Browsing by Author "Vaheddoost, Babak"

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A comparison of several methods in tracking short-term trends associated with the precipitation time series
(Bursa Uludağ Üniversitesi, 2020-03-03) Vaheddoost, Babak
Precipitation trends can be linked to large-scale climatic events or cyclic behaviors. However, exploring these patterns in short data records can be problematic. In this study, the monthly precipitation time series recorded across the Bursa district in Turkey were addressed between January 2005 to October 2018. Stations with the minimum data loss and the longest time records in the region were selected for the analysis. Therefore, Osmangazi, Keles, Uludag, Gemlik, Iznik, Karacabey, and Mustafakemalpasa stations were selected. Linear trend (LT), moving average (MA), Mann-Kendall (MK), turn points (TP), Spearman rank-order correlation (SROC), innovative Şen (IS), innovative trend analysis (ITA), changes in distribution (CD), and standardized precipitation index (SPI) methods were used to detect short-term trends in the precipitation time series. Results indicated that the trends, reported by the previous studies could not be reproduced at a monthly scale when using LT, MK, SROC, IS, ITA, and MA. However, the trends observed by the SPI-48 were also tracked down using CD, and SPI methods. It is concluded that the detection of the short-term trends is problematic whilst the outliers deviate results of the analysis. Hence, a combination of CD, ITA, and IS methods is a key in evaluation of the short-term trends within a data run.
Gemlik district wind power plant potential site analysis
(Geomatik Journal, 2023-01-01) Vaheddoost, Babak; Yılmaz, Damla; Aslan, Serife Tülin Akkaya; AKKAYA ASLAN, ŞERİFE TÜLİN; Bursa Uludağ Üniversitesi/Ziraat Fakültesi/Biyosistem Mühendisliği Bölümü.; 0000-0001-5129-8642; 0000-0002-4767-6660; N-9721-2013
The majority of energy demand is supplied by fossil energy sources, which greatly increases the possibility of future energy shortages. Non-renewable energy sources are being depleted rapidly and the damage to the environment is striking, alternative energy sources that are commercially convenient and least harmful to the environment have been preferred. Wind energy is a convenient energy source as it is sustainable, low maintenance, production costs. In this study, it is aimed to determine the wind power plant (WPP) construction site selection in Bursa, which is very suitable for WPP installation accordingly Turkey's wind energy potential map, by using the Analytical Hierarchy Process (AHP), which is one of the Multi -Criteria Decision Making Analysis (MCDA) methods based on Geographic Information Systems (GIS). It has been determined that wind speed of the Gemlik District is quite high and provides suitable conditions for the plant installation area. Because more than one criterion is effective the installation of the WPP, 7 main criteria analyzed. These criteria were analyzed according to their weight ratios using the AHP method, and a result map was obtained accordingly their suitability classes. Findings showed to 20% of the district area has medium and high suitability for WPP.
A laboratory scale investigation of manning roughness coefficient in open channel bed with different grain size and slopes
(Bursa Uludağ Üniversitesi, 2023-07-11) Yılmaz, Damla; Aras, Egemen; Vaheddoost, Babak
Efforts for getting the maximum efficiency from the existing water resources and to implement new projects are getting more attention these days. Determining the flow resistance for the project design and control process in open channels requires sophisticated applications. It is usually essential to be aware of the characteristics of the channel and flow to determine the hydraulic roughness, which represents the resistance of the flow. Hence, empirical calculation and evaluation of the hydraulic roughness will support future design and planning processes. In this study, four different particle sizes (d50= 28mm, 17.5mm, 4mm, and 1.75mm) that were fixed on blocks were used. These particle sizes were then used as the bed covering together with, three different horizontal bed slopes, and flow rates in the experiments to determine the associated Manning roughness, n. During the experiment, Froude number values were examined and it was determined that, in 32 experiments the flow regime can be considered as subcritical. Alternatively, the Lotter method was used to confirm the roughness values obtained by the Manning equation. It was concluded that the roughness values obtained by the selected methods have good concordance with each other.