Standard Practice for Preliminary Karst Terrain Assessment for Site Development

Importancia y uso:

5.1 This practice may serve to assist qualified professionals in conducting preliminary karst assessments, and helping design professionals, plan reviewers, public works officials, and jurisdictional regulators in determining the minimum elements that should be expected in a site evaluation. It should be emphasized that the protocol presented herein is not intended to serve as a substitute for detailed subsurface investigations, or to supersede any existing karst regulations or codified protocols.

5.2 According to Gutiérrez et al. (3) it is important to understand that geo-hazards in karst terrain differ considerably from other natural settings. These geo-hazards are exacerbated by the redirection and concentration of water draining into the subsurface and removal of soil or other natural cover over karst openings. The karst system is often unable to manage the effects of heavy rainfall and flash floods, resulting in the formation and/or reactivation of sinkholes, soil subsidence or slope movement, and these effects become exaggerated by human alteration of the natural drainage. In addition, the lack of filtration inherent to karst hydrogeologic systems can result in transport and migration of a diverse variety of water-borne contaminants, including but not limited to pathogens, heavy metals, sediments, free-product, and dissolved-phase chemicals, as well as residual-phase contaminants adsorbed on sediment. The removal of cover by grading will reduce support over cavities in the subsurface and increase the potential for collapse or subsidence, particularly where surface water concentration occurs.

Subcomité:

D18.27

Volúmen:

04.09

Número ICS:

07.060 (Geology. Meteorology. Hydrology)

Palabras clave:

cave; closed depression; hydrogeology; karst; karst drainages; pinnacled bedrock; sinkhole; soluble bedrock;