Browsing by Author "Yenigun, K."

Now showing 1 - 2 of 2

Hydrological low flow and overlapped trend analysis for drought assessment in Western Black Sea Basin
(2024.01.01) Aydin, H.; Yenigun, K.; Isinkaralar, O.; Isinkaralar, K.
Drought is a major disaster known for hundreds of years, but its impact has recently increased due to climate crisis, making it a common concern of the whole society worldwide. There is no clear definition of drought, as many disciplines evaluate it from different perspectives. Utilizing water and reducing the impact of drought are directly related issues. It is essential to determine our rivers' future conditions, reveal the effects of possible changes on drought, and take the necessary precautions against them in advance to prevent possible economic and social crises. In this study, among the 126 flow observation stations whose records were kept in the Western Black Sea Region, 26 observation stations with suitable data between 1984 and 2020 were selected to evaluate the drought effect. The Mann-Kendall Rank Correlation test was used to determine the starting years of the detected trends. In order to detect trends, the Spearman's Rho (SR) test, the Mann-Kendall (MK) test, Sen's Trend Slope (TS) method, & Scedil;en's Innovative Trend Analysis (ITA) test, and, Mann-Kendall Order Correlation (MKOC) test. According to all analysis methods, decreasing trends were detected at stations D13A014, D1A032, and E13A036. In addition, MKOC test results showed the trend starting in 2001 was at D13A014, 1990 at D13A032, and 1990 at E13A036. However, no significant trend was detected in minimum flows at other stations. It would be appropriate to make such studies on the evaluation of water resources a country policy and to conduct studies on the direction and value of drought in the basin in the future using trend analysis or other methods.
Modeling flood hazard impacts using GIS-based HEC-RAS technique towards climate risk in Şanlıurfa, Türkiye
(2024.01.01) Guven, D.S.; Yenigun, K.; Isinkaralar, O.; Isinkaralar, K.
Climate change triggering extreme weather events and the fact that settlements are at risk have made flood disaster analysis a more critical issue. The economic, social, and environmental risk areas of Karakoyun, S & imath;rr & imath;n, and Cavsak streams located in & Scedil;anl & imath;urfa city center were determined using flood risk analysis. Thus, it aims to determine low, medium, high, and very high probability flood areas in the area, to collect the necessary data for establishing early warning systems and precaution packages, and to create an infrastructure for similar studies. While performing the risk analysis, we used Q5, Q10, Q25, Q50, Q100, Q500, and Q1000 flood recurrence flows of the mentioned streams. Many criteria were considered, including stream routes, natural water retention capacities, land topography, and general hydrological and geological features. In the light of the data provided, digital elevation models of the streams were created in the ArcGIS 10.3 program, all information was transferred to the hydraulic modeling HEC-RAS 5.07 software, and risky areas were determined by performing a 1D flood analysis. At Q2 flow rate, Karakoyun has 7.09, Cavsak 2.67, S & imath;rr & imath;n 6.603 m3 s- 1, and at Q1000 flow rate, Karakoyun has 167.550, Cavsak 90.77, S & imath;rr & imath;n 151.298 m3 s- 1 hydrograph peak values. As a result of the analysis, it was appointed that there was a flood risk in many parts of the stream sections. The flooding phenomenon has happened to be one of the most devastating floods for economic and environmental damages that occurred in & Scedil;anl & imath;urfa City in 2023. People lost their lives, and many were injured during flooding; also, the urban economy affected nearly $15 million in the region. The risk of residences, shopping malls, and commercial areas in the city is revealed spatially.