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Anthropogenic disasters

"1 I I I I I r 10-3 10-2 10-1 1 101 102 103 Spatial scale (km2)

Figure 7.3 Spatial and temporal characteristics of some natural and anthropogenic disasters, after Vitousek (1994) and Di Castri and Hadley (1988). The temporal dimension is being depicted by the specific recovery times after the disturbances have taken place.

"1 I I I I I r 10-3 10-2 10-1 1 101 102 103 Spatial scale (km2)

Anthropogenic disasters

Ground water Pollution exploitation Urbanisation Modern Salination agriculture Acid Slash and rain burn Oil spill

~~1 I I I I T~ 10-3 10-2 10-1 1 101 102 Spatial scale (km2)

Figure 7.3 Spatial and temporal characteristics of some natural and anthropogenic disasters, after Vitousek (1994) and Di Castri and Hadley (1988). The temporal dimension is being depicted by the specific recovery times after the disturbances have taken place.

holon. Consequently, the biological potential is modified and then also higher levels of the hierarchy can be affected.

In the 1900s, another important feature of disturbance has been discussed: There are certain disasters, which provoke disturbances that are necessary for the long-term development and stability of the affected system. For instance, forest fires are events that necessarily belong into the developmental history of forests. Therefore, the concepts of stratified stability or incorporated disturbances have been set up (e.g., Urban et al., 1987; van der Maarel, 1993). They can today be used as illustrative examples for the natural functioning of the adaptive cycle concept.

This cannot be assigned to the anthropogenic disturbances. Although in the figure only a small selection of such processes can be found, it is obvious that the balance of the natural disasters is not reached by these processes. The influences seem to be so manifold and complex, that only a minor scale dependency can be found. Furthermore, the recovery potential may be based on internal processes and is therefore not dependent on the quantification of openness.

The figure can also be used to illustrate the quantification of openness as introduced in Section 2.6 (Table 2.3). The recovery time is approximately proportional to the periphery of the affected area and can be represented by the square root of the area. As seen in the figure for natural disasters, a meteor strike is affecting an area of approximately 6 orders of magnitude higher than rainstorms. The recovery time after the strike should therefore require 3 orders of magnitude longer time than after the rainstorm. This is approximate due to the relationships of the peripheries, which expresses the exposure of an area to the environment.

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The Basic Survival Guide

The Basic Survival Guide

Disasters: Why No ones Really 100 Safe. This is common knowledgethat disaster is everywhere. Its in the streets, its inside your campuses, and it can even be found inside your home. The question is not whether we are safe because no one is really THAT secure anymore but whether we can do something to lessen the odds of ever becoming a victim.

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