5
Archived Theses
0
DOIs Assigned
0%
DOI Rate
Discipline
Kuraklık tehlike haritalarının SPI indisi ve CBS kullanılarak oluşturulması Pilot çalışma: Fars vilayeti, İran
Drought is one of the main natural hazards affecting the economy and the environment of large areas .Semi-arid and arid regions worldwide regularly confront drought. Some of the potentially significant and far reaching consequences of drought include impacts on: poverty rates, health, ecosystem services, land sustainability, and economic development. Unfortunately, recent climate change models predict that over the next 40 years, semi-arid and arid regions worldwide will experience an increase in the severity and intensity of drought as these regions encounter more aridity and less precipitation. Most populated regions, especially in arid and semi-arid environments, are experiencing substantial conflicts over freshwater resources as governments try to meet agricultural and urban water demands and leave flows for the environment. And while the global supply of freshwater resources has been nearly constant for the last 2,000 years recent predictions from climate change models suggest less precipitation and hence further reductions in freshwater supplies in many of the already water-stressed semi-arid and arid regions worldwide, including parts of the Europe, Africa, Australia, and western United States. Important efforts for developing methodologies to quantify different aspects related to droughts have been made, such as the spatial differences in the drought hazard, the prediction of droughts by means of the use of atmospheric circulation indices and the mitigation of drought effects. However, more efforts have been made to develop drought indices, which allow an earlier identification of droughts, their intensity and surface extent. During the twentieth century, several drought indices were developed, based on different variables and parameters. Drought indices are very important for monitoring droughts continuously in time and space , and drought early warning systems are based primarily on the information that drought indices provideThe majority of drought indices have a fixed time scale. Some of them have many problems related to calibration and spatial comparability. To solve these problems, scientists developed other indices like the Standardized Precipitation Index (SPI),which can be calculated at different time scales to monitor droughts in the different usable water resources.in recent years, Geographic information system (GIS) has played a key role in studying different types of hazards either natural or man-made. As well as, Iran is a dry land with very low atmospheric precipitation such that rainfall in Iran is less than one third of the average rainfall throughout the world. Meanwhile, the precipitation time and its place do not conform to an agricultural need which is the main consumer of water in the country. Fars province has had remarkable record in crop production especially wheat yield in the country. On the other hand, comprehensive management and decision making in the field of water resources requires reliable prediction of drought area, duration and severity. To study drought and mapping this thesis Standardized Precipitation Index (SPI) and spatial interpolation in GIS is used. It is practical and simple method. The base of this index is precipitation. To study the drought, Records from10 stations within the same period of 13 years (1994-2006) and 17 stations within the same period of (2007-2011) in scale of annual. For better results three spatial interpolation is compared and Inverse Distance Weighted (IDW) interpolation is more practical for this study area. The result of analysis, is showed that the least SPI and drought magnitude has happened in Sadedorodzan station , in the north of Fars province for 17 stations between 1994-2011 and 10 stations between 2007-2011. For 10 stations during 1994-2006 ,the least SPI is related to the Lamerd station. Figures that produced by interpolation method between 1994-2011 illustrated that drought was generated in the south and it was rapidly extended to north and northeast and northwest. This prediction is used in Fars province to manage the drought .It is the first attempt of its kind in this region and studying such researches by taking into consideration of climate changes may prove to be useful for regional planners, and policy makers for agricultural and environmental strategies, not only in Southern Iran but also in other countries facing similar problem.
A tool to automate the process of flood risk areas detection due to climate change
Flooding is a major hazard in the world, with increase in climate change its occurrence has also accelerated over the years. Recent major floods especially in the coastal areas that are associated with increase in sea level rise and storm surge have created a major need for predicting, monitoring and planning for future flood occurrence. Inundation affects and vulnerability of the coastal areas need to be accessed. Using Spatial Information Science knowledge and using tools GIS software packages like ArcGIS, GRASS, QGIS and so many others has made the exposure of ecosystem services, population, and environmental hazards location easier within the different years. But these software packages come with a lot of sophisticated methodologies and many processes to delineate the flood plain thus raise the concern of automating the process. This thesis presents a GIS-bases toolbox that was written in python scripting language to automate the process of detecting flood risk areas due to climate change. The toolbox takes the advantages of the python scripting by using the Arcpy library which allows the direct access to methodologies that are used in ArcMap (ESRI) software.
