DOCUMENTATION IN DEVELOPMENT

Introduction

The Integrated Reservoir Model is a General Adapter module written in Java, developed by Deltares. The model class is part of the Delft-FEWS code base.

The Reservoir model is developed and designed as a relatively straightforward reservoir routing model, that simulates flow through a reservoir with a level-release table defined. Specifically, the model is able to precisely replicate the uncontrolled outlet reservoir behaviour of the legacy Deltares RTC-Tools 1 codebase, which is no longer developed and supported. Because the adapter model is based on Java, it can run on Windows/Linux systems.

The model is introduced in the 2021.01 BoM Delft-FEWS version. The model adapter will be part of the Delft-FEWS code base of Delft-FEWS versions 2023.01 and onwards with in-memory options, to be set in the General Adapter configuration.

Directory structure

The data directories and configuration files that are required for operating the FEWS Reservoir Model Adapter are shown below.

FEWS_SA
+---Config
|   +---ColdStateFiles
|   |   |       namoi_keepit_KeepReservoir_Historical_IRM Default.zip........coldState file
|   +---IdMapFiles
|   |       IdExportIRMReservoir.xml
|   |       IdImportIRMReservoir.xml.........................................custom mappings for the IRM variables and locations
|   |         
|   +---ModuleConfigFiles 
|   |   |   Reservoir_1h_Forecast_IRM.xml....................................main configuration file of the adapter
|   |           
|   +---ModuleDataSetFiles
|   |   |   Reservoir_Exe.zip................................................zipped IRM bin files, transported to Modules\reservoir directory
|   |   |   
|   |   |   namoi_IRM_Reservoir_Forecast.zip.................................zipped IRM model files for a specific reservoir, transported to Modules\Reservoir directory
|               
+---Modules
|   +---delft-adapters........................................................directory which contains all IRM adapter java files
|   |   |       
|   +---reservoir
|   |   +---Keep_IRM
|   |   |       diag.xml......................................................output FEWS-PI diagnostics file, imported by Delft-FEWS
|   |   |       export.xml....................................................output FEWS-PI time series files, imported by Delft-FEWS
|   |   |       exportState.xml...............................................FEWS-PI state output time series file, imported by Delft-FEWS
|   |   |       import.xml....................................................input FEWS-PI time series files, exported by Delft-FEWS
|   |   |       importState.xml...............................................FEWS-PI state input time series file, exported by Delft-FEWS
|   |   |       Keep_IntegratedReservoirModel.xml.............................IRM model file
|   |   |       run_info.xml..................................................a file generated by FEWS containing paths, run options
|   |   |       statePI.xml...................................................PI State file (definition)
|   |   |

General Adapter configuration

The General Adapter defines forms the interface between the Delft-FEWS system and the Reservoir model.

The data is provided in a standardized XML interface format, the FEWS Published Interface. For more details about general structure of the General Adapter please check 05 General Adapter Module.

general

Configuring a pi-version 1.8 is required for the diagnostics of the model. The model will write diagnostics to the filename that is configured in the General Adapter (the model reads it from the outputDiagnosticFile field in the run_info file). The logging will be to the level that is configured in Delft-FEWS (typically debug/info/warn/error).

idMapping

The location/parameters used in Delft-FEWS can be transformed to model variableId locations/parameters by ID-mapping. The configuration files for ID-mapping can be of a general form, as long as the reservoir model have been set up with identical variables for the inputs/outputs. The model will look for the required variables (as configured in the IRM model file) in the parameter field of the PI timeseries.

IdMapping is dependent on how the variables have been defined in the model. The Reservoir Model code will try to parse the configured model variables (like IIn, QOut, etc) from the parameterId of the PI timeseries, the locationId is not used. This means that the parameterId's of all the input timeseries need to be unique (and identical to the model variables). When writing the output timeseries, the locationId used in the import PI xml files will be used as the locationId in the output PI xml files.

exportStateActivity

The Reservoir model can work with a stateConfigFile, exported from Delft-FEWS. This file should follow the conventions and list the read/write locations. When defined, the model will write an output state timeseries file for the complete run period, for all model export variables.

exportTimeSeriesActivity

The reservoir model requires at a minimum the following timeseries:

level or state value (at model start time)
inflow timeseries (complete run period)
release timeseries (optional)

exportRunFileActivity

A run_info file is required input for the Reservoir model, so an exportRunFileActivity needs to be configured in the General Adapter. The Reservoir Model expects a model property in the run_info file, that specifies the name of the actual Reservoir model to be run.

