Dursun Zafer Seker

Photogrammetry and geographic information systems for quick assessment, documentation and analysis of earthquakes

Abstract After a catastrophe like an earthquake, one on the most important problems is to provide shelter and housing for the homeless. To this end, it is necessary to decide if a building is still habitable, or if it is has to be renovated or even torn down. A prerequisite for such decisions is the detailed knowledge about the status of the building. Earlier earthquakes revealed problems in the processes of documenting and analysing the building damage, as they demanded much effort in terms of time and manpower. The main difficulties appeared to be because of the analogue damage assessments which created a great variety of unstructured information that had to be put in a line to allow further analysis. Apart from that, documentation of damage effects was not detailed and could only be carried out on the spot of a disaster. The aim of this study is to make an improvement, using combination of Geographic Information Systems (GIS) as a management and data analysis tool and photogrammetry as a documentation method. Photogrammetric data acquisition is achieved using a CCD camera and the digital photogrammetric software package PICTRAN by Technet. The information system part is the GIS package ArcView by ESRI. The combination of rapid data acquisition and GIS offers a quick assessment of the situation and the possibility of its objective and holistic analysis. This is the prerequisite for a quick initiation of appropriate measures to help people.

A Novel Algorithm for Coastline Fitting through a Case Study over the Bosphorus

Abstract Decrease of habitat, coastal erosion, and shoreline changes are recent issues for coastal management. In this study, an algorithm which extracts coastlines efficiently and automatically by processing low- or medium-resolution satellite images has been developed. The junction of sea and land is a common result yielded by the automatic coastline extraction method. In this study, CORONA (1963), IRS-1D (2000), and LANDSAT-7 (2001) satellite images for the same region in Istanbul, Turkey were used. A novel algorithm was developed for automatic coastline extraction. The algorithm is encoded in a C++environment. The results of automatic coastline extraction obtained from different images were compared to the results derived from manual digitizing. Random control points which are seen on every image were used. The average differences of selected points were calculated. Obtained results from selected points were rendered as 3 pixels on the CORONA and IRS-1D images and as 2 pixels on the LANDSAT-7 image. These show that the differences are similar, although different images were used. On the other hand, the results are acceptable compared to manual digitizing.

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 GIS in epidemiology: a case study in Istanbul.

In this study, the procedure of using GIS for tracking the distribution of measles in a district of Istanbul was performed. The aim of the study is to present the available questionnaire data, which were collected during the measles epidemic, by means of maps. The designed maps show the relation and the distribution of individual cases on time and spatiality. A database is designed according to the questionnaires. Geo-spatial distribution of measles cases was analyzed. The obtained results were discussed and presented.

Multi-Temporal Analysis and Mapping of Coastal Erosion Caused by Open-Mining Areas

Coastal zones are exposed to erosion due to natural and human-induced activities around the world. The land use of the coastal zone in the northern part of Istanbul, Turkey, has been changing due to open-pit coal mining begun in 1980. The objective of this study is to determine the changes that occurred in a selected coastal zone by utilizing interpretations of multi-temporal LANDSAT satellite data. Satellite images of the zone taken during the years 1984, 1992, and 2001 were transformed to the universal transverse mercator (UTM) coordinate system, and 17 bands of images for each of these years were interpreted using layer-stack method. A new red, green, and blue (RGB) image including infrared band of each year was created. These findings show that 304.7 ha area of sea was filled with soil between years 1984 and 1992. However, the total area filled between 1984 and 2001 was only 67.7 ha, due to the fact that 237.0 ha was removed by coastal erosion after year 1992.

Monitoring Spatial and Temporal Land Use/Cover Changes; a Case Study in Western Black Sea Region of Turkey

Rapid land use/land cover changes have taken place in many cities of Turkey. Land use and land cover changes are essential for wide range of applications. In this study, Landsat TM satellite imageries date from 1987, 1993, 2000 and 2010 were used to analyse temporal and spatial changes in the Western Black Sea Region of Turkey. Zonguldak and Eregli two largest and economic important cities which have been active coal mining and iron fabric areas. Maximum Likelihood Classification technique was implemented and the results were represented in classes of open area, forest, agricultural, water, mining, urban and pollution in the sea. Urban areas on both cities increased from 1987 to 2010. The agricultural and open areas from 1987 to 2010 decreased in parallel to land use and land cover change in both cities. Meanwhile, forest areas increased continuously with about 20 % from 1987 to 2010 in both cities. As industrial activity, the coal fields doubled from 1987 to 2010.

