Detecting seasonal cycle shift on streamflow over Turkey by using multivariate statistical methods

Gunes, Mehmet Samil
Gökalp Yavuz, Fulya
Yildiz, Dursun
Climate change analysis includes the study of several types of variables such as temperature, precipitation, carbon emission, and streamflow. In this study, we focus on basin hydrology and, in particular, on streamflow values. They are geographic and climatologic indicators utilized in the study of basins. We analyze these values to better understand monthly and seasonal change over a 40-year period for all basins in Turkey. Our study differs from others by applying multivariate analysis into the streamflow data implementations rather than on trend, frequency, and/or distribution-based analysis. The characteristics of basins and climate change effects are visualized and examined with monthly data by using cluster analysis, multidimensional scaling, and gCLUTO (graphical Clustering Toolkit). As a result, we classify months as lowflow and high-flow periods. Multidimensional scaling proves that there is a clockwise movement of months from one decade to the next, which is the indicator of seasonal shift. Finally, the gCLUTO tool is utilized in a novel way in the hydrology field by revealing the seasonal change and visualizing the current changing structure of streamflow.


The importance of allochthonous organic matter quality when investigating pulse disturbance events in freshwater lakes: a mesocosm experiment
Caldero-Pascual, Maria; Yildiz, Dilvin; Yalçın, Gülce; Metin, Melisa; Yetim, Sinem; Fiorentin, Claudia; Andersen, Mikkel Rene; Jennings, Eleanor; Jeppesen, Erik; Ger, Kemal Ali; Beklioğlu, Meryem; McCarthy, Valerie (2021-11-01)
Extreme precipitation is occurring with greater frequency and intensity as a result of climate change. Such events boost the transport of allochthonous organic matter (allo-OM) to freshwater ecosystems, yet little is known about the impacts on dissolved organic matter (DOM) quality and seston elemental stoichiometry, especially for lakes in warm climates. A mesocosm experiment located in a Turkish freshwater lake was designed to simulate a pulse event leading to increased inputs of allo-OM by examining the ...
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Fluctuations in temperature and precipitation amounts due to climate change influence recharge rate of groundwater. Any variations in the amount of precipitation recharge and artificial discharge directly affect groundwater level and so the salt water intrusion rate in the aquifers, which are in contact with sea water. The purpose of this study is to determine the overall historical precipitation recharge trend in Selçuk sub-basin and to detect whether there is a decrease or increase in recharge amounts due...
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Quantitative precipitation estimates are obtained with more uncertainty under the influence of changing climate variability and complex topography from numerical weather prediction (NWP) models. On the other hand, hydrologic model simulations depend heavily on the availability of reliable precipitation estimates. Difficulties in estimating precipitation impose an important limitation on the possibility and reliability of hydrologic forecasting and early warning systems. This study examines the performance o...
Identifying impacts of climate change on water resources using CMIP6 simulations: Havran basin case
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This study aims to investigate climate change effect on precipitation, temperature and discharge in Havran basin which has thousands of decares of agricultural lands. Changes in precipitation and temperature were determined using 10 global climate models (GCMs) for total precipitation and 13 GCMs for average temperature from Coupled Model Intercomparison Project Phase 6 (CMIP6) for the historical period, SSP2-4.5 (moderate-case) and SSP5-8.5 (worst-case) scenarios. Both station observations and ERA5-Land re...
Investigating the effects of climate change on the surface runoff potential over Kızılırmak basin
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The aim of this study is to analyze the expected change in the surface runoff potential that will occur due to climate change in the Kızılırmak Basin until 2100. HBV hydrological model was run in this study to investigate the expected change in 3 sub-basins (SB 1535, SB 1541, and SB 1545) of Kızılırmak Basin. Total of 56 CMIP5-based GCM/RCM daily model datasets, downloaded from CORDEX EUR-11 at 0.110 spatial resolution and reflect RCP 8.5 emission scenario, were utilized. Among these model datasets, 10 of t...
Citation Formats
D. YILDIZ, M. S. Gunes, F. Gökalp Yavuz, and D. Yildiz, “Detecting seasonal cycle shift on streamflow over Turkey by using multivariate statistical methods,” THEORETICAL AND APPLIED CLIMATOLOGY, pp. 1143–1161, 2018, Accessed: 00, 2020. [Online]. Available: