Hydrologic Model

1. PDSI SM Percentile Applications of Medium Range To Seasonal/Interannual Climate Forecasts For Water Resources Management In the Yakima River Basin of Washington State Shraddhanand Shukla, Donee Alexander, Anne Steinemann, Andy Wood University of Washington Project Overview Progress in Monitoring and Prediction Activities • For Washington State, a model-based hydrologic monitoring and prediction system is being created, currently offering: • spatial maps of soil moisture and SWE • basin average conditions for all “water resources inventory areas” (WRIAs) State-of-the-art seasonal climate forecasts, such as the NOAA CPC seasonal outlooks, offer the potential to mitigate drought impacts in vulnerable sectors such as agriculture, but these information resources are largely untapped by water managers and users. • This study will bridge the gap by working directly with users in the transition of NOAA climate forecasts, coupled with hydrologic assessments, to water resources operations and drought management. • Our research focuses on water management in Washington State’s Yakima River Basin, home to the state's most valuable irrigated crops, and on state-level drought policy in Washington. • There are three main goals of the project: • Collaborate with U.S. Bureau of Reclamation (USBR) to evaluate the uses of streamflow forecasts. • Interact with water users and managers to identify the factors that influence the degree of adoption of hydrologic forecasts in decision-making. • Explore potential uses of model-based monitoring and prediction of hydrologic indicators of drought as triggers for management actions. Hydrologic Model PROJECT SETTING Daily update of WRIA basin averages. Current Water year Precipitation, Temperature, Soil moisture, SWE, Runoff (cumulative and 5-day averages) plotted against 1971-2000 climatological data) • The USBR Yakima Project supports approximately 464,000 irrigated acres (via four irrigation districts -- Roza, Yakima-Tieton, Sunnyside Valley and Kittitas -- and the Wapato Division). • Most of the water in the Yakima River comes from snowmelt, and is caught in a series of reservoirs to ensure sufficient water supply throughout the season. http://www.hydro.washington.edu/forecast/sarp/ Other Products Other variables Progress in Forecast User Interaction Activities Interviews have been conducted with USBR operators and agricultural water users. Shown below are the typical operations of water managers/users in a calendar year. SWE Jan--------Feb-------Mar-------Apr--------May--------Jun--------Jul--------Aug--------Sep--------Oct--------Nov--------Dec-- Initial Monthly Water Forecast Issued ------------------------------ Water Deliveries ---------------------------------- Reservoir Operations For Fall Crop Reservoir Drawdowns For Flood Control Summer Water Allocations Decided Reservoir Refill IN development: Cumulative runoff and precip over varying periods (e.g., 1-, 3-, 6-, 12-months and longer) Nowcast system at 1/16 deg resolution Weekly update of time-series plots of Drought indexes (e.g. PDSI, PHDI etcs) Fields Prepped Seed Bought Repairs / Preparations for irrigation season In good years, Fall Crop In drought years, decisions about selling water & fallowing fields ------------------------------Irrigation Season---------------------------------- Future Plans Water users have expressed the following perspectives on climate forecasts: • Implement streamflow forecasting (focusing on Yakima R. Basin), using a VIC 1/16th degree model • Develop drought onset and recovery forecasts using traditional (e.g., PDSI) and advanced drought indices • Provide 15-day spatial flood risk forecasts based on dynamic model reforecasts from NCEP/ESRL • Work with water managers and users to integrate climate and hydrologic forecast information into decision-making in the Yakima River basin • Funding has been provided by the NOAA Sector Applications Research Program (SARP). • Reliable hydrologic forecasts and other predictive tools are needed earlier in the year. • More detailed forecasts are needed, with explanations of skill, accuracy, and uncertainty that are meaningful to users. • Users are willing to work with forecasters to develop products that are understandable, easily interpreted, and useful in their decision-making processes. Acknowledgements