Change Detection of Built-up Areas on the Coast Using Spatially Enhanced SPOT Panchromatic and Landsat TM images

Abstract

This paper aims to map and analyze past and present spatial patterns of built-up areas in a coastal town on the Mediterranean coast of Turkey, which undergone rapid development of multistory summer apartments in the last three decades. Resolution merge operations were employed for each date using SPOT Panchromatic and Landsat TM images to produce spatially and spectrally enhanced images. Built-up features on the enhanced images were analyzed and the resulting maps were analyzed in terms of changes of the built-up areas and landscape transformations that they created. Causes of these changes and the resulting change patterns were discussed.

Key Words: change detection, built-up areas, resolution merge, Mediterranean coast

Introduction

Urban growth patterns, which reflect expansion of built up areas, vary across different regions and countries for different time periods (Wu and Zhang, 2012). Urbanization process is a major factor of change in the Mediterranean region, where pre-urban cities and new urban settlements have raised over the past decades (Weber and Puissant, 2003). Urbanization is a complex process that causes profound changes not only in cultural, sociological and economical aspects but also in ecological aspects of the environment (Wu and Zhang, 2012).  Conversion of natural land cover and rural agriculture to mostly residential uses is the greatest source of landscape fragmentation (Munroe et al., 2005).  It results from the complex interaction between policy, biophysical characteristics and socioeconomic development pressure (Munroe et al., 2005). Landscape fragmentation due to road construction, urbanization, land use/land cover change (LUCC) and other anthropogenic factors leads to more and smaller habitat patches, increased isolation among habitat patches, decreased complexity of patch shape, and higher proportions of edge habitat (Saunders, Mislivets, Chen, & Cleland, 2002). The need to detect and monitor urbanization is increasing, given its multifaceted nature and the diversity of environmental problems that it creates.

The eastern Mediterranean part of Turkey has the largest continuous extent of natural coastal habitats on the Turkish Mediterranean coast (Berberoğlu, 2003). However, this coastal region is undergoing rapid development with consequent impacts (Berberoğlu et al., 2004). Agricultural expansion and urbanization are the most prominent forces fueling destruction trends in (semi)natural vegetation cover in the Mediterranean. Agriculture expands over marginal areas, while urban areas grow at the expense of highly productive croplands on the coast, leading to even more increased demand for new agricultural areas (Alphan and Yılmaz, 2005).

The main objective of this paper is to provide a methodology for evaluating change of the built-up areas on a narrow coastal strip using image enhancement and change detection techniques. The changes were discussed from landscape transformations and environmental resource management points of view. 

Study Area and Methodology

Study area is located in the Eastern Mediterranean coast of Turkey. The area is subject to dramatic landscape changes mainly driven by development of multistory summer apartments occupying a narrow strip on the coast.

This area has recently undergone rapid and extensive changes due to unprecedented tourism development on prime agricultural lands and agricultural expansion on the foothills of Taurus Mountains. This process changes spatial configuration of agricultural areas from previously dominant citrus plantations existed on the coast to a mixed pattern of greenhouses and citrus plantations behind the developed coastal land (Alphan and Derse, 2012). Development that started in mid-1980s and concomitant improvement of transportation infrastructure have made the region accessible from many different parts of the country.

This study focuses on producing change information of built-up areas. The impacts of these developments on this coastal environment such as landscape fragmentation were interpreted on the basis of spatial characteristics of the change. Resolution merge operations were employed using SPOT Panchromatic and Landsat TM images. Built-up features on spatially and spectrally enhanced images were mapped. The results were interpreted in terms of changes of the built-up areas and landscape transformations that they created. Causes of these changes and the resulting change patterns were discussed.

Results

                The aim of this paper is to detect spatial coverage of built up areas and its change over time in the case of a coastal town located on the Mediterranean region of Turkey. Changes were quantified and the results showed that building development has taken place both on the coastline and in the inner coast (i.e., 100-500m landwards from the coastline). However, characteristics of the development were quite different. Providing change information helped to understand development trends on the coastline and inner coast from past to present and underlying driving forces. Built-up areas along the coastline consisted of large multistory buildings, sometimes as tall as 60 m. Building development behind the coastline, however, mostly occurred due to expanding local settlements that consist of small residential single-story buildings.

Acknowledgements

This project is supported by Scientific and Technological Research Council of Turkey (TUBITAK) under the grant number CAYDAG 111Y253.