Outcomes of The Living Murray Icon Sites Application Project

Stuart Little

Project Officer, The Living Murray

Environmental MonitoringeWater CRC Participants Forum 23rd November 2011

Context – The Living Murray

The Living Murray aims to return an average of 500GL (long term cap equivalent) per annum of environmental water to 6 “Icon Sites” in the Murray system. Environmental works and measures are being

constructed to support water delivery.

Scope of Project

The Murray Icon sites Application will produce a tool which:

– models ecological responses to watering scenarios; and

– informs trade-offs and decisions when prioritising environmental water allocation under the MDBA's Living Murray program.

Eco Modeller will convert daily time series data from MSM Bigmod

scenario runs into measures of environmental consequence for each

icon site.

These environmental consequences can then be compared across

sites for different environmental watering strategies.

The Plan• Implement existing ecological response models from the Murray

Flows Assessment Tool (MFAT)

• Link ecological response models to improved hydrological modelling

developed for the Icon Sites

• Refine MFAT ecological response models using findings of monitoring

and research at the Icon Sites since MFAT development

• Develop easily interpreted reports of modelling results to inform the

prioritisation of environmental water allocation under the MDBA's

Living Murray program

Tasks of the Project Phases

Phase 1 – 2008 to 2010

• Linking MDBA hydrological modelling to Eco Modeller

• Modelling system development

• Conceptual models of Icon Site responses to flow and ID key ecological assets

• Developing and implementing Ecological Response Models

• Compilation of research data and resources

• Designing and implementing methods of aggregation and reporting of model results

Phase 2 – 2010/2011

• Refine Eco Modeller as required

• Add to MSM Bigmod, to provide

the input time series required

• Develop relevant models for the

remaining Icon Sites

• Develop new models for pest

species

• Model testing to calibrate and

validate habitat prediction models

• Design and implement an

aggregation and reporting format

Linking MDBA Hydrologic Modelling to Eco Modeller – Phase 1

Developed a data handler that:

– Identifies Bigmod files

– Allows users to select a time series for a particular point

in the Murray system

– Search function to make selection of time series easier

Modelling system development – Phase 1

• Aim to fully implement the MFAT models into Eco Modeller,

then upgrade the elements using additional science and data.

• Base models in MFAT had a level of complexity that was not

able to be duplicated in the original design of Eco Modeller

• New ecological models relevant to the Icon Sites were also

too complex

• Need to develop a structure that would allow various

numerical model forms, that must also conform to providing

output in a similar way

Summary

Limitations

Confidence

Plug –in model

Developing and implementing Ecological Response Models – Phase 1

MFAT contained models for up to 30 assets per icon site

– an asset may have several life history stages; and

– be calculated at several sub sites for each site

– used a range of complex equations that also included scores from variables

that remain static when comparing scenarios

30 assets x 6 Icon Sites x 2-3 habitat requirements/life history stages

equals “lots of models”

To handle the implementation of so many models a “generic species

plug in model” was developed

The TLM Generic model principles

A successful water event can be characterised as:

Magnitude or Threshold– minimum depth, discharge, spatial extent

Duration – how long does it last

Timing – what time of year does it occur

Period between events – how long has it been since the last successful watering

Rate of Change – the speed at which the water rises and falls

Bigmod Output

Event

Duration

Timing

Return Period

Result

Threshold

Ecological Modelling – Phase 1

To demonstrate the application of Eco Modeller, two alternative

flow scenarios were modelled, ‘Natural’ and ‘Current’.

• Simple species based comparison showed that in most cases,

the ‘Current’ scenario had much lower average habitat

suitability scores. The current scenario also had a marked

increase in the number of ‘poor’ years across most models.

• There were also some marked differences between species

and even between the life history stages of the same species,

demonstrating the value of modelling habitat requirements at

the life history stage level.

Outcomes from Phase 1

• The Eco Modeller software changed significantly, the changes

show the benefits of eWater’s Application Project/Focus

Catchment approach to software development.

• The results provided an indication of the potential of the Eco

Modeller software to inform water allocation at the flow-regime

scale (i.e. >10 years).

• Changes to software functionality, the individual ecological

response models and improved aggregation and reporting

were recommended to further refine the product to address

the original scope of the project.

Next Steps – Phase 1 leading to Phase 2

• Compilation of research data and resources for all Icon Sites

• Testing and calibration of the ecological response models

• Review of model outputs for various scenarios and

comparisons to actual watering events

• Creating aggregation, reporting and interpretation tools

• Creation of new and/or modification of existing ecological

response models into the future as greater knowledge

becomes available

Testing and Validation - Phase 2

In order to use the habitat suitability models to inform water resource

management options, the models should ideally be well calibrated to

observed habitat condition output.

Limitations

• biological measures are not the same variable as that being

predicted by the models

• lack of long term biological datasets against which to test

The approach used here was to test the performance of the habitat

suitability models against these small biological datasets.

Testing and Validation - Phase 2

Key Steps

• compile appropriate biological data,

• model areas of inundation for Hattah Lakes (for fish and

vegetation analysis) and for all icon sites for the bird

analysis,

• test habitat suitability models with the available data as

well as relate the biological data to simple measures of

inundation

Findings of Testing and Validation

Waterbird models as they stand have limited use due to:

• lack of long term suitable data

• limited understanding of links between inundation and waterbird

responses

Floodplain vegetation models improved via the adaptive process:

• incorporation of rainfall and a decay factor improved correlation

between field data and model scores

• However, the correlation for vegetation models were typically low.

The limited frequency of field sampling is a limitation for validating the

fish ecological response models, and indeed the waterbird and

vegetation models as well.

Lessons Learnt and Recommendations

• Project outcomes are directly proportional to the ability of the

coordinator to drive the project forward

• Calibration and/or validation of models requires long-term,

appropriate datasets

• The development and maintenance of Eco Modeller model

libraries needs to be treated like an adaptive management

process

• Consider the possibility of incorporating uncertainty into the

ecological response models, e.g. by a Bayesian network

approach

Outcomes of the Application Project

We did:

• Use a real-world application of Eco Modeller to improve the tool and add

greater functionality that was relevant beyond the TLM Icon Sites

application

• Develop a generic model format that can be used to build ecological

response models based on flow requirements

We did not:

• Successfully develop and validate models of ecological response for the

TLM Icon Sites

• Develop an aggregation and reporting tool that could be used to inform the

prioritisation of environmental water allocation under the MDBA's Living

Murray program

Thank You

For further information:

Stuart Little

Murray-Darling Basin Authority

stuart.little@mdba.gov.au

02 6279 0568 or 0466 770188