Sürdürülebilir Kalkınma Amaçları

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• MakaleYalnız künye2026/r/gumushane/12204
  Monthly precipitation trends in Türkiye under complex topography and varying climate: a seasonal Mann–Kendall and innovative polygon trend framework

  Şan, Murat; Nacar, Sinan; Kankal, Murat

  The impacts of climate change are increasingly sensible, and Türkiye with its varied topography and diverse climate types is particularly exposed to these shifts. Understanding how precipitation patterns are evolving across its regions is therefore critical. While trend analysis is a widely used tool for this purpose, conventional approaches overlook periodicity, limiting their practical value for water resource management and irrigated agriculture. Therefore, this study aims to examine seasonal trends in long-term (1969–2020) monthly total precipitation in Türkiye, in which each calendar month is treated as a separate season in the sense of seasonal trend-analysis terminology, accounting for altitude, slope, geographical region, and Köppen climate classification. For this purpose, the seasonal Mann-Kendall (SMK) test and the innovative polygon trend Wilcoxon significance test (IPWST), a relatively new graphical method, were used, and the two approaches were comparatively evaluated. According to the study’s results, the rate of increase in coastal areas, specifically the Aegean and Black Seas, exceeds the rate of decrease. In contrast, the reverse is observed in inland and eastern regions. The IPTWST method indicates a more pronounced increasing trend in the Marmara and Mediterranean regions. Furthermore, although analogous trends are observed at lower slopes and altitudes, analyses indicate that these trends are more strongly related to altitude, with the rate of increase decreasing as altitude increases. The IPTWST identified significant or weak trend signals at a larger number of stations than the SMK, particularly in relation to altitude. Nationwide, the two methods revealed significant increases of 7% and decreases of 6%, respectively; this pattern was supported by statistical tests, reflecting the variability of regional climates and the influence of topographic factors on trend analysis.

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• MakaleYalnız künye2025/r/gumushane/12374
  Analysis of drought in upper Moulouya Basin (Morocco): a combination of drought indices, classic and innovative trend tests

  Qadem, Zohair; Hadria, Rachid; Ettaqy, Abderrahim; Kankal, Murat; Şan, Murat; Nacar, Sinan

  This study aimed to examine the temporal and spatial variation of drought in the upper Moulouya Basin, Morocco’s arid and semi-arid region. For this purpose, the Standardized Precipitation Index (SPI) was calculated at various time scales (3, 6, 12, and 24 months) using precipitation data collected from eight stations between 1977 and 2019. The data trends were analysed by classical modified Mann-Kendall (MMK) and Innovative Trend Analysis (ITA). Severe drought events were identified in the 1980s, and 1998–2000, while exceptionally wet years were recorded in periods 1996–1997 and 2008–2012. SPI trend analyses revealed a holistic increase on almost all timescales and at all stations. The increase was found to be higher in more extended time scales. Except for a few stations, SPI values in dry, normal, and wet classes of ITA method increased in the second half (1998–2019) compared to the first half (1978–1997). The ITA method detected different trends for different classes at two stations compared to the MMK method. This situation revealed the importance of analysing the trends of different methods in drought studies. These results are essential for water resources management and adaptation to climate change in arid and semi-arid zones.

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• MakaleYalnız künye2021/r/gumushane/14969
  Innovative and polygonal trend analyses applications for rainfall data in Vietnam

  Şan, Murat; Akçay, Fatma; Linh, Nguyen Thi Thuy; Kankal, Murat; Pham, Quoc Bao

  It is a known fact that the size, frequency, and spatial variability of hydrometeorological variables will irregularly increase under the impact of climate change. Among the hydrometeorological variables, rainfall is one of the most important. Trend analysis is one of the most effective methods of observing the effects of climate change on rainfall. Recently, new graphical methods have been proposed as an alternative to classical trend analysis methods. Innovative Polygon Trend Analysis (IPTA), which evolved from Innovative Trend Analysis (ITA), is currently one of the proposed methods and it does not contain any assumptions. The aim of this study is to compare IPTA, ITA with the Significance Test and Mann-Kendall (MK) methods. To achieve this, the monthly total rainfall trends of 15 stations in the Vu Gia-Thu Bon River Basin (VGTBRB) of Vietnam have been examined for the period 1979–2016. The analyses show that rainfall tends to increase (decrease) in March (June) at nearly all stations. IPTA and ITA with the Significance Test are more sensitive than MK in determining the trends. While trends were detected in approximately 90% of all months in IPTA and ITA with the Significance Test, this rate was only 23% in the MK test. Although the arithmetic mean graphs in the 1-year hydrometeorological cycle are considerably regular at almost all stations, their standard deviations are relatively irregular. The most critical month for trend transitions between consecutive months for all the stations is October, which has an average trend slope of −1.35 and a trend slope ranging from −3.98 to −0.21, which shows a decreasing trend.

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