Sponge like City: An Urban Growth Absorption Model

By - Anoop Jha

Growth and density saturation due to city built mass limitation

Considering city as a sponge with its intricate complexity of mass and void representing interplay of built mass and open spaces of city, both of these masterpieces of structure and space share a very important and similar trait i.e. absorption capacity. One can absorb and hold liquid in its recesses and voids while other can absorb population in its built mass, a slight external pressure on a sponge can cause absorbed liquid to move to and fro within the cavities of sponge and a little higher pressure can cause liquid to be discarded from the sponge. Similarly if we compare city population with that liquid in sponge it is also dynamic in nature and moves to and fro within and outside the city limit, but one crucial thing to be notice here is that both the systems have a limit to absorb in other words they reach a saturation point after some point, after which liquid as well as population is forced to make its way outward towards and beyond the edge of sponge and city respectively. This phenomenon of absorption is related to physical properties of sponge and city.

When it comes to planning or redevelopment of a city, the question here is that who is to decide the critical saturation point of an existing or new city and What should be the absorption limit of a city or urban settlement after which it would be a compromise with the quality of life of inhabitants considering there is no change in built mass of city?  What should be the ideal density of a city considering the emerging new technological possibilities to create large sustainable building complexes, faster horizontal and vertical transport technology? Have we already reached the critical point in most of the cities throughout the world or there is enough scope for population absorption by restructuring, redeveloping any city. Are we able to somewhat predict the sustainable density for a city based on some magical formula?

The challenge here is for the urban planners is to draft a strategic blueprint to create a city flexible and scalable enough to renews itself from time to time adopting latest technological, architectural and planning interventions to absorb the varying growth in course of time for a sustainable future,  considering the scarce land and other urban resources.