Characterization of hydrogeomorphology of the natural and restored wetlands in St. Lawrence River Valley, NY

Abstract:

Understanding of local hydrology and landscape setting is essential for evaluating systematic functions and services of the wetlands because the ecosystem components are sensitive to hydrodynamics and topography, particularly in vegetation composition and abundance. Wetland hydrogeomorphology provides a general sense of the wetland structure such as plant community and hydroperiod, but it can be easily altered by human activity and disturbance. In order to achieve a successful wetland restoration on the altered landscape and topography, recovery of hydrology for adaptation should be prioritized. In this study, regional hydrogeomorphic classification of 18 natural and 48 restored wetlands in the St. Lawrence River Valley area in the northern New York State was conducted and wetland-upland interactions were investigated using pairs of water level measurements at a groundwater well and standing water in randomly selected 5 natural and 17 restored wetlands. The wetlands over large area were broadly classified in terms of geomorphic setting, water source, and hydrodynamics. Water level was monitored on an hourly basis for an entire Water Year of 2015 to understand a hydroperiod and hydrodynamics at each site. Horizontal hydraulic gradient from upland groundwater to standing water in the wetlands was also calculated from the observation data to estimate groundwater contribution as an input source of the wetlands. The characterized hydrology was categorized into the regional hydrogeomorphic classes and further statistically analyzed. The regional wetland classification and functional assessment will provide useful tools to make a proper restoration plan.