Minnesota s Runoff Risk Advisory Heather Johnson Hydrologist 3 October 16, 2018
What is Runoff Risk? The Minnesota Runoff Risk Advisory (RRAF) system is a website tool designed to help farmers and commercial applicators determine the best time to apply manure. Precipitation, snow melt or other conditions can cause recently applied manure to move off target. The movement can decrease productivity and increase the risk of impairing local bodies of water. The MDA, in partnership with the National Weather Service, developed the RRAF system for Minnesota. It is part of a regional risk advisory forecast project.
Partner States
Goals of the MN Runoff Risk Advisory Increase information available to producers to make informed, daily decisions about when and where to spread. Identify and alert manure applicators of days when the risk of runoff is high. Use existing models from NWS to determine level of risk. Use actual on-farm/research data to evaluate model performance.
Goes Beyond Is it going to rain tomorrow? Continuous soil moisture & runoff models 7 days of future precipitation (QPF) 10 days forecast temperatures Specific model states evaluated for risk conditions Runoff, soil saturation, meteorological driver Basin specific thresholds based on 60+ year simulation Post-processing ran on output to produce risk events Some of the components to build daily risk for Oct 3, 2018
www.mda.state.mn.us/rraf
1 day Risk
Levels of Risk October 4, 2018 Day 1 risk
Risk on Oct 4 2018 Pop Up Table
Precipitation
Soil Temperature
Survey Results Have you heard of the RRAF before? 21 Does the RRAF provide useful information for your work? 18 170 150 Yes No
Survey Results 60% When would you like to get an alert? Perent Respondents 50% 40% 30% 20% 10% 0% 6 to 9 am 11 am to 1 pm 5 pm to 7 pm any time of the day Time of Day
Site sign ups and site usage June - Total Project 430 sign ups. October Total Project 583 sign ups. RRAF website usage 2018 Planting Time of May and June Probable uptick with fall manure spreading
Model Comparison to Real time data 1 day forecast, July 19, 2018
Success
Hits Optional Tagline Goes Here mn.gov/websiteurl
Hits Rainfall event Runoff
Miss
Miss Rainfall event Runoff
Further Comparison Comparing 7 edge of field sites where we monitor overland flow, there were 72 events that occurred from May 1 through August 15, 2018. Of those events, 60 (83%) were predicted to have some level of event. However, there were also 67 events predicted where no runoff occurred, 23 of those being a severe prediction.
Further Summary and Acknowledgment This is a new tool that can be used help make daily application decisions. We will continue to review our edge of field data against the model data and provide feedback to the National Weather Service for improvement on the model. Make sure to sign up for Runoff Risk text and email alerts at: www.mda.state.mn.us/rraf Presentation Acknowledgment: Dustin Goering, NWS Katie Rassmussen and Scott Matteson, MDA MNIT Services
Thank you! Heather Johnson Heather.johnson@state.mn.us 651-201-6098 www.mda.state.mn.us/monitoring MDA Monitoring and Assessment
What is driving the risk of runoff? Precipitation Timing of event intensity Runoff Soil Moisture Minnesota Discovery Farms data indicates: On average, 41% of the annual surface runoff occurs as snowmelt in February and March. On average, 31% of the annual surface runoff occurs in May and June.