Systems Dynamic Model of

Horowhenua- Workshop 2

SYSTEMS DYNMAIC MODEL - WKSHP 2: HOROWHENUA

Manaaki Taha Moana

Manaaki Taha Moana is a six year research programme primarily funded by the Foundation of

Research Science and Technology ($6.6 million). It runs from October 2009 to October 2015. It has two case

study regions Tauranga Harbour, and the Horowhenua coast.

The aims of the research programme are:

Restoring and enhancing coastal ecosystems that are important to Iwi. This will achieved through a better

knowledge of these ecosystems and the degradation processes that affect them, and then using that

knowledge to influence decision-making by councils and others.

Iwi/hapū Capacity Building. This will be achieved by a strong focus on developing iwi-based researchers and to

build hapū/iwi future leaders in the area of coastal management.

Research Providers:

- School of People Environment and Planning, Massey University

- Taiao Raukawa Trust

- Manaaki Te Awanui Trust

- Waka Digital Ltd

- Cawthron Institute

Systems Dynamic Modelling– Horowhenua 2014

The aim of this systems dynamic modelling project is to understand the broad interrelationships between

ecological "issues/problems" and their "causes" on the defined Catchment and surf zone in the Horowhenua.

Key representatives from Horowhenua, including local iwi participants, will provide a robust set of

perspectives in the system dynamic workshops, defining the ecological, economic, social and cultural impacts

on the defined catchment and surfzone in the Horowhenua.

What is System Dynamic Modelling?

System dynamics is an approach to understanding the behaviour of complex systems over time. It uses a

computer simulation modelling technique to deal with internal feedback loops and time delays that affect the

behaviour of the entire system, incorporating feedback loops and stocks and flows. This approach allows us to

frame, understand, and discuss complex issues and problems to help us better understand the dynamic

behaviour of complex systems. The basis of the method is the recognition that the structure of any system —

the many circular, interlocking, sometimes time-delayed relationships among its components — is often just as

important in determining its behaviour as the individual components themselves. It is also claimed that

because there are often properties-of-the-whole, which cannot be found among the properties-of-the-

elements, in some cases the behaviour of the 'whole' cannot be explained in terms of the behaviour of its

parts. Thus, a systems dynamics approach to examination of an issue considers all the aspects of that issue,

taking holistic view of how changes in one component impact on the other components within the system,

which may then in turn impact back upon the original component that underwent a change.

What is a 'system'?

A system is an organised collection of parts (or subsystems) that are highly integrated to accomplish an overall

goal. The system has various inputs, which go through certain processes to produce certain outputs, which

together, accomplish the overall desired goal for the system. So a system is usually made up of many smaller

systems, or subsystems. Systems range from simple to complex. Complex systems, such as social systems, are

comprised of numerous subsystems, as well. These subsystems are arranged in hierarchies, and integrated to

accomplish the overall goal of the overall system. Each subsystem has its own boundaries of sorts, and

includes various inputs, processes, outputs and outcomes geared to accomplish an overall goal for the

subsystem. Complex systems usually interact with their environments and are, thus, open systems. A high-

functioning system continually exchanges feedback among its various parts to ensure that they remain closely

aligned and focused on achieving the goal of the system. If any of the parts or activities in the system seems

weakened or misaligned, the system makes necessary adjustments to more effectively achieve its goals.

Systems Thinking:

The approach of systems thinking is fundamentally different from that of traditional forms of analysis.

Traditional analysis focuses on the separating the individual pieces of what is being studied; in fact, the word

"analysis" actually comes from the root meaning "to break into constituent parts." Systems thinking, in

contrast, focuses on how the thing being studied interacts with the other constituents of the system, a set of

elements that interact to produce behaviour, of which it is a part. This means that instead of isolating smaller

and smaller parts of the system being studied, systems thinking works by expanding its view to take into

account larger and larger numbers of interactions as an issue is being studied. This results in sometimes

strikingly different conclusions than those generated by traditional forms of analysis, especially when what is

being studied is dynamically complex or has a great deal of feedback from other sources, internal or external.

Stella Software:

For this project we will be using Stella software. Stella supports a wide range of storytelling features.

We will use STELLA to:

• Simulate a system over time

• Enable participants to creatively change systems

• Teach participants to look for relationships – see the Big Picture

• Clearly communicate system inputs and outputs and demonstrate outcomes

Key Features of Stella include;

Mapping and Modelling:

• Icon-based graphical interface simplifies model building

• Stock and Flow diagrams support the common language of Systems Thinking and provide insight into how

systems work

• Enhanced stock types enable discrete and continuous processes with support for queues, ovens, and

enhanced conveyors

• Causal Loop Diagrams present overall causal relationships

• Model equations are automatically generated and made accessible beneath the model layer

• Built-in functions facilitate mathematical, statistical, and logical operations

• Arrays simply represent repeated model structure

• Modules support multi-level, hierarchical model structures that can serve as “building blocks” for model

construction

Simulation and Analysis:

• Simulations "run" systems over time

• Sensitivity analysis reveals key leverage points and optimal conditions

• Partial model simulations focus analysis on specific sectors or modules of the model

• Results presented as graphs, tables, animations, QuickTime movies, and files

• Dynamic data import/export links to Microsoft® Excel

Communication:

• Flight simulators and dashboards describe model components and facilitate manipulation

• Input devices include knobs, sliders, switches, and buttons

• Output devices highlight outcomes with warning flashers, text, graphs, tables, and reports

• Storytelling supports step-by-step model unveiling

• Causal Loop Diagrams present dominant feedback loops within structure

• Sketchable graphs allow easy comparison of expected results with actual simulations

• Export for NetSim support publishing and sharing model over the web using isee NetSim add-on software

• Save as Runtime option creates full-screen, runtime models

• Multimedia support triggers graphics, movies, sounds, and text messages based on model conditions

Horowhenua Project Team – Systems Dynamic Modelling

Huhana Smith

Aaron McCAllion

Moira Poutama

Aroha Spinks

Nigel Thomas

Steven Mason

Wider Manaaki Taha Moana Research Group

Information gatherers and Experts as needed

Framework for the Horowhenua Systems Dynamic Model

The group decided that the Model Simulation Specifications would be based on

Temporal scale: Annual time step from 1950 to 2070

Time steps: Model to run in annual time steps

Spatial scale: Hokio Stream to South Otaki River

Model Questions:

The main questions we want the current model to answer.

1. How do Kaitiaki establish a sustainable harvest for Toheroa Shellfish – Model may at a later date be

extended to include other harvestable species- Cockles, Tuatua and Pipi?

Note: In workshop two it was decided to change from a focus on Toheroa due to the lack of credible

scientific data.

2. What are the factors that most threaten the Population and Health of Horowhenua

3. What solutions (policies), to identified root causes, can make an impact and how much? (ie what

actions can produce the most positive overall outcomes, to address root causes of problems). We

want the model to help us prioritise the underlying issues that we need to tackle first.

4. What social values can we modify to effect solutions?

The big issues (symptoms) that seem to be emerging from discussion are:

Wormholes/Ghost Shrimps (Predators)

Loss of fish species that attack Toheroa predators.

Note: Direction has changed.

1. Eutrophication;

Increased industrial/economic activity depleting ecosystems and their services; coastal

development and urban pressures and associated pollution;

Sedimentation (Tidal Zone impact)

River and Stream Plumes (Nutrient, hormones, applications of fertiliser, photochemical,

ground water contamination and Effluent)- Water Quality

Vehicle access to Dunes and Tidal Zone

2. Sedimentation

3. Loss of things such as kaimoana, habitat loss. The inherent processes/factors that are causing

these issues are: 1) increased industrial/economic activity depleting ecosystems and their

services; coastal development and urban pressures and associated pollution; system not

“counting” ecosystem services.

