Note to Editors: Clark will make his presentation at the annual fall meeting of the American Geophysical Union. The Press Room number is (415) 905-1007.
University of Colorado at Boulder researcher Martyn P. Clark and colleagues have developed improved methods of forecasting water availability in streams and rivers designed to help water managers make better decisions about how to use water resources.
Clark, a researcher with CU-Boulder's Cooperative Institute for Research in Environmental Sciences, or CIRES, will give a talk titled "Advances in Stream Flow Forecasting Capabilities on Intra-Seasonal Timescales" at the fall meeting of the American Geophysical Union being held in San Francisco Dec. 6 to Dec. 10.
"These forecasts are especially helpful to reservoir managers, who have to make multiple decisions about generating hydropower, providing irrigation water, maintaining river levels for recreation, and more," Clark said. "The methods we have developed so far significantly improve current practices."
Current methods of predicting runoff use hydrologic models to estimate snow cover and soil moisture at the start of a forecast period and then use historical observations in the hydrologic models to get a range of runoff forecasts, Clark said.
In a collaborative study involving CIRES, a joint institute of CU-Boulder and the National Oceanic and Atmospheric Administration as well as the U.S. Geological Survey and the National Weather Service, the researchers used forecasts of precipitation and temperature to more accurately estimate runoff.
To obtain local temperature and precipitation forecasts, the researchers used data from a global forecast model run back in time over the last 20 years. With statistical functions, they developed relationships between this information and measurements for the same period taken at stations in individual river basins.
The researchers then introduced the local-scale forecasts of temperature and precipitation hydrological computer models. The models predict how snow pack will accumulate and melt and how forecasted temperature and precipitation will affect spring runoff.
The team also used satellite snow-cover data to get better estimates of initial conditions, which will improve forecasts of water runoff.
The new modeling methods will be used this spring along with existing methods and results from both techniques will be compared, Clark said.