Unifying remote sensing and web GIS infrastructure design and implementation of weighted overlay analysis on vegetation indices
Development momentum of satellite technologies; • enables us tracking seasonal changes in vegetation regionally or globally via remote sensing phenology, • leads us observing the invisible light spectrum and its meanings inside. As living in information age, people have started to understand mathematical chains through the nature and environment. We get values identified by sensors as inputs, write functions for various analysis that helps us to visualize and figure out of enhanced outputs from raw imagery. This thesis study concentrates on the topic of GIS and remote sensing using a multispectral imaging system for vegetative research and its use mainly in agricultural applications. Applications may be used for classification of the forests, change detection on burned area, site selection of specific varieties of agricultural goods, acquiring the health or stress level of vegetation, resource optimization along with sustainable environment and more else with researchers vision. 'Spectr-Agri-ITU' app is a GIS based modelling, geo-design collaborated web app which spectrally transforms the raw imagery into valued information. The input must be an image containing red, green, blue (RGB), near infra-red (NIR), and shortwave infrared (SWIR 1-2) spectral bands. Otherwise some analyzes will not work. Spectral imagery use for vegetation manner is mainly based on red and infrared light because of reflectance and scatter. Selectable analysis and indices which user may specify, applied to uploaded spectral image. Mostly known and used analysis is normalized difference vegetation index (NDVI) which is a key for quickly identifying vegetated areas and their "condition," and it remains the most used index to detect live green plant canopies in multispectral remote sensing data. There are more vegetation indices which are mathematical combination or transformation of spectral bands that emphasize the spectral characteristics of greenness. Enhanced imagery is created as numerous raster data, presents information for next step. Weighted overlay analysis (WOA) provides us to associate, weight and rank various types of information so to evaluate multiple factors at once. Percentage settings of weights form the final output. Finally output raster data has meanings to visualize with smart mapping styles, color ramps and symbology. Customizable styles let user to understand spectral imagery insights of research. This innovative application puts these cut-edge technologies forward in World Wide Web environment with Web-GIS architecture.
GIS based analysis and assessment of tsunamy risk case study of Gocek Bay–Turkey
The event of tsunami has a high considerable impact in local and global level. The risk of tsunami cannot be eliminated but it can be efficiently assessed and analyzed for setting a possible solution to reduce its impact. During the hazard prevention, human lives and properties can be saved and environmental damage can be reduced. Determine the spatial location of the tsunami and its impacts has a vital importance for disaster management. At that stage, geographical information system becomes a major concern with its ability to provide accurately and spatially information about such a risk. Geographical Information System (GIS) as "a set of tools used for capturing, storing, manipulate, analyzing and displaying spatial data related to a spatial location for a specific problem" is used effectively to assess and analyze the risk of tsunami and help to response strategy plan. Tsunami event numerical data from historical document have been manipulated to determine the probability of tsunami event which might occurred. The aim of this study is to combine and examine different spatial data used to determine the risk relied on tsunami hazard. The obtained results are successfully used for the area where under the risk such as Göcek Bay in Turkey. Göcek is situated in north west of Fethiye District of Mugla province and it is one of the most popular Turkish premier yachting locations. Its potential tourism activity contributes on the national economic development. Furthermore, the use of GIS technology necessitates of different types of spatial data such as digital elevation Model (DEM), satellite imagery, and land use/land cover. The compilation of these data generates the elevation map, land use land cover map, inundation map and the risk map depending of different tsunami intensity values. This study combined both risk vulnerability components and data analysis for developing a tsunami mitigation planning. This approach is used to achieve this analysis and assessment that includes physical, social and economic factors, developing methodology integrating hazard measure and its risk vulnerability and apply different risk frameworks for the Göcek area. The study presents the hazard information, the vulnerabilities and different map outputs. The risk map combined the vulnrability score and hazard information while the inundation map is based on physical and historical data. The result obtained in this study can be used for different relocation process in the coastal area required by local and central government.
Otomatik bağımlı gözetim-yayını güvenlik analizi
Devlet Hava Meydanları İşletmesi istatistiklerine göre 2016 yılında Türkiye havalimanlarında yolcu, yük ve ticari uçaklar dahil olmak üzere toplam 1.829.028 uçak ve 173.959.159 yolcu trafiği gerçekleşmiştir. 2019 yılı için öngörü bu rakamların yaklaşık yüzde 25 daha fazlasıdır. Bu denli yüksek rakamların geçtiği uçak trafiğinde yeni jenerasyon uçuş kontrol sisteminin en önemli adımı olan Otomatik Bağımlı Gözetim-Yayını(ADS-B)'nda kullanılan haberleşme protokolündeki güvenlik açıkları, hem sivil hem de askeri uçuşlar için tehlikeli riskler barındırmaktadır. Bilgi güvenliği alanındaki bilgi sistemlerinin artan kullanımı nedeniyle siber güvenlik, havacılık ve güvenlik açıkları arasındaki ilişkinin kapsamlı bir literatür taraması yapılmıştır. Sivil havacılık, yeni teknolojilerin devreye sokulması yoluyla hava trafiği yönetim sisteminin gelişim sürecindedir. Dolayısıyla, havacılık haberleşmesinin modernizasyonu henüz giderilmemiş birtakım güvenlik sorunlarını yaratmaktadır. Çalışmanın amacı Otomatik Bağımlı Gözetim Yayına karşı siber saldırıların sistematik bir şekilde okuyucuya tanıtmak ve niteliksel güvenlik analizini yapmaktır. Bu tez, havacılıkta siber güvenlik tehditlerinin etkisini anlamak için bir referans kılavuzuI olarak ve haberleşme protokolünün neden olduğu güvenlik sorunlarıyla yüzleşmek, bilinçlendirmek ve uzmanlık seviyesini artırmak için kullanılabilir. Bu çalışmada, ADS-B teknolojisinin güvenlik analizi, atak çeşitleri yöntemlerine göre sınıflandırılarak okuyucuya sunulmuştur. ADS-B teknolojisini güvenli hale getirmek için bir dizi metodlar karşılaştırmalı olarak anlatılmış, uygulanabilirlikleri hakkında yorumlar yapılmıştır.