Yazar "Tusat, Ekrem" seçeneğine göre listele

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    Assessment of resistance of wheat genotypes (T. aestivum and T. durum) to copper toxicity
    (WFL PUBL, 2013) Karaman, M. Rustu; Tusat, Ekrem; Er, Fatih; Turan, Metin; Dizman, Mumin
    Copper (Cu) availability to plants depends on a large number of factors and their interactive relationships. Especially, localized excess soil Cu is often a great risk for plant growth on the agricultural lands. Development of resistant varieties to Cu toxicity is a high priority on these regions, where the soils have high levels of Cu. Thus, this study aimed to assess the resistance of wheat genotypes to Cu toxicity using the agronomic and physiologic parameters. For this aim, a pot experiment, based on a completely randomized design with three replications, was conducted using the soil of calcareous usthochrepts. In the study, twenty different wheat genotypes of T. aestivum and T. durum were used. Copper fertilizer at the levels of 0 (-Cu) and 20 mg Cu kg(-1) (+Cu) as CuSO4 center dot 5H(2)O was applied to the pots. After harvest, plant dry matter yield was recorded, and total Cu concentrations in tops of wheat plants were determined. The results indicated the existence of a large genotypic variation among wheat genotypes to their physiologic and agronomic susceptibility to Cu toxicity. Resistance of bread wheat cultivars of T. aestivum to Cu toxicity were higher than that of wheat cultivars of T. durum under the Cu toxicity condition. Thus, evaluation of assessment of new wheat cultivars to Cu toxicity could also be used in breeding programs in order to develop more Cu-tolerant cultivars.
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    COMPARISON OF GIS BASED INTERPOLATION METHODS IN ASSESSING OF SITE SPECIFIC PHOSPHORUS VARIABILITY ON THE APPLE ORCHARD
    (PARLAR SCIENTIFIC PUBLICATIONS (P S P), 2013) Karaman, M. Rustu; Horuz, Ayhan; Susam, Tekin; Er, Fatih; Tusat, Ekrem
    Evaluating of geostatistical approaches in monitoring of spatial variability of some chemical contaminants such as agricultural phosphorus (P) will provide valuable data for large agricultural areas. In this study, performance of varied GIS based geostatistical interpolation methods were tested in assessing of site specific P variability on the apple orchard. For this aim, soil samples were systematically collected from the agricultural apple area using the grid sampling system. The samples were taken at two depths (025 cm and 25-50 cm), the distance on the Y direction is 10 m and in the X direction is 20 m. The soil samples were prepared for analysis, and some physical and chemical analyses were made in the samples by routine methods. The data concerning with soil P levels were analyzed comparatively according to GIS based interpolation methods of Ordinary Kriging (OK), Simple Kriging (SK) and Universal Kriging (UK). The interpolation methods were also tested with varied semivariogram models of Spherical, Exponential and Gaussian. As a result of cross validations, the best optimal method was found to be interpolation method of UK (Universal RMSE, +/- 0.472) with semivariogram model of guassian for topsoil, whereas it was found to be interpolation method of SK (Simple RMSE, +/-0.323) with semivariogram model of exponential for topsoil. Predicted P values were significantly (p< 0.01) correlated with measured values for both topsoil (r = 0.993) and subsoil (r = 0.980), respectively. Soil P distribution maps were adequately performed by using selected kriging interpolation methods and suitable sernivariogram models. The results indicated that monitoring of site specific P variability on the apple orchard using these GIS based interpolation methods will help to create the effective schemes for agricultural chemical managements such as P fertilization resulting in optimal yield and quality with reduced environmental pollution.
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    A Comparison of the Accuracy of VRS and Static GPS Measurement Results for Production of Topographic Map and Spatial Data: A Case Study on CORS-TR
    (UNIV OSIJEK, TECH FAC, 2018) Tusat, Ekrem
    The on-going developments in Global Navigation Satellite Systems (GNSS) technology affect techniques in geographic information and associated documents. The national Continuously Operating Reference Station (CORS) networks, which operate on the Real Time Kinematic (RTK) principle, are multi-purpose geodetic networks and offer services to a large portion of society including all the public institutions and other organizations, military and civilian users and to scientific researchers. It is possible to utilize these networks both in real time positioning applications using the Network Real Time Kinematic (NRTK) method and in static applications using the Receiver Independent EXchange (RINEX) format data from reference stations. In this study, Virtual Reference Station (VRS) and static GNSS measurements were undertaken based on a Continuously Operating Reference Station-Turkey (CORS-TR) network in a test network established in Turkey. As a result of the measurements, repeatability attained using the VRS method was examined. Moreover, the coordinates obtained from VRS measurements based on CORS-TR network were compared with the coordinates calculated as a result of static observations. From the accuracies and repeatability, an investigation was implemented to determine the extent to which NRTK applications in real-time GNSS networks can be used to produce spatial data and create topographic maps.
