GoldSim Technology Group LLC, 2006 Slide 1 Water Balance Modeling Techniques.
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Transcript of GoldSim Technology Group LLC, 2006 Slide 1 Water Balance Modeling Techniques.
GoldSim Technology Group LLC, 2006
Slide 1
Water Balance Modeling Techniques
GoldSim Technology Group LLC, 2006
Slide 2
Overview
Reservoir basics– Overflow_Rate, Withdrawal_Rate, changing upper bound– Using Extrema elements to track high and low extremes– Using Status elements to track the status of a Reservoir (and
control actions such as pumping) Using Time Series elements for precipitation and other
histories Using Material Delay elements to simulate seepage and flow Using Convolution elements to simulate a runoff using a
unit hydrograph Generating stochastic precipitation, evaporation and flow
histories Using Allocators and Splitters Using the Reliability Module to simulate equipment failure Share your own techniques
GoldSim Technology Group LLC, 2006
Slide 3
Reservoir Basics
Overflow Rate Using the Withdrawal Rate output Varying the Upper Bound (to simulate silting
up)
Using an Extrema to track peaks/valleys Using a Status element to track status of a
Reservoir and control actions (such as pumping)
GoldSim Technology Group LLC, 2006
Slide 4
Using Time Series Elements in Water Balance Models
Useful for inputting precipitation, evaporation and other time series
Important to:– Differentiate between rates and values– Differentiate between instantaneous flows
and averages flows Can import data from spreadsheets
GoldSim Technology Group LLC, 2006
Slide 5
Using Material Delay Elements to Simulate Seepage and Flow
Delay Time is mean velocity of flow Dispersion can simulate spreading
– Both can be specified as a function of hydrogeologic properties
– Both may change with time (e.g., is material at field capacity?)
GoldSim Technology Group LLC, 2006
Slide 6
Using Convolution Elements to Simulate a Runoff Using a Unit Hydrograph
A Convolution element converts an input signal to an output signal via a transfer function– You provide an input signal (e.g., rainfall rate)
and a transfer function (the unit hydrograph)– The convolution integral applies the transfer
function and computes an output (e.g., runoff)
A Delay is a specialized instance of a convolution integral
GoldSim Technology Group LLC, 2006
Slide 7
Generating Stochastic Precipitation, Evaporation and Flow Histories
Option1: Build your own Markov (or other) model manually
Option2: Using autocorrelated Stochastics Option3: Use the History Generator element
GoldSim Technology Group LLC, 2006
Slide 8
Splitters and Allocators
Should be very powerful elements for water balance models
Splitters split (distribute) flows Allocators route flows based on specified
demands and priorities
GoldSim Technology Group LLC, 2006
Slide 9
Using the Reliability Module to Simulate Pumps and Other Equipment
Simulate pump failure, as well as pumps turning on and off
GoldSim Technology Group LLC, 2006
Slide 10
Do you have any favorite techniques that you would like to share?