Contents:
 
Abstract
Introduction
Objectives
Methods
    Stream data archive
    Water balance and nutrient transport modeling
    Web interface
Results
    GIS database
    Stream data archive
    Water balance and nutrient transport modeling
    Web interface
    Links to other related projects
Discussion
Technology transfer
Technology commercialization
Scientific and academic achievement
Literature cited

Abstract

The goal of this CICEET project was the development of a regional, GIS-based characterization system for drainage basins that empty into the Gulf of Maine. The Gulf of Maine Watershed Information and Characterization System (GM-WICS) provides the basis for links between a number of geographically specific data sets to spatially explicit loading and riverine delivery models. The components of this characterization system include:
(a)a data bank of relevant GIS-based data sets from which individual drainage basins of the Gulf of Maine can be classified and characterized. Synoptic statistics related to land use, soils, and climatic variables have been assembled;
(b)an archive of available discharge and water chemistry data sets that serve as model calibration / validation targets;

(c)terrestrial mobilization and riverine transport / processing models to route water and water borne materials into and through river corridors; and,

(d)a World Wide Web server that acts as an online reference source for digital map and station-based monitoring data (www.gm-wics.unh.edu).

This poises us for additional detailed analysis of nutrient fluxes to the Gulf of Maine coastal zone. In the follow-up project (The Gulf of Maine Watershed Information and Characterization System (GM-WICS): Outreach Activities Using Innovative Information Technology), also funded by CICEET, we intend to continue to carry-out nutrient transport modeling for basins within the Gulf of Maine Watershed, improve model validation datasets and increase regional understanding of the seasonality of nutrient transport and snowpack nutrient storage through snow and river sampling in New Hampshire and Maine watersheds. Through a companion project with the Plum Island Ecosystem Long Term Ecological Research Group, we will focus on these issues for the Ipswich and Parker Rivers in northern Massachusetts.

Keywords:Gulf of Maine Watershed, Nutrient Flux, Pollution Sources

Introduction 

The management of inland landscapes and freshwater resources is a key determinant of coastal zone water quality, but one that is still poorly understood (Hobbie 2000, NAS 1994). Within this context, river loadings of biotically-active elements are known to have increased several-fold since the beginning of the Industrial Era (Nixon 1995, Smil 1990). And, from numerous individual river basin and coastal zone studies (e.g. the Baltic region, Rosenberg et al. 1990; Mississippi River / Gulf of Mexico, Ortner and Dagg 1995, Turner and Rabelais 1994; Northern Adriatic, Justic et al. 1995a,b; the Black Sea, Mee 1992) we know that excessive river borne nutrients, shifts in nutrient limitation, coastal eutrophication, toxic phytoplankton blooms, and bottom-water hypoxia go hand-in-hand. Loadings associated with population growth and the byproducts of economic development (i.e. non point source inputs from agriculture and atmospheric deposition, sewage loadings, etc) are now an important contributor to riverine fluxes of nutrients to the coastal zone. The quantitative significance of such fluxes is not restricted to the local scale. Indeed, they have been shown to be significant over continental domains and at the regional scale as exemplified by the Northeastern US (Howarth et al. 1996).Because of its high population density and industrial activity, New England provides an excellent opportunity for better understanding how human-dominated landscapes ultimately interact with coastal ecosystems over a multi-state domain. 

By their very nature, rivers display spatial variability in terms of both discharge and biogeochemical flux. From a scientific perspective our work seeks to improve understanding of how drainage basin attributes contribute to the observed patterns of fluvial transport. We seek to identify which key determinants – mappable using our GIS systems – can account for these patterns. In addition, rivers display an enormous degree of temporal variability that is of direct consequence to coastal receiving waters. The variations are river –specific and are a manifestation of drainage basin characteristics which themselves may change substantially over time. For example, for suspended sediment flux, the key controlling factors are both static (i.e. drainage basin area, geology and soils, presence of wetlands and lakes) and time-varying (i.e. precipitation and snowfall patterns, land management, creation of impoundments) (Milliman and Syvitski 1992, Hadley and Walling 1985).

Despite the importance of land-coastal zone interactions, we did not have, for the Gulf of Maine, 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 Estuarine Research Reserve (NERR) sites. Our primary aim in this proposal was 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.