Proposed Construction of the Model, and Associated Discussion:

Catchment Human Population Module

Land Cover and Use Module

Actions, Solutions and Agency Spend Module

Ecosystem Services Module

Major External Factors

1. Bio Security Risk

2. Tsunami

Fresh water from Catchment to Coast Module

Economic Profile of Horowhenua Module:

Horowhenua Wastewater

Urban Storm Water

Horowhenua Nutrient loads

Dairying Effects on Shallow Groundwater

Catchment Human Population Module

This module will simulate the Human Population of the Catchment

Data Inputs needed

Birth Rate

Death Rate

Immigration rate

Emigration rate

History Population

Why: To calculate population increase and decrease

Possible Graphical Output:

TBC

Data Sources:

www.stats.govt.nz

Land Cover and Use Module:

This module will simulate the predominant and projected land use and land cover changes from 1950 till 2070.

It also will show the contribution of different land uses to the total sediment loads into the Tidal Zone. This

module may also estimate the total sediment trapping from wetlands. The ‘total sediment’ may be linked with

‘sediment impact on Toheroa’ from the ‘Ecosystem Services’ module, and ‘Pollutant Loads’ from the ‘Total

Pollutant Loads Toheroa Catchment’ module to simulate the possible impacts.

Data Inputs needed

Pine Forrest on steep slopes in ha

Other natural capital

Rest of Horowhenua coastline area in ha

Introduced Forest in ha

Scrubs

Pasture in ha

Wetlands Paulstrine and ripariariin ha

Bare earth in ha

Grassland

Urban and Infrastructure in ha

Horticulture and Cropping in ha

Wetlands Estuarine and Saltmarshes in ha

Indigenous forest history

Exotic Forest History

Scrub History

Bare Ground History

Wetlands History

Grassland History

Urban Built History

Horticulture History

Possible Graphical Output:

Changes in Land use overtime and effect on Sedimentation & Wetlands

Sedimentation in Tonnes 1950-2070

Riparian maps

Wetland growth/Decline

Data Sources:

TBC

Actions, Solutions and Agency Spend Module:

Data Inputs needed

- Identify the major actions/spend already underway in the Catchment; and collect their details (what, where,

when, and what are the monitored or expected impacts!)

- Identify the proposed actions in the catchment and estimate their details (what, where, when, and what are

their expected impacts!) example – RESEEDING

Annual Plans of Councils and agencies in the Catchment

Nitrogen reduction in % from stock exclusion and riparian 2

Stock exclusion and riparian planning cost per km

Length of stock exclusion required 2

Stock exclusion

Wetland restoration rate

Wetland hectares restored

Cost of wetland restoration per ha

Create a coordinated hub for wetland restoration

Consented land based nutrient management prevents 80% to 90%

Maximum cost of indigenous forest restoration

Maximum ha indigenous forest restored

Actual ha indigenous forest restored

Restoration indigenous forest

Forest restoration rate

Total farms

Maximum cost herd homes

Nitrogen reduction in % from herd homes 2

Herd homes 2

Farms with N mgt

Indicators: This module will simulate the measures that reflect or indicate the state of the health of

Horowhenua and its catchments.

What are the indicators that there is a problem? E.g. Ghost Shrimp Population – Growth of Ghost Shrimp is an

indication of a problem somewhere else in the system

Note: To be discussed in workshop three

Data Source:

TBC

Ecosystem Services Module:

This module will simulate the services that ecosystems provide humans and the impact of sedimentation,

Toxins, Pollutants on these ecosystems. One way of doing this, is to place a monetary value on the 'services'

that 'ecosystems' provide humans. Wetlands, for example, provide a number of ecosystem services including

trapping and stabilizing sediments, nutrient recycling, nursery for fisheries, and the provision of habitat for

animal and plant species. By placing a monetary value on these ecosystem services, their value becomes

'visible' and decision makers can appreciate their true worth. A further monetary valuation can be put on the

food resource of Toheroa. The annual harvested values of these species could be measured and the impact of

food resource loss via predators, toxins, bans and other impacts could be measured over the Scenario period

(1950-2070).

