The Republic of Azerbaijan occupies the southeast part of the Caucasus isthmus and its small southern part. It covers the southeast of the Greater Caucasus, a part of the Lesser Caucasus, the Talysh Mountains with the vast Kura-Araks depression in between. Geographically the republic is located within the limits of the part of Eurasia, which is closely connected with the Aral -Caspian depression and is located near the conventional border between Europe and Asia.

In addition to the continental part, the republicOs territory also includes several islands located along the Caspian coastline. These islands include: Nargin, Zhiloy, Bulla, Svinoy and Glinyany. Latitudes 38*25O and 41*55O North and longitudes 44*50O and 50*23O East outline the 86.6 thousand sq. km territory, excluding the islands some of which are located beyond the above mentioned eastern meridian. Azerbaijan borders with the Dagestan Republic of the Russian Federation in the North (approximately 340 km), with Georgia in the northwest (approximately 340 km), with Armenia in the southwest (approximately 760 km), while Armenia separates Azerbaijan from the autonomous republic of Nakhichevan which borders Turkey (11 km), and Iran in the south (more than 600 km). The eastern border lies through the Caspian Sea between Russia, Turkmenistan and Iran, the coastline being more than 850 km. The main part of the border is of natural origin (rivers and mountain ranges) and it only lies on conventional lines in some parts.

The average height of the republic equals 384 m with the highest elevation being 4466 m (Mount Bazardyuzu) and the lowest point - 27 m along the Caspian coastline. 18% of the territory is located below the ocean level; plains and lowlands consist of more than 39%; low and average hills (up to 2500 m) - 39.5%; high mountains (higher than 2500 m) - 3.5% of the republic's territory. The four main relief features are: the Greater Caucasus (part of the Main Caucasus range); the Lesser Caucasus (including the eastern part of the Lesser Caucasus range and Nakhichevan); the Kura- Araks depression and the Talysh Mountains together with the Lenkoran depression.

The southeast part of the Greater Caucasus is located on the territory of Azerbaijan. Both the southern and northern slopes of the Watershed range - the main range of the Greater Caucasus (the south-eastern slopes as far as Mount Bazardyuzu), as well as the eastern extremity of the northern side range of the Greater Caucasus, known as the Side Range, are located in Azerbaijan. This mountain range reaches its highest point at Shakh-Dag Peak (4252 m) and lowers to the southeast. The southern slopes of the Watershed Range are comparatively narrow - 15 to 18 km. They consist of tertiary and partially Cretaceous formations and are covered by alluvia and accumulations of ancient Caspian terrace.

The southern slopes of the Watershed range of the Greater Caucasus are high and include middle- elevation ranges, which drop off rather abruptly and form the Alazan and Agry-chay River Valleys. These slopes consist of a complicated system of folds, and their relief is dissected by transverse gorges and river valleys, flowing from the Watershed range to the southwest and thus representing a system of separate transverse watershed crests of mainly erosion origin. These are separated from one another by the gorges and valleys mentioned above.

The southern slopes of the Watershed range are considerably narrow - 15 to 25 km, with foothills in the southwest. This foothill line stretches

• Rivers of western and central Azerbaijan, belonging to the Kura basin.
• Rivers of north-east Azerbaijan, flowing directly into the Middle Caspian.
• Rivers of south-east Azerbaijan, flowing directly to the South Caspian.

The river network of Azerbaijan accounts for more than 8350 rivers of different sizes with an overall length of 33,665 km. All these rivers can be divided into five groups: the smallest of which is less than 25 km in length; small = 26-50 km; medium-length = 51-100 km; long = 101-500 km; and the longest, more than 500 km; their combined area being more than 85500 km2.

The Kura River is the biggest water way not only of Azerbaijan, but also of the whole Caucasus. Within the Republic's territory its length is about 900 km, with a total length of more than 1500 km.