Our initial focus was on developing this overall framework for three test sites: the Great Bay NH and Wells ME Estuarine Reserves, and the Parker River/Plum Island Sound Land-Margin Ecosystem Study Area in northern Massachusetts. This initial development effort proceeded in close conjunction with the proposed work of F. Rubin (CICEET project 22, 1997-2000) to develop land cover templates and that of T. Loder (CICEET project 11, 1997-1999) to monitor river discharge and nutrient chemistry in these study sites.

Objectives

Our overall goal was to produce a synoptic picture of the status of fluvial inputs to the Gulf of Maine coastal zone and support this activity with a GIS-based analysis of how riverine biogeochemical fluxes are influenced by seasonal and interannual variability as well as anthropogenic activities that take place within drainage basins. The capacity for monitoring and interpretation are necessary precursors for correctly understanding changes in the long-term state of the region’s coastal zone and formulating strategies for protecting these resources, which increasingly are subject to human disturbance.

In order to accomplish this goal we focused on four objectives.

1.Development of a data bank of relevant GIS-based data sets from which individual drainage basins of the Gulf of Maine were classified and characterized. Synoptic statistics related to population density, land use, soils, level of industrial activity, for example, were also be assembled.

2.Bringing together Canadian and United States data to compile an archive of available discharge and water chemistry data sets that serve as model calibration / validation targets.

3.Creation of terrestrial mobilization and riverine transport / processing models to route water and water borne materials into and through river corridors.

4.Development of a World Wide Web server and data examination tools that act as online references for digital map and station-based monitoring data. Providing an interface by which the state of Gulf of Maine drainage systems can be assessed by scientists, coastal managers, and citizen groups.

Methods

GIS Database

In close collaboration with our CICEET co-Investigator (F. Rubin) we identified a suite of GIS data layers that characterize the contributing drainage basins of the Gulf of Maine.These data sets are divided into three categories (i) landscape characteristics by which point and non-point source loads can be estimated, (ii) a template for organizing basin and sub-basin attributes, and (iii) geographically detailed transport corridors for water and nutrients. We made use of tools and data sets that were already available from prior studies of continental and global scale hydrology (Vörösmarty et al 1997 a,b). These tools provided the computer codes that permitted integration of geographically-specific data sets, station monitoring data, simulated river networks, and fluvial models.
We chose the EROS Data Center GTOPO30 Digital Elevation Model (DEM), the 1-km land cover from USGS EROS Data Center, soils data from the FAO Digital Soils Database of the World and data available from the NOAA Gulf of Maine Land-based Pollution Sources Inventory to represent landscape characteristics for the Gulf of Maine Watershed area. These data sets were downloaded from the web and from CD-ROM and resampled to 2 arc-minute grid resolution. The land cover and soils data classifications were converted to the UNH Water Balance Model categories.
A 2 arc-minute resolution Simulated Topological Network, representing the Gulf of Maine Watershed river network was created using tools available in the Global Hydrological Archive and Analysis System – RiverGIS (GHAAS-RGIS), a GIS system developed at UNH. The grid-based structure was error-checked and edited using 1:1M digital line graph templates from the Digital Chart of the World, high resolution EPA River Reach files and the EDA/CDA basin boundaries from the NOAA Gulf of Maine Land-based Pollution Sources Inventory.
Air temperature and precipitation time series data sets were developed from data downloaded from the US NCDC Cooperative Summary of the Day Archives and the Environment Canada Climate Normals CD-ROM for data between 1970 and 1999. These data were interpolated to create climate fields for the Gulf of Maine Watershed.

