CONTENTS

 

Abstract

Introduction

Purpose and scope

Acknowledgments

Hudson River and study area

Study area

Tidal and nontidal flow

Salt front

Modeling approach

Model selection

Branch-Network Dynamic Flow model

Branched Lagrangian Solute-Transport model

Data

Stage, inflow, and wind velocity

Tide stage and flow measurements

Salinity

Relation of specific conductance to chloride concentration

Relation of chloride concentrations at West Point to those at Chelsea and Clinton Point

Relation of specific conductance at Hastings-on-Hudson and West Point to salt-front location

Relation of tide levels at West Point and inflows to salt-front location

Application of salinity equations to recent and historical data

Flow simulation by one-dimensional flow model

Calibration and verification

Channel geometry

Boundary conditions

Theta and Chi

Bed friction and internal friction

Wind velocity

Results

Salt‑front movement simulation by the branch-network flow model

Simulated effect of withdrawals and flow increases

Withdrawals at Kingston, Chelsea, and Newburgh

Increased rates of withdrawals at Newburgh

Increased flow at Green Island

Salt‑front movement simulation by the BLTM solute-transport model

Model calibration

Turkey Point to Bowline Point

Boundary conditions

Initial conditions

Results

Turkey Point to West Point

Boundary conditions

Initial conditions

Results

Effects of withdrawals and flow augmentations on salt-front location

Withdrawals at Chelsea during high flow

Withdrawals at Chelsea or Newburgh

Withdrawals at Hyde Park

Flow augmentations at Green Island

Chloride increases at West Point

Summary and conclusions

References cited

Glossary

Appendix

 

FIGURES

 

1‑2. Maps showing:

1. Location of major geographic features of the Hudson River estuary, N.Y, including gage station locations

2. Locations of additional geographical features of the Hudson River estuary, N.Y.

3. Chart showing schematization of the lower Hudson River for the Branch-Network Dynamic-Flow model.

(A) Nodal point numbers. (B) Cross-sectional channel geometry at six selected locations between Green

Island and Hastings-on-Hudson

4‑16. Plots showing:

4. Relation between sample depth and specific conductance at left bank, center, and right bank of Hudson River

on selected dates, 1989-91. (A) Bowline Point, (B) West Point, (C) Clinton Point, and (D) Poughkeepsie

5. Relation between specific conductance and chloride concentration in the lower Hudson River, N.Y., based on

analyses of 1,033 water samples collected prior to 1991

6. Computed and observed relation between salt‑front location and daily mean specific conductance: (A) 100-mg/L

salt-front location based on specific conductance values at Hastings-on-Hudson. (B) 100-, 250-, and 500-mg/L

salt-front locations based on specific conductance at West Point

7. Observed and computed stage at Clinton Point, September 26-27, 1989

8. Observed and computed discharge of Hudson River at nine sites in spring and summer of 1989 and 1990

9. Water density as a function of location at selected flows in 6.6‑mile reach between Clinton Point and

Hastings-on-Hudson: (A) August and September 1989. (B) July and August 1990

10. Friction coefficient in relation to specific conductance at Bowline Point for 17.8-mile reach from West Point to

Bowline Point

11. Travel of a conservative particle downstream of Green Island, July 18 through August 13, 1990:

(A) Travel in 10 reaches during three different flows, (B) Particle speed in relation to discharge at Green

Island, and (C) Effect of three increases in flow at Green Island on particle travel

12. Observed and simulated chloride concentrations at West Point as a function of time during three solute-transport

model calibrations in 1990: (A) April 10 through June 30. (B) July 1 through August 31. (C) August 1-29

13. Observed and simulated chloride concentrations during solute‑transport‑model calibration, August 9-31, 1991:

(A) At Chelsea. (B) At Clinton Point

14. Simulated chloride concentration of Hudson River at selected sites in reach from Turkey Point to

Haverstraw, in relation to hypothetical water-withdrawals at: (A) Chelsea, based on high-flow

(April 1-June 30, 1990) data. (B) Newburgh and Chelsea, based on low-flow (July 1-August 31, 1990) data.

(C) Combined results from (A) and (B) showing upriver movement of 100-mg/L chloride front as a function of

withdrawals at Chelsea during high and low discharges (25,200 and 7,150 cfs at Green Island). (D) Bard Rock

near Hyde Park, based on low flow (August 9-31, 1991) discharges

15. Simulated chloride concentration at selected sites between Hyde Park and Newburgh resulting from simulated

10-day flow increases of 1,000, and 5,000 cubic feet per second at Green Island, August 9-31, 1991

16. Chloride concentration in Hudson River at selected sites between Rhinecliff and West Point resulting from

simulated chloride increases of 1,000, and 2,000 milligrams per liter at West Point, August 9-31, 1991

 

TABLES

 

1. Locations of sites on Hudson River, N.Y., from which stage and flow data were measured for BRANCH flow model

2. Hudson River discharge measurements used for calibration of BRANCH flow model

3. Location, type of stage-recording device, and reference point information for tide-stage recorders in Hudson

River, New York, 1989-90

4. Stage corrections applied to 1989-90 Hudson River tide-stage data used in BRANCH flow model

5. Observed chloride concentration at West Point, and computed concentrations at Chelsea Pump Station and

Clinton Point, August 9-31,1991

6. Equations relating daily mean chloride concentration in Hudson River upstream from West Point to daily mean

specific conductance at West Point

7. Equations relating salt-front location in the Hudson River, N.Y, to daily mean specific conductance at West Point

8. Observed and computed salt-front locations based on combined inflow from Hudson River at Green Island and

5 tributaries and tidal elevations at West Point

9. Salt-front locations during severe storms of the 20th Century

10. Nodal point and corresponding BRANCH data used in flow model of the Hudson River between Green Island and

Hastings-on-Hudson

11. Nodal-point and corresponding boundary conditions used in BRANCH flow model

12. Effect of varying flow-resistance coefficients for the reach between West Point and Bowline Point on error in flow

computations and varying water density for the reach between Clinton Point and Hastings-on-Hudson, N.Y.

13. Specific conductance at Hastings-on-Hudson and Bowline Point, and flow-resistance coefficient (eta) for West

Point to Bowline Point, N.Y. in 1989-90 flow simulations

14. Bias in simulated successive ebb- and flood-flow volumes of Hudson River at Newburgh, August 22-23, 1989,

resulting from simulated increase in wind velocity

15. Calibration error for discharge and stage measured at five locations on Hudson River between Green Island

and Clinton Point, N.Y., before 1981

16. Calibration and verification error for discharge and stage measured at seven locations on Hudson

River between Green Island and Hastings-on-Hudson, N.Y., after 1981

17. Effect of simulated withdrawals and augmented inflow on conservative particle movement 26 days after entry,

July 18 through August 13, 1990

18. Observed and simulated chloride concentrations in the Hudson River between Turkey Point and West Point,

N.Y., August 9-31, 1991