Hfam II

 

 

 

Hfam II is based on the Stanford, HSP, HSPF,  SRFM and Seafm family of models. It is a continuous simulation model that does historical or forecast analysis and it includes probabilistic or ensemble forecasts of streamflows, reservoir levels and releases or power production.

 

Hfam II uses and or simulates physical ‘elements’ in time. These elements are;

 

            Time Series

Meteorological Station Data – precipitation, actual evapotranspiration, wind, solar radiation, air temperature, and (optional) lapse rates

Streamflows, aquifer levels, snow course measurements, reservoir levels

Diversion demands, instream flows, minimum or maximum reservoir content, reservoir or reach seepage, irrigation applications, pumping from aquifer elements, hydro power demand, minimum and maximum streamflows below reservoirs, atmospheric loading

 

            Land Segments

            Reaches

            Aquifer Segments

            Glacial Segments

            Reservoirs

                        Diversions

                        Powerhouses

                        Spillways

                        Low Level Outlets

 

The number of physical elements in a watershed is unlimited. Simulation runs hourly.

 

Figure 1 Hfam II Operations, Main Screen

 

Hfam II does four types of ‘runs’;

 

            Forecast

            Analysis

            Probabilistic

            Optimization

 

Forecast runs are made with deterministic weather forecasts, and are often used for flood forecasts and flood operations.

 

Analysis runs are made using historic and real-time data for model parameter calibration and for period of record studies of reservoir operations or water yields.

 

Probabilistic runs (also called Ensemble runs) give exceedance probability for watershed and reservoir conditions in the future based on the current watershed state and future weather.

 

Optimization runs solve for the current optimal release from a reservoir given current and future values of releases and exceedance probabilities for reservoir inflows.

Meteorological time series inputs for Hfam II are stored in three data bases; forecast, historic and real-time. These data bases can be seamlessly connected in any model run.

 

Output from Hfam II includes flows and storage in physical elements, heat exchange, and mass and concentration for sediment and nutrients. Statistical summaries of both inputs and outputs are available. Model input and output are in XML, and all model inputs can be verified with Schemas before they are used by the model.

 

Model outputs are available for all time series. Any XML conversant program, like EXCEL or WORD can use these outputs directly.

 

Examples of model screens follow:

 

 

Figure 2 Tolt River Snow Water Equivalent

 

 

Figure 3 Snowpack Conditions at Alpine Meadows Snotel

 

 

Figure 4 Heat Exchange at Alpine Meadows Snotel

 

 

Figure 5 Vegetation, Soil and Groundwater Storages

 

 

Figure 6 Precipitation and Soil Moisture Flux

 

 

Figure 7 Simulated and Observed Streamflows

 

 

Figure 8 Simulated and Observed Streamflow Summary Data

 

 

Figure 9 Watershed Summary Data, Cumulative above Reaches or Reservoirs

 

 

Figure 10 Exceedance Probability for Cumulative Conditions above a Reach or Reservoir

 

 

Figure 11 Flood Frequency

 

 

Figure 12 Historical Snowpack Water Equivalent, Period of Record ( selected weather year in red)

 

 

Figure 13 Watershed Soil Moisture Probability

 

 

Figure 14 Watershed Snow Water Equivalent Probability

 

 

Figure 15 Aquifer Segment Storage, Inflow and Outflow

 

 

Figure 16 Aquifer Segment Storage Probability

 

 

Figure 17 Reservoir Levels and Frequency Data

 

 

Figure 18 Reservoir Operations

 

 

Figure 19 Reservoir Operations, Demands and Release

 

 

Figure 20 Powerhouse Demand and Generation

 

 

Figure 21 Reservoir Elevation, Period of Record (selected weather year in red)

 

 

Figure 22 Optimization Detail at a Reservoir

 

 

Figure 23 Interactive Parameters and Files, Reservoir

 

 

Figure 24 Meteorological Time Series Linkages

 

 

Figure 25 Input Time Series, Air Temperature

 

 

Figure 26 Data Availability Summary (maintained by Hfam II)

 

 

Figure 27 Instream Flow Specification

 

 


Figure 28 Snow Water Equivalent, Tuolumne River

 

 

 

Figure 29 Snow Water Equivalent Detail, Central Tuolumne

 

 

Summary

 

Hfam II is a comprehensive modeling system that simulates hydrologic processes (runoff from rainfall and snowmelt, channel flow) and the operation of existing or planned water resource facilities (reservoirs, hydro plants, irrigation systems).

 

Hfam II is use for both design and operation of projects. For design, proposed facilities are added to a watershed and the operation of the facilities is explored. This allows comparison of project alternatives, and economic analysis of reservoir characteristics,  hydroplant capacities, diversions, and other facilities. Output from Hfam II can be loaded directly into Excel, Word, and other programs. [1]

 

Hfam II does historic analysis, forecasts, probabilistic and optimization runs. When used for operation of projects, Hfam II shows future reservoir outflows, irrigation diversions, conditional flood frequency, and reservoir elevation probability.

 

History and Applications

 

Many concepts in the system were first explored in research at Stanford University . HFAM II and it predecessor models have been use for design or operations analysis for many large irrigation, water supply and hydroelectric projects. [2]

 

Model applications in North America include;

 

Middle Fork Nooksack, Lake Whatcom , Washington (City of Bellingham Water Supply)

 

Housatonic River , Connecticut , Hydropower system

 

Saco, Androscoggin, and Kennebec Rivers , Maine , Hydropower systems

 

Tolt and Cedar Rivers , Washington (City of Seattle Water Supply)

 

Tuolumne River , California (Irrigation, Hydropower and Water Supply System)

 

Baker River , Washington (Hydropower)

 

 

Model applications in South America include;

 

Tucuri Dam , Brazil , in the Tocantins-Araguaia basin, the fourth-largest hydroelectric project in the world, spillway design

 

Rio Nare-Guatape , Colombia , San Carlos , Jaguas Hydroelectric Projects, flow forecasting for real-time operations.

 

Rio Paranaiba, Brazil, Embocacao Hydroelectric project, spillway design

 

Rio Ica , Peru , Flood Control, Flood Frequency Analysis.

 

Rio Santa , Peru , Irrigation Analysis.

 

Rio Grande , Bolivia , Hydroelectric project, spillway design

 

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Hydrocomp, Inc.

 

 

 

 

 



[1] Hfam II uses XML input and output. Historic, real-time, and forecast data bases are maintained.

[2] Predecessor models are the Stanford Watershed Model IV (1966), HSP (1972), HSPF (1980), SRFM (1987), SEAFM (1990), and HFAM 1.1 (1997). These models have been applied in thousands of watershed worldwide.