Impacts of climate anomalies on water resources in the Carolinas

1. Impacts of climate anomalies on water resources in the Carolinas Dan Tufford, Greg Carbone, Jim Hussey, Kirstin Dow University of South Carolina Climate Prediction Application Science Workshop Chapel Hill, NC 06 March 2008

2. Evaluating ENSO Impacts in the Carolinas Stakeholders’ perceptions of ENSO impacts Discerning and communicating variability of ENSO expression

3. Regional assessment • North and South Carolina • COOP and USGS • 1950 – 2004 • Monthly total precipitation and streamflow • Assign ENSO phase by month (CPC) • Cool (La Niña), neutral, warm (El Niño) • Assign AMO phase by year • Warm – 1950-1963, 1995-2004 • Cool – 1964-1994 • Each month assigned to a season • Winter = DJF, Spring = MAM, etc. • SAS Proc GENMOD • Gamma distribution • Significance at p ≤ .05

4. ENSO and AMO analysis

5. Precipitation Winter – AMO n/a Stream flow

6. Precipitation Winter – AMO cool Stream flow

7. Precipitation Winter – AMO warm Stream flow

8. ENSO and AMO analysis • Winter – warm AMO, both precipitation and streamflow • El Niño > Neutral > La Niña

9. ENSO and AMO analysis • Winter – warm AMO, both precipitation and streamflow • El Niño > Neutral > La Niña • Spring – similar relationships • Not as strong as winter • Summer – significant precipitation only • Both El Niño, La Niña > Neutral when AMO cool • Both El Niño, La Niña < Neutral when AMO warm • Autumn – both precipitation and streamflow • Greater regional differences – interior v coastal • Differences between precipitation and streamflow

10. Influence of tropical storms

11. Dams R Us • Analysis of only unregulated stations does not significantly alter the interpretation of the results. • Suggests actual inflow to reservoirs impacts their operations as much or more than weather.

12. Uses of these results/methods • Hydrologic modeling • Effect of interannual and multidecadal phase • Both short- and long-term scenarios • Value of subregional analysis for water management and planning • Climate driven interannual weather patterns do vary over the study area • Provides another perspective of the impacts of land use change • Streamflow is more important than precipitation for some sectors • Analysis may provide a basis for seasonal differentiation among these sources of water

13. Regional drought implications • Prior knowledge that La Niña is associated with dry winter conditions in the southeast • These results show this effect is associated with the warm phase AMO • Providing AMO and ENSO phases with monitor reports and seasonal forecasts would make them more information rich

14. Drought implications example • Telephone surveys of horticultural industry in NC/SC • “If drought continues residential planting will be minimal due to watering restrictions” • Planting decisions are made months in advance • Influenced by an indirect effect • Some do their own monitoring to stay abreast of local conditions

15. Additional acknowledgements • Jinyoung Rhee, PhD – USC Geography • Graduate students • Kirsten Lackstrom, Richard Murphy, Sara Yorty • Undergraduate students • Lauren Felker, Grandon Wilson