 

Stream Data Archive

Data from the USGS NWIS-W stream discharge archive and from the Environment Canada HY-DAT CD-ROM were downloaded for all stream gauging stations in the Gulf of Maine Watershed. These data were geographically co-registered to the STN-2min river network. Water quality data, for rivers in the United States, were extracted from the USGS Selected National Stream Water-Quality Monitoring Network CD-ROM. Additional water quality data were obtained through collaborative work the Plum Island Ecosystem LTER (Ipswich and Parker Rivers in Massachusetts), and T. Loder (CICEET project 11, 1997-1999) for the Lamprey, Oyster and Salmon Falls Rivers in Maine and New Hampshire and the Androscoggin/Kennebec Rivers in Maine. With the help of volunteers, we carried out a year-long sampling program at the mouth of the Kennebec and the Androscoggin and below the confluence of these rivers. We also worked with seven schools (Oakland, Carrabassett Valley, Gardiner, Dixfield, Oxford Hills, Lewiston and Auburn) in the Kennebec/Androscoggin drainage to develop weekly time series of river nutrient concentrations.
Our sampling in the Kennebec/Androscoggin basin also included five intensive river and three intensive snowpack sampling trips (River: February 1999, December 1999, January 2000, February 2000 and March 2000; Snow: February 1999, January 2000, February 2000). Between 40 and 60 samples were taken on each intensive river survey. Grab samples were taken from the river mainstems and tributaries. Between 25 and 30 samples were taken on each intensive snow survey. Samples were taken in undisturbed areas, 100 meters or more from tertiary roads.

Water Balance and Nutrient Transport Modeling 

Water balance modeling was carried out using the Water Balance Model (WBM). Both vertical and horizontal fluxes associated with the terrestrial water cycle are routinely simulated. The local water cycle is determined from climate and other biophysical drivers on discrete 2min x 2min (latitude x longitude) grid cells. The WBM computes vertical components of the terrestrial water fluxes (i.e. change in soil moisture, evapotranspiration, runoff). Full descriptions of the algorithms and required biophysical data sets are given in (Vörösmarty et al. 1989; Vörösmarty and Moore 1991; Federer et al. 1996; Vörösmarty et al. 1996, Vörösmarty et al. 1998). Modeling of the Gulf of Maine Watershed was carried out during year three of this project.

Web Interface

The Gulf of Maine Watershed Information and Characterization System (GM-WICS) World Wide Web interface was designed and an initial homepage was put online during the summer of 1999. During the fall of 1999 climate and discharge station data was made available online. The Interactive Data Explorer was developed during the winter and put online in the spring of 2000. Online access to the UNH archive of USGS real-time data was made available during the summer of 2000.
Results

GIS Database

We developed a GIS-based characterization system for all drainage basins that empty into the Gulf of Maine. The Gulf of Maine watershed includes parts of eastern Massachusetts, southeastern New Hampshire, all of Maine, a small section of Quebec, southwestern New Brunswick, and northwestern Nova Scotia. In close collaboration with our CICEET co-Investigator (F. Rubin) we assembled a suite of GIS data layers that characterize the contributing drainage basins of the Gulf of Maine.These data sets are divided into three categories (i) landscape characteristics by which point and non-point source loads can be estimated, (ii) a template for organizing basin and sub-basin attributes, and (iii) geographically detailed transport corridors for water and nutrients.
The point and non-point source data sets were based on the 1-km land cover from USGS EROS Data Center, soils data from the FAO Digital Soils Database of the World and data available from the NOAA Gulf of Maine Land-based Pollution Sources Inventory.The original land cover categories were converted to the UNH Water Balance Model land use categories in preparation for hydrological simulations. Likewise, the soil data was converted to Water Balance Model soil texture categories.
The basin and sub-basin attribute files and the river corridor files were generated from the EROS Data Center GTOPO30 Digital Elevation Model (DEM), which represents topography at 30-second resolution. After tests of several different grid resolutions on portions of the basin, we discovered that a 4-km resolution gridded networking system would be suitable for application at the regional scale. This network has more than 150,000 individual grid cells within the Gulf of Maine Watershed area. The final 2min resolution river network represents 825 individual basins, 400 of these have more than a single cell. There are 190 named basins in the network. Total watershed area at 2min resolution is 174,825 sq km. This data set represents a topological structure by which a hierarchy of nested basin and sub-basin characteristics was derived using existing software we had already developed (Global Hydrological Archive and Analysis System -- GHAAS).The grid-based structure was error-checked and edited using 1:1M digital line graph templates from the Digital Chart of the World, high resolution EPA River Reach files and the EDA/CDA basin boundaries from the NOAA Gulf of Maine Land-based Pollution Sources Inventory.This river network serves as the organizational structure upon which the land characterization is based. Summary statistics for these basins in the Gulf of Maine Watershed include stream order, stream length, and basin drainage area.
Monthly air temperature and precipitation interpolations were developed from United States and Canadian climate station data. We geo-registered and error-checked data from 1154 precipitation stations, 913 air temperature stations and 327 snow stations. Time series and climatology data sets were created for the period 1970-1993. These data sets are currently being updated to include data through 1999.

