İnşaat Mühendisliği Bölümü / Department of Civil Engineering
Permanent URI for this collectionhttps://acikerisim.antalya.edu.tr/handle/20.500.12566/21
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Item Riparian soil pollution caused by sediment metal transport: Seasonal changes and ecological risk assessment(MDPI, 2024) Çelebi, Ahmet; Şengörür, Bülent; Torabi Haghighi, Ali; Danandeh Mehr, Ali; Danandeh Mehr, Ali; 0000-0003-2769-106X [Danandeh Mehr, Ali]; 275430 [Danandeh Mehr, Ali]The accumulation of pollutants in the sediment along surface water may negatively affect riparian zones and increase ecological risk. This article investigates the effects of metal sediments on riparian soil via field monitoring and ICP-OES analysis. To this end, pollution levels, seasonal changes, and potential sources of the pollutants were determined for the Melen River watershed, Turkey. The ecological statuses (contamination factor, enrichment factor, index of geo-accumulation, pollution index, modified pollution index, and potential and modified ecological risk indexes) of the watershed were also analyzed. Although no significant seasonal differences in the metal sediments were observed, their spatial distribution in the sediments and riparian soils varied markedly. Cr (11.4 to 136), Co (7.7 to 21.52), Cu (11.4 to 76.6), and Ni (14.06 to 128.2) recorded as mg/kg significantly increased from the upstream to the downstream. The metals possessing the highest risk in the sediment and riparian soil regarding the river health were Cu, Co, and Ni. The risk values were found to be heavily polluted (PI > 3 and MPI > 10), and the risk indexes were above the “desired environment without the risk”. The risk index was found to be more than 50, and the modified risk indexes exceeded 200 at many points. The transportation of pollutants in surface water became evident in the sediment, resulting in adverse effects on the riparian zone and the ecological system.Item A novel approach to predictor selection among large-scale climate indices for seasonal rainfall forecasting in small catchments(Taylor & Francis, 2024) Modaresi, Fereshteh; Ebrahimi, Kumars; Danandeh Mehr, Ali; Danandeh Mehr, Ali; 0000-0003-2769-106X [Danandeh Mehr, Ali]; 275430 [Danandeh Mehr, Ali]Utilizing identical climate indices as predictors for all climate divisions within large basins may result in unreliable rainfall forecasts at the sub-basin scale. This study aimed to develop a new approach to identify the most effective predictors among large-scale climate indices for seasonal rainfall forecasting in small areas. The proposed approach combines a selective singular value decomposition method (SSVD) with a non-linear sequential forward selection method (NLSFS). Applying the new algorithm for seasonal rainfall forecasting within two climate divisions in Karkheh basin, Iran, indicated that the climate indices identified by the SSVD differed between the study areas. The combination of these indices exhibited a correlation with seasonal rainfall approximately 11% higher than those derived from the SVD method. Moreover, NLSFS significantly enhanced the forecast accuracy compared to the frequently employed linear sequential forward selection (SFS) method, and the optimal predictors chosen by the two methods differed across all seasons.Item Drought assessment across erbil using satellite products(MDPI, 2023-04-14) Alee, Mohammed Mustafa; Mehr, Ali Danandeh; Akdeğirmen, Özgün; Nourani, Vahid; Danandeh Mehr, Ali; Akdeğirmen, Özgün; 0000-0003-0955-0052 [Akdeğirmen, Özgün]; 0000-0003-2769-106X [Danandeh Mehr, Ali]; 275430 [Danandeh Mehr, Ali]; 229725 [Akdeğirmen, Özgün]In this article, meteorological and agricultural droughts across the Erbil province, Iraq, were assessed using remote sensing data and satellite products. To this end, the long-term (2000–2022) Standardized Precipitation Evapotranspiration index (SPEI) at 1- and 3-month accumulation periods (SPEI-1 and SPEI-3) as well as the Normalized Difference Vegetation Index (NDVI) across Erbil were utilized. While the former was retrieved from the global SPEI data repository, the latter was derived from Moderate Resolution Imaging Spectroradiometer (MODIS) products. The spatiotemporal variations in the SPEI indices indicated that two to nine extreme drought events occurred in the province with an increasing northward pattern. An increasing trend in the long-term NDVI series was also detected, having more diversity in vegetation coverage in the northern part of the province. The relationship between the SPEI and MODIS-NDVI was found to be positive but insignificant. Thus, we concluded that short-term meteorological droughts were not the only reason for the agricultural droughts in Erbil. Furthermore, the climate characteristics related to the cumulative water balance over a previous season is not an important trigger for the spatial