      <exportFile>run_info.xml</exportFile>
        <properties>
            <string key="model" value="$RESERVOIR$_IntegratedReservoirModel.xml"/>
        </properties>
    </exportRunFileActivity>

A typical run_info.xml file will contain the following information:

executeActivity

The executeActivity runs the model. The model runs of the Delft-FEWS JRE, so the ReservoirModelAdapter binaries can be specified within the binDir element. The class itself is called nl.deltares.fews.reservoirmodel.ReservoirModelAdapter. It is required to provide the path of the run_info file as an argument to the model.

            <executeActivity>
                <description>Run Reservoir module</description>
                <command>
                    <className>nl.deltares.fews.reservoirmodel.ReservoirModelAdapter</className>
                    <binDir>$REGION_HOME$/Modules/delft-adapters/fews-reservoirmodel-adapter-bin</binDir>
                </command>
                <arguments>
                    <argument>%ROOT_DIR%/run_info.xml</argument>
                </arguments>
                <timeOut>100000</timeOut>
                <ignoreDiagnostics>true</ignoreDiagnostics>
            </executeActivity>

importActivity

The model results (typically consisting of level, storage, inflow and release timeseries) can be imported using the importActivities. The importFile name configured will be written to the run_info file and consequently be created by the Reservoir model. Note that specific idImport configuration is required.

Model

The model definition for the reservoir can be configured in file that follows the Integrated Reservoir Model schema. The model options are described below.

Schema

An example Integrated Reservoir Model file is attached.

<IntegratedReservoirModel xmlns="http://www.wldelft.nl/fews" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.wldelft.nl/fews https://fewsdocs.deltares.nl/schemas/version1.0/adapter-schemas/IntegratedReservoirModel.xsd">
    <general>
        <missingValue>-999</missingValue>
    </general>
    <reservoir id="H555001">
        <general>
            <description>reservoir management H555001</description>
            <poolRoutingScheme>levelPoolMethod</poolRoutingScheme>
            <dynamicInterpolation>true</dynamicInterpolation>
            <elevationInterpolationMethod>linear interpolation</elevationInterpolationMethod>
            <elevationInterval>0.00005</elevationInterval>
        </general>
        <!--Height (LGH) vs. Storage (m3)-->
        <storageCharacteristics>
            <storageTable>
                <elevationStorageRecord elevation="292.9" storage="0"/>
                <elevationStorageRecord elevation="293.0" storage="500"/>
                ...
                <elevationStorageRecord elevation="335.4" storage="720992000"/>
                <elevationStorageRecord elevation="335.6" storage="732795000"/>
            </storageTable>
        </storageCharacteristics>
        <!--Height (LGH) vs Spill (m3/s-->
        <uncontrolledOutlet id="outlet">
            <capacityCharacteristics>
                <outletTable>
                    <elevationOutletRecord elevation="292.9" outlet="0"/>
                    <elevationOutletRecord elevation="293.0" outlet="0"/>
					...
                    <elevationOutletRecord elevation="335.4" outlet="9768"/>
                    <elevationOutletRecord elevation="335.6" outlet="10278"/>
                </outletTable>
            </capacityCharacteristics>
            <input>
                <release>QOut</release>
            </input>
            <output>
                <release>QOut</release>
            </output>
        </uncontrolledOutlet>
        <input>
            <inflow>IIn</inflow>
            <level>HIn</level>
        </input>
        <output>
            <inflow>IOut</inflow>
            <release>QOut</release>
            <storage>SOut</storage>
            <level>HOut</level>
        </output>
    </reservoir>
</IntegratedReservoirModel>

general

In the general section, a missingValue element needs to be configured. It is important to match the missingValue as defined in the Delft-FEWS General Adapter configuration for the model run.

