Determining the performance of ecosystem services at the city or regional level cannot accurately take into account the fine differences between green or gray structures. The supply of regulating ecosystem services in, for instance, parks can differ as parks vary in their land cover composition. A comprehensive ecosystem service assessment approach also needs to reflect land use to consider the demands placed on ecosystem services, which are mostly neglected by current research yet important for urban planning.

Land use change models are powerful tools that allow planners and policy makers to assess the long-term spatial and environmental impacts of their decisions. In order for these models to produce a realistic output, they should be properly calibrated. This is usually achieved by comparing simulated land-use maps of dates in the past to reference land-use maps of a corresponding date. As land-use data are often not readily or frequently available, we propose a two-stage calibration framework that includes existing land-use maps as well as remote sensing derived maps of the urban extent.

Scientific interpretation of the relationships between urban landscape patterns and water quality is important for sustainable urban planning and watershed environmental protection.

Detailed, up-to-date information on intra-urban land cover is important for urban planning and management. Differentiation between permeable and impermeable land, for instance, provides data for surface run-off estimates and flood prevention, whereas identification of vegetated areas enables studies of urban micro-climates. In place of maps, high-resolution images, such as those from the satellites IKONOS II, Quickbird, Orbview and WorldView II, can be used after processing.

Dhaka city in Bangladesh has been passing through a hasty process of urbanization and population growth since the last few decades. Rapid growth of population, unplanned urbanization and industrialization in the periphery has generated pressure to the changes in land use pattern, which has also caused huge urban expansion. This expansion process is engulfing cultivated land, vegetation, wetlands and water bodies without considering their environmental impacts.

Climate change and energy saving are challenging the city and the territorial organization. Innovative spatial and urban planning methods and procedures are required, and new approaches and instruments must be elaborated and applied in order to shift from the building scale to the urban and territorial ones.

Today, more than half the world’s population lives in cities. By 2030, it is projected that 6 in 10 people will be urban dwellers. By 2050, the figure will have risen to 6.5 billion people; representing two-thirds of all civilization. Taking into account the increasing rural to urban migration and the rapid growth of cities in the developing world, it is clear that cities face a myriad of problems that may hinder planned growth and development.

This paper has been compiled by Ndifuna Ukwazi following extensive consultation with practitioners and experts in housing finance, architecture, social housing, city planning, urban design, and local and provincial government.

• There is an accute lack of well-located urban housing that is adequate, secure, and affordable. The global affordable housing gap is currently estimated at 330 million urban households and is forecast to grow by more than 30 percent to 440 million households, or 1.6. billion people, by 2025.

The New Urban Agenda represents a shared vision for a better and more sustainable future – one in which all people have equal rights and access to the benefits and opportunities that cities can offer, and in which the international community reconsiders the urban systems and physical form of our urban spaces to achieve this.

In September 2015, the United Nations Sustainable Development Summit adopted a new framework to guide development efforts between 2015 and 2030, entitled “Transforming our world: the 2030 Agenda for sustainable development”.1

Cities function in an efficient, equitable and sustainable manner only when private and public spaces work in a symbiotic relation to enhance each other. Public space generates equality, however in the past decades it has been drastically been reduced. Inadequate, poorly designed, or privatized public spaces generate exclusion and marginalization.