Köyceğiz, Cihangir
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Köyceğiz, C. Koyceğiz, Cihangir Koycegiz, Cihangir Koycegiz, C.
Job Title
Email Address
ckoycegiz@ktun.edu.tr
Main Affiliation
02.02. Department of Civil Engineering
Status
Current Staff
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ORCID ID
Scopus Author ID
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID
Research Topics
Domains
Physical Sciences
Fields
Environmental Science
Subfields
Global and Planetary ChangeWater Science and TechnologyEnvironmental Engineering
Specific Research Areas
Hydrology and Drought Analysis
Hydrology and Watershed Management Studies
Climate variability and models
Hydrological Forecasting Using AI
Plant Water Relations and Carbon Dynamics
Sustainable Development Goals
1NO POVERTY
0
Research Products
2ZERO HUNGER
6
Research Products
3GOOD HEALTH AND WELL-BEING
0
Research Products
4QUALITY EDUCATION
0
Research Products
5GENDER EQUALITY
0
Research Products
6CLEAN WATER AND SANITATION
9
Research Products
7AFFORDABLE AND CLEAN ENERGY
0
Research Products
8DECENT WORK AND ECONOMIC GROWTH
1
Research Products
9INDUSTRY, INNOVATION AND INFRASTRUCTURE
1
Research Products
10REDUCED INEQUALITIES
0
Research Products
11SUSTAINABLE CITIES AND COMMUNITIES
5
Research Products
12RESPONSIBLE CONSUMPTION AND PRODUCTION
0
Research Products
13CLIMATE ACTION
15
Research Products
14LIFE BELOW WATER
0
Research Products
15LIFE ON LAND
1
Research Products
16PEACE, JUSTICE AND STRONG INSTITUTIONS
0
Research Products
17PARTNERSHIPS FOR THE GOALS
1
Research Products
Documents
13
Citations
157
h-index
7
Documents
16
Citations
169
Publication Collaboration
| Affiliation Name | Count |
|---|---|
| Konya Technical University | 23 |
| General Directorate of Highways | 2 |
| Istanbul Technical University | 2 |
| Shanghai Institute for Science of Science | 1 |
| Necmettin Erbakan University | 1 |
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Data obtained from OpenAlex
Scholarly Output
54
Articles
23
Views / Downloads
140/301
Supervised MSc Theses
0
Supervised PhD Theses
1
WoS Citation Count
167
Scopus Citation Count
165
Patents
0
Projects
0
WoS Citations per Publication
3.09
Scopus Citations per Publication
3.06
Open Access Source
33
Supervised Theses
1
| Journal | Count |
|---|---|
| Water Supply | 2 |
| Journal of Water and Climate Change | 2 |
| Environmental Earth Sciences | 1 |
| European Journal of Science and Technology | 1 |
| Konya Journal of Engineering Sciences | 1 |
Current Page: 1 / 5
Scopus Quartile Distribution
Competency Cloud
54 results
Scholarly Output Search Results
Now showing 1 - 10 of 54
Conference Object Temporal Analysis of Land Cover/Use Change in a Semi-Arid Basin With Modis Data(2021) Köyceğiz, Cihangir; Büyükyıldız, Meral; Şen, Ömer LütfiWith the increase in population, industrialization, agricultural activities and urbanization are increasing. In addition to this situation, when the effect of climate change is taken into account, the land cover changes quite rapidly. In this study, the change of land cover/use over time in Konya Closed Basin (KCB), which is a semiarid closed basin, was investigated. Land cover/use data were obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS). The International Geosphere-Biosphere Program (IGBP) land cover classification scheme was preferred. The study was carried out for the period 2001-2018. The spatial resolution of the data provided annually is 500 m. Land cover/use data were cut according to KCB boundaries. Temporal analysis was performed by calculating the total area of each class belonging to the IGBP classification within the KCB for the 2001-2018 period. According to the results, the classes with the most area in the KCB are grasslands and croplands. Grasslands have decreased significantly over time, while croplands have increased.Article Investigation of Precipitation and Extreme Indices Spatiotemporal Variability in Seyhan Basin, Turkey [2](Iwa Publishing, 2022) Köyceğiz, Cihangir; Büyükyıldız, MeralSpatial and temporal variability of precipitation increases with the effect of climate change. In this study, the Seyhan Basin has been deter-mined as the study area. It is aimed to examine the spatiotemporal variability of precipitation and extreme precipitation indices in the SeyhanBasin. For this purpose, the period 1970-2019 was divided into three periods with the change point detection methods (Pettitt, BuishandRank and Standard Normal Homogeneity Test). Trends were examined by applying Modified Mann Kendall and Spearman's Rho tests to pre-cipitation