Rapid economic development and phenomenal urbanization rates in practically all countries in every region of the world have been leading to an unprecedented transformation of urban land. One facet of this transformation is quantitative. Huge quantities of additional land are being brought under urban uses by cities which are continually gaining population and expanding their productive and supporting infrastructure bases through the dynamics of development and population concentration. A large number of villages in the shape of new towns or townships are being created. Quite often the additional urban land requirements are being met at the cost of valuable agricultural lands. In several countries, especially in Asia and Europe where total land resoruces are inadequate in relation to their present demographic pressures or current productivity levels or both, this aspect causes considerable concern. Even in countries, such as the United States, Canada and Australia, where man-land ratios are quite comfortable and resources are not as scarce as in the developing nations, the task of procuring and more than that, preparing the huge amounts of land needed for urban uses pose serious practical difficulties arising particularly out of prohibitive land values, the nature of land tenures and legal, political and organizational impediments.
The other and more important facet of this transformation is qualitative. Land under existing urban uses is providing inadequate while rising space standards and new activities are making their own competing demands on urban land. Advancing technology, the expanding productive apparatus, widening and deepening urban infrastructure and diversifying economic bases do in fact necessitate nothing less than a drastic restructuring and reallignment of the urban, and especially metropolitan, land use patterns consistent with modernization trendss. In varying degrees in various cities of different countries and continents urban land use patterns are being altered very materially and substantially to accomodate the new techno-economic, physical and social changes.