The river sources are in Turkey, in the Gel hollow, at the northern foot of the Chaldir watershed at a height of 2741 m above sea level. The river basin covers a vast territory of central and eastern Transcaucasia, a part of Turkey and Iran and accounts for 188042 km2. According to the slopes and geomorphology the Kura River is divided into three areas: upper - from its source to the Borjom ravine inclusive (Georgia); middle - from the ravine to the mouth of the Alazani River; and lower - from the Alazani River (from the Mingachevir duct entrance) to the Kura mouth. The Kura River has very low banks, which are mainly formed by its own alluvia. Being a typical mountainous river in its upper reaches the Kura River performs considerable erosive work there and carries in its waters a great amount of suspended material, from coarse pebbles to fine sands. Because of fine and sandy slime the river water has a typical chocolate-grey and grey color. After the river flow is regulated by a cascade of dams (Shamhkor, Mingachevir), the main mass of alluvia accumulates in water reservoirs, where their weight reaches more than 1.5 million tons.

The second big water way of the Republic is the Araks River, the right tributary of the Kura River. Its source is in Turkey, on the slopes of the Bingel-dag ridges, at a height of 2600 m. Its length is 1072 km, the basin area - 101937 km2. Starting from the upper lands of Julfa and before reaching the plain area, it flows in a deep ravine, which in some places resembles a narrow canyon. In some places the banks of the river rise to a height of 50 meters and more. A high current velocity influences the character of alluvia carried by the river. Bottom alluvia in the southern area consists of pebbles and course sands, downstream the pebbles and sands are replaced by sandy, and closer to the mouth, by sandy-silt material. The Araks is one of the most turbid rivers in the world. On average it carries 2,5 g/l of suspended particles, which is a higher quantity than that contained in the Nile. According to the amount of Osolid' discharge the Araks together with the Kura also stands out among other rivers of the world: during one year the river bears about 18 million tons of suspended matter, and together with the Kura this value reaches 44-46 million tons. In addition the presence of dissolved salts is very typical of the Araks River, which is explained by climatic conditions of the region and the existence of soluble rocks in the basin of the Araks River.

Other rivers of the Republic can be divided into two distinct groups, mountain rivers and plains rivers. The mountain rivers start high in the mountains, at a height of 2000-3500 m, flow in deep ravines, have big slopes, form overfalls and waterfalls on their way, and when reaching the plain area form significant cones of drift, break up into numerous branches, bifurcate (go under ground), and very often do not have permanent river-beds (blind rivers), being lost in the steppe or becoming marsh-ridden. These rivers get their supply of water from rains, melted

water sources have been discovered in the Republic.

Mineral springs of the Republic are divided into three categories: carbonaceous, hydrocarbon, and hydrogen sulfide mineral springs. They are mainly located in mountainous parts and associated with certain tectonic areas representing 5 major districts:

• The tectonic area of the Lesser Caucasus system, where more than 30 groups of springs have been identified, the water of which is characterized by a considerable content of spontaneous carbon dioxide, alkali, hydrocarbons and iron ions. The most famous among them are: Istisu, Koturin and Minkend in Kurdistan; Shirlan and Lisogorskie in Nagorno-Karabakh; and Slavyanka in Gedabek.
   
• The area of the Greater Caucasus is characterized mainly by hydrogen sulfide water. According to the type, especially distinctive are hydrocarbon and hydrocarbon-chloride springs, the waters of which contain a considerable amount of sodium, potassium and magnesium salts. Among these springs the Elisuy group, Boom group, Girdimanchay springs, Pirsaatchay springs and others are of great interest. The Gonakhkend group, Kholtan group, Shirvan-Istisu, Khinalig, also the mineral springs of Divichi and the thermal springs of the Khudat region and others are the most important springs located on the northeastern slope. An interesting group of hydrogen sulfide waters in the Surakhany oil region of the Apsheron Peninsula are of particular value.
   
• The Talysh area occupies the extreme southern part of Azerbaijan. There are cold, warm and hot springs, territorially associated with 5 regions in this area: Astara (7 springs), Lenkoran (11), Masally (5), and others. The majority of springs are of sulfide-chloride-sodium-potassium type. Their temperature reaches 6 C. The content of iodine and bromine in these waters is extremely interesting.
   
