6
2.1
Definitions of flooding
Definitions of floods are useful for assessing the health effects, the damage to infrastructure and the financial toll they can cause and deciding on a trigger for activation of emergency response. There is, however, no universal definition of what constitutes a flood. Examples of currently used definitions include: •
the presence of water in areas that are usually dry; a “flood disaster” is a flood that significantly disrupts or interferes with human and social activity (9);
•
an increase of water that has a significant impact on human life and well-being (10);
•
a significant rise of water level in a stream, lake, reservoir or coastal region (11); and
•
any case where land not normally covered by water becomes covered by water (12).
New definitions of flooding and coastal erosion include “flood risk” as the relation between the probability of occurrence and the associated consequences, which are then listed, with health as the first concern, followed by social and economic welfare (12). Three ways are suggested for defining a flood for health purposes: as scientific thresholds, as descriptions of population effects and as temporal perspectives. A scientific threshold could be a specified depth of water or a temporal or spatial boundary, i.e. the length of time and/or the area of land that is flooded (4). Population effects could be broad, such as medical, social and economic disruption to normal life, or specific, such as the number of deaths or people affected (9). A temporal perspective or latency approach would take into account immediate outcomes, during or immediately after flooding; short-term outcomes, in the days or early weeks after flooding; and long-term outcomes, occurring after flooding and/or lasting for months or years (13). The variety of definitions reflects the difficulty of finding an adequate way to describe the overall effects of flooding from a health perspective. Temporal health perspectives are probably the most helpful. Table 1 lists the definitions for triggering emergency plans reported in the questionnaires returned by Member States. Descriptions that represent scientific thresholds and population effects predominate, while the temporal health perspective is underrepresented, and some descriptions are based on combinations of approaches. This is not unexpected, because floods cause so much damage to infrastructure and upheaval to people's everyday lives. In Europe, a threat to health may not be considered the defining factor for activating an emergency plan, especially as the number of deaths from floods is relatively low in most countries. Table 1. Flood conditions that would trigger activation of an emergency plan
Country
Definition
Category of definition
Albania
Critical depth of groundwater
Scientific threshold
Armenia
No specific definition, case-by-case basis
Azerbaijan
Massive flooding in several districts
Scientific threshold
Bosnia and Herzegovina
Shortage of safe water and/or houses flooded with water; extensive flooding endangering population settlements, infrastructure, roads, railways, etc.
Population effects
Croatia
Disastrous flood
Population effects
Czech Republic
Third level of emergency plan
Population effects