Nebiye Musaoglu

Use of Remotely Sensed Data for Analysis of Land-Use Change in a Highly Urbanized District of Mega City, Istanbul

The study forms an example on monitoring and understanding urban dynamics by using remotely sensed data. The selected region is a rapidly urbanizing district of the mega city Istanbul, Gaziosmanpasa, whose population has almost doubled between years 1990 and 2000. The significance of this district besides its urban sprawl is that 61% of its land lies within the boundaries of an important drinking water reservoir watershed of the mega city, the Alibeykoy Reservoir. The land-use/cover changes that has occurred in the years of 1987 and 2001 are analyzed by utilizing a variety of data sources including satellite images (Landsat TM image of September 1987 and Landsat ETM+ image of May 2001), aerial photographs, orthophoto maps, standard 1:25000 scale topographic maps, and various thematic maps together with ground survey. Land-use changes are analyzed on the basis of protection zones of the reservoir watershed and the conversion of bare land and forests to settlements are clearly observed despite the national regulation on watershed protection. The decline of forests within the protection zones was from 69% to 63.6% whereas the increase in settlements was from 0.8% to 3.9%. The associated impact of establishing new residential sites with insufficient infrastructure is then linked with the water quality of the reservoir that has already reached to Class III characteristics regarding the recently revised national legislation stating that any class exceeding Class II cannot be used as a drinking water supply that in turn, had consequences on regulating the water services such as upgrading the existing water treatment plant. The paper aims to help the managers, decision-makers and urban planners by informing them of the past and current land-use/cover changes, to influence the cessation of illegal urbanization through suitable decision-making and environmental policy that adhere to sustainable resource use.

Use of remote sensing and geographic information systems in the determination of high-risk areas regarding marine traffic in the Istanbul Strait

Istanbul Strait, Bosphorus, is one of the important waterways of the world due to its combination of natural beauty, human resources, and the high number of oil-carrying tankers passing through it. A considerable increase in the number of vessels over the past decade has indicated the high potential for oil spillage and fire hazards. This study aims to determine the coastal areas that are under an oil spill/fire/explosion risk in the Istanbul Strait by using geoinformatics. Remote sensing technology, providing relatively quick and low-cost analysis of large areas, is used for classifying the shoreline and land-use activities in the fore-scene and back-scene zones followed by assigning risk scores to various GIS data layers and suitability evaluation based on the weight of each score. The risk components are prioritized and layers are allocated according to their risk scores. Major components that classify risk-posing areas are accident likelihood, number of historical assets, human-use resources, population, and lack of critical facilities. Segment-wise risk levels that resulted in comparatively higher scores indicate the vulnerable areas along the Strait to draw the attention of the society and the decision-makers who are responsible for the policy implications. The study acts as a guideline for developing coastal management strategies and implementing corresponding human policies.

Assessing the vulnerability of a forest ecosystem to climate change and variability in the western Mediterranean sub-region of Turkey: future evaluation

This study evaluates the multifactorial spatial modelling used to assess vulnerability of the Düzlerçamı (Antalya) forest ecosystem to climate change. This was done to produce data, to develop tools to support decision-making and the management of vulnerable Mediterranean forest ecosystems affected by climate change, and to increase the ability of these forest ecosystems to adapt to global change. Based on regionally averaged future climate assessments and projected climate indicators, both the study site and the western Mediterranean sub-region of Turkey will probably become associated with a drier, hotter, more continental and more water-deficient climate. This analysis holds true for all future scenarios, with the exception of RCP4.5 for the period from 2015 to 2030. However, the present dry-sub humid climate dominating this sub-region and the study area shows a potential for change towards more dry climatology and for it to become semiarid between 2031 and 2050 according to the RCP8.5 high emission scenario. All the observed and estimated results and assessments summarized in this study show clearly that the densest forest ecosystem in the southern part of the study site, characterized by mainly Mediterranean coniferous and some mixed forest and maquis vegetation, will very likely be influenced by medium and high degrees of vulnerability to future environmental degradation, climate change and variability.