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    GEOGRAPHIC INFORMATION SYSTEM FOR KONYA CLOSED BASIN PROJECT
    (BULGARIAN CARTOGRAPHIC ASSOC, 2012) Ustun, Aydin; Bildirici, I. Oztug; Ustuntas, Taner; Tusat, Ekrem; Ozkan, Ihsan; Eren, Yasar; Ozdemir, Adnan
    The main goal of the Konya Closed Basin Project is to investigate land subsidence within the basin. The vertical changes have been investigated through GPS measurements and InSAR images taken at different dates. In order to decide whether the land subsidence is significant for land use in residential and agricultural areas within the basin, a GIS system is necessary. For this purpose GoogleEarth, MapInfo and Generic Mapping Tools (GMT) were chosen as GIS software packages. At first, a preliminary study has been performed using I: 100 000 and 1: 250 000 topographic maps which are scanned and registered. A continuous mosaic of map sheets created from them is overlaid on the terrain in the Google Earth. GPS deformation network was designed over the mosaic map considering land use and hydrogeological properties of the KCB. Other data that the system contains are GPS points, wells, at which water depth is measured, InSAR images, geologic layers created from geological maps, and land use maps created by using NVDI method. The geology maps are digitized in MapInfo. After the completion of data collection, GIS analyses will be undertaken in order to evaluate land subsidence potential of the basin.
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    The importance and development of national geodetic networks in map production: A Turkish case study
    (ACADEMIC JOURNALS, 2010) Tusat, Ekrem
    Maps are a fundamental requirement for all kinds of infrastructure and engineering projects. Maps are produced by various institutions and organizations for different purposes. The important issue is that these maps from different sources are combined, archived, and stored in way that facilitates the economic use of a country's resources and promotes effective data exchange. For the combining and storing of maps produced by different institutions it is necessary to have accurate knowledge of the datum, coordinate system, projection and accuracy of the map, which is directly related to the datum, scope and accuracy of the national geodetic networks are used in map production. There have been considerable innovations in measurement technologies parallel to the general technological developments that have changed and improved national geodetic networks utilized in map production. This paper will investigate the role of the national geodetic networks in large scale map production in Turkey, taking into account changes in these networks and the geodesic structure and the development of national geodetic networks.
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    Land subsidence in Konya Closed Basin and its spatio-temporal detection by GPS and DInSAR
    (SPRINGER, 2015) Ustun, Aydin; Tusat, Ekrem; Yalvac, Sefa; Ozkan, Ihsan; Eren, Yasar; Ozdemir, Adnan; Bildirici, I. Oztug
    Konya Closed Basin that includes two depression blocks, Konya and Tuz Golu, is the biggest endorheic basin in Turkey. A lowering in the ground levels of the depositional areas has been shown with respect to the surrounding mountains. In the past, this process was controlled by geological and hydrogeological phenomena; nowadays, it has gained a new dimension due to the excessive pumping of groundwater to the Earth's surface. The geodetic techniques such as Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) reveal a considerable land subsidence resulting in the rate of 1-4 cm/year in Konya sub-basin. It seems that the calculated amounts are responsible for changing environmental conditions like seasonality. Both GPS and differential InSAR techniques verify these relatively small fluctuations in the subsidence development. Target districts that should be observed primarily are agricultural zones where groundwater is overused for irrigation and regions where human population density is high. The geocoded interferogram and vegetation index map verify the spatial relation between the subsidence and green areas. In this study, a project dealing with the investigation of the land subsidence occurrences and of their possible causes and consequences within a specific part of Konya Closed Basin is introduced.
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    Preliminary Results of Land Subsidence Monitoring Project in Konya Closed Basin Between 2006-2009 by means of GNSS Observations
    (Copernicus Gesellschaft Mbh, 2010) Üstün, A.; Tusat, Ekrem; Yalvaç, S.
    One of the potential dangers that might arise as a result of bringing excessive amounts of groundwater to the surface of the Earth is land subsidence. Such surface deformations - these velocities may vary from a few millimetres to a few metres per year - do the greatest damage to infrastructure facilities and buildings in residential units. Agricultural lands, in which excessive irrigation is performed, and densely populated cities are more likely to suffer from land subsidence. Konya Closed Basin (KCB), where a rapid groundwater withdrawal has been observed during the last 30-40 years, is faced with such a threat. In this study, the possibility of the occurrence of land subsidence, related to groundwater withdrawal for the KCB, is assessed and the geodetic studies conducted up to now, with the intention of identifying land subsidence, are introduced. The vertical displacements of between -12 and -52 mm/year have been detected through GNSS observations collected on the 6-point test network. The land subsidence phenomenon has been developing in the areas where the groundwater is extensively used for irrigation and daily life. The results support the findings derived from the historical leveling records and point out the need of an extended study based on both GNSS and InSAR techniques for spatial and temporal mapping of land subsidence in the KCB.