reservoir

The reservoir element contains the following sections:

general
uncontrolledOutlet
input
output

general

The general section of the reservoir element contains the follwing fields:

poolRoutingScheme
dynamicInterpolation
elevationInterpolationMethod
elevationInterval
storageCharacteristics

poolRoutingScheme

for the poolRoutingScheme element, one can choose the following options:

levelPoolMethod
backwardsEulerMethod

levelPoolMethod

The Level Pool method is a well known method for reservoir routing. in FEWS the method described in Applied hydrology from V.T.Chow is used. The level pool routing method is also referred to as Storage routing, the Storage-Indication method, or the Modified Puls method.

The reservoir routing procedure in the Level Pool method is as follows:

We define the value G is a function of Storage and Outflow, defined as G[S] = 2*S/Δt + O

where:

S represents the reservoir storage
O represents the reservoir release
Δt represents the time step

For each row in the the uncontrolledOutlet capacityCharacteristics outletTable, we can now precompute a G[S] value. This allows us to look up the release O for a given G.

The level pool method makes use of the following relations, that follow from the water balance equations (details in the handbooks):

K[t] = G[t-1] - 2*O[t-1]

G[t]= ( I[t-1] + I[t] )+K[t]

For the computation, we loop over all time intervals from t=1 to t=t_end.

If t=0
1. Use the state values as provided in the input files. If either a level, or a storage are provided, look up the equivalent value.
2. In case both level and storage are provided, use the lookup value to determine any inconsistencies. If found, the level is used as the basis and the storage at t=0 is recalculated
3. no computation takes place at t=0
If t=1 then
1. K[1] = 2*S[0]/Δt - O[0] (inital storage and release values are known)
2. G[1] is computed with G[1]= ( I[0] + I[1] )+K[1]
3. Compute O[1] by linear interpolating the table using O(S) and G(S).
4. In case an O_input[1] timeseries is provided, O[1] = O_input[1]
5. S(1) = S(0) + Δt* ( I[1] - O[1] )
If t>1 then
1. K[t] = G[t-1] - 2*O[t-1]
2. G[t] is computed with G[t]= ( I[t-1] + I[t] )+K[t]
3. Compute O(t) by linear interpolating the table using O(S) and G(S).
4. In case an O_input[t] timeseries is provided, O[t] = O_input[t]
5. S(t) = S(t-1) + Δt* ( I[t] - O[t] )

backwardEulerMethod

The backward Euler reservoir routing scheme is an implicit scheme that uses the backward difference approximation for the derivative. The equation for the backward Euler reservoir routing scheme can be written as follows:

S[t+1] = S[t] + Δt* ( I[t+1] - O[t+1,S[t]] )

where:

S[t+1] represents the reservoir storage at the next time step (n+1)

S[t] represents the reservoir storage at the current time step (n).

Δt represents the time step.
I[t+1] is the inflow into the reservoir at the next time step (n+1).
O[t+1,S[t]] is the reservoir release at the next time step (n+1), based on the storage-release relation using S[t] for the lookup input.

dynamicInterpolation

When the dynamicInterpolation element is set to true, the level/storage and level/outlet tables are dynamically (every timestep) interpolated to the precise value, using the elevationInterpolationMethod. In this case, the elevationInterval element is ignored.

When the dynamicInterpolation element is set to false, the level/storage and level/outlet tables are precalculated (only once) using the elevationInterpolationMethod, to the specified elevationInterval.

elevationInterpolationMethod

Linear interpolation is the only available interpolation method

elevationInterval

The elevationInterval or elevation resolution at which the configured level/storage and level/outlet tables need to be recalculated. Note that the level output at each timestep is processed to that elevationInterval. When a value needs to be determined from the table the largest entry that is still smaller than the precalculated table elements is used (the model always rounds down). The consequence is that reservoir inflows/releases at a timestep that result in level/storage changes that are smaller than the interval/resolution will not be taken into account. This means that the model will underestimate the flow and water balance will not be closed.

storageCharacteristics

The storageCharacteristic storageTable contains a storage-level lookup table that is strictly increasing. Note that this table should have the identical storage inputs as the capacityCharacteristics outletTable from the uncontrolledOutlet.

uncontrolledOutlet

The uncontrolledOutlet element contains capacityCharacteristics outletTable which relates storage-release. Note that this table should have the identical storage inputs as the storageCharacteristic storageTable.