Stream Data Archive

Observational data for water quantity and quality were geographically co-registered to the gridded stream topology.Observed discharge data were compiled from the USGS NWIS-W historical archive, the USGS provisional real-time web pages and the Environment Canada HYDAT CD-ROM. Geo-referencing the discharge stations to the stream network provided the linkage for comparisons of model results to verification data sets. This process was also an integral part of editing the network. The combined stream discharge data set includes 196 gauging stations.
Water quality data, for rivers in the United States, were extracted from the USGS Selected National Stream Water-Quality Monitoring Network CD-ROM. This provided 35 monthly time series data sets for rivers within the United States. Based on this limited number of water quality locations, we chose to focus our analysis of nutrient transport on four basins within the Gulf of Maine Watershed: the Ipswich and Parker Rivers, Great Bay rivers, the coastal rivers and streams at Wells NERR, and the Androscoggin /Kennebec basin. The analysis for the Ipswich and Parker Rivers was done in collaboration with Plum Island Ecosystem LTER researchers. We worked closely with T. Loder (CICEET project 11, 1997-1999) on analysis of data from the Lamprey, Oyster and Salmon Falls Rivers in the Great Bay drainage. In addition, we worked with T. Loder (CICEET project 11, 1997-1999) on sampling the Androscoggin/Kennebec river system. With the help of volunteers, we carried out a year-long sampling program at the mouth of the Kennebec and the Androscoggin and below the confluence of these rivers. We also worked with seven schools (Oakland, Carrabassett Valley, Gardiner, Dixfield, Oxford Hills, Lewiston and Auburn) in the Kennebec/Androscoggin drainage to develop weekly time series of river nutrient concentrations.
Samples taken at the mouth of the Androscoggin/Kennebec have been used to estimate seasonal nutrient flux to the coast (Bredensteiner et al., in preparation). We estimate that 1621 metric tons of dissolved inorganic nitrogen (DIN), 127 metric tons of phosphate (PO4), and 19272 metric tons of silicate (SiO4) were delivered to the coastal zone by the Androscoggin/Kennebec Rivers in 1999 (Bredensteiner et al., in preparation). Of particular interest is the snowmelt contribution to this flux. In order to calculate the contribution of snowpack storage and subsequent melt to river nutrient flux, we completed five intensive river and three intensive snowpack sampling trips (River: February 1999, December 1999, January 2000, February 2000 and March 2000; Snow: February 1999, January 2000, February 2000). We have developed estimates of river nutrient flux and snowpack storage of inorganic nitrogen, phosphorus and silica from this data set. We estimate that the snowpack in the Androscoggin/Kennebec basins stored 760 metric tons of DIN, 11 metric tons of PO4, and 46 metric tons of SiO4 in 1999, and 1020 metric tons DIN, 13 metric tons of PO4, and 35 metric tons of SiO4 in 2000 (Bredensteiner et al. in preparation).

Water Balance and Nutrient Transport Modeling 

Water balance modeling was carried out using the UNH Water Balance Model (WBM). Modeling of the Gulf of Maine Watershed was carried out during year three of this project.
Beyond a simple descriptive study of riverine nutrient fluxes, we have been seeking a broader interpretation of how seasonal, episodic, and progressive changes in drainage basins influence the behavior of New England river systems. We hypothesized 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 Gulf of Maine watershed. Such properties include the timing and distribution of precipitation and runoff, land cover, topography, soils, point and non-point source pollution. These are the data sets and model outputs we assembled during this project.
An important validation target for the models has been a set of concentration vs. runoff (C vs. Q) curves, which have been observed to vary in a predictable fashion in many rivers (Meybeck 1993, Hem 1989, van Bennekom and Salomons 1982). We conjectured that the spatial distribution and relative predominance of contrasting source and sink terms would provide a fundamental control on the nature of the C vs. Q curve for each drainage basin analyzed.
A full understanding of the mechanisms by which drainage basins mobilize, re-work and transport sediments, organic matter, and nutrients requires GIS-based process models of component terrestrial, freshwater, wetland, and recipient coastal zone ecosystems (Vörösmarty et al. 1997c, Billen et al. 1991). This project has focused on to spatially-distributed modeling that combines a statistical characterization of river basins with a simple set of within-basin processing kinetics.

