Effects of land use, soils, and human populations on export of water, C, N, and P from the Mid-Atlantic coastal plain

abstract | participants | publications | related student projects

Abstract

Over the last 350 y, the Atlantic coastal plain of North America was largely deforested. European settlers cleared the region primarily for agriculture due to the relatively good soils, although urbanization has increasingly claimed more area in the last 100 years. The disturbance and intensive use has led to greater export of N and P in stream discharge, leading to declining water quality of lakes and estuaries. Reversing this trend requires detailed information on watershed export, but it is difficult to measure fluxes of water, C, N, and P from many places in coastal plain watersheds because of the low relief and tidal or salt intrusion. Most gauged areas on the coastal plain are quite far inland and represent only a small fraction of the basin draining into coastal waters (e.g., the gauged areas in the Choptank and Chester basins on the Delmarva Peninsula represent <20% of the total basin area). In many cases, the areas of greatest anthropogenic impact are closer to the coastline, making the spatial extrapolation of fluxes from small gauged areas unrepresentative of the basin as a whole.

We are addressing this problem by regional application of our case study results from the Choptank and Chester basins. Under previous NASA LCLUC funding, we investigated the history of land use change over the previous 350 years using a combination of crop rotation models, historical maps, aerial photographs, and satellite imagery. In addition, we successfully employed the hydrochemical model GWLF to estimate fluxes of water, N, and P from the ungauged portions of the watershed using the local land use, soil characteristics, and human populations (see other poster). In the next phase of this project, we will extend the model capability to C export and apply GWLF to 15-20 watersheds within the Mid-Atlantic region of the coastal plain, using local gauged areas as calibration and validation sites. The goal will be to provide detailed maps or coverages of the Mid-Atlantic coastal plain (New York to South Carolina) showing current land use, soil properties, human populations, and area-based export rates of water, C, N, and P. Land use will be developed from ETM+ imagery, supplemented with existing databases. The hypothesis which we will test is that land use, soils, and human populations are the main determinant of CNP export from the Atlantic coastal plain, as determined from our success in calibration and validation of GWLF in other coastal plain basins. The results will be useful both for local and regional watershed management, and also for evaluating the terrestrial flux of C into the coastal zone.

Participants

-Thomas R. Fisher, Professor, principal investigator
-Jorge A. Benitez, graduate student (PhD 2001)
-Adrienne Sutton, graduate student (PhD 2005)
-Jason J. Traband, graduate student (MS 2003)
-Kuang-Yao Lee, postdoctoral researcher
-Anne B. Gustafson, faculty research assistant
-Gregory M. Radcliffe, faculty research assistant
-Roger Stone, collaborator (US Fish & Wildlife Service)
-Antony P. Goodyear, intern (Parkside High School, Salisbury MD)

Publications

Fisher, T. R., K.-Y. Lee, H. Berndt, J. A. Benitez, and M. M. Norton. 1998. Hydrology and chemistry of the Choptank River basin in the Chesapeake Bay drainage. Water Air Soil Poll. 105: 387-397

Rochelle-Newall, E. J., T. R. Fisher, C. Fan, and P. M. Glibert. 1999. Dynamics of chromophoric dissolved organic matter and dissolved organic carbon in experimental mesocosms. Int. J. Rem. Sens. 20: 627-641

Lee, K.-Y., T. R. Fisher, T. E. Jordan, D. L. Correll, and D. E. Weller. 2000. Modeling the hydrochemistry of the Choptank River basin using GWLF and Arc/Info: 1. Model calibration and validation. Biogeochem. 49: 143-173

Norton, M. G. M. and T. R. Fisher. 2000. The effects of forest on stream water quality in two coastal plain watersheds of the Chesapeake Bay. Ecol. Engin. 14: 337-362

Fisher, T. R., D. Correll, R. Costanza, J. T. Hollibaugh, C. S. Hopkinson, R. W. Howarth, N. Rabalais, J. E. Richey, C. Vorosmarty, R. Wiegert. 2000. Synthesizing Drainage Basin Inputs to Coastal Systems, pps. 81-101 IN: J. E. Hobbie (ed.) Estuarine Science: A Synthetic Approach to Research and Practice, Island Press, Washington, DC, 539 pps.

Lee, K.-Y., T. R. Fisher, and E. Rochelle-Newall. In press. Modeling the hydrochemistry of the Choptank River basin using GWLF and Arc/Info: 2. Model Application. Biogeochem.

Rochelle-Newall, E. J. and T. R. Fisher. In press. Chromophoric dissolved organic matter and dissolved organic carbon in Chesapeake Bay. Mar. Chem.

Rochelle-Newall, E. J. and T. R. Fisher. In press. 3 dimensional excitation-emission spectra of chromophoric dissolved organic matter in Chesapeake Bay. Mar. Chem.

Rochelle-Newall, E. J. and T. R. Fisher. In press. Are phytoplankton a direct source of CDOM? Mar. Ecol. Prog. Ser.

Rochelle-Newall, E. J., T. R. Fisher, G. Radcliffe. Wet deposition of atmospheric CNP on a Delmarva coastal plain basin. sub. to Atmos. Envir.

Related Student Projects

-Effectiveness of Maryland's CREP: Reducing the nutrient load to the Chesapeake Bay

-Removal of Wastewater Nitrogen and Phosphorus by an Oligohaline Marsh