Edits made by Don Brown on 15 July 2015
Poor residents in South Asian cities live together in high numbers that easily surpass the limits set in planning regulations. What can be done to create more housing for the poor without compromising on safety and liveability?
Using satellite imagery, census data and historical maps, we report on density variation among cities the world over. We find significant differences in the average population density in the built-up areas of a global sample of 120 cities: In 2000, average density was 28±5 persons per hectare in cities in land-rich developed countries, 70±8 in cities in other developed countries, and 135±11 in cities in developing countries.
Economists have emphasized the importance of geography in growth and competitiveness, yet rarely has there been literature that identifies the cause of growth in some cities but not in others. Why was the city of Bangalore more attractive for industries than Karachi? What are the defining characteristics of successful cities? This book seeks to answer these questions through multiple consultations with leading experts and in-depth research on urban centers.
Although only a small percentage of global land cover, urban areas significantly alter climate, biogeochemistry, and hydrology at local, regional, and global scales. To understand the impact of urban areas on these processes, high quality, regularly updated information on the urban environment—including maps that monitor location and extent—is essential.
This paper aims to make transparent one economist’s views on density. I start by clarifying different definitions and their relationship to one another – which helps to explain why people have such very different ways of thinking about density.
Land development is an important component in sustainable development because it is where our food and raw materials come from and it is also the habitat for wildlife and fauna.
We created a new data set comprising the universe of all 3,649 named metropolitan agglomerations and cities that had populations in excess of 100,000 in the year 2000, their populations in that year, and their built-up area identified in the MOD500 map, currently the best satellite-based global map of urban land cover.
Abstract
Cities the world over are highly fragmented. The fragmentation of the built-up area cities by the open spaces interpenetrating them is a key attribute of urban-sprawl, and sprawl as fragmentation, as distinct from sprawl as lower-density development, is now a universal feature of cities. Using satellite images and census data for 1990 and 2000 for a global sample of 120 cities, we find that cities typically contain or disturb vast quantities of open spaces, equal in area, on average, to their built-up areas.
