Surface-water quality and flow Modeling Interest Group
USGS, Water Resources Division
221 N. Broadway Ave.
Urbana, IL 61801
Internet: alishii@usgs.gov
Phone: (217) 344-0037 x3026
FAX: (217) 344-0082
Du Page watersheds
Lake County runoff
FEQ verification
Lake County peak flows
Salt Creek
Illinois River
Fox Chain-of-Lakes
Flood-plain mapping
Design-flood estimation
Flood-forcast system
Regional rainfall-runoff relations were simulated for watersheds in Du Page County, Ill. Rainfall and streamflow data collected from December 1985 through September 1993 were utilized to calibrate and verify a continuous-simulation rainfall-runoff model for three watersheds (11.8-19.0 square miles in area). Classification of land cover into three categories of pervious (grassland, forest/wetland, and agricultural land) and one category of impervious subareas was sufficient to accurately simulate the rainfall-runoff relations for the three watersheds.
Rainfall-runoff relations, defined through joint calibration of the rainfall-runoff model and verified for independent periods, presented in this report, allow estimation of runoff for watersheds in Du Page County, Ill., with an error in the total water balance less than 4.0 percent, an average absolute error in the annual-flow estimates of 17.1 percent with the error rarely exceeding 25 percent of annual flows, and correlation coefficients and coefficients of model-fit efficiency for monthly flows of at least 87 and 76 percent, respectively. Close reproduction of the runoff-volume duration curves was obtained. A frequency analysis of storm-runoff volume indicates a tendency to undersimulate large storms, which may result from underestimation of the amount of impervious land cover in the watershed and errors in measuring rainfall for convective storms. Overall, the results of regional calibration and verification of the rainfall-runoff model indicate the simulated rainfall-runoff relations are adequate for stormwater-management plannning and design in Du Page County.
Duncker, J.J., 1997, Regional rainfall-runoff relations for simulations of streamflow for watersheds in Du Page County, Illinois: U.S. Geological Survey Open-File Report 97-xxx, in review.
Rainfall and streamflow data collected in Lake County, Ill., from March 1990 through September 1993 were used to (1) calibrate a rainfall-runoff model for an area encompassing three watersheds (individual areas of 17.2, 35.7, and 37.0 square miles) and (2) verify the regional model parameter set obtained from the calibration by applying the parameter set to rainfall-runoff models for an additional small (6.3 square miles) watershed and a large (59.6 square miles) watershed. In addition, rainfall and stream-flow data collected from April 1991 through September 1993 were used to calibrate the rainfall-runoff model for three single land-use watersheds (38.2-305 acres), called hydrologic response units (HRU's). Significant differences were found between the best parameters used in the HRU models and in the larger watershed models. The main channels in the HRU's are intermittent streams; thus, the parameters in the HRU models were selected such that a fluctuating water table could be simulated; runoff from the larger watersheds is not as sensitive to the effects of a fluctuating water table. Classification of land cover into two pervious subareas (forest and grass) and one impervious subarea (including parking lots, streets, and rooftops, among others) was sufficient to simulate the rainfall-runoff relations for all watersheds accurately. The model parameters presented in this report, which were refined through regional calibration and verified for watersheds not considered in the calibration, allow simulation of runoff in watersheds in Lake County, Ill., with approximately 93-percent accuracy in the total water balance, an average absolute error in the annual-flow estimates of 10.9 percent (and an error rarely exceeding 25 percent for annual flow), and monthly water balances with correlation coefficients of 93 percent and coefficients of model-fit efficiency of 86 percent. The models closely reproduced the partial-duration series of runoff and storm-runoff frequencies for the modeled watersheds.
Duncker, J.J., Vail, T.J., and Robinson, S.M., 1994, Rainfall in and near Lake County, Illinois, December 1989-September 1993: U.S. Geological Survey Open-File Report 94-113, 228 p.
For detailed descriptions of the FEQ and FEQUTL models, project progress and plans, and links to the Computational Problem Diagnostic Guide and Flowchart, see the Unsteady Flow Model Verification and Documentation Project Homepage
This data set and the dye, stage, and discharge data collected during a period of unsteady flow on the Fox River for a previous project (IL091) will be documented in a report and modeled using FEQ, and for the dye data, BLTM. Additionally, sewer pipe flow data, measured in a laboratory will be used to test the FEQ model routines. The induced or natural floodwaves will be routed through the models and the differences between the simulated and measured flows and elevations compared. For the Fox River model, the simulated flow field will be input to a transport model and the simulated dye concentrations compared to the measured dye concentrations.
