Browsing by Author "Aydin, Mahsum"

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Are Co2 Emissions a Reason of Drought in the United States
(Iwa Publishing, 2024) Aydin, Mahsum
In this study, the relationship between carbon dioxide (CO2) emissions and drought (Standardized Precipitation Evapotranspiration Index) is investigated using data from 51 states in the US for the period 1997-2020. For this purpose, firstly, information about previous studies and the results of these studies are given in the study. Later, as empirical analysis, cross-section dependency tests, slope homogeneity tests, unit root analyses, cointegration tests, and causality analyses were performed. Then, short- and long-term parameter estimates are made for the entire panel and for each case. Lastly, impulse-response analyses are made. When the results are evaluated in general, it is found that CO2 emissions and drought in the US affect each other in the short and long term. CO2 emissions have been shown to have an increasing effect on drought, especially in most of the states located in the southeastern region of the US. On the other hand, CO2 emissions have been found to cause an increase in the incidence of wet periods in a significant part of the states located in the northeastern region of the US.
Development of a New Method for Detecting Outliers and Calculating Flood Discharge
(Turkish Chamber Civil Engineers, 2018) Aydin, Mahsum; Tuna, Ahmet
In this study a new method has been proposed which was developed for detecting outliers and calculating flood discharge. In the study the data of six gauging stations on Euphrates basin have been used. The data of these stations were analyzed and the outliers were detected by using Rosner test, Dixon Thompson test and the proposed method. The flood discharge which can occur in a certain recurrence interval has been calculated by using the proposed method. After the outliers were removed from the datasets, the flood discharges were calculated by using probability density functions (PDF) which were determined by using goodness of fit tests. In addition, flood discharges are calculated regionally by using PDF whose parameters were determined by the L moments method. When the flood discharge values were calculated by using the proposed method, and when the flood frequency analysis and L moments methods were compared, it has been concluded that the values determined by the proposed method and flood frequency analysis are more suitable and usable than the values determined by the L moments method.
Gravity Center Trend Analysis (Gcta) as a New Method for Determining the Trends of Hydro-Meteorological Data
(Elsevier, 2025) Aydin, Mahsum
This paper introduces Gravity Centre Trend Analysis (GCTA), a new method developed to analyse the trends of time series without any data constraints. The method provides both graphical identification of trends and easy calculation of trend magnitude. In the study, the applicability of GCTA is tested using monthly precipitation data and global land-ocean temperature index between 1869-2018 in New York Central Park. The findings revealed that there is a general increasing trend in annual precipitation data, but this trend shows periodic changes in monthly data. Significant increasing trends were found in April, May and November, while decreasing trends were found in February, July and October. An increasing trend was detected in the Global Land-Ocean index data. It was evaluated that the negative impact of this increase in global warming on precipitation regimes will increase in the coming years and the frequency of flood and drought events in the region may increase.
The Procedure of Detecting Drought Trend by Using Sen's Innovative Trend Analysis Methodology
(Emerald Group Publishing Ltd, 2024) Aydin, Mahsum
The increasing effect of drought causes negative effects on water resources. To prevent these negative effects, it is of great importance to know the trend of drought over time. Many methods are used in the literature to determine the severity of drought. One of these methods is the Standard Precipitation Index (SPI), which is calculated based on precipitation data. The SPI method was chosen in this study because it is widely used in the literature for its simplicity, flexibility, and effectiveness in characterizing drought duration and intensity. There are different classifications for drought severity in the SPI method. Therefore, it is of great importance to know the individual trends for each classification. Classical trend detection methods (such as Mann-Kendall) require a separate analysis for each drought classification. However, with Sen's Innovative Trend Analysis (ITA) method, it becomes possible to determine the trends for all drought classifications on a single graph. In this way, the change of drought events over time can be easily determined for all drought classifications.
Structural Performance of Masonry Buildings Under Harsh Climate and Seismic Loads
(Springer int Publ Ag, 2022) Erdil, Baris; Korkut, Fuat; Aydin, Mahsum; Yaltay, Namik
Masonry buildings in Van which is a city located at the eastern border of Turkey exposed to several earthquakes in 2020 while continuously being subjected to harsh weather conditions. Two earthquakes with Mw = 5.9 occurred on the same day and four months after another one hit the region. Besides the earthquakes 124 freeze-thaw cycles occur annually and the region has snow and rain approximately 103 days. Both continuously and periodically applied environmental exposures due to harsh weather conditions and earthquakes that is significant in a short period, affects the structural performance of the masonry buildings adversely. During the field investigations after the earthquakes, it was realized that none of the buildings comply with the available codes, foundations, and walls damaged due to the environmental exposures and those damages either increased or end up with total collapse due to the seismic loading. Besides the damaged buildings, it was observed that some buildings were strengthened locally at the corners. L shaped reinforced concrete columns were added to the cracked corners to increase the lateral capacity of the walls. That strengthening seemed to be adequate for low seismicity because no significant damage was seen.