Water-Resources Investigations Report 02-4224
U.S. Geological Survey Water-Resources Investigations Report 02-4224, 52 pages (Published 2002)
By Stephanie J. Moore and Scott K. Anderholm
Prepared in Cooperation with the NEW MEXICO OFFICE OF THE STATE ENGINEER
This report is available online in pdf format: USGS WRIR 02-4224 (15 MB)
Streamflow and water quality vary spatially and temporally in the Rio Grande from Del Norte, Colorado, to El Paso, Texas. The variations in streamflow and in concentrations of selected waterquality constituentsdissolved solids, dissolved nitrite plus nitrate as nitrogen, total phosphorus, and suspended sedimentare described in this report. A multivariate linear regression model, ESTIMATOR2000, was used to estimate loads for selected constituents.
Streamflow decreases in the downstream direction throughout most of the basin because outflows (due to agricultural use, leakage to ground water, and evapotranspiration) are greater than inflows. Streamflow increases between Rio Grande above the mouth of Trinchera Creek, near Lasauses, Colorado, to Rio Grande at Otowi Bridge, near San Ildefonso, New Mexico, because ground-water and tributary inflow are greater than outflow.
Concentrations of dissolved solids, dissolved nitrite plus nitrate, total phosphorus, and suspended sediment generally increase in the downstream direction. Concentrations of dissolved solids, dissolved nitrite plus nitrate, and total phosphorus decrease between Rio Grande above the mouth of Trinchera Creek, near Lasauses, Colorado, and Rio Grande at Otowi Bridge, near San Ildefonso, New Mexico, because of dilution by tributary inflow. Concentrations of dissolved nitrite plus nitrate, total phosphorus, and suspended sediment decrease between Rio Grande Floodway at San Marcial, New Mexico, and Rio Grande below Leasburg Dam, near Leasburg, New Mexico, because of reservoir effects (nutrient uptake and settling of sediment).
Several instances of decreasing streamflow and increasing loads indicate the presence of inflows with large constituent concentrations (relative to those of the Rio Grande immediately upstream from that inflow); this occurs (1) between Rio Grande near Del Norte, Colorado, and Rio Grande above the mouth of Trinchera Creek, near Lasauses, Colorado, for dissolved solids, (2) between Rio Grande at Otowi Bridge, near San Ildefonso, New Mexico, and Rio Grande Floodway at San Marcial, NewMexico, for all constituents, and (3) between Rio Grande below Leasburg Dam, near Leasburg, New Mexico, and Rio Grande at El Paso, Texas, for all constituents. Streamflow increases along every reach of the Rio Grande between the streamflow-gaging station Rio Grande above the mouth of Trinchera Creek, near Lasauses, Colorado, and the station Rio Grande at Otowi Bridge, near San Ildefonso, NewMexico. These increases in streamflow result in increases in the loads of dissolved solids, total phosphorus, and suspended sediment regardless of changes in concentrations.
Foreword
Abstract
Introduction
Purpose and scope
Description of study unit
Surface water
Surface-water and ground-water interactions
Anthropogenic structures
Water quality
Study methods
Data collection
Box plots
Loads
Load estimation
Streamflow
Spatial variations in streamflow
Temporal variations in streamflow
Downstream temporal variations in streamflow
Dissolved solids
Spatial variations in dissolved-solids concentrations
Temporal variations in dissolved-solids concentrations
Downstream temporal variations in dissolved-solids concentrations
Estimated dissolved-solids loads
Nutrients
Dissolved nitrate concentrations
Spatial variations in dissolved nitrate concentrations
Temporal variations in dissolved nitrate concentrations
Downstream temporal variations in dissolved nitrate concentrations
Estimated dissolved nitrate loads
Total phosphorous concentrations
Spatial variations in total phosphorous concentrations
Temporal variations in total phosphorous concentrations
Downstream temporal variations in total phosphorous concentrations
Estimated total phosphorous loads
Suspended sediment
Spatial variations in suspended-sediment concentrations
Suspended-sediment/streamflow relations
Estimated suspended-sediment loads
Effects of variations in streamflow and concentrations on loads in the Rio Grande Valley study unit
Summary
Selected references
This report is available online in pdf format: USGS WRIR 02-4224 (15MB)
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Moore, Stephanie J.; Anderholm, Scott K., 2002, SPATIAL AND TEMPORAL VARIATIONS IN STREAMFLOW, DISSOLVED SOLIDS, NUTRIENTS, AND SUSPENDED SEDIMENT IN THE RIO GRANDE VALLEY STUDY UNIT, COLORADO, NEW MEXICO, AND TEXAS, 1993-95: U.S. Geological Survey Water-Resources Investigations Report 02-4224
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