1. Hydrology and Water Management Applications of GCIP Research
Dennis P. Lettenmaier
Department of Civil and Environmental Engineering
University of Washington
for presentation at
Stakeholder Session
Mississippi River Climate and Hydrology Conference
New Orleans
May 14, 2002

2. GEWEX and GCIP Goals
Scientific goal: “To observe and model the hydrologic cycle and energy fluxes in the atmosphere, and at the land and ocean surface”
Applications goal: “Demonstrate skill in predicting changes in water resources on time scales up to seasonal, annual and interannual”

3. GCIP Contributions for Water Management
Data sets
Macroscale land surface model development and improvements
Land Data Assimilation System (LDAS)
Forecast method and product development

4. Data Sets Many, key examples include:
WSR-88d retrospective archive ( )
GOES solar radiation
LDAS retrospective (model forcing, e.g., precipitation, and model-derived, e.g., soil moisture)
LDAS real time

5. LDAS Modeling Domain Domain is North America between 25º and 53º N
Resolution 1/8º
77,000 grid cells through domain (56,000 in Continental U.S.)
Model developed for 15 sub-regions
Model forcing data ( ) derived from observations
Run at a 3-hour time step

6. LDAS Derived Soil Moisture - Active Range
Long term spatial data set allows characterization of variability
Dynamic range of the soil column
Degree to which source of variability (P) is buffered by soil column
Level of hydrologic interaction of soil column
50-Year Soil Moisture Range Scaled by Annual Precipitation

8. Macroscale land surface model development and improvements

9. VIC Hydrologic Model

11. Land Data Assimilation System (LDAS)

12. LDAS land surface model (LSM) and coupled model interaction

13. LDAS real-time soil moisture

14. Forecast method and product development

15. Coupled GCM
Embedded
Regional CM
Macro-Scale
Hydrology
Model (VIC)
SST
Forecast

17. How NCEP makes experimental ensemble climate forecasts
Coupled Ocean-AGCM
20 different
Initial states
of the atmosphere
20 unique forecasts of the climate over the next six months
2x2 degree AGCM
Initial and
Predicted
SST for next
6 months
We use the raw model output at this point.
…but, we must recognize the scale mismatch

18. GSM PCP
OBS PCP
PROB
PROB
RAW FORECAST PCP
BIAS-CORR PCP

19. East Coast Apr ’00 forecast for May-Jun-Jul
forecast median shown as percentile of climatology ensemble

20. CRB May forecast
forecast
hindcast “observed”
forecast
medians

21. CRB May Forecast cumulative flow averages
important point(s):
plotted against the streamflow climatology used by other agencies, the forecast ensemble medians for average flow in the first 3 months of the forecast period (top) and over all six months (bottom) end up between the 1977 and 1988 runoff averages.
Given the uncertainties in the snow pack estimation used as initial conditions for the forecast runs, particularly the fact that our estimation is somewhat less dire than that of the NRCS (putting initial snowpack below their estimates for 1977), these results could be looked at as conservative – that is, 2001 runoff could actually be lower than we are showing here.
forecast
medians

22. Information Xfer to Stakeholders: How well did GCIP succeed in “demonstrating skill”?
Conclusion: Quite well, if the goal is taken literally
but
Demonstrated use of GCIP “products” by water managers is minimal
why?

23. Scientists are not particularly skilled, or even interested in, “technology transfer”
Practitioners are stuck in “paradigm lock”; institutional inertia on algorithms and methods
GCIP/GAPP has provided science, not applications funding -- focus on many small projects of limited duration discourages long-term view
Possible solution: better liaison with RISAs as mechanism for breaking “paradigm lock”