Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Aksu, Gül Aslı(1)
- Algan, Irmak Yay(1)
- Başoğlu, Mustafa Engin(1)
- Bilgilioğlu, Burhan Baha(1)
- Demirbilek, Mehmet(1)
- Döner, Fatih(1)
- Erten, Esra(1)
- Gunes, Alper(1)
- Ilbeyli, Nurdane(1)
- Kaygusuz, Abdullah(1)
- Musaoğlu, Nebiye(1)
- Oliver-Cabrera, Talib(1)
- Orhan, Osman(1)
- Ozmen, Suleyman Fatih(1)
- Sertel, Elif(1)
- Topaloğlu, Raziye Hale(1)
- Wdowinski, Shimon(1)
- Yakar, Murat(1)
- Yalcin, Fusun(1)
- Yalcin, Mustafa Gurhan(1)
- Yalvac, Sefa(1)
- Şallı, Betül(1)
- Şirin, Samet(1)
Yayınlar
- MakaleAçık Erişim2021Land subsidence and its relations with sinkhole activity in karapınar region, turkey: A multi-sensor insar time series study
Orhan, Osman; Oliver-Cabrera, Talib; Wdowinski, Shimon; Yalvac, Sefa; Yakar, Murat
The Karapinar basin, located in the Central Anatolian part of Turkey, is subjected to land subsidence and sinkhole activity due to extensive groundwater withdrawal that began in the early 2000s. In this study, we use Interferometric Synthetic Aperture Radar (InSAR), Global Navigation Satellite System (GNSS), and groundwater level data to monitor and better understand the relations between groundwater extraction, land subsidence, and sinkhole formation in the Karapinar basin. The main observations used in the study are InSAR-derived subsidence velocity maps calculated from both Sentinel-1 (2014–2018) and COSMO-SkyMed (2016–2017) SAR data. Our analysis reveals broad areas of subsidence with rates exceeding 70 mm/yr. The InSAR-derived subsidence was compared with GNSS data acquired by a continuously operating GNSS station located in the study area, which show a similar rate of subsidence. The temporal characteristic of both InSAR and GNSS time series indicate a long-term subsidence signal superimposed by seasonal variability, which follows the overall groundwater level changes, with over 80% cross-correlation consistency. Our results also indicate that sinkhole activity is limited to slow subsidence areas, reflecting strong cohesion of near-surface rock layers that resist subsidence but yield to collapse in response to aquifer system deformation induced by groundwater extraction.
- MakaleAçık Erişim2021Analysis of salt lake volume dynamics using sentinel-1 based SBAS measurements: A case study of lake Tuz, Turkey
Bilgilioğlu, Burhan Baha; Erten, Esra; Musaoğlu, Nebiye
As one of the largest hypersaline lakes, Lake Tuz, located in the middle of Turkey, is a key waterbird habitat and is classified as a Special Environmental Protection Area in the country. It is a dynamic lake, highly affected by evaporation due to its wide expanse and shallowness (water depth <40 cm), in addition to being externally exploited by salt companies. Monitoring the dynamics of its changes in volume, which cause ecological problems, is required to protect its saline lake functions. In this context, a spatially homogeneous distributed gauge could be critical for monitoring and rapid response; however, the number of gauge stations and their vicinity is insufficient for the entire lake. The present study focuses on assessing the feasibility of a time-series interferometric technique, namely the small baseline subset (SBAS), for monitoring volume dynamics, based on freely available Sentinel-1 data. A levelling observation was also performed to quantify the accuracy of the SBAS results. Regression analysis between water levels, which is one of the most important volume dynamics, derived by SBAS and levelling in February, April, July and October was 67%, 80%, 84%, and 95% respectively, for correlation in the range of 10–40 cm in water level, and was in line with levelling. Salt lake components such as water, vegetation, moist soil, dry soil, and salt, were also classified with Sentinel-2 multispectral images over time to understand the reliability of the SBAS measurements based on interferometric coherence over different surface types. The findings indicate that the SBAS method with Sentinel-1 is a good alternative for measuring lake volume dynamics, including the monitoring of water level and salt movement, especially for the dry season. Even though the number of coherent, measurable, samples (excluding water) decrease during the wet season, there are always sufficient coherent samples (>0.45) over the lake.
- MakaleAçık Erişim20203D digital representation of cadastral data in Turkey-Apartments case
Döner, Fatih; Şirin, Samet
With the widespread use of three-dimensional (3D) geographic information technologies, studies for 3D digital representation of property units in cadasters have increased in recent years. In Turkey, a project named 3D City Models and Cadasters was initiated by the General Directorate of Land Registries and Cadasters in 2018. With this project, which is planned to last four years, it aims to create 3D models of individual units (apartments) in buildings and provide visual representations of these individual units with legal information. Transition from the current 2D representation towards a 3D digital cadaster requires not only replacing analog drawings with 3D models but also examining the workflow for forming the property units. In this study, the process of registration of property rights for individual units is examined and possibilities and challenges for successful completion of the 3D cadaster project are evaluated from a legal, an organizational, and a technical point of view. Government plays a lead role by adopting the digital transformation as a state policy. However, new regulations and organizational settings may have to be introduced. Modeling and visualization alternatives for 3D data should be studied further.