Assessing vulnerability of a forest ecosystem to climate change and variability in the western Mediterranean sub-region of Turkey

Climate change is a real, pressing and significant global problem. The concept of ‘climate change vulnerability’ helps us to better comprehend the cause/effect relationships behind climate change and its impact on human societies, socioeconomic sectors, and physiographical and ecological systems. In this study, multifactorial spatial modelling evaluated the vulnerability of a Mediterranean forest ecosystem to climate change and variability with regard to land degradation. This produced data and developed tools to support better decision-making and management. As a result, the geographical distribution of Environmental Vulnerability Areas (EVAs) of the forest ecosystem is the estimated Environmental Vulnerability Index (EVI) values. These revealed that, at current levels of environmental degradation, physical, geographical, policy enforcement, and socioeconomic conditions, the area with a “very low” degree of vulnerability covered mainly the town, its surrounding settlements and agricultural lands found principally over the low, flat travertine plateau and the plains to the east and southeast of the district. The spatial magnitude of the EVAs of the forest ecosystem under current environmental degradation was also determined. This revealed that the EVAs classed as “very low” accounted for 21% of the area of the forest ecosystem, those classed as “low” for 36%, those classed as “medium” for 20%, and those classed as “high” for 24%.

Spatial Analyses for Environmental Impacts of Landfill Areas

This study presents significant spatial and temporal aspects of solid waste management on a case study conducted at the Istanbul Metropolitan area, where existing models of waste management have significant limitations due to limitations of handling spatiality and temporality. Since the decision making process should be performed over time and across space, remote sensing technology provides mature solutions. In order to analyze the changes IRS 1C PAN (5×5 m spatial resolution and dated 2000) and the IKONOS MS (4×4 m spatial resolution and dated 2004) images have been used. For the landfill areas, Istanbul Metropolitan area currently involves two sites, 1/5000 scaled map and both satellite images were overlaid in order to visualize the differences between reserved area and used area of the landfill. In order to analyze the flow direction of landfill areas towards watershed areas a Digital Elevation Model (DEM) was constituted and analyses were performed. The spatial and temporal changes of the two landfill areas were detected and results were discussed.

Impacts Assessment of Newly Constructed Highways via Spatial Information Sciences

This paper presents a comprehensive framework for determining the interaction between transport, land-use and environmental impacts, where the developed concepts were tested using a case study. Two bridges, connecting Europe in Asia and their peripheries, and one of the alternatives of the newly planned third bridge at the Istanbul Metropolitan area were selected. The constructed transportation infrastructures had drastically changed the land-use profile and still have negative impacts on environment. After exploring the interaction systematically, possible impacts of the new bridge were investigated in this study. In order to detect changes and to predict the potential impacts, former land-use, transport infrastructure data were integrated with satellite images retrieved in 1963, 1987, 1992, and 2002. A four kilometers band was created referencing the center-line of the highway and this process was repeated for all satellite data. The land-use classes for exploring the interaction were settlement, transportation infrastructure, green land and forest, water and barren land. Within this range, the images were classified and results were compared statistically, in order to analyze the impact of transportation infrastructure. In order to explore the interaction between transport, land-use and environment, a spatio-temporal conceptual data model was designed to project the impacts of the newly planned third bridge. The results show that, easy accessibility caused by the development in transportation infrastructures created an attraction in this region and urban areas expanded rapidly. In year 1987, where the construction of the second bridge was recently begun, the 23% of the selected band was determined as settlement. In the year 1992, after the second bridge was full in operation, the percentage of the settlements was increased 12% only within a period of 5 years. In order to estimate the impacts of third bridge to the study area, the second bridge feet at the Asian side was selected. According to the classification results of the year 1963, the settlement class retrieved showed an increase of 339.5%, where 44.2% decrease was detected in the green areas. By means of the shortly described methodology and achieved results, integrated data collection and analysis was highly emphasized and the new proposed framework might be used effectively for aiding authorities and decision-makers to better understand the main causes of interaction, to inform them of the changing conditions and monitoring similar projects elsewhere.