Economic risk criteria for dams considering the relative level of economy and industrial economic contribution

When a dam breaks, huge floods will be generated that may inundate urban areas, enterprises, farmlands, and infrastructure and cause giant economic losses. Economic risk criteria are a kind of basis for determining dam risk levels and to decide whether risk control measures should be taken or not. However, compared to loss-of-life risk criteria, much fewer economic risk criteria for dams have been proposed and implemented for two main reasons: (a) The ability of most areas to endure economic losses caused by dam breach changes over time because of the constant development of their economic levels; and (b) Economic development levels in an area are distinct from the levels in other areas, resulting in significant differences in the ability of different areas to endure economic losses caused by a dam breach. Therefore, an equivalent economic scale (EES) that indicates the relative economic level of an area to the whole country in a given period of time is a preferred measure. It was shown in this paper that EES has much more stable values than do ordinary economic measures; therefore, it was taken as the basic index for establishing economic risk criteria. Furthermore, due to the distinct economic loss rates of different industries, the index of industrial economic contribution (IEC) was introduced to determine the correction coefficient to modify the ESS to reflect the potential economic loss of the area to be evaluated. This is the first research that pays careful attention to the change of ability to endure economic losses, in which the established economic risk criteria are applicable over a relatively long time and for different areas based on the consideration of the relative level of the economy and the industrial economic contribution.