During the early phases of the project we focused on the approach of White et al. (1992) due to its ability to treat point and non-point sources from urban and non-urbanized watersheds. We also considered specific elements of other distributed and semi-distributed drainage basin models, such as the EPA BASINS modeling framework, the EPA NPSM (Non-Point Source Model) N), HSPF (Johnson et al. 1980), ANPS (Young et al. 1987), and ANSWERS (Beasley et al. 1980). Our initial focus was on the SPARROW methodology, applied by Smith et al. (1994), Smith et al. (1993), and White et al. (1992). This methodology uses a straightforward set of constitutive equations applied to each element of the simulated river networks. For dissolved biotically active chemicals in rivers,White et al. (1992) assume a simple first-order decay.

After careful consideration of existing models, we decided to develop our own nutrient transport model. Our detailed review of several prominent models (Brown & Barnwell, 1987; Johnes, 1996; Smith et al., 1997; Johanson & Imhoff, 1984) determined these models to be inadequate for our purposes. The weaknesses include issues such as the need for inordinate quantities of detailed nutrient inventory data (Johnes, 1996; Export Coefficient Model), mismatch between spatially-detailed but temporally static statistical flux models which give only mean annual flux estimates (Smith et al. 1997; SPAtially Referenced Regression On Watershed attributes (SPARROW)), complex process-based kinetics for instream processes to the virtual exclusion of land-based nutrient loading (Brown & Barnwell, 1987; Enhanced Stream Water Quality Model (QUAL2E)), and highly parameterized, vector representations of water quality processes (Johanson & Imhoff, 1984; Hydrological Simulation Program-Fortran (HSPF)).

The NTM hydrology sub-model is based on our existing Water Balance Model (WBM). Detailed water budget calculations trace precipitation (as rain or snow), through snowpack growth and decay, soil recharge and drainage, plant canopy interception and transpiration, surface runoff, groundwater recharge and discharge, and stream flow. NTM simulations using site-specific parameterizations have produced encouraging results for several Gulf of Maine watersheds including the Oyster and Lamprey Rivers in NH, the Parker and Ipswich in MA, and the Androscoggin/Kennebec in ME. An NTM simulation of three years (1985-1987) resulted in an underestimate of 35 mm in cumulative runoff, representing a less than 3% difference from the observed value.

The NTM nutrient sub-model (Figure 1) predicts nitrogen flux at the mouth of a watershed by linking measured hydrologic and nitrogen (N) inputs, the hydrology sub-model, and results of a process-based terrestrial ecosystem model. Nitrogen deposition occurs as both wet and dry deposition to the soil surface unless snowpack is present, in which case N is sequestered in the pack until snowmelt begins.Nitrogen uptake and mineralization are determined via statistical relationships with temperature and soil moisture. These relationships were derived from the well- validated terrestrial ecosystem model, PnET-CN (Aber et al., 1997; Aber and Driscoll, 1997).Nitrate is dissolved in soil water, so leaching to groundwater or runoff to wetlands, lakes, and streams is controlled by hydrologic turnover times.The system of differential equations in both the hydrology and nutrient sub-models are solved via an adaptive Runge-Kutta differential equation solver.

Figure 2 shows the current hydrologic and nutrient flux results for the Lamprey River watershed, Rockingham County, NH (474 km2). Graph A shows mirror images of the observed runoff and NTM predicted runoff. Graph B shows NTM predicted nutrient flux. The current lumped-watershed version of NTM, which considers upland connected to downslope wetlands, is being further developed, through our CICEET 2000 project and our work on the Plum Island Ecosystem (PIE) Long Term Ecological Research (LTER) project, in a spatially distributed GIS framework so that it may be used to evaluate the influence of land use and land-use topology on water and nutrient runoff. Archival time series data sets stored in GM-WICS for runoff, precipitation, and air temperature and gridded fields of precipitation, air temperature, elevation, soils, and land cover can be used as inputs to the NTM. 

