Öz
Kızılırmak which drairıs an area about 78.180
km* 2 is one o f the most importnt rivers o f Turkey. Its mean
annual discharge is 187 m3/sec. (at înözü) The climate
conditions and topographical peculiarities o f the catchment
area play a very important role on the flov) o f the river. The
existence o f gypsum formations around Sivas and Çankırı and
evaporation during summer causes a loss o f the river flow. The
use o f surface water fo r irrigation usually requires great
guantities o f water.
During the mnter, the flow o f the river decreases because o f
snowfall and low temperatures. İn the spring the flo v increases
due to melting snow, high temperatures, and rainfall. The
varying amount rainfall and runoff affects the different
tributaries (Gökırmak, Devrez, Deliceırmak) to form a complex
regime causing a flux in the annual discharge.
The rainfall över the river basin ranges from 294 mm. to över
750 mm. and its heaviest distributton is centered about
December-January and April-May, Runoff is concentrated
betv/een the same periods. This varying rainfall pattem is
reflected in the seasonal distribution o f runoff from the
different tributaries.
The natural vegetation throughout the basin is largely affected
by cilamet characteristics, thus antropogenic steppes and
steppe vegetation are dominant in the middle and upper
catchment areas.