טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentBauer Bnaya
SubjectBranching Morphologies - Cities and Corals
DepartmentDepartment of Architecture and Town Planning
Supervisors Dr. Ariel Tibi
Professor Uri Shavit
Full Thesis text - in Hebrew Full thesis text - Hebrew Version


Abstract

Urban growth enables conservation of wild areas, equal opportunities for individuals to develop their abilities and the cultural-economical-scientific progress of mankind. Altogether there is a cost emerging from the rapid expansion of cities in all three dimensions. This expansion was based upon morphology intended for thousands, not for the millions of people inhabiting cities today.


One of the problems cities face today is poor air flow in city centers. The existing urban morphology “blocks” air flow, causing various phenomena such as air pollution and “urban heat islands” to multiply. This research compares the urban morphology with the natural morphology of branched corals, where water flow phenomena are essential to the survival of the colony, in order to face this challenge.


Branched corals are colonies of marine invertebrates, named polyps, that build together a calcareous exoskeleton. The branched morphology enables the water flow of the ocean to penetrate deeply into the colony providing nutrients and allow the exchange of oxygen, carbon-dioxide and waste.


The research goal is to compare geometrical parameters that define the urban and coral morphology while emphasizing on flow related parameters.

In order to compare cities and corals, this research focused on three systems: the city of Manhattan as an example of orthogonal urban system, and Acropora Humilis and Pocillopora Damicornis, representing branched coral morphologies. A three-dimensional digital model was built for Manhattan while the corals were scanned using a C.T. scanner. This morphological data set was divided into three main levels: the whole system; horizontal sections through the systems, and discrete elements (buildings or coral branches).


Several significant results were found: The porosity of Manhattan and the corals are significantly different from other systems such as soil and forests. This validates our basic assumption: cities and corals have a common morphological base for comparison. The average tortuosity and the permeability of all three systems also showed similarities. On the other hand, the spread of coral branches and city buildings at various heights are different.


Two primary conclusions were drawn: Manhattan is built upon orthogonal grid which is beneficial at the ground level, but a hexagonal grid, as corals have, might generates several advantages. Second, the urban morphology is based upon extrusion of the ground level grid. Changing the extrusion characters in different heights will enable a more anisotropic and yet deeper penetration of natural air flows into urban centers while decreasing the effect of the current morphology on the heat island phenomenon.