Abstract
An investigation on urban change detection was undertaken in Can Tho City, Vietnam, situated on the southern bank of the Hau River in the Mekong Delta. By using multi-temporal satellite images from 1972 to 2007, spatial urban expansion in Can Tho City and temporal trends in its urban development were elucidated to comprehend the city's evolution during different periods. The Vegetation-Soil-Water (VSW) index was applied for calculating the built-up areas, while the Normalized Difference Vegetation Index (NDVI) was adopted for enhancing accuracy of land cover classes. Land cover classification based on the Support Vector Machine (SVM) was found to provide better results than the Decision Tree (DT) method that was used by previous researchers such as Huang et al. (2002), and Shafri and Ramle (2009).
The study revealed that the main direction of urban expansion in Can Tho City was north-westerly during the last 10 years followed by the rapid enlargement of the city along South-East and South-West directions. The results suggest that the more recently urbanized regions may become economically important, and therefore require quick improvements in social, economic and environmental planning. It was further observed that central districts have a population density 7 to 19 times higher than rural districts. Planned urbanization in the western direction needs to be encouraged in order to provide more opportunities for international trade and tourism in Kien Giang province due to its closer proximity with Thailand, Cambodia and Malaysia. On the other hand, the central areas of Can Tho City witnessing a high rate of urbanization may face risk of flooding and environmental degradation especially during the rainy season. Measures for better flood management in the outskirts of Can Tho City, using high resolution satellite images also need to be evaluated, with some urgency.
This study is considered useful for planners and decision makers interested in urbanization patterns of Can Tho City, which is rapidly emerging as a growth center poised to become the economic hub of the Mekong Delta by 2020.
