EFFECTS OF CLIMATE CHANGE AND ARIDITY ON ERGENE RIVER BASIN WATER PRODUCTIVITY
International conferance on climate change and midle east past, present and future
20-23 november Istanbul
Prof. Dr. M. Doğan KANTARCI
Istanbul University, Faculty of Forestry, Department of Soil Science and Ecology
The annual mean temperature in the temperate zones in Northern Hemisphere has increased by 1.4C due to the changes in climate and it is expected that this increase will reach 2.5C in the near future. At present, the mean annual temperature increase of 1.4C leads to a net increase of around 2.0-2.5C during the hot months of summer; resulting in increased evaporation from the water and soil surfaces while amplifying the transpiration from the plant leaves. Atmospheric CO2has reached 376 ppm as of year 2000 leading to a green-house effect and melt-down of glaciers, increased frequency and magnitude of hurricanes in oceans. Meanwhile, high mountains in Turkey also lost glaciers, large lakes such as Lake Tuz and Lake Burdur shrank, and shallow lakes such as Lake Akşehir and Lake Eber vanished. Increased evapo-transpiration could further expand the impact of the increase in temperatures by leading to escalation of summer aridity, potential harms on forests and agricultural lands, detrimental effects on fruit trees and vineyards, and amplified need for irrigation
Ergene River basin, which is the major river basin in the central plains of Thrace region of Turkey, occupies 1 453 739 hectares. Agricultural land of this basin covers 73.4% and is a lowaltitude land (<300m). Mountainous area, which provides water for irrigation reaches ~1000m and together with the forests, covers 19.3% of land. Currently, irrigated agriculture is performed on 123 827.86 hectares and this has been projected to be increased by another 257 493 hectares. The required water for irrigation of this land is 988 780 000 m3 and will reach 1 914 590 000 m3 by the projected increase in irrigated agricultural land. Together with the water required for drinking and house-hold use, total amount of water resources should reach 2 149 600 000 m3 in near future.
Lüleburgaz Meteorological Station is located in the heart of Ergene River Basin and represents the most arid site. The analysis of the meteorological data from 1993 to 2005 has shown that the mean increase in temperature over the last 12 years was 1.2C compared to the means between 1929 and 1970. Meanwhile, the temperature increase during the same period in time in other urban centers in the basin such as Edirne was +0.3C, in Kırklareli +0.2C, in Çorlu +0.4C, and in Tekirdağ +0.4C. Annual precipitation changes by ±5%. Taken together, water production in Ergene Basin decreased by 765 million m3 between 1993 and 2005 compared to 1929-1970 and annual water deficit reached 798 million m3.
The majority of deficit in water is observed in and around agricultural lands (726 million m3). These data suggest that the Ergene Basin is going through a very severe aridity and the model represented by Ergene Basin in this study demonstrates the dangerous transition of low agricultural lands to arid areas as a result of climate changes