Data Inputs needed:

Any relevant information/data associated with the following:

Customary gathering data

Legal or illegal gathering

Sediment Impacts on Toheroa

Biomass and Land catch data of Toheroa.

Values of Ecosystem services in USD$

Wetland, Indigenous forest area in Ha

Bird Species

Health (health reports)

Estimates of Customary and Recreational Food Gathering

Predator identification (Ghost shrimp) eradication program data???

Fisheries data ( For fish that are predators to crabs who in turn are predators to ghost shrimp)

Note: Direction has changed

ES Wetland ave Value Per Ha Per Annum

ES Grassland Value per Ha per annum

ES indigenous forest value

Ecosystem Service functioning of indigenous forests

ES Rest of Horowhenua av value

Rainfall Event

Algea Max

Microbiological Limits for shellfish quality

Viral and Bacterial Indicators

Invasive species

trawling impact on shellfish

sediment impact on shellfish

Seafood restoration

Maori shellfish oral history

Seafood decline scenario 1

Seafood recovery scenario

Boat Numbers

Ramps

Moorings

Marinas

RV of Horiowhenua index

bathing quality

Tuna (Eels) Species

Hao

Pango

Puhi

Papka

Paraharahara

Pehipehi

Shell Fish

Pipi

Oyster

Tohemanga Toheroa

Marine Fish

Snapper

Flounder

Tarakihi

Cockles in tonnes biomass

Q- Is the ghost shrimp a predator or only displaces Toheroa

Possible Graphical Outputs:

TBC

Data Source:

TBC

Major External Factors

This module will simulate the external factors affecting of the Catchment

Climatic and Oceanic factors

Beach Morphology

Breach community dynamics

Toxic Algal Blooms

Desiccation

Storm events

Down welling/upwelling

Phytoplankton concentration

Temperature and Salinity Shock

Sea Level Rise

Tsunami Risk

Bio security risk

Note: Direction has changed

Fresh water from Catchment to Coast Module

This module will simulate the fresh water flow of the Catchment to the Coast to calculate factors such as

rainfall in mm etc.

Data Inputs needed

evaporation in MM3

Aquifers

Watering needs per animal

Freshwater Threshold

AVE annual per person water use in MM3

Industrial water demand in MM3 per year

urban water demand in MM3 per year

Irrigation requirements per ha Pasture and Horticulture

Data Source:

TBC

Economic Profile of Horowhenua Module:

This module will simulate the economic Profile of Horowhenua.

Data Inputs needed

Potential Funding

Annual Govt Contribution rate

Central Government

GDP-Horowhenua

Horticulture Fruit and Lifestock value per ha

Freshwater Carrying capacity index

introduced forest value per cub per year

Cattle price

Cattle per ha

harvest rate in cub meteres per year per ha

services to agriculture hunting and trapping

Fishing

Other Primary industries

Manufacturing

Utilities

Service Industries

Construction

Services inc local and central government

Other Farming

Note: Direction has changed

Other Departments

MPI

Department of Conservation

Natural Environment Support

Annual Plan Forecasted Expenditure Other

Annual Plan Revenue Forecast 2011

Annual Plan Forecasted Expenditure Other HCC

environmental policy

Environmental Planning

Environmental Compliance & Monitoring

Coastal Protection

Note: Data Above needed to calculate Direct Horowhenua Environmental Spend by Agencies

Data Source:

TBC

GDP-Horowhenua

Horticulture Fruit and Livestock value per ha

introduced forest value per cub per year

Cattle per ha

Cattle price

Cattle price

services inc local and central government

Construction

Service Industries

Utilities

Manufacturing

Other Primary industries

Fishing

services to agriculture hunting and trapping

harvest rate in cub meters per year per ha

Forestry and Logging from IO

Horticulture and Fruit Growing IO

Livestock and Cropping farming IO

Potential Sources of Eco-funding (NEW)

Annual Govt Contribution Rate

Central Government

Data Source:

TBC

Horowhenua Wastewater

This module will simulate the Wastewater of the Catchment to estimate various amounts of chemicals such as

Ammonia Nitrogen etc.