The <input><release> element can be set to the timeseries variable that can overwrite (take precedence) the lookup value for the release.

The <output><release> element determines where the resulting release timeseries is saved to

input / output variables and files

In the input section, the model input variables will be configured. The model will look for the required variables in the parameter field of the PI timeseries (see idMapping). The Reservoir Model code will try to parse the configured model variables (like IIn, QOut, etc) from the parameterId of the PI timeseries, the locationId is not used.

n the output section, the model output variables will be configured. When writing the output timeseries, the locationId used in the import PI xml files will be used as the locationId in the output PI xml files.

The naming convention of the input and output timeseries filenames are free, the model will determine which files to read for the input based on the inputTimeSeriesFile filed in the run_info file. The following two input timeseries files are suggested:

importState.xml
- level values, or (HIn)
- storage values (SIn)
import.xml
- inflow (IIn)
- release (optional) (QIn)

Note that for the suggested variableId's, the postfix In and Out are used to denote if the series are Inputs for, or Outputs from the model.

The startDateTime and endDateTime in the run_info file are used by the model to determine the start (startDateTime) and end (endDateTime) of the model run. The model will pick the starting (state) value for level/storage (level has precedent in case of an inconsistency), inflow, release from the inputTimeSeriesFiles at the specific . If a starting level value is missing, the model will use the starting storage value. If both starting level/storage cannot be determined from the input files, the model will throw an error. Inflow and release values at the starting time are not required at the first timestep. When they are not found, a value of 0 is used.

The following output timeseries file is suggested:

export.xml
- inflow (IOut)
- release (QOut)
- storage (SOut)
- level (HOut)

In case state functionality is configured in the run_info file (inputStateDescriptionFile is defined), the model will also write the outputs to the write location as defined in the stateLocation file (e.g. exportState.xml)

Reservoir Model specifics

The model can be considered "timestep ending", similar the the timestep definition of Delft-FEWS.
No calculations/processing is performed at the first timestep (t=0, startDateTime as set in the run_info.xml file)

Ensembles

The Reservoir Model can be run in parallel from Delft-FEWS. The runInLoop element of the workflow should be set to false. The general section of the General Adapter configuration should contain the %TEMP_DIR% property as the model rootDir. And lastly, to enable the parallel running of ensemble members the runInLoopParallelProcessorCount entry must be set in the global properties file. Here you either specify the number of cores to use or specify 100 to use all available cores.

In the workflow

    <activity>
        <runIndependent>true</runIndependent>
        <workflowId>Reservoir_Forecast</workflowId>
        <ensemble>
            <ensembleId>ENSEMBLE</ensembleId>
            <runInLoop>false</runInLoop>
        </ensemble>
    </activity>

The general section of the General Adapter configuration

<general>
  <rootDir>%TEMP_DIR%</rootDir>
  <workDir>%ROOT_DIR%/work</workDir>
  ...
</general>

In the global properties

Config Example	# to use 4 cores/cpu's: runInLoopParallelProcessorCount=4

See the following page for more details.

In-Memory execution

From Delft-FEWS version 2023.01 onwards, it will be porssible to run the Reservoir Model adapter "in-memory" from Delft-FEWS, using the inMemoryFileTransfer element of the general section set to True. In that case, all exported and imported files are transferred in memory between Delft-FEWS and the executed Reservoir Model.

Page tree

Integrated Reservoir Model

Introduction

Directory structure

General Adapter configuration

general

idMapping

exportStateActivity

exportTimeSeriesActivity

exportRunFileActivity

executeActivity

importActivity

Model

Schema

general

reservoir

general

poolRoutingScheme

levelPoolMethod

backwardEulerMethod

dynamicInterpolation

elevationInterpolationMethod

elevationInterval

storageCharacteristics

uncontrolledOutlet

input / output variables and files

Reservoir Model specifics

Ensembles

In-Memory execution