• The Nakhchivan area is rich in mineral springs numbering more than 50. This area's mineral waters can be divided into 4 types according to their chemical composition, which is associated with certain geological conditions: bitter-salt (Kizil-Van, Djuga, Toroshin, and Dostin); salt and bitter- salt (arsenic springs Dari-Dag, Vaykhir and others); carbonaceous-lime (Batabat, Gumurg and others); and alkaline (Sirab, Nagadjin and others).
   
• The area of the Kura and Araks valleys is of great interest due to iodine brine springs with 35.65 g/l mineralization, while their iodine content equals 117 mg/l. There are also cold sulfurous springs in the Eldar steppe and Baba-Zanan, the waters of which are of the potassium-chloride type. A number of mineral springs are associated with mud volcanoes; their waters have a peculiar chemical and gas composition. The Naftalan medicinal oil field should be specially mentioned, which is unique in the world due to its balneological and physical-chemical properties.

An artificial irrigation system has been created in Azerbaijan, which includes 6 main, 3 collector channels and more than 50 water reservoirs, including 5 reservoirs with a volume of more than 1 million m3 each and different types of flow regulation, which are of great importance as water resources.

The climate of Azerbaijan is mainly influenced by its geographical position, relief and the Caspian Sea. The Greater Caucasus Mountains protect the major part of the territory from cold northern winds, and the Lesser Caucasus protects it from the south from the continental influence of the Armenian plateau. The Suram range absorbs the humidity of the Black Sea, and the Caspian Sea smoothes temperature drops and enriches the air with humidity and softens the influence of dry and warm winds blowing from the Central Asian deserts. However, the climate changes in higher areas and becomes very cold at a height of 3000-4000 m.

The highest air temperatures occur in the Kura-Araks Lowland and the Caspian coastline, from the Apsheron Peninsula to the Lenkoran Lowland. The average annual temperature here is 14-15? C. With the increase in the territory's height above the sea level in the mountains of the Greater Caucasus, as well as in the Talysh Mountains the temperature gradually decreases. The coldest month is January. However, in the Kura-Araks Lowland and on the Caspian coast winters are soft and warm. The average temperature is usually about 0? C. Only seldom during cold winters are there short-term and weak frosts in the lowland. In the mountains, winters are cold, snowy, and at the height above 3000 m winters are as cold as in the Arctic.

The warmest months are July and August. The average temperature in the lowlands reaches more than 25? C. In summer droughts occur in this region. The annual precipitation varies across the territory of Azerbaijan. In the Kura-Araks Lowland, on the Apsheron Peninsula and in Nakhchivan precipitation is 200-400 mm/year. In the Lesser Caucasus Mountains precipitation increases to 700- 800 mm/year, and on the slopes of the Greater Caucasus it increases to 1200-1300 mm/year. Precipitation mostly falls in the southern part of the Talysh mountains (up to 1700 mm) and in the south of the Lenkoran Lowland, providing a humid subtropical climate with luxuriant vegetation. There are great differences of precipitation across the Republic according to the months and seasons. In the east of the Republic the rainiest seasons are autumn and winter. In summer there is very little rain. In the west, precipitation falls primarily in spring and early summer, and in Nakhchivan primarily in late autumn and winter.

Precipitation considerably depends on winds, which are of different types in the Republic. Weak winds of monsoon character (the Caspian monsoon) dominate the Kura-Araks Lowland. Breezes are characteristic of the Caspian coastal area. The mountain-valley winds blow from the valleys to the mountains during the day, and from the mountains to the valleys at nights. The Apsheron Peninsula is distinguished by its strong northern winds, which are the cold 'khazri' or 'Baku- north' wind, and which blow throughout the year.

In addition, in certain parts of the Republic hot dry winds - 'fens' are observed. Fens occur mainly in winter in the Lesser Caucasus and on the north-east slopes of the Greater Caucasus. Hot dry winds are typical for the warm part of the year and most commonly occur in the lowland areas.

In Azerbaijan, depending o