variation in vegetation coverage across the province.Item Enhancing nutrient absorption through the influence of mangrove ecosystem on flow rate and retention time in salt marshes(Science of the Total Environment, 2024) Danandeh Mehr, Ali; Partani, Sadegh; Jafari, Ali; Danandeh Mehr, Ali; 0000-0003-2769-106X; 275430This study investigates the impact of pneumatophores (the aerial roots of Avicenna marina) on water flow rate, retention time, contact time, and consequently on nutrient absorption through the sediment in sub-tropical salt marshes. The goal is to realize how the density of mangroves in salt marshes influences the kinematic factors of streamflow at estuaries. To this end, a field experiment was carried out to assess nutrient and organic compound levels in the sediment and water samples, spanning six sampling stations along the Chabahar River discharging to the Chabahar Bay, Iran. Then, we delved into the influence of altering environmental parameters, such as density and geometry, on the kinematic features of the flow through statistical analysis and hydraulic modeling. The results showed that the aerial roots reduce the flow rate and increase both retention and contact times. The longest retention time was observed at station #5 due to increased vegetation density and decreased instream velocity. In addition, measurements of total organic matter, total organic carbon, and total nitrogen indicated that an extended contact time resulted in increased absorption flux to the stream by sediments. As a result, pneumatophores can serve as an effective sink for organic matter in ecotones in salt marshes.Item Sensitivity of Standardized Precipitation and Evapotranspiration Index (SPEI) to the choice of SPEI probability distribution and evapotranspiration method(Elsevier, 2024) Danandeh Mehr, Ali; Lee, Sanghyun; Moriasi, Daniel N.; Mirchi, Ali; 58150194100 [Danandeh Mehr, Ali]; Danandeh Mehr, Ali; 0000-0003-2769-106X [Danandeh Mehr, Ali]; 275430 [Danandeh Mehr, Ali]The standardized precipitation evapotranspiration index (SPEI) is a widely used meteorological drought index that incorporates potential evapotranspiration (PET) into a precipitation-based index. However, the understanding of the appropriate PET method for SPEI across different temporal scales in non-arid climate conditions remains limited. We compared Thornthwaite (TW), Hargreaves (HG), and Penman-Monteith (PM) equations for SPEI at various accumulations, considering three temporal scales: 1) long-term (25 years), 2) event-based, and 3) monthly. Also, we examined the log-logistic and generalized extreme value distributions to test the normality of SPEI computed from the three PET methods. To do this, we utilized high-quality climate datasets measured at 107 stations across the state of Oklahoma, United States, which has a diverse climate ranging from semi-arid to humid subtropical.Item A novel qualitative risk assessment using the interval-valued spherical fuzzy extension of TOPSIS method: a case study in rail transit systems(Springer, 2023) Ak, Muhammet Fatih; Demir, Emre; 57191904300 [Ak, Muhammet Fatih]; 57204833871 [Demir, Emre]; Ak, Muhammet Fatih; Demir, Emre; 0000-0003-4342-296X [Ak, Muhammet Fatih]; 0000-0003-0013-4482 [Demir, Emre]; 279243 [Ak, Muhammet Fatih]; 203339 [Demir, Emre]This article introduces an innovative approach for risk assessment in rail transit systems, addressing the limitations of traditional methodologies. Our proposed method combines the modified Fine–Kinney approach with the interval-valued spherical fuzzy extension of the technique for order of preference by similarity to ideal solution (IVSF-TOPSIS). By leveraging interval-valued fuzzy sets and spherical fuzzy sets, we capture nuanced uncertainties more effectively. This study differs from previous risk assessment methods by integrating IVSF sets into Fine–Kinney methodologies. Unlike traditional methods, our approach integrates IVSF sets to enhance the handling of uncertainty, resulting in a more comprehensive risk assessment. The proposed model includes parameters such as cost, preventability, and personal protective use, alongside severity, probability, and frequency. This inclusion, alongside expert opinions, enriches the analysis and ensures a more realistic risk evaluation. Applied to the Antalya rail transit (ANTRAY) system in Turkey, the study demonstrates the method’s applicability through a comprehensive case study. Four experts with extensive field and academic experience in rail transit systems and risk analysis contributed their evaluations, ensuring the thoroughness and accuracy of the results. Limited experts’ input yields consistent and high-correlation findings, enhancing result validity and applicability. Eight most exposed hazard groups, analyzed in this study, aid in producing applicable solutions for risk mitigation. The outcomes provide a prioritized