Geomorphology and environmental impact assessment: a methodologic approach

Two different paths to define geomorphologic environmental impact assessment are outlined. The first considers the relationships between a project and landforms or raw materials, the second the relationships between a project and geomorphologic processes. The term "impact' (I) refers to the relationships among a project, landforms and geomorphologic raw materials, and can be expressed as: I = Ga × F × Ha where: Ga=geomorphologic asset, F=fragility, Ha=human activity related to a project. The term risk (R) refers to the relationships between a project and geomorphologic processes, and covers the expected numbers of lives lost and persons injured, damage to property and the disruption of economic activity by a natural phenomenon. Risk can be expressed as: R=E × V × H, where: E=element at risk, V=vulnerability (ie the degree of loss that a set of elements at risk might suffer if a natural phenomenon of given magnitude recurs at given intervals), H=natural hazard (ie a potentially damaging phenomenon, often expressed as the probability of occurrence in a given area within a specific period). There are four methods of assessing hazards: direct measurements; mechanical models and calculations; overlaying thematic maps of potential causal factors; the statistical approach to effects, including recurrence. -from Authors