NAWQA Nutrient Synthesis Past, Present, and Future

1. NAWQA Nutrient SynthesisPast, Present, and Future USGS Workshop on Nutrient Processes in the Upper Mississippi River Basin UMESC, LaCrosse, WI March 25 – 26, 2002 Jeff Stoner Dave Mueller Norm Spahr Tom Nolan Barb Ruddy Mark Munn Richard Alexander

2. NAWQA Past1992 - 2000 • Status of streams and rivers • Status of ground water • Relations to land use to water quality Streams (NO3+NO2, NO2, NH4+OrgN, NH4, TN, DP, OPO4, TP, DOC, SOC) Ground water (NO3+NO2, NO2, NH4, OPO4, DOC) Stream habitat, basin and well characteristics, soils, geology, land use and cover, chemical use

3. Center Creek - Missouri - 760 km2 350 7 Sample 300 6 250 5 200 4 Predicted Nitrate (mg / L) Streamflow (m3/s) 150 3 100 2 50 1 0 0 O N D J F M A M J J A S O N D J F M A M J J A S Water years 1994-95

4. Total Phosphorus in Streams Agricultural Areas

5. Total Nitrogen in Streams Agricultural Areas

6. Total Nitrogen in Large Rivers Mixed Land Use

7. Mean-Annual Nitrogen in StreamsNAWQA 25-50-75th percentiles (1993-98) 113 sites 75th 50th 169 38 25th 48

8. Extrapolating Nitrate in Ground Water Calibrated Logistic-Regression Model

9. Nitrate Probability in Shallow Ground Water To be published in ES&T, B.T. Nolan and others, 2002

10. OVERALL VERIFICATION OF NO3 MAP (1991 AND 1994 WELLS)

11. Influence of Land Use on Water Quality and Aquatic Biology in Small Streams and Ground WaterUMIS NAWQA Study Unit

12. Streams Ground Water

13. Nutrient yields are largest in streams draining agricultural areas

14. Interrelations Between Physical, Chemical and Biological Variables, even for Large Rivers, may best be Explained by Study-Unit Investigators Sediment Nitrite + nitrate Chlorophyll a Phosphorus

15. Major Tributaries Have Opposite Influences on Main Stem TN and TP Concentrations

16. Nutrient Questions from UMIS NAWQA Sources and Transport of Agricultural Chemicals in Streams and Ground Water • What is the source of phosphorus/sediment in the Minnesota River? Bank erosion? Streambed erosion? • How do differing agricultural practices influence the sources and transport rates of agricultural chemicals in streams and ground water? • What is the relative contribution of contaminants from ground water, land surface runoff, and tile drains? Effects of Nutrient Enrichment on Agricultural Streams • How do management practices influence the rate of nutrient assimilation in streams? • Does nutrient enrichment contribute to the presence of toxic algae in agricultural streams?

17. NAWQA Present • Status of streams and ground water (add data from study units begun in 1997) • Nutrient relations to land use and seasons • Final summary results of the Midwest synoptic for algal-nutrients relations in streams (S.D. Porter) • Planning the next 10-yr. cycle

18. Seasonal TotalNitrogen in Streams Agricultural Areas Undetermined Combinations of colors indicate multiple Seasons Winter (January-March) Spring (April-June) Summer (July-September) Fall (October-December) seasons of high concentrations, ex. winter-spring

19. NAWQA Future2001 - 2011 • Reduced to 42 study units. • Status of streams and ground water continued. • Changes in water quality (8 – 12 yr.) and why. • Better explain relations to land use and biogeochemical processes.

20. Start Year

21. Stream Sites in the NAWQA Trends Program Compare: 505 to 145 sites; 1st to 2nd decade

22. NAWQA Trend Sites on Large Rivers (2001 – 2010+)

23. NAWQA Trend Sites on Targeted Land Use (2001 – 2010+)

25. Nutrient Enrichment Effects Topic (NEET) Determine how biological communities and processes respond to varying levels of nutrient enrichment in agricultural streams from contrasting environmental settings. • Define the relations between biological communities and nutrient conditions in streams. • Describe how biological processes and nutrients interact at the watershed and reach scale. • Determine whether the relations between biological communities and nutrient conditions can be extrapolated to unmonitored areas.

26. USEPA Research Needs • Periphyton chlorophyll measurements • Algal growth requirements • Stream models that include periphyton • Stream bank, riparian zone, and denitrification • Dissolved oxygen and pH amplitude • Community effects (ecoregions, metrics, indicator taxa) • Fluvial geomorphology as a controlling factor • Whole stream enrichment studies • Seasonal relationships between nutrient and biomass

27. Solar Land UseNutrients SedimentPesticides Wooded riparian corridors Water clarity Shading Habitat -cover-food Algal Seston Filter Feeders SW flux Immigration Invertebrates Export Drift Scrapers Collectors GW flux Benthic Algae Nutrient uptake DO, pH, SOC relations Fish & Wildlife GW-SW relationsSoil Permeability

28. NEET Stratification

29. Factors used to define hydrologic landscape regions Precip – Potential evapotranspiration Percent sand Aquifer permeability Topography

30. Hydrologic landscape regions • A statistical clustering (20) of hydrologically important landscape and climate factors • Among-region variability in the factors is maximized and within-region variability is minimized

31. Proposed data collection scheme • Stratified by hydrologic landscape • ~ 28 basins (avoid nesting) • Constrain flow • Large nutrient gradient • Measure stream habitat

32. Past Large and consistent nutrients data base for streams and ground water at multiple scales. Relations to broad categories of land use. Future Continue status of nutrients conditions and improve confidence in statistical correlations to land use on other physical factors. A consistent look at time trends and why. Improve understanding of biogeochemical processes within streams and near hyporheic zones (NEET) . Summary NAWQA Nutrients Synthesis