The Iowa Watershed Approach Antonio Arenas Assistant Research Engineer

Transcription

1 A vision for a more resilient Iowa Antonio Arenas Assistant Research Engineer antonio-arenasamado@uiowa.edu 1

2 Average annual precipitation (inches). Estimates are based on the 30-year annual average ( ). About News & Events Contact Us (Data source:

3 Observed change in heavy precipitation (the heaviest 1%) between 1958 and Figure taken from The Climate Science Special Report (Easterling et al. 2017) ( Date Grundy Center ppt (inches) 7/10/ /25/ /29/ /4/ /6/ /30/ /11/ /27/ /1/ /13/ (Data source: oregonstate.edu/) Date Vinton ppt (inches) 8/12/ /30/ /15/ /12/ /4/ /1/ /9/ /17/ /8/ /18/ Date Cedar Rapids ppt (inches) 6/17/ /12/ /17/ /12/ /18/ /10/ /26/ /14/ /15/ /18/

4 50 40 Cedar River upstream of CR (a) Rain (inches) Streamflow / Rain (-) (b) 80% 70% Cedar River at CR 60% 50% 40% 30% 20% 10% 0% Baseflow / Streamflow (-) 100% (c) 95% Cedar River at CR 90% 85% 80% 75% 70% 65% 60%

5 5 Raw data source:

6 6 Raw data source:

7 7 Raw data source:

8 8

9 Analysis of Watershed Scenarios High Runoff Potential Areas Increased rainfall intensity Analysis of Flood Mitigation Strategies Native Prairie Mitigating the Effects of High Runoff with Increased Infiltration/Cover Crops/No-Till Mitigating the Effects of High Runoff with Distributed Storage 9

10 Hydrologic Model Calibration and Validation Observed and simulated average monthly runoff depth (in inches) for the Middle watershed. Results are shown for both the calibration and validation periods ( ). Top: Cedar River at Cedar Rapids, Bottom: Wolf Creek near Dysart. Simulated versus observed annual maximum peak daily discharges (cfs) for the Middle Cedar. Top: Cedar River at Cedar Rapids, Bottom: Wolf Creek near Dysart. 10 Observed and simulated daily flow time series. Calibration period. Top: Cedar River at Cedar Rapids, Bottom: Wolf Creek near Dysart. Measured flows were obtained from USGS gauge stations USGS , USGS

11 Runoff Coefficient 11

12 Pond Locations and Index Points Index Point Description USGS Beaver Creek 1 at New Hartford USGS Black Hawk 2 Creek at Hudson 3 Middle Cedar at Gilbertville USGS Wolf Creek 4 near Dysart 5 High Flood Risk Spring Creek 6 Bear Creek Near Hinkle Creek Inflow Vinton Blue Creek - Tributary to Cedar 8 River 9 Dry Creek at Palo Otter Creek above Cedar River 10 Flood Plain 11 Prairie Creek at Fairfax USGS Cedar River at 12 Cedar Rapids Ponds (684) placement in the Middle Cedar 12

13 Projected change in heavy precipitation. Twenty-year return period amount for daily precipitation for mid- (left maps) and late-21 st century (right maps). Results are shown for a lower emissions scenario (top maps; RCP4.5) and for a higher emissions scenario (bottom maps, RCP8.5). Figure taken from The Climate Science Special Report (Easterling et al. 2017) ( ov/).

14 Scenario Results/Historic Precipitation/Increased Precipitation

15 Scenario Results/Historic Precipitation/Increased Precipitation (IP) Native Vegetation. 100% adoption. Cover Crops/Soil Health/No-Till scenario. 100% adoption. Distributed Storage. 684 ponds. 20 acre-ft. 12 outlet pipe. 15

16 Scenario Results/Historic Precipitation/Increased Precipitation (IP) Native Vegetation. 100% adoption. Cover Crops/Soil Health/No-Till scenario. 100% adoption. Distributed Storage. 684 ponds. 20 acre-ft. 12 outlet pipe. 16

17 Scenario Results/Summary Cedar River at Cedar Rapids Native Vegetation. 100% adoption. Cover Crops/Soil Health/No-Till scenario. 100% adoption. Distributed Storage. 684 ponds. 20 acre-ft. 12 outlet pipe. Wolf Creek near Dysart 17

18 A vision for a more resilient Iowa Iowa Flood Center The University of Iowa 100 C. Maxwell Stanley Hydraulics Laboratory Iowa City, IA

19 About News & Events Contact Us Average annual precipitation (inches). Estimates are based on the 30- year annual average ( ). (Data source:

20 20 Raw data source:

21 Counties: Des Moines, Buchanan, Butler, Howard, Muscatine, Louisa, Montgomery, Chickasaw, and Wapello 21 Raw data source: