Lake level responses to semi-arid climate and their social impacts in Turkey
by
Nizamettin Kazancı
Geological Engineering Department, Ankara University, 06100 Besevler, Ankara, Turkey
Coauthors: Ediz Kırman, Fatih Uysal and Sonay Boyraz

Turkey which is a country in the Middle East is subjected to a Mediterranean-type, semi-arid climate typified by wet and cold winter and hot and dry summer. However, local morphologies cause local climatic differences, e.g. mountainous Turkish coasts of the Black Sea and the Mediterranean Sea take much more precipitation than the central Anatolian plateau even the whole country lives four seasons. Apart from seasonal and morphological changes, short- and long-term droughts and fluvial and lacustrine floods based on lack and extreme presence of precipitation respectively are not rare events in this country. Particularly shallow lakes are fairly sensitive to annual water budget there and consequently settlements nearby lakes have been strongly affected by oscillations of water level since archaeological times. The economic and social consequences resulted by rising of lake levels are sudden and drastic but those by falling of water levels are long-lasted and dramatic in Turkey. Here are the two examples of them; many people from the town of Burdur in the southwest-central Anatolia were sent to Germany as worker in 1966-68, because farmlands of these villagers were flooded by rising water of Lake Burdur. In 1994-95 the water level of Lake Van in the eastern Anatolia increased as much as 1.5 m invading buildings and coastal infrastructures and many people had to live in temporary houses and tents for months. In contrast, falling of the lake level has been thought as a chance by local people previously since new lands were provided from the lake. Recently farmlands around lakes have been left fallow when water levels decreased significantly, however there are also other reasons for migration. The Anatolian lakes particularly fresh water ones were also important in the past as the country is a land bridge for human movements till Late Pleistocene between Asia and Europe. The most ancient archaeological sites, Çatalhöyük near the palaeo Konya lake and Hacılar near Lake Burdur are two typical examples for “near lake settlement”. Our sedimentological data showed that the Hacılar settlement was left due to salinisation of the water of Lake Burdur in the early Mid Holocene.

Turkish lakes show a great variety of surface area, origin of lake depression, water type and depth. For example Lake Van is the largest soda lake of the globe with a water surface of 3740 km2 and Tuz Lake with area of 1640 km2 is the largest evaporite lake of Europe. Water surface area of nine lakes are between 650 km2 - 100 km2, seven lakes 90-50 km2 and fifteen lakes 40-10 km2. The majority of these lakes are shallow and their water depths are below 10 m. Water level oscillations of the fresh water lakes reflect well seasonality but they are not typical for moderate or long-term changes due to natural outlets or man-made regulations. The closed lakes have cyclic oscillations even if they are not regular. In such various lakes, both number of cycles in the calendar and the duration of each cycle in last half century were not consistent and correlative. However local changes in the precipitation and temperature have typically impacted lakes after a lag of 10-15 months in the whole country. This lag provides a chance for local people to search measures against to drought or floods which are resulted by lake level changes.

Date received: January 18, 2005

Copyright © 2005 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # caod-70.