Résumé :
|
Characterizing wetland hydrology is key to assessing relative function over a range of wetland types. However, hydrologic data are often lacking. To address this lack of information, we categorized a set of 24 reference wetlands by hydrogeomorphic (HGM) subclass from 1993 to 1995, installed monitoring wells and piezometers, and assessed local water-table levels, pH, and specific conductance by month. Four HGM wetland subclasses were common to central Pennsylvania (riparian depression (n = 8), slope (n = 7), mainstem floodplain (n = 5), and headwater floodplain (n = 4)) and formed the basis for our analysis. Median depth to water in the wells differed by HGM subclass. Riparian depressions had the shallowest depth to water (-8 cm) and headwater floodplain wetlands the greatest (-70 cm). Comparisons of the percent occurrence of a piezometric head (from comparisons between paired piezometer and slotted wells) indicated that riparian depressions and slopes had significant ground-water inputs (47 and 48%, respectively), whereas the mainstem floodplain (31%) and headwater floodplain wetlands (23%) were more surface-water-driven systems.
|