WETLAND HYDROLOGY AND HYDRAULICS: WATER QUALITY ASSESSMENT

Abstract

Wetlands  function  in  the transitional  environment  between terrestrial  and aquatic ecosystems and their impact on water quality enhancement   (as well as  biological diversity)  is  directly  dependent  on  the  hydrologic,  or  hydraulic  factors  controlling  the residence,  or detention  time  of the water within  the wetland.  Similarly,  constructed  wetland performance,  in terms of  wastewater  treatment  efficiency,  also  depends on the processes affecting water detention within the system. In many cases, however, both the hydrologic, or hydraulic  factors  and  the  actual  degradation   processes  or  mechanisms  associated   with particular constituents of concern are only poorly understood. Successful wetland restoration, or design of constructed wetlands for wastewater treatment requires a thorough understanding of the site hydrology, or flow hydraulics as well  as an assessment of the specific constituent degradation  mechanisms  of concern.  In this  paper,  some of the current  literature  associated with  development  of  the concepts outlined  above is  reviewed.  Examples  of  how  these concepts may apply to a range  of wetland types are considered; including a sub-alpine bog/fen, a tidal marsh, and constructed surface and subsurface flow wetlands.