El medio físico en la planificación y gestión del territorio. Algunos ejemplos

Abstract

Physical environment has exerted a noteworthy influence on the location of human settlements. Modern cities have deeply changed their environment, often with negative a impact. The inclusion of the physical environment analysis into land-use planning can be justified by its restrictions on the urban growth, the necessity of minimizing the changes on the dynamics of natural systems, and the efficiency in the natural ressources management. According to their objectives, physical environment studies can be classified in land-use planning and environmental impact studies.

The Besos river delta is shown as an example of conflictive physical environment management. Last decades pumping sites in the delta shifted and changed the groundwater levels. Basements built while levels were low, were drawn after the abandonment of the wells. To solve this problem, intensive pumping was decided in some cases to withdraw the water table. This solution along with new wells performed, induced the marine water to penetrate into the delta, forcing tlie abandonment of some water supply wells.

Decission-makers hardly perceive the consequences of their decissions on the environment because of the natural processes time-scale.

This is especially important in complex natural systems. In the Ebro river basin, headwater corrective works and water schemes are responsible for the present instability and regression at the delta front. We conclude that only a global management that takes into account the dynamics of natural systems would be able to give an answer to the problems created.