuuli is chosen as the contractual border between middle and south Caspian.
It is noteworthy that Mangyshlak bulge, as an underwater elevated strip with the depth of less than 10 meters,
constitutes the natural border between north and middle Caspian from Tiob-Karagan peninsula to Cape Kulali and
to Chechnya peninsula (Mammadov and Khoshravan, 2012). The Absheron bulge also naturally divides the
middle and south Caspian. This asymmetric underwater bulge continues from Absheron peninsula to Cheleken
peninsula. The seasonal waterways and rivers which flow into the Caspian Sea resulted in development of various
deltaic shapes, the best example of which is the Volga river delta (Mammadov and Khoshravan, 2012). In the
backshore and near shore zone of the north Caspian, the coast has a gentle slope. One of the important features of
the northern coast of Caspian Sea is the low coastal regions which are sensitive to water logging cause by storm
tide and seawater quick fluctuations. The Dagestan coast which is situated in the northwest of Caspian Sea is a
narrow erosional plain and in its edges the novo Caspian terraces are observable (Mammadov and Khoshravan,
2012). In the south of Camur river delta, the coast is step-shaped and the gravel and sand alleviate sediments are
observable on the terraces. The coastal structure of Kizlar region is very interesting. In this place, the great
Caucasus Mountains end in Caspian Sea, and as a result the coast is rugged. In this place, the coastal plain
narrows and its width reaches to 1 or 2 km. The shoreline in the western area of Caspian Sea is straight and flat,
except from the Absheron peninsula region in where a compound series of synclines and arching cut the coastline.
Kura Delta has severely progressed toward the sea and is considered as an important morphological component of
the Caspian Sea southwest coast. The coast in the south of Lankaran is in shape of a marine plain and is connected
to the present sand coast. This coast is restricted by strips of sand ridges in westward. Within the limit of Iran’s
coastal strip, the Alborz Mountains range approaches the coast, so that the coast width narrows down and the
breadth of the coastal strip reaches to 2 to 40 km. In the Iranian coasts of Caspian Sea, there are two big bays:
Gorgan Bay (former Astarabad) and Anzali bay and there are Ashooradeh great island; and some small islands.
