Remote Sensing of Wetland Restoration Hydrology in Maryland
Hydrology and Remote Sensing Laboratory
2012 Annual Report
1a.Objectives (from AD-416):
To improve the ability to assess the effectiveness of wetland conservation practices.
1b.Approach (from AD-416):
Satellite-based synthetic aperture radar (SAR) will be used to remotely monitor changes in hydrology on a 1,800-acre site enrolled in the Wetlands Restoration Project (WRP). Supplemental data will be collected to calibrate the SAR, and consists of soil moisture measurements, groundwater table depth, canopy height, canopy cover, and forest basal area. All these data except for canopy height and basal area will be collected coincident with SAR acquisition. At least 2 areas of the WRP site, differentiated by soil and vegetation, will be monitored by this method. Synthetic aperture radar (SAR) imagery will be collected once in the first spring and three times each of the 2nd and 3rd springs (ideally, 2 years pre-restoration and 1 year post-restoration), weather and satellite acquisition permitting. The SAR and field data will be processed and analyzed to determine hydropattern and infer depth to saturation.
Additional monitoring will be conducted to assess changes in watershed hydrology and peak storm flow attenuation. A flow meter and rain gauge will be installed at the site to evaluate changes in stream flow pre- and post-restoration. The flow meter will be installed at the outlet to the main the watershed. Data will be collected automatically via data loggers and analyzed for effects on peak flow attenuation and base flows. One groundwater monitoring data logger will be installed at each of the 2 areas for comparison with the remotely sensed data.
Extensive ground instrumentation was maintained at the study site including groundwater monitoring wells fitted with level loggers and continuously monitoring soil moisture probes at various soil depths. Additionally, water levels on a ditch weir were recorded to ascertain water and nutrient flux. Synthetic Aperture Radar (SAR) data was collected on one occasion during the spring and supporting soil moisture measurements were collected for calibration.