Field Experiment and Data Collection
A continuous tracer injection was initiated on January 7, 1992. Water samples were collected at 8 locations downstream (0, 9, 213, 457, 610, 762, 945, and 1052 m downstream of the injection).
Field Sample Analysis
Samples were filtered and analyzed for lithium (flame AA spectroscopy) and bromide (ion exchange chromatography).
Model approach
Inversse modeling to fit advection-dispersion-storage model to observed tracer breakthrough curves. Estimated parameters represent average values for each model reach.
Modeling code used
Study consisted of both flow and transport modeling. A kinematic wave model based on DR3M was used to develop a time-series of flow and cross-sectional area. These time series were used as input to the OTIS solute transport model (software).
The routing model is not publicly available (although the DR3M is at http://water.usgs.gov/software/DR3M/).
OTIS available at: http://water.usgs.gov/software/OTIS
OTIS Model input files: We provide copies of the OTIS input parameter in files in a zipped archive.
Routing input files are not available.
Software : DR3M dr3m - Distributed Routing Rainfall-Runoff Model--version II
Published in 1982
Authors: W. M. Alley, P. E. Smith, D. R. Dawdy
Description: DR3M is a watershed model for routing storm runoff through a Branched system of pipes and (or) natural channels using rainfall as input. DR3M provides detailed simulation of storm-runoff period selected by the user. There is daily soil-moisture accounting between storms. A drainage basin is represented as a set of overland-flow, channel, and reservoir segments, which jointly describe the drainage features of the basin. This model is usually used to simulate small urban basins. Interflow and base flow are not simulated. Snow accumulation and snowmelt are not simulated.
How to install: http://water.usgs.gov/software/DR3M/code/UNIX/README
Citation: Alley, W.M., and Smith, P.E., 1982, Distributed routing rainfall-runoff model--version II: U.S. Geological Survey Open-File Report 82-344, 201 p.
Methodology: The rainfall-excess components include soil-moisture accounting, pervious-area rainfall excess, impervious-area rainfall excess, and parameter optimization. The Green-Ampt equation is used in the calculations of infiltration and pervious area rainfall excess. A Rosenbrock optimization procedure may be used to aid in calibrating several of the infiltration and soil-moisture accounting parameters. Kinematic wave theory is used for both overland-flow and channel routing. There are three solution techniques available: method of characteristics, implicit finite difference method, and explicit finite difference method. Two soil types may be defined. Overland
flow may be defined as turbulent or laminar. Detention reservoirs may be simulated as linear storage or using a modified-Puls method. Channel segments may be defined as gutter, pipe, triangular cross section, or by explicitly specifying the kinematic channel parameters alpha and m.
Version history: 1991 - DR3M-version II, added option to output simulated time-series data to Watershed Data Management (WDM) file. Output file modified to reduce width from 132 characters to 80 characters or less.
1984 - DR3M-version II, WDM file replaces "card" input of time-series data.
1982 - DR3M-version II, added two solution techniques for kinematic wave routing. Improved general output.
1978 - Original DR3M version, incorporated the routing component from a version of the Massachusetts Institute of Technology catchment model into the lumped parameter rainfall-runoff model.
1972 - A lumped parameter rainfall-runoff model for small rural watersheds
Data Requirements:
Daily precipitation, daily evapotranspiration, and short-interval precipitation are required. Short-interval discharge is required for the optimization option and to calibrate the model. These time series are read from a WDM file. Roughness and hydraulics parameters and sub-catchment areas are required to define the basin.
Six parameters are required to calculate infiltration and soil- moisture accounting. Up to three rainfall stations may be used.
Two soil types may be defined. A total of 99 flow planes, channels, pipes, reservoirs, and junctions may be used to define the basin.
Ouput Requirements:
The computed outflow from any flow plane, pipe, or channel segment for each storm period may be written to the output file or to the WDM file. A summary of the measured and simulated rainfall, runoff, and peak flows is written to the output file. A flat file containing the storm rainfall, measured flow (if available), and simulated flow at user selected sites can be generated. A flat file for each storm containing the total rainfall, the measured peak flow (if available), and the simulated peak flow for user-selected sites can be generated.
System Requiremets:
DR3M is written in Fortran 77 with the following extension: use of include files. The UTIL, ADWDM, and WDM libraries from LIB are used.
A subset of these libraries is provided with the code and may be used instead of the libraries, this subset uses INTEGER*4 and mixed type equivalence. For more information, see System Requirements in LIB.