**2.3 Demographic explosion effect**

Facing the need of expansion due to economic growth, cities used to be thought of in a centrifuge manner. The borders moved faster than the planning authorities attempted to solve or even understand problems. The growth had been predictable or at least reachable by remedial strategies for centuries, but the demographic explosion of the 60´s made an abrupt change on the previous inertia, mainly in the named "developing world". In this part of the earth, the situation has not just been severe because of the rapid urban rendering, expansion and consequent deterioration of places, but it has been aggravated by social unbalance, socio-political complex situations, and extreme environmental damage as well as consequent landscape disfigurement.

Facing the growth from this time onwards, planning authorities were at the beginning focused to solve issues from a single functional point of view, ordering and distributing land uses, as if the habitat were independent of inhabitants. That was the time of "zoning", a technical exercise that minimized the importance of the human behaviour of the diverse groups of population and communities and the significance of natural determinants of the territory.´

The evident dysfunction of that planning system and the increasing social set of problems drove planners attention to society; that is to say, to the collective human factor. Aspects such as education, health, the right to work, social security, among others became even more

Facing the need of expansion due to economic growth, cities used to be thought of in a centrifuge manner. The borders moved faster than the planning authorities attempted to solve or even understand problems. The growth had been predictable or at least reachable by remedial strategies for centuries, but the demographic explosion of the 60´s made an abrupt change on the previous inertia, mainly in the named "developing world". In this part of the earth, the situation has not just been severe because of the rapid urban rendering, expansion and consequent deterioration of places, but it has been aggravated by social unbalance, socio-political complex situations, and extreme environmental damage as well as

Facing the growth from this time onwards, planning authorities were at the beginning focused to solve issues from a single functional point of view, ordering and distributing land uses, as if the habitat were independent of inhabitants. That was the time of "zoning", a technical exercise that minimized the importance of the human behaviour of the diverse groups of population and communities and the significance of natural determinants of the

The evident dysfunction of that planning system and the increasing social set of problems drove planners attention to society; that is to say, to the collective human factor. Aspects such as education, health, the right to work, social security, among others became even more

Fig. 3. Adelaide, South Australia. Source: Google Earth 2012

**2.3 Demographic explosion effect** 

consequent landscape disfigurement.

territory.´

important than the assignation of uses to the land. In Colombia the beginnings of this kind of planning attitude could be placed in the 80´s decade, to be followed in the 90´s by the environmental worry.

Environmental issues have been much treated since the Stockholm Conference in 1972. But in the developing world it started to be important enough to be incorporated in local law two decades afterward. In general, the complex environmental problem seems to be increasing in a geometrical tendency, while the solutions increase in an arithmetical way.

Meanwhile, economical factors and land speculation go over the common sense of preserving resources and to treating them in a real sustainable manner. Words such as ecology, green, and sustainable, have lost their actual meaning and are used without measure. The "green wash" has invaded contemporary discourses hiding the real environmental question posed by the urban expansion.

To complete the spectrum, of zoning + social + environment, and rooted in its agglutinative and unifying role, many signals seem to point to this time being that when the integrator par excellence: THE LANDSCAPE occupies the deserved place as an important determinant in planning decision and purposes. As Sir Geoffrey Jellicoe thought *The world is moving into a phase when landscape design may will be recognized as the most comprehensive of the arts* (Jellicoe 1982).

To deal with the complex issue of indiscriminate urban expansion and moving peripheries a strategic coordination of many actors and factors is necessary. Of course the landscape design discipline is not enough but its contribution is indeed necessary first in helping to understand and balance the multiplicity of facets of the urban-rural border phenomena, and second to promote integrated answers to the complex trouble.