The model documentation (task 3) will result in a report documenting (a) river network visualization and schematization, flow-governing equations, and solution procedures used in FEQ; (b) governing equations and tabular representations used in the well-established features of FEQUTL; and (c) input formats for FEQ and FEQUTL.
The final task (task 4) is to write and test a user's guide that describes a specific, typical application of the model in sufficient detail to provide guidance to first-time users and a ready reference of key features for experienced users. This guide will be tested on first-time users within the Illinois District and revised prior to publication.
Turner, M.J., 1994, Data-collection methods and data summary for verification of a one-dimensional, unsteady-flow model of the Fox River in Illinois: U.S. Geological Survey Open-File Report 93-483, 40 p.
Turner, M.J., Pulokas, A.P., and Ishii, A.L., 1996, Implementation and verification of a one-dimensional, unsteady-flow model for Spring Brook near Warrenville, Illinois: U.S. Geological Survey Water-Supply Paper 2455, 35 p.
In Press:
Ishii, A.L., and Turner, M.J., 1997, Verification of a one-dimensional, unsteady flow model for the Fox River in Illinois: U.S. Geological Survey Water-Supply Paper 2477, in press.
Franz, D.D., and Melching, C.S., 1997, Full Equations (FEQ) model for the solution of the full, dynamic equations of motion for one-dimensional unsteady flow in open channels and through control structures: U.S. Geological Survey Water-Resources Investigations Report 96-4240, in press.
Franz, D.D., and Melching, C.S., 1997, Approximating the hydraulic properties of open channels and control structures, during unsteady flow using the Full Equations Utility (FEQUTL) program: U.S. Geological Survey Water- Resources Investigations Report, 97-4037, in press.
In Review:
Franz, D.D., and Ishii, A.L., 1997, User's Guide for the Full-Equations (FEQ) model of one-dimensional, unsteady, open-channel flow: U.S. Geological Survey Open-File Report 97-___, in review.
Design hydrographs computed from design storms, simple models of abstractions (interception, depression storage, and infiltration), and synthetic unit hydrographs provide vital information for stormwater, flood-plain, and water- resources management throughout the United States. Rainfall and runoff data for small watersheds in Lake County collected between 1990 and 1995 were studied to develop equations for estimation of synthetic unit-hydrograph parameters on the basis of watershed and storm characteristics. The synthetic unit-hydrograph parameters of interest were the time of concentration (TC) and watershed-storage coefficient (R) for the Clark unit-hydrograph method, the unit-graph lag (UL) for the Soil Conservation Service (now known as the Natural Resources Conservation Service) dimensionless unit hydrograph, and the hydrograph-time lag (TL) for the linear-reservoir method for unit-hydrograph estimation. Data from 66 storms with effective-precipitation depths greater than 0.4 inches on 9 small watersheds (areas between 0.06 and 37 square miles) were utilized to develop the estimation equations, and data from 11 storms on 8 of these watersheds were utilized to verify (test) the estimation equations. The synthetic unit-hydrograph parameters were determined by calibration using the U.S. Army Corps of Engineers Flood Hydrograph Package HEC-1 (TC, R, and UL) or by manual analysis of the rainfall and runoff data (TL). The relation between synthetic unit-hydrograph parameters, and watershed and storm characteristics was determined by multiple linear regression of the logarithms of the parameters and characteristics.
Separate sets of equations were developed with watershed area and main channel length as the starting parameters. Percentage of impervious cover, main channel slope, and depth of effective precipitation also were identified as important characteristics for estimation of synthetic unit-hydrograph parameters. The estimation equations utilizing area had multiple correlation coefficients of 0.873, 0.961, 0.968, and 0.963 for TC, R, UL, and TL, respectively, and the estimation equations utilizing main channel length had multiple correlation coefficients of 0.845, 0.957, 0.961, and 0.963 for TC, R, UL, and TL, respectively.
Simulation of the measured hydrographs for the verification storms utilizing TC and R obtained from the estimation equations yielded good results without calibration. The peak discharge for 8 of the 11 storms was estimated within 25 percent and the time-to-peak discharge for 10 of the 11 storms was estimated within 20 percent. Thus, application of the estimation equations to determine synthetic unit-hydrograph parameters for design-storm simulation may result in reliable design hydrographs; as long as the physical characteristics of the watersheds under consideration are within the range of those for the watersheds in this study (area: 0.06-37 square miles, main channel length: 0.33-16.6 miles, main channel slope: 3.13-55.3 feet per mile, and percentage of impervious cover: 7.32-40.6 percent). The estimation equations are most reliable when applied to watersheds with areas less than 25 square miles.
