ABSTRACT
In certain ways there are larger systems with which we must also be concerned. Human adaptations of the environment are now on such a large scale that entire cities form a system. In a case such as Hong Kong (Fig. 1.2), the city itself forms such a complex physical structure, positioned very close to the sea, that the interaction with the principal form of action from strong winds requires an added degree of sophistication to any analysis. In the particular case of Hong Kong, the situation is made even more complex by the close proximity of buildings, causing interaction, and excitation from traffic (Fig. 1.3) and from construction (Fig. 1.4). In a case such as San Francisco (Fig. 1.5), the earthquake risk is compounded by the use of infill in some areas. The juxtapositioning of sea, city and mountains is exemplified by the Lagoa region in Rio de Janeiro (Fig. 1.6), although in this case the wind action is rather less important than issues of economically induced quality assurance.
