Skip Links

USGS - science for a changing world

Scientific Investigations Report 2010–5221

Simulation of Streamflow in the Pleasant, Narraguagus, Sheepscot, and Royal Rivers, Maine, using Watershed Models

By Robert W. Dudley and Martha G. Nielsen


Right-click to download or Save As (7.92 MB)

The U.S. Geological Survey (USGS) began a study in 2008 to investigate anticipated changes in summer streamflows and stream temperatures in four coastal Maine river basins and the potential effects of those changes on populations of endangered Atlantic salmon. To achieve this purpose, it was necessary to characterize the quantity and timing of streamflow in these rivers by developing and evaluating a distributed-parameter watershed model for a part of each river basin by using the USGS Precipitation-Runoff Modeling System (PRMS). The GIS (geographic information system) Weasel, a USGS software application, was used to delineate the four study basins and their many subbasins, and to derive parameters for their geographic features. The models were calibrated using a four-step optimization procedure in which model output was evaluated against four datasets for calibrating solar radiation, potential evapotranspiration, annual and seasonal water balances, and daily streamflows. The calibration procedure involved thousands of model runs that used the USGS software application Luca (Let us calibrate). Luca uses the Shuffled Complex Evolution (SCE) global search algorithm to calibrate the model parameters. The calibrated watershed models performed satisfactorily, in that Nash-Sutcliffe efficiency (NSE) statistic values for the calibration periods ranged from 0.59 to 0.75 (on a scale of negative infinity to 1) and NSE statistic values for the evaluation periods ranged from 0.55 to 0.73.

The calibrated watershed models simulate daily streamflow at many locations in each study basin. These models enable natural resources managers to characterize the timing and amount of streamflow in order to support a variety of water-resources efforts including water-quality calculations, assessments of water use, modeling of population dynamics and migration of Atlantic salmon, modeling and assessment of habitat, and simulation of anticipated changes to streamflow and water temperature resulting from changes forecast for air temperature and precipitation.

First posted March 9, 2011

For additional information contact:
U.S. Geological Survey
Maine Water Science Center
196 Whitten Road
Augusta, Maine 04330

Part or all of this report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge.

Suggested citation:

Dudley, R.W., and Nielsen, M.G., 2011, Simulation of streamflow in the Pleasant, Narraguagus, Sheepscot, and Royal Rivers, Maine, using watershed models: U.S. Geological Survey Scientific Investigations Report 2010–5221, 31 p., at




Description of the Study River Basins

Physiography, Land Cover and Use, and Surficial Geology



Methods of Study

Data Used

Watershed Model

Characterization of the Basins and Initial Parameterization

Meteorological Data Input

Calibration of the Watershed Models

Simulation of Streamflow in the Pleasant, Narraguagus, Sheepscot, and Royal Rivers, Maine

Results, Uncertainties, and Limitations of the Watershed Models



References Cited

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
[an error occurred while processing this directive] URL:
Page Contact Information: Contact USGS
Page Last Modified: Thursday, 10-Jan-2013 19:23:07 EST