ARS | Publication request: RADAR MONITORING OF WETLAND HYDROLOGY IN AN AGRICULTURAL WATERSHED: NEW INFORMATION FOR IMPROVED WATER QUALITY MANGEMENT IN THE CHOPTANK RIVER WATERSHED, MARYLAND

Submitted to: Soil and Water Conservation Society
Publication Type: Abstract
Publication Acceptance Date: August 22, 2006
Publication Date: October 11, 2006
Citation: Lang, M.W., Walthall, C.L., Hively W.D. 2006. Radar monitoring of wetland hydrology in an agricultural watershed: New information for improved water quality management in the Choptank River Watershed, Maryland [abstract]. Soil and Water Conservation Society. p. 86.

Technical Abstract: Water quality is influenced by the interaction of processes that occur in multiple landscape elements (e.g., agricultural fields, forests, urban areas, and wetlands). Wetlands are hydrologically dynamic ecosystems that have the potential to store, transform, and release chemicals and sediments, which affect water quality. In the Choptank Watershed, the majority of wetlands are forested and interspersed with agricultural fields and animal production facilities. These wetlands have the potential to improve water quality by reducing pollutants in agricultural runoff, through processes such as denitrification and sedimentation. Unfortunately, the majority of wetlands in the Choptank Watershed have been lost since European colonization and remaining wetlands are at high risk for future loss, due to inadequate legal protection and rapid population growth. Hydrology (flooding and soil moisture) controls wetland function and extent, and must be better understood to conserve remaining wetlands, monitor wetland function, and improve water quality management. More specifically, the ability to monitor forested wetland hydrology through time will allow researchers to judge the impact of climate and agricultural management practices, such as ditching, topographic contouring, and controlled drainage, on wetland hydrology and function. Broad-scale forested wetland hydrology is difficult to monitor using ground-based and traditional remote sensing methods (i.e., aerial photography). C-band synthetic aperture radar (SAR) data could improve the capability to monitor forested wetland hydrology, but the abilities and limitations of these data need further investigation. Initial research has been conducted which supports the use of C-band SAR to monitor hydrology in forested wetlands and forest hydrology is currently being mapped over a broader area, within the Choptank Watershed, Maryland. Maps of forested wetland hydrology were compared with the U.S. Fish and Wildlife Service¿s National Wetlands Inventory, the Natural Resources Conservation Service¿s Soil Survey Geographic Database, and in situ data. Preliminary results are encouraging and opportunities are being explored to include this forest hydrology metric, as well as other biophysical parameters, in a spatially explicit water quality model.