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 (NO3NO2, NO2, NH4OrgN, NH4, TN, DP,
OPO4, TP, DOC, SOC) Ground water (NO3NO2, 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 EST, 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 Total Nitrogen in Streams Agricultural
Areas
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)
24
(No Transcript)
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.

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.

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
Land Use Nutrients Sediment Pesticides
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 relations Soil 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
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) .