and extreme indices for all periods and sub-periods. Then, temporal and spatial analyses of extreme indices were performed.According to the results obtained, there is no precipitation homogeneity throughout the basin. While the threat of drought comes to thefore with the decrease in rainy days and precipitation in the north, the risk offlooding is effective with the increase in precipitation intensityin the southConference Object Hydrometeorological Trend Analysis For 1990 2017 A Case Study Sarız Turkey(2021) Köyceğiz, Cihangir; Büyükyıldız, MeralClimate change significantly affects the variability of hydro-meteorological parameters. Within the scope of this study, a trend analysis study was conducted for Sarız district in the Seyhan basin. Monthly data for the period 1990- 2017 were provided for the parameters of flow, temperature, precipitation, relative humidity and wind speed. In the study, Mann Kendall (MK), Spearman's Rho (SRho) and Innovative Şen Trend (IŞT) methods were used for trend analysis. According to the results obtained, a significant trend in precipitation and temperature could not be determined. While there was a significantly decreasing trend in flow and wind speed, a significant increasing trend was revealed for relative humidity.Article Citation - WoS: 7Comparison of Innovative Trend Analysis Methods for Hydrometeorological Parameters in the Karasu Sub-Basin(Konya Teknik Univ, 2023-07-22) Köyceğiz, Cihangir; Büyükyıldız, MeralTürkiye, which has a complex climate structure, is shown among the countries that will be most affected by climate change with the effect of global warming. These effects will differ in different regions due to their topographic structure, location, and orographic characteristics. Trend analyzes are used to determine the direction and magnitude of this variability. In this study, trend analysis was carried out by using hydrometeorological data obtained from streamflow and meteorology stations located in the Karasu Sub-Basin located in the Euphrates-Tigris Basin. Three innovative trend methods, namely the Şen-Innovative Trend Analysis, Onyutha Trend Test, Combination of Wilcoxon Test and Scatter Diagram trend tests, were used together with the classical Mann-Kendall method in the monthly scale analysis of hydrometeorological data of the 1979-2020 period. Both graphical and statistical trend analysis can be done with innovative methods. The results obtained in the study, in which trend analyses were evaluated at the α=0.05 significance level, reveal significant and insignificant decreasing trends in the parameters of mean streamflow, maximum precipitation, total precipitation, mean and minimum relative humidity. Significant and insignificant increasing trends were determined in the maximum, minimum, and mean temperature, maximum relative humidity, and mean wind speed data. The trends obtained in the methods used in general are consistent with each other. The findings of this study could lead to a better knowledge of the region's hydrology and contribute sustainable water management. The trend analysis methods used in the study are thought to be quite helpful in the analysis of hydro-meteorological time series.Conference Object Estimating Fractal Dimension With Shifted Box-Counting Analysis Method a Case Study in Seyhan Basin(2019) Köyceğiz, Cihangir; Büyükyıldız, MeralFractal Geometry is often used to understand and interpret complex geometries in nature. Basic geometric shapes are not successful in defining objects in nature (mountains, trees, coastlines, etc.). Therefore, the understanding of the shapes that develop due to the repetition of complexity gives the opportunity to have detailed information about their formation. For this reason, fractal dimension analysis helps to establish a relationship by providing information about the complexity levels of unrelated shapes. Shifted Box-Counting Analysis Method is one of the methods used in fractal dimension analysis. In this study, fractal dimension analysis was performed for daily flow data (2017 year) of E18A028 station in Seyhan Basin. The applicability of Shifted Box-Counting Analysis Method on the flow data was tested and the results obtained were interpreted. As a result of the study, it was found that there is a linear relationship for different threshold values, up to ε=180 days. Threshold values are determined as 0, 0.5, 1, 1.5 and 2 times of 2017 average flow values.Article Citation - WoS: 21Citation - Scopus: 19Applications of Innovative Polygon Trend Analysis (ipta) and Trend Polygon Star Concept (tpsc) Methods for the Variability of Precipitation in Konya Closed Basin (turkey)(Springer Wien, 2023-12-13) Koyceğiz, Cihangir; Buyukyıldız, MeralClimate change-induced precipitation unpredictability has disastrous consequences for closed basins with sensitive hydrological equilibrium. Identifying changes and trends in precipitation characteristics in such catchments is an important step towards minimizing potential disasters. This study explores the precipitation variability of the Konya Closed Basin (Turkey), an over-exploited semi-arid basin. For this purpose, monthly precipitation data for the period 1971-2020 (50 years) of 11 meteorological observation gauges operated by the Turkish State Meteorological Service in the basin were utilized. Precipitation data were examined using two graphical innovative trend methods namely innovative polygon trend analysis (IPTA) and trend polygon star concept (TPSC) approaches. With these methods, periodic features in monthly precipitation data and trend transitions between months can be interpreted visually and linguistically. IPTA and TPSC methods were applied separately to both arithmetic mean data and standard deviation for each month's precipitation data of 11 stations. A general increasing trend in precipitation was obtained in most of the months for the stations used in the IPTA application. Most of the TPSC arrows, which were distributed throughout all four regions for both the arithmetic mean and standard deviation, were in the I and III regions. Based on the TPSC graphs, the longest transition arrows between two consecutives occurred in the first months of autumn (highly increasing) and summer (highly decreasing) in most of the stations. The results of this study are of great importance for the policies to be sustained regarding the ongoing climate change in the agricultural sector in KCB, which is both a water scarce basin and a region with intensive agricultural activities.Article Citation - WoS: 5Citation - Scopus: 5Performance of Data-Driven Models Based on Seasonal-Trend Decomposition for Streamflow Forecasting in Different Climate Regions of Türkiye(Pergamon-Elsevier Science Ltd, 2024-12-01) Yılmaz, Volkan; Koyceğiz, Cihangir; Buyukyıldız, MeralThis study examines the ability of different methods such as machine learning, ensemble models, and meta- heuristic algorithms to predict streamflow. For this purpose, five different methods were used: Artificial Neural Networks (ANN), Support Vector Machines (SVM), Adaptive Boosting, Particle Swarm Optimization (PSO), and BSPSO hybridized with Band Similarity (BS), a relatively new method. Additionally, the impact of seasonality and trend components obtained through Seasonal-Trend decomposition using LOESS (locally weighted regression and scatterplot smoothing) (STL) data decomposition technique on prediction success was investigated. Models were developed in three basins with three different climate characteristics: continental, temperate, and arid. The results showed higher prediction success in input structures including seasonality and trend components. While higher prediction successes were achieved at Karasu in the continental climate class and Kork & uuml;n in the temperate climate class, model performances were lower at K & uuml;& ccedil;& uuml;k Muhsine in the arid climate class. While the most successful modeling for K & uuml;& ccedil;& uuml;k Muhsine (NSE = 0.696) and Karasu stations (NSE = 0.811) was obtained with the BSPSO method, the SVM method produced the best results for Kork & uuml;n station (NSE = 0.818). Moreover, BSPSO models outperformed the prediction successes obtained by using PSO alone for each scenario at all three stations. The percentages of the BSPSO method improving the prediction success according to the NSE metric ranged from 3.53% to 17.40% at K & uuml;& ccedil;& uuml;k Muhsine, 0.49%-3.72% at Karasu, and 1.24%-7.24% at Kork & uuml;n. The competitive results achieved by the BSPSO approach compared to ANN and SVM in flow prediction constitute the innovative aspect of this study.Conference Object Analysis of Temporal Rainfall Variability Wıth Multiple Change Point Detection Methods: a Case Study Rize, Türkiye(2023) Köyceğiz, CihangirClimate change significantly affects each part of the hydrological cycle. Precipitation is one of these components. Türkiye is surrounded by seas on three sides and has a sensitive location where climate change is felt intensely. Rize province, which receives the highest rainfall in Türkiye and has a mountainous topography, was determined as the study area. In this study, the temporal variability of monthly total precipitation obtained from Rize meteorological station was analyzed. The study period was 1934-2020. Multiple change point detection methods were used to determine the sub-periods. These are A Pruned Exact Linear Time (PELT) and Dynamic Programming (DP) methods. 