Tuğba CANGEL (1) (2), Pelin KARAÇAY(2)
Kocaeli University, Hereke Ö.İ.Uzunyol Vocational School, the Gulf-Kocaeli, Turkey. (1) Istanbul Technical University, Civil Engineering Faculty, Division of Hydraulics, Maslak, Turkey.
In many regions of the world, increasing and decreasing trends are observed on volume of river flows. Climate change has different effects in different regions. As an effect of the change of rainfall, river flows and groundwater levels are also changed. However climate change has effects on water resources, the demand for water is also increasing by the increasing population and economic development.
Istanbul as the biggest metropolis in Turkey has a big water demand. Because of the population and the climate change, water resources’ planners decided to find alternative water resources for Istanbul. Authorities decided to transport water from near basins. A big project called “Big Melen and Istanbul Water Supply System” is started in 2000. In this project water is transported from Adapazarı which is 155 km far from Istanbul.
In this study, similarity between Istanbul’s and Big Melen River’s rainfall was investigated. First of all, “Run Analysis” was applied on rainfall data of Istanbul for the purpose of obtaining the longest drought periods for different thresholds and the rainfall needed in these times. After that, these needed rainfall amounts with the rainfall in Big Melen River was compared. Finally, “Mann-Kendall Test” was applied on both of the cities’ stations to find out if there is a trend.
As a result, by defining these data as a probability density function, the longest periods of the drought and the rainfall needed on these times were calculated. The trends (increasing and decreasing) were seen in these both regions. These results are in agreement with the other drought and trend studies in these regions.
Key words: Drought, Water...