SPARROW Modeling in the Mississippi River Basin Iowa Science Assessment Davenport, IA Nov. 14, 2012 (608) By Dale M. Robertson* and David A. Saad, USGS, Wisconsin Water Science Center

Early results suggested this was driven by Nitrogen Loading from the basin, now maybe both Nitrogen and Phosphorus Gulf Hypoxia

Typical Goals of SPARROW Modeling: 1. Determine P and N loading to various receiving waters over large spatial scales. 2. Determine where are the main contributing basins (Rank contributing basins based on loads and yields). 3. Determine what are the main causes of the high loads (Describe the relative importance of nutrient sources). 4. Provide information to various states and regional organizations to support regional interpretation and guide local, more indepth studies.

Land-to-water transport Sources SPARROW Mass Balance modeling approach: Monitored load Long-term Detrended Instream Transport and Decay Upstream Flux ss DD II II - Regress water-quality conditions (monitored load) on upstream sources and factors controlling transport

National 1987 and 1992 SPARROW Models

Robertson et al. (2009) SPARROW N Model Yield, kg/km 2

Sources Contributions to Stream Nutrient Flux Conclusions from the National SPARROW model applied to the Miss. River Basin Alexander et al., 2008

90% Confidence Intervals for Yields and Ranks Horizontal Bars demonstrate the 90% confidence limits on the individual ranks Robertson, et al. 2009

Upper Midwest SPARROW Model Calibration One Source: 2002 Farm Fertilizer TP inputs, kg One Land-to-Water Delivery: Soil Permeability River Network – RF1 Long-term detrended Loads for 810 sites Calibration

Distribution in Incremental Phosphorus Yields Total Phosphorus Yields (kg km -2 ) 0 – – 2,980 Superior Huron Michigan Erie Ontario Total Phosphorus Yields (kg/km 2 ) 0 – – 2,980 Superior Huron Michigan Erie Ontario Distribution in Incremental Phosphorus Yields

How do the yields to the Great Lakes Basins compare with each other and with those from other nearby large river basins? Phosphorus Yields

2002 TN Sites (937 sites > 856 sites) 2002 TP Sites (1,192 sites > 988 sites) Modeling Sites 2002 load estimates for SPARROW model (then removed sites with poorly predicted loads or large potential biases) # # # # # # # # # # TN Load kg/yr TP Load kg/yr

MARB 2002 Refined Nitrogen SPARROW Model Preliminary Results

Fertilizers Manure Fixation plus other Ag Geologic Nitrogen Sources Phosphorus Sources

Future SPARROW Modeling – NHD Plus Scale (1:100,000) Using HydroSPARROW to predict the effects of changes in Climate (hydrology) and Land Use

Methods to demonstrate results and help guide decisions (Being Demonstrated Tonight!) 2. Decision Support System 1. SPARROW Mapper – Easy and simple way to get SPARROW results

SPARROW MAPPER

Methods to demonstrate results and help guide decisions 1. SPARROW Mapper 2. Decision Support System Scientists/Managers – Capable of using to visualize SPARROW output and run various scenarios. Booth et al., 2011

Decision Support System

Display Catchment Information

Display Detailed Information

Scenario Testing

Scenario Results – Graphical Presentation of Changes

SPARROW Modeling in the Mississippi River Basin Iowa Science Assessment Davenport, IA Nov. 14, 2012 (608) By Dale M. Robertson* and David A. Saad, USGS, Wisconsin Water Science Center