1951 and 1975 were determined as the change years. Depending on the change years, the monthly total precipitation time series is divided into three temporal sub-periods. Basic statistical values (maximum and average), rainfall anomaly, and long-term seasonal average tools were used to analyze rainfall variability. Accordingly, high rainfall averages were observed in the first period and low rainfall averages were observed in the second period. Average values were obtained in the third period compared to the other periods. The lowest rainfall occurred in April and May for all periods. The slopes in the linear regression equations of the sub-periods are all positive.Article Rainfall Trends in the Transboundary Euphrates-Tigris River Basin(Springer, 2025-08-01) Acar, Ramazan; Akbas, Ergun; Koycegiz, Cihangir; Esit, MusaClimate change and anthropogenic factors have a significant impact on rainfall variability. In this study, the trends of monthly total precipitation in the transboundary Euphrates-Tigris River Basin (ETRB), where these effects are intensely observed, were analyzed by trend analysis methods with various perspectives. After decomposing the monthly total rainfall series (1964-2021) obtained from 18 stations representing 12 months of the year, statistical (Mann-Kendall, Wilcoxon, Onyutha), graphical (Innovative Polygon Trend Analysis, IPTA), Trend Polygon Star Concept, TPSC), sub-trend (Onyutha) and spatial trend analyses were performed. Based on the results, it was observed that rainfall in the basin has significant spatial and temporal variability. A monotonic strong decreasing trend was observed in cold months with high rainfall, while an increasing trend was observed in warm months with low rainfall. Extreme rainfall during the winter months has shifted towards the end of the cold months. Graphical and statistical analysis methods have shown strong consistency in identifying monotonic trends. However, the implementation of various methods provides specific insight (transition, sub-trend, etc.) into the temporal and spatial variability of rainfall. Sub-trend analysis shows that rainfall characteristics in the cold months show a significant change before and after the 1990-2000 period. In warmer months, this variability is significantly affected by local and global driving forces. The central and marginal parts of the ETRB have different rainfall characteristics. During cold months, the monotonic trend (decreasing) is significant in the central part. In warm months, the monotonic trend (increasing) increases its intensity in the eastern parts.Article An Investigation of the Variability of Short-Term Drought With SPEI-Based Severity, Duration and Magnitude Parameters in a Transboundary Basin(Springer Basel AG, 2026-01-22) Akbas, Ergun; Acar, Ramazan; Esit, Musa; Koycegiz, CihangirClimate change-induced variability in the water budget leads to significant drought events. In this study, severity, duration, and magnitude parameters obtained from 1-month and 3-month series of the Standardized Precipitation Evapotranspiration Index (SPEI) were used to investigate short-term drought from different perspectives. The lower part of the Euphrates-Tigris Basin, which is a transboundary basin, was preferred as the study area within the borders of T & uuml;rkiye. In this study, monthly total precipitation and monthly mean temperature data for the period 1963-2021 were used. Both graphical (& Scedil;en Innovative Trend Analysis) and statistical (Mann-Kendall, Spearman's Rho, Sen's Slope Estimator) trend analysis methods were applied to detect, categorize, and analyze the variability of drought. The Combination of Wilcoxon Test and Scatter Diagram (CWTSD) method, which offers both graphical and statistical trend analysis capabilities, was preferred to enhance consistency and facilitate comparison of results. According to the findings, more severe droughts are observed in the eastern part of the basin compared to the western part. Across the basin, severity and magnitude are decreasing, while duration is increasing. The increase in duration indicates that droughts are shifting from short-term to long-term periods. This situation is of great importance in terms of planning agricultural strategies.