NAWQA Nutrient Synthesis Past, 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 NAWQA Past 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 Center Creek - Missouri km 2 Streamflow (m 3 /s) Water years ONDJFMAMJJASONDJFMAMJJAS Predicted Nitrate (mg / L) Sample Total Phosphorus in Streams Agricultural Areas Total Nitrogen in Streams Agricultural Areas Total Nitrogen in Large Rivers Mixed Land Use Mean-Annual Nitrogen in Streams NAWQA th percentiles ( ) sites th 50th 25th Extrapolating Nitrate in Ground Water Calibrated Logistic-Regression Model Nitrate Probability in Shallow Ground Water To be published in ES&T, B.T. Nolan and others, 2002 OVERALL VERIFICATION OF NO3 MAP (1991 AND 1994 WELLS) Influence of Land Use on Water Quality and Aquatic Biology in Small Streams and Ground Water UMIS NAWQA Study Unit StreamsGround Water Nutrient yields are largest in streams draining agricultural areas Sediment Phosphorus Nitrite + nitrate Chlorophyll a Interrelations Between Physical, Chemical and Biological Variables, even for Large Rivers, may best be Explained by Study-Unit Investigators Major Tributaries Have Opposite Influences on Main Stem TN and TP Concentrations 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? 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 seasons of high concentrations, ex. winter-spring Winter (January-March) Summer (July-September) Spring (April-June) Fall (October-December) Seasonal Total Nitrogen in Streams Agricultural Areas Seasons NAWQA Future 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. Start Year Stream Sites in the NAWQA Trends Program Compare: 505 to 145 sites; 1 st to 2 nd decade NAWQA Trend Sites on Large Rivers (2001 2010+) NAWQA Trend Sites on Targeted Land Use (2001 2010+) 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. 1.Define the relations between biological communities and nutrient conditions in streams. 2.Describe how biological processes and nutrients interact at the watershed and reach scale. 3.Determine whether the relations between biological communities and nutrient conditions can be extrapolated to unmonitored areas. 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 Solar Land Use Nutrients Sediment Pesticides GW-SW relations Soil Permeability GW flux SW flux Algal Seston Benthic Algae Filter Feeders Scrapers Collectors Water clarityShading Habitat -cover-food Wooded riparian corridors Export Immigration Drift Invertebrates Nutrient uptake DO, pH, SOC relations Fish & Wildlife NEET Stratification Precip Potential evapotranspiration Percent sand Aquifer permeability Topography Factors used to define hydrologic landscape regions 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 Proposed data collection scheme Stratified by hydrologic landscape ~ 28 basins (avoid nesting) Constrain flow Large nutrient gradient Measure stream habitat Summary NAWQA Nutrients Synthesis 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).