Web Interface

The Gulf of Maine Watershed Information and Characterization System (GM-WICS) World Wide Web interface was designed and an initial homepage was put online during the summer of 1999. During the fall of 1999 climate and discharge station data was made available online. The Interactive Data Explorer was developed during the winter and put online in the spring of 2000. The Data Explorer provides an interactive tool for through which point data and gridded Gulf of Maine Watershed data layers can be examined. Real-Time stream discharge data is available for USGS stations within the Gulf of Maine Watershed. These data are downloaded from the USGS web sites daily and archived at UNH. Broad suites of specific data sets have been included on our WWWeb site. The site was expanded to contain two components: (i) the original site expanded to include focus basins and tiled datasets (http://www.gm-wics.sr.unh.edu/) and (ii) a new Interactive Data Explorer (http://www.gm-wics.unh.edu/explorer). These data repositories provide both station-based point data and gridded geospatial data. Table 1 lists the GM-WICS data sets gathered for this project.
Links to Other Related Projects 
Several other projects, which look at nutrient transport issues, have been pursued in conjunction with this research. In collaboration with PIE LTER researchers (Bruce Peterson and Chuck Hopkinson) based at MBL in Wood Hole, an analysis of nutrient loading and transport in the Parker and Ipswich basins is being carried out by Wil Wollheim (graduate student with PI at UNH). The focus of this research is the development of a spatially explicit version of the Nutrient Transport Model (NTM). The Principal Investigator continues to participate in the SCOPE International Nitrogen Flux Study, as the leader of Working Group #1. This project is identifying suitable regional models for nutrient transport estimates to the oceans. The Principal Investigator has also participated in the Liaison Committee of the USGS New England Coastal Basins (NECB) National Water-Quality Assessment Program Study. In addition the Principal Investigator and graduate students have attended meeting and workshops hosted by the New England Interstate Water Pollution Control Commission (NEIWPCC).

Discussion

Work under our current CICEET project (Grant #NA97OR0338) has combined (i) data development, (ii) GIS analysis, and (iii) modeling efforts.Data development and GIS analysis efforts have focused on creating a GIS database for the entire Gulf of Maine Watershed. Currently, the Gulf of Maine Information and Characterization System (GM-WICS) contains data sets describing the soils, vegetation, river network typology, meteorological data, and stream discharge for the Gulf of Maine Watershed. Nutrient input and export data is also being collected and added to this database. This database provides the necessary input layers for spatially-distributed watershed modeling using the Water Balance Model (Vörösmarty et al., 1998), Water Transport Model (Fekete et al., 2000; Vörösmarty et al., 1989) and Nutrient Transport Model (under development). Modeling efforts have focused on construction and testing of a Nutrient Transport Model (NTM) which combines a physically-based extension of the WBM/WTM hydrology model with a nutrient biogeochemistry module. Currently, NTM is being developed to simulate nitrogen transport, and will be expanded to model other constituents. 

As an aid to model development, we have been collecting time series data from local coastal rivers to determine nutrient loads into the Great Bay NERR. This monitoring has been done through the current CICEET-funded project by the Co-I (T. Loder: Innovative Technologies for the Measurement of Fluvial Inputs of Nutrients to Estuarine Systems, NOAA Grant #NA97OR0338). Figure 3 shows fifteen-day running averages of the dissolved inorganic nitrogen concentration for the Lamprey, Salmon Falls and Androscoggin/Kennebec Rivers. The Lamprey River and Androscoggin /Kennebec River graphs (Figs 3a and 3c) show seasonal variations in concentration, as would be expected from many previous studies, e.g. Davis and Keller (1983) and Webb and Walling (1985). The Salmon Falls River (Fig 3b) concentrations are much higher and do not show the seasonal variations.Such behavior is characteristic of landscapes with high nutrient loading (Stoddard, 1994) and indeed this river is known to have high nitrogen inputs.

