The relation between urban form, its density (aerial and accessible) and the distribution of functions

Paper in proceeding, 2011

Mixed use development, one of the “mantras in contemporary planning” is a multi-criterion and multi-scalar concept which has various definitions. For this research mixed-use is defined as functional mixed-use and our main interest is to understand the spatial conditions needed to increase the diversity of uses (mix) by combining compatible functions. To analyse the compatibility of land uses and the importance of specific spatial conditions, the three most relevant factors of urban form are chosen: density, accessibility and mixed-use composition. The chosen factors are measured by methods of spacematrix, place syntax and MXI, using the city of Rotterdam (southern part) as case study. The three levels of analysis that are used are: (1) between all the urban blocks, (2) between mixed-use and mono-functional blocks, (3) within different types of mixed-use blocks. The results demonstrate interrelationships between the intensity of land uses on different scale levels. For example, residential density in a biking neighbourhood (radius 1.000) correlates to the density of commercial services in the same or a lower radius, but with of density of cultural and recreational services in a higher radius. In other words, cultural and recreational services need a larger catchment. Furthermore it is demonstrated that mixed-use blocks are denser and have higher accessibility to residential/work and commercial functions. Concerning mixed-use blocks, the results demonstrate a complementary behaviour between the existing functions within a mixed-use block and its surrounding. For instance, blocks with a bi-functional mix of housing and amenities are located in the vicinity of blocks with more work opportunities and blocks consisted of housing and working have a higher access to amenities in their surrounding. Identifying such spatial interrelations between land uses can be of great importance for urban planning and design. It can assist in the process of decision making by providing answers to the questions such as: If we want to create a city centre here, where should we improve accessibility then? Or, where should we, based on the existing distribution of shops, increase the residential density to use the existing potential best?