- MakaleAçık Erişim2020Estimation of natural radionuclides’ concentration of the plutonic rocks in the Sakarya zone, Turkey using multivariate statistical methods
Yalcin, Fusun; Ilbeyli, Nurdane; Demirbilek, Mehmet; Yalcin, Mustafa Gurhan; Gunes, Alper; Kaygusuz, Abdullah; Ozmen, Suleyman Fatih
The study aimed to determine the natural radioactivity levels of226Ra,232Th, and40K by the Gamma-Ray spectrometry method, and radiological hazard parameters of the plutonic rocks in the Western and Central Sakarya Zone and to analyze the data using multivariate statistical methods. The average radiological values of samples were determined as40K (1295.3 Bq kg−1) >232Th (132.1 Bq kg−1) >226Ra (119.7 Bq kg−1). According to the skewness values of the distributions of the examined radionuclides,226Ra (2.1) and232Th (0.7) seemed to be positively right-skewed while40K (−0.2) had a negatively right-skewed histogram. On the other hand, the following kurtosis values were calculated for the distributions:226Ra (5.8 > 3),232Th (−0.7), and40K (−0.8). Kolmogorov–Smirnov and Shapiro–Wilk tests were applied to the data to test their normality. Therefore, Spearman’s correlation coefficient method was performed. The radionuclides of226Ra and232Th were found to have a positive correlation with radiological hazard parameters of the samples. 2 (two)-related factors identified, and the cumulative value was calculated to be 98.7% on the basis of the Scree Plot. According to the hierarchical cluster analysis, the samples that are grouped with those from Camlik region are prominent. The average radioactivity values of Camlik, Sogukpinar, Karacabey, and Sogut (except for232Th) regions were detected to be higher than the world averages while the value of40K was also found to be higher than the average values of various countries in the world.
- MakaleAçık Erişim2019A fast GMPPT algorithm based on PV characteristic for partial shading conditions
Başoğlu, Mustafa Engin
Photovoltaic (PV) modules experience some partial shading conditions (PSC) due to some various factors. In that kind of a condition, a few maximum power points (MPPs) possibly appear on the power-voltage (P-V) curve, which increases the tracking difficulties. It is known that maximum power point tracking (MPPT) may not be realized by hill climbing (HC) based conventional MPPT algorithms under PSCs. In this context, this paper presents a novel micro converter based algorithm that was developed by using P-V characteristics of PV modules. Unlike voltage or duty ratio scanning techniques, this paper introduces a new deciding method to determine the correct global MPP (GMPP) region. For this, the proposed method uses some duty ratios that were calculated corresponding to each MPP region. Thus, the initialization of duty ratio is done properly, which results in high tracking speed and accurate tracking of the GMPP. The other advantages of the proposed algorithm are structural simplicity, less computational burden, and ease of implementation with a basic microcontroller. The simulation results show that this algorithm has fast tracking capability and it manages to track GMPP for PSCs correctly, since it includes an artificial scanning procedure. Single ended primary inductance converter (SEPIC) is built in order to validate the proposed global maximum power point tracking (GMPPT) algorithm. The performance of the proposed GMPPT technique is verified by experimental studies. The results show that the proposed GMPPT technique is fast by up to five times than an adaptive full scanning strategy and improved IC algorithm. Furthermore, the proposed algorithm can be commercially used in micro converters, since it is compatible with small number of bypass diodes in a module.
- MakaleAçık Erişim2018Comparison of landscape metrics for three different level land cover/land use maps
Sertel, Elif; Topaloğlu, Raziye Hale; Şallı, Betül; Algan, Irmak Yay; Aksu, Gül Aslı
This research aims to investigate how different landscape metrics are affected by the enhancement of the thematic classes in land cover/land use (LC/LU) maps. For this aim, three different LC/LU maps based on three different levels of CORINE (Coordination of Information on The Environment) nomenclature were created for the selected study area using GEOBIA (Geographic Object Based Image Analysis) techniques. First, second and third level LC/LU maps of the study area have five, thirteen and twenty-seven hierarchical thematic classes, respectively. High-resolution Spot 7 images with 1.5 m spatial resolution were used as the main Earth Observation data to create LC/LU maps. Additional geospatial data from open sources (OpenStreetMap and Wikimapia) were also integrated to the classification in order to identify some of the 2nd and 3rd level LC/LU classes. Classification procedure was initially conducted for Level 3 classes in which we developed decision trees to be used in object-based classification. Afterwards, Level 3 classes were merged to create Level 2 LC/LU map and then Level 2 classes were merged to create the Level 1 LC/LU map according to CORINE nomenclature. The accuracy of Level 1, Level 2, Level 3 maps are calculated as; 93.50%, 89.00%, 85.50% respectively. At the last stage, several landscape metrics such as Number of Patch (NP), Edge Density (ED), Largest Patch Index (LPI), Euclidean Nearest Neighbor Distance (ENN), Splitting Index (SPLIT) and Aggregation Index (AI) metrics and others were calculated for different level LC/LU maps and landscape metrics values were compared to analyze the impact of changing thematic details on landscape metrics. Our results show that, increasing the thematic detail allows landscape characteristics to be defined more precisely and ensure comprehensive assessment of cause and effect relationships between classes.
- DergiElectronics (Switzerland)
- DergiLand
- DergiISPRS International Journal of Geo-Information
- DergiRemote Sensing