Of the province area, 53.4% is covered by mountains, 32.9% is covered by plateaus and13.7% is covered with plains. Elevations in Van Basin range between 1.650–2.600m. There are Kavuşşahap Mountains in the south of Lake Van and Erek Mountain continues in mountain range in the east. The heights of Pir Rashit, Isa Bey, Erk, Sudis,Baset, Ispiriz, Hirabit and Kars Mountains are among the mountain ranges that peak around Iran territory and slope down towards the lake. Various mountains in the south and east of Lake Van was exposed to tectonic on dulations and cracks in various geological periods, causing the ancient layers to crop out to the surface².
As a result of the eruption of Mount Nemrut and the lava spreading to form a wide set, the Muş-Van pits were filled and divided into two areas. Water accumulated in the Van Basin which lost its connection to Murat River and formed Lake Van. Van, Erciş, Arin, Adilcevaz and Ahlat plains are located around Lake Van. There are lakes of various sizes around Lake Van. Aygır Lake and Nemrut Lake are the crater lakes with freshwater. Arın Lake was separated from Lake Van by an alluvion wall. Erçek Lake, which is located in the east of Lake Van, was formed as a result of the tectonic movement.
Van Lake roughly resembles a right-angled triangle. The hypotenuse of the triangle corresponds to the widest part of the lake. From its southeast to the north east it is located approximately between the geographical latitudes 38º - 15’ and 38º– 58’. Lake Van is located between the provinces of Van and Bitlis⁴.
The surface area of the lake is 3,713 km² and the its lake altitude is 1647 m from sea-level. Lake Van is supplied by many rivers around it. The significant rivers are; Zilan Stream, Bend-i Mahi Stream, Hosap Stream, Karasu Stream, DeliStream, Arpak Stream and Memedik Stream⁵.
The water level of Lake Van shows some fluctuations from 3 to 4 m, apart from the seasonal changes. According to the available data, it reached its maximum water levels between 1810–1850 and 1880–1892. On the other hand, between 1852 and1892, the water level was very low. There are Aghtamar, Adır, Üçak and Kuşislands in the lake. The length of the lake from east to west is 125 km and its width is 65 km. The average depth of the lake is 100 m. and its deepest point is 451 m.6
The settlements around the lake have a continental climate. The average temperature varies according to latitude and altitude. The average annual temperature is 8.8°C inVan and in 10°C Ahlat, Gevaş and Adilcevaz.7
Although Lake Van Basin has a rich vegetation, the mountains of the region are without trees in general. Steppe vegetation is prominent in the region⁸.
¹ Erinç-Öngör, a.g.e, 100–103.
² Sırrı Erinç, Doğu Anadolu Coğrafyası, İstanbul, 1953, 67 v.d.
³ Turizm ve Tanıtma Bakanlığı,Van Gölü Çevresi Turizm ve Rekreasyon Master Planı, Ankara, 1990, 16. v.d.; Erinç, a.g.e.,60-65.
⁴ Ahmet Ardel, “Van Gölü”, Beşinci Üniversite Haftası Van, İstanbul, 1944, 205, v.d.
⁵ Yeni Rehber Ansk., C. XX., 42, v.d.
⁶ Sırrı Erinç, a. g. e., 70. v. d.; Van Kütüğü, Ankara, 1993, 5-20.
⁷ Turizm ve Tanıtma Bakanlığı, a.g.e., 26-32.
⁸ Yeni Rehber Ansk., C.XX., 48.