An Integrated Approach to Temporal Monitoring of the Shoreline and Basin of Terkos Lake

ABSTRACT Bayram, B.; Seker, D.Z.; Acar, U.; Yuksel, Y.; Guner, H.A.A., and Cetin, I., 2013. An integrated approach to temporal monitoring of the shoreline and basin of Terkos Lake. In this study, the combinatorial shoreline and land-use/cover (LULC) changes in the shoreline and basin of Terkos Lake were examined using Landsat satellite images taken in 1986, 2001, and 2009. Terkos Lake is one of seven freshwater-supplying reservoirs of Istanbul, and its borders are very close to the Black Sea. Terkos Lake is in danger because of the approach of its borders to the Black Sea. Changes in the lakes shoreline have been measured using an algorithm based on a hybrid region growing image-segmentation method. The LULC changes have been monitored using object-oriented image-processing software to provide understanding of the impact of these changes on the shoreline. Overall accuracy of the classification reached 92% for 1986, 94% for 2001, and 93% for 2009. The maximum shoreline change measured was 280 m in 23 years. Also, the obtained shoreline and LULC changes have been integrated into the long-term analysis of wave and wind characteristics and sediment-transport calculations. The calculations have been validated with shoreline changes, which have been automatically extracted from Landsat satellite images. The basic outcomes and proposals have been suggested to deal with uncontrolled human activities in the study area.

Application of Water Quality Modelling as a Decision Support System Tool for Planned Buyuk Melen Reservoir and Its Watershed

Istanbul, the largest metropolis of Turkey and one of the most crowded metropolises in the world, is facing the risk of water scarcity. Analyses indicated that one of the alternative solutions coping with this problem is water transfer from a watershed that is located outside the administrative boundaries of Istanbul. Due to its water potential and relatively less degraded water quality, Buyuk Melen Watershed was considered to be the most feasible option. As the result of analyses, State Hydraulic Works (DSI) has planned construction of a reservoir in the Buyuk Melen Watershed to supply the required amount of water for Istanbul also in low flow seasons. Since the reservoir will be located at the downstream region of the watershed, its water quality will be affected by human-induced activities, thus measures need to be taken to prevent pollution prior to reservoir construction. Quantifying the response of the planned reservoir to external pollution loads is an important step in the planning and management of the watershed. Mathematical modelling is a useful tool for estimating the future water quality and understanding the possible responses of the reservoir to various pollution loads. In this study, a water quality model capable of simulating hydrodynamics, transport and water quality in reservoirs is used for preliminary estimation of possible impacts of several management options in the watershed. Model results indicated that, all of the point sources in the watershed must be controlled by advanced wastewater treatment and should be diverted from the streams and the planned reservoir. Model results also indicated that reduction of agricultural diffuse loads by 30–40% is expected to have a perceptible improvement of reservoir water quality.

Use of a geographic information system in an epidemiological study of measles in Istanbul

A geographic information system was used in an epidemiological study of measles in Istanbul, Turkey. The aim was to obtain more reliable results and to increase the facilities for spatial monitoring in epidemiological studies. The Gaziosmanpasa district of Istanbul was selected as it experiences the highest level of migration, and currently has the highest population growth rate of the citys districts. The epidemic distribution of measles was investigated on the basis of examination of 320 children. The number, geographical distribution, complications and time of measles outbreaks were analysed and represented in thematic maps (a small selection is shown in this paper). The results were evaluated and, in view of these results, new vaccination plans were arranged.

GIS based spatial pattern analysis: Children with Hepatitis A in Turkey

ABSTRACT This study aimed to provide an insight into the geographic distribution of Hepatitis A incidence considering their temporal distribution, spatial patterns, hot spots and clusters identification in three different age‐group (0–4, 5–9 and 10–14) in Turkey. Province based tabular data, including monthly numbers of Hepatitis A cases in children, and the populations from 2001 to 2011 were used as the basic input of the study. Time series maps were created using Geographic Information Systems (GIS) to introduce the temporal changes in the morbidity rates of Hepatitis A. The spatial variation of Hepatitis A was measured using Morans I at the global level and the local indicators of spatial associations (LISAs) Morans I and Getis‐Ord Gi *(d) in order to identify influential locations through clusters and hot spots detection of Hepatitis A cases. The morbidity rates in children under the age of 5 were found significantly lower than the other age‐groups, whereas the age‐group 5–9 revealed the highest morbidity rates in the study area. The morbidity of Hepatitis A was detected very high for the years 2001, and 2005–2007. The identification of the highly vulnerable provinces was conducted using local Morans I and local Getis‐Ord Gi *(d). The majority of clusters and hot spots were detected to be agglomerated in the Eastern Mediterranean and South‐Eastern Anatolian Regions and Ceyhan, Asi and Southeast part of Firat‐Dicle river basins in Turkey. HighlightsAge‐group 5–9 reveals the highest morbidity rates.Hepatitis A morbidity reaches the highest in 2001, and between 2005 and 2007.Clusters mostly appear in the South‐Eastern regions of Turkey.Hepatitis A is significant in Ceyhan, Asi and Southeast of Firat‐Dicle basins.