Urban Wastewater Loads: This module may estimate the pollutants loads from all urban waste water

discharges in the catchment.

Need to find the number of urban wastewater treatment plants which discharge in to the catchment area.

Data Needs:

- List of all major pollutants to be considered from urban wastewater discharges

- All urban discharge consents and their loading rates of identified pollutants: Quantity discharges (e.g. cubic

m per day or year) and concentrations of different pollutants (g per cubic m)

Calculations Needs:

- Aggregate the urban wastewater discharges and loadings (total quantity with weight average

concentrations) per pollutant+

Module Developments:

- Further develop the module according to the identified pollutants in urban wastewater discharges

- Populate the module with collected and estimated town wastewater discharges data

Industrial Wastewater Loads: This module estimates the pollutants loads from all industrial wastewater

discharges.

Need to find the number of industrial wastewater discharges into the catchment. As expected, they will have

different amounts of discharges and pollutant loadings both in terms of quantity and concentrations.

Data Needs:

- List of all major pollutants to be considered from Industrial wastewater discharges

- All Industrial discharge consents and their loading rates of identified pollutants: Quantity discharges (e.g.

cubic m per day or year) and concentrations of different pollutants (g per cubic m)

Calculations Needs:

- Aggregate the industrial discharges and loadings (total quantity with weight average concentrations) per

pollutant

Urban storm water Loads: This module may estimate the pollutants loads from storm water from urban

areas.

Data Needs:

- List of all major pollutants to be considered from Storm water

- Storm water consents

- investment

Calculations Needs:

- Aggregate the storm water discharges and loadings (total quantity with weight average concentrations) per

pollutant

Pastural Farming Loads Module: This module estimates the pollutants loads from Pastural farming sector. The

approach of ‘cows per ha’ would allow us to simulate the impact of dairy intensification (increasing stock per

ha) as well as increase in dairy farming in hectares.

If there are proposed changes, it would require determining what proposed changes mean, i.e. % reduction in

different pollutant loadings rates from % of dairy farming area!

Data Needs:

- List of all major pollutants to be considered from Pastural farming sector

- Identified pollutant loading rates, in e.g. kg N per cow per year (these loading rates should consider the

attenuation coefficients!)

Calculations Needs:

- How to calculate E-coli concentrations and loads

Module Developments:

- Further develop the module according to the identified pollutants from the Pastural farming sector

- Populate the module with collected and estimated Pastural farming data

Horticulture and Cropping Loads: This module may estimate the pollutants loads from Horticulture and

Cropping farming sector.

Data Needs:

- List of all major pollutants to be considered from Horticulture and Cropping farming sector

- Identified pollutant loading rates, in e.g. kg N per ha per year (these loading rates should consider the

attenuation coefficients!)

Total Pollutants Loads: This module will add up all the pollutants estimated from all point and non-point

sources.

Reports Collected to Date

TBC

Note: Direction has changed

Urban Storm Water

Data Needs:

Suspended Solids Concentrations in Storm water in Horowhenua Area

Annual Av Rainfall in mm

Storm water consents

Investment

Improved SW management

Data Source:

TBC

Horowhenua Nutrient loads

This module will simulate Nutrient loads of the Catchment

Data Needs:

Rivers, Lakes and Streams:

Total phosphor

Total E coli

Suspended solids

Total DRP

Total Enterococci

Faecal Coliforms

Data Source:

TBC

Dairying Effects on Shallow Groundwater

Data Needs:

Phosphorus in kg per ha per year

Nitrogen in kg per ha per year

Untreated dairy effluent to ground soakage

Untreated dairy shed effluent to land irrigation

Discharge of treated dairy effluent to ground soakage

Discharge of treated dairy shed effluent to surface waters

Treated dairy shed effluent to land irrigation

Data Source:

TBC

Next Steps

Workshop 3 – Data gathering