list of risks and actionable insights for managing these risks effectively. By combining quantitative and qualitative data through intervalvalued fuzzy sets, our approach bridges the gap between different types of information, resulting in a holistic and reliable risk assessment. Consequently, our novel methodology not only overcomes the limitations of traditional approaches but also offers a practical and comprehensive framework for decision making. By providing a clearer understanding of uncertainties and their impacts, our approach contributes to safer and more efficient rail transit operations.Item Pythagorean fuzzy based AHP-VIKOR integration to assess rail transportation systems in Turkey(Springer, 2023) Demir, Emre; Ak, Muhammet Fatih; Sarı, Kaan; 57204833871 [Demir, Emre]; 57191904300 [Ak, Muhammet Fatih]; Demir, Emre; Ak, Muhammet Fatih; 0000-0003-0013-4482 [Demir, Emre]; 0000-0003-4342-296X [Ak, Muhammet Fatih]; 203339 [Demir, Emre]; 279243 [Ak, Muhammet Fatih]Rail transit systems, one of the important public transportation (PT) systems, are widespread in large cities to satisfy passengers or commuters for their daily trips. However, rail transportation (RT) investments are costly, and the budgets are minimal. Thus assessing RT systems in big cities play a crucial role in deciding on the best RT investment. In this study, for the first time, a two-stage fuzzy set is used among the multi-criteria decision-making (MCDM) studies in the area of transportation. The proposed method is a unique technique integrating the Analytic Hierarchy Process (AHP) and Vise Kriterijumska Optimizacija I Kompromisno Resenje (VIKOR) techniques with an extension of Pythagorean fuzzy sets. In this manner, datasets from the observations of three rail lines in Antalya, one of the largest cities in Turkey, are applied to the proposed method. Fuzzy Analytic Hierarchy Process (FAHP), a commonly used MCDM method, is used to weighting four main criteria and thirteen sub-factors. AHP is strengthened by interval-valued Pythagorean fuzzy numbers (IVPFNs). The Fuzzy VIKOR (FVIKOR) approach is then applied for the prioritization of three rail line alternatives. Results are achieved by analyzing not only real RT service observations, also actual RT expenditures or costs. Consequently, the uncertainty in results is thus minimized. Outcomes of the case study reveal the most serviceable RT line in the city evaluating the main criteria, namely economy, comfort, environment, and safety. Therefore, the proposed approach methodologically contributes to adopting a new insight into the integration of MCDM methods with fuzzy set.Item Path inference implementing the cluster path covering method(2024) Akgöl, Kadir; Demir, Emre; Aydoğdu, İbrahim; Demir, Emre; 0000-0003-0013-4482 [Demir, Emre]; 203339 [Demir, Emre]Determination of the optimal route in transportation activities is one of the major problems in transportation. Therefore, efficient techniques deserve our utmost attention to detect optimal routes. In this study, a novel method called Cluster Path Covering (CPC) has been developed and introduced to identify a route based on a sequence of location points on a network. There are already models to minimize the total path cost between the pair of nodes following a kind of sequence. However, our method aims to minimize the path cost, including the neighbourhood accessibility of the path nodes on the network. One of the major challenges for the new model is to reveal the accessibility costs between the nodes. The methodology presents the CPC method clustering the location points on a network and indicating the optimum point for each cluster. Then, the CPC method generates the best path by connecting the specific location points representing the clusters. Moreover, the shortest covering of the neighbourhood path problem (SCNPP) is introduced in this study. The novel CPC method is utilized for SCNPP, a distinctive version of the shortest covering path problem (SCPP). The performance of the CPC method is then tested on two different benchmark networks. According to the results, it provides robust and efficient outcomes for decreasing the routes' transportation costs (e.g., distances). The issues that can be solved via the CPC method include the accessibility costs of public transportation paths and the locations of stops by minimizing the costs.Item A TOPSIS-based evaluation of urban transportation and supermarket accessibility: A case study of Konyaaltı in Antalya(BIDGE Publications, 2023) Demir, Emre; Demir, Emre; 0000-0003-0013-4482 [Demir, Emre]; 203339 [Demir, Emre]Item Development of physical parameters within transportation systems and their implications on traffic assignment(3rd International Congress on Multidisciplinary Natural Sciences and Engineering, 2023) Demir, Emre; Demir, Emre; 0000-0003-0013-4482 [Demir, Emre]; 203339 [Demir, Emre]