Water-quality processes in the Salt Creek watershed in northeastern Illinois were simulated with a computer model. Selected waste-load scenarios for 7-day, 10-year low-flow conditions were simulated in the stream system. The model development involved the calibration of the U.S. Environmental Protection Agency QUAL2E model to water-quality constituent concentration data collected by the Illinois Environmental Protection Agency (IEPA) for a diel survey on August 29-30, 1995, and the verification of this model with water-quality constituent concentration data collected by the IEPA for a diel survey on June 27-28, 1995. In-stream measurements of sediment oxygen demand rates and carbonaceous biochemcial oxygen demand (CBOD) decay rates and by the IEPA and traveltime and reaeration-rate coefficients by the U.S. Geological Survey facilitated the development of a model for simulation of water quality in the Salt Creek watershed. In general, the verification of the calibrated model increased confidence in the utility of the model for water-quality planning in the Salt Creek watershed. However, the model was adjusted to better simulate constituent concentrations measured during the June 27-28, 1995, diel survey.
Two versions of the QUAL2E model were utilized to simulate dissolved oxygen (DO) concentrations in the Salt Creek watershed for selected effluent discharge and concentration scenarios for water-quality planning: (1) the QUAL2E model calibrated to the August 29-30, 1995 , diel survey, and (2) the QUAL2E model adjusted to the June 27-28, 1995 diel survey. The results of these simulations indicated that the QUAL2E model adjusted to the June 27-28, 1995, diel survey simulates reliable information for water-quality planning. The results of these simulations also indicated that to maintain DO concentrations greater than 5 milligrams per liter (mg/L) througout most of Salt Creek for 7-day, 10-year low-flow conditions, the treatment plants (STP's) must discharge effluent with CBOD and total ammonia as nitrogen concentrations substatially below the permit limits. If the STP's discharge effluent with CBOD and total ammonia as nitrogen concentrations at the permit limits for 7-day, 10-year low-flow conditions, DO concentrations less than 5 mg/L are expected for all of Salt Creek downstream from Fullerton Avenue (river mile 23.1).
Turner, M.J., 1996, Traveltime and reaeration characteristics of Salt Creek in northeastern Illinois: U.S. Geological Survey Open-File Report 95-771, 14 p.
The Illinois River flows from it point of origin southwest of Chicago, at the confluence of the Des Plaines and Kankakee Rivers, to the mouth at the Mississippi River just above St. Louis, Missouri. The river has a low gradient, with many off channel lakes and is subject to variable backwater. Currently, the streamflow at the gaging station at Valley City, Illinois, is computed using the slope-station computation method, where slope is determined using the auxiliary gage 9.5 miles upstream at Meredosia. As its name implies, only slope and stage of the river are considered in the computational scheme. As both storage and acceleration are considered to be additional important factors, an effort to improve the computation of daily mean water discharge is being made by implementing the fully dynamic one- dimensional flow model, FEQ, on this stretch of the river. Stage data collected at both Meredosia and Valley City as will be used for the upstream and downstream boundary conditions for the simulation.
The Fox Chain of Lakes, a glacial lake system, is one of the most heavily used recreational boating waterways in the United States because of its close proximity to the Chicago Metropolitan Area. This system is managed by the Fox Waterways Agency (FWA), which has the responsibility to maintain the waterway for boat use. With the average depth ranging from 2 to 4 feet, effective management of the Lake system includes dredging of channels to allow boat traffic. Dredging is ongoing because of refilling of the dredged channels. Inflow from the Fox River and Nippersink Creek are large contributors of sediment to the system; however, resuspension of sediments from boat traffic is believed to be an even larger sedimentation problem. In an effort to more effectively manage the system, the USGS and Fox Waterways Agency are cooperating on a project to determine:
Flood-mitigation structures can be operated to provide maximum flood-elevation reduction at minimum cost by timing structure operations to make the best use of the dynamic characteristics of a flood wave. Each flood wave is unique, because the shape is determined both by the storage and routing characteristics of the watershed and stream channel the wave travels, and by the rainfall distribution (in time and space), and magnitude of the storm event or events that produced it. The optimal operation of flood-mitigation structures depends on accurate forecasts of flood-wave characteristics and near real-time assessment of the effect of flood-mitigation structure operation.
The U.S. Geological Survey (USGS), in cooperation with Du Page County has installed an intensive raingage network throughout the county that is providing detailed real-time rainfall data by radio telemetry. The retrieval, storage, and display operations will be done utilizing software being developed by the USGS to update the home pages provided for World Wide Web access. The software routines will include analysis and formatting capability to make the data accessible and readable for the purpose of updating the watershed and streamflow models of Salt Creek. Floods can be forecasted, and operational scenarios reviewed prior to operating the flood-control structures.
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