Gulf of Maine
Watershed Information and Characterization System
Dr. Charles J. Vorosmarty
University of New Hampshire (Durham NH, USA)
in Co-operation with the NOAA-UNH CICEET Program
The goal of this project is to develop a regional, geographic information system (GIS) based characterization system for drainage basins that empty into the Gulf of Maine. This characterization system includes an archive of relevant GIS-based data sets, historical and near real-time discharge and
water chemistry data, and the results of water balance and water chemistry modeling. Our goal is to provide an online reference source for scientists, coastal and freshwater managers, citizen groups and students of digital maps and water quality monitoring data for the basins of the Gulf of Maine
Our research here at UNH is striving to produce a synoptic picture of the status of fluvial inputs to the Gulf of Maine coastal zone. This water and nutrient synopsis is being developed from a GIS-based analysis of the anthropogenic activities that take place within drainage basins influencing riverine biogeochemical fluxes. A key focus of this research is to gain an understanding of the seasonal and inter-annual variability in the Gulf of Maine watershed basins. The capacity for both monitoring and interpretation is a necessary precursor for correctly understanding changes in the long-term state of the region's coastal zone and formulating strategies for protecting these resources which are
increasingly subject to human disturbance.
The management of inland landscapes and freshwater resources is a key determinant of coastal zone water quality. Observations of water quality in many parts of the world show that river loadings of biotically active elements have increased several fold since the beginning of the Industrial Era. Water monitoring in numerous individual river basins and coastal zone areas have connected these excessive levels of river borne nutrients and associated shifts in nutrient ratios to shifts in nutrient limitations, coastal and freshwater eutrophication, toxic phytoplankton blooms, and bottom-water hypoxia. Nutrient loadings associated with human population growth and economic development are now important contributors to riverine fluxes of nutrients to the coastal zone. In order to gain a clear understanding of the impact of these changes in nutrient loading, a thorough survey of the point source (i.e. industrial waste water and sewage waste water) and non-point source (i.e. inputs from agriculture, logging, construction, and atmospheric deposition) inputs must be available.
Despite the importance of land-coastal zone interactions, we currently lack a consistent system for monitoring and assessing the dimensions of such change at anything but the local scale, for example at NSF Land-Margin Ecosystem Study (LMER) or National Esturarine Research Reserve (NERR) sites.
Our primary aim is to develop a diagnostic GIS-based methodology to monitor and interpret the status of the Gulf of Maine watershed with respect to watershed characteristics and to the fluvial transport of water and nutrients. Beyond a simple descriptive study of riverine nutrient fluxes, we seek a broader interpretation of how seasonal, episodic and progressive changes in drainage basins influence the behavior of New England river systems. We hypothesize that the export of water and biogeochemical constituents at river mouths can be explained by a finite set of processes and characteristics operating in the upland drainage basin. Such properties include the timing and distribution of precipitation and runoff, land cover,
topography, soils, point and non-point source pollution.
In order to enhance our understanding of the seasonal flux of nutrients in the Gulf of Maine watershed basins, we have been pursuing several river and snow sampling programs. In the local Great Bay area, Erin Penfold and Ted Loder have been monitoring the Oyster River, Lamprey River and Salmon Falls
River. At a larger scale we have been focusing on the Androscoggin and Kennebec basins. We have made several intensive river and snow sampling trips: February 1999, December 1999, January 2000, February 2000. The purpose of these trips is to gain an understanding of winter nutrient flux and storage. We are also working with volunteers from seven schools in the Androscoggin and Kennebec basins and from the Friends of Merrymeeting Bay. These volunteers are taking weekly river samples through the fall, winter
and spring and periodic snow samples.
In order to develop predictions of the nutrient flux to the coastal zone, we are developing a Nutrient Transport Model (NTM) that will be applied using the GM-WICS data base. This model is currently being developed using STELLA model development software.