ASSESSMENT OF BUILT-UP EXPANSION
CHAPTER ONE
INTRODUCTION
1.0 Background of the Study
Built-up means the built- up areas, while Expansion is a space through which anything is expanded (Advanced English Dictionary). Built-up areas have been expanding throughout the world. Monitoring and prediction of the built-up is not only important for the economic development but also acts as sentinels of environmental decline important for ecologically sustainable development of a region. (ARER, 2003).
In the year 2000, urban areas occupied only about 2% – 3% of the earth’s surface; However, they sheltered nearly half the world’s population. The rapid expansion of urban areas, is dramatically changing the landscape of the urban-rural fringe, clearly highlighting the intensity of the ecological footprints of cities. The ecological footprint is defined as “the total area of productive land and water required continuously to produce all the resources consumed and to assimilate all the wastes produced, by a defined population, wherever on earth that land is located”. Kitzes, etal (2007). The wealthy quarter of the world’s population consume over three-quarters of world’s resources, and of the total global resource depletion and pollution, contribution from cities is probably 70% or more. (RWWMEIA, 1996). For example, the per capital ecological footprint of North Americans is 4-5 ha/capita, which accounts for three times their fair share of the Earth’s bounty. Similarly Japan’s footprint is about 2.5 ha/capita and the Netherland’s is 3.3 ha/capita, accounting for about eight and is times greater than the areas of total domestic territories respectively. Lenzen and Murray found Australian’s ecological footprint to be about 13.6 ha/capita, if determined in terms of actual land use on all types of land. These footprints are associated with the provision of non-farm job opportunities, shifts to higher-valued farm enterprises (such as vegetables, fruits, or livestock) to meet the demands of urban consumers.
On the other hand, the provision of environmental services and landscape amenities place heavy demands on the ecological system in terms of resource extraction, disposal of waste, and discharge of pollutants. Urbanization is mostly taking up agricultural lands and it is estimated that one to two million hectares of cropland are being taken out of production every year in developing countries to meet the land demand for housing, industry, infrastructure, and recreation. The 20th century witnessed some of the most dramatic urban transformations in the history of earth’s terrestrial environments. Lenzen, etal (2007).