To support project outreach efforts, we also have been working with colleagues from the Marine Biological Laboratory in Woods Hole (C. Hopkinson, E. Rastetter, J. Vallino; NSF-LTER Grant #OCE-9726921) to monitor and understand nutrient outflows from the Parker and Ipswich River systems into Plum Island Sound, MA. In addition, we have completed four snow and river sampling trips to characterize the nutrient storage of snowpack in the Androscoggin/Kennebec basins and are working with volunteers from the Friends of Merrymeeting Bay, and seven schools in the Androscoggin/Kennebec basins to develop additional river and snowpack time series data sets.

In the case of the Parker and Ipswich Rivers, similar per unit area rates of nutrient export for nitrogen have been recorded (B.J. Peterson, MBL, unpublished data) despite the differences between these basins with respect to point and non-point source loadings.The trapping and loss of nutrients inside wetlands is a possible mechanism (Jacks et al., 1994; Jansson et al., 1994) and we are exploring how the spatial organization of the upstream landscape ultimately defines the mouth-of-river fluxes.These site-specific results form the focus for our NTM simulation studies, and are important in providing guidance in our effort to expand our understanding to larger landscape units including the Androscoggin/Kennebec and ultimately the entire GOM watershed. For example, it was found in the Lamprey and Oyster Rivers that the majority of the annual nitrogen loading occurs during the winter and snowmelt time frame, as it does in the larger and more spatially complex Androscoggin/Kennebec. 

We believe the inclusion of regional scale studies is important since such work will help to identify critical and emerging problem areas. This has been a central focal point of our work. This is especially important as the region continues to develop economically. We believe that important insights can be gained by comparative monitoring/modeling studies of river basins and the manner in which they load constituents into the coastal zone (Hobbie 2000, National Academy of Sciences 1994, Boynton et al. 1982).

Technology Transfer and Management Application

The Gulf of Maine Watershed Information and Characterization System (GM-WICS) is now operational and constitutes an archive of relevant GIS-based data sets, available discharge and water chemistry data, and a WWWeb server that will act as an online reference source for digital map and station-based monitoring data. We also needed to refine and continue the testing of our Water Balance and Nutrient Transport Model (NTM), which we pursued during this period. We invite readers to visit the site and explore the project’s major vehicle for technology transfer (http://www.gm-wics.sr.unh.edu/).
Technology Commercialization

The products of this research have not been patented, copyrighted, or licensed in anyway. We are currently requesting permission to disseminate Canadian hydrologic and climatic data as a part of our Gulf of Maine Watershed Web site.

Scientific and Academic Achievement

Undergraduate Student (senior honors project):

­Matt Hill, Civil Engineering Department, University of New Hampshire

Graduate Student:

­Kim Bredensteiner, Earth Science Department, University of New Hampshire

The data sets and finding presented above have been summarized and presented as a set of documents. These are listed below:

Reports and Papers

­Vörösmarty, C.J. and B.J. Peterson. 2000. Macro-scale models of water and nutrient flux to the coastal zone. In: J. Hobbie (ed). Estuarine Science: A Synthetic Approach to Research and Practice. Island Press.

­Bredensteiner, K., C. Vörösmarty, T. Loder, E. Penfold, and W. Wollheim. 2000. Regional Estimation of Snowpack Nutrient Storage. (In preparation for submission to Estuaries).

­Bredensteiner, K. 2000. Gulf of Maine Watershed Information and Characterization System Database Development (Update of 1999 M. Hill report). Water Systems Analysis Group Technical Paper. University of New Hampshire, Durham NH.

­Hill, M. 1999. Data Development for the Gulf of Maine Basin Characterization System. Senior Honors Project Final Report. Civil Engineering Department, University of New Hampshire, Durham NH.

Presentations

­Bredensteiner, K., C. Vörösmarty, T. Loder, E. Penfold, and W. Wollheim. 2000. Regional Estimation of Snowpack Nutrient Storage. Poster. Long Term Ecological Research Network All Scientists Meeting. Snowbird, UT.

­Bredensteiner, K. 1999. Overview of Gulf of Maine Project. Plum Island Ecosystem. Long Term Ecological Research Site. All Scientist Meeting. Marine Biological Lab, Woods Hole MA.



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Bredensteiner, K., C. Vörösmarty, T. Loder, E. Penfold, and W. Wollheim. 2000. Regional Estimation of Snowpack Nutrient Storage. (In preparation for submission to Estuaries).

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