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DRAFT
Dr. John R. Anderson
Centre for Coastal Management Southern Cross University
Foreword & Publication Information
4 Description of the Software Package
5 Operating the Software Package
The overall aim of this study was to develop a software based classification system for management of urban waterways. A decision support system was required that used biologically important physical attributes to classify the streams and waterways in terms of asset value, capability for rehabilitation or enhancement, physical and environmental condition, and key constraints limiting restoration. This report provides a demonstration package for the decision support system in the form of a set of games ('Let's fix Urban Streams'). This report describes the system and provides an installation and operational manual.
The software package produces a set of easily used screen and forms, with extensive use of graphics and 'buttons' to simplify its operation. The layout and design are in the form of a computer game.
The demonstration package uses a database of ratings and various hypothetical 'skeleton maps' to establish a simulated set of sections in a drainage network. The ratings for various habitat components in these sections can be displayed by pressing buttons, and used in various combinations using formulae and selection criteria to address various management issues.
The ratings included are:
| Habitat Condition And Value Ratings | Habitat Classification Indices | Depth Parameters | Sediment Particle Size Parameters | Waterway Classification Indices |
| Riparian Vegetation | Channel Habitat Diversity | Pool | Pools | Average Buffer Naturalness |
| Environs | Riparian Zone Width | 'Flowing section' | 'Flowing section' | Pollution Source Index |
| Aquatic Habitat | Riffle | Suitability for Natural Design | ||
| Bank Stability | Cascade | Constraints and Opportunities for Rehabilitation | ||
| Bed and Bar Stability | Buffer to Bankfull Ration | |||
| Aquatic Vegetation | Modification Index | |||
| Conservation Value | ||||
| Overall Condition |
The derived ratings for each of the 'homogeneous section' in the hypothetical drainage network can be displayed in data boxes. The individual ratings can be displayed individually or the user can build various formulae and selection criteria by combining these ratings. A hypothetical map of a drainage network is also displayed. A standard set of 10 categories and colours are used to display the ratings produced for each of the sections by the various attributes and formulae. The displays show the interrelationship between the various ratings. They also provide a simple audit of condition of the sections within the catchment areas displayed on the maps, in terms of how many of the sections fall within the various categories ranked from highly degraded to pristine condition. The package also demonstrate how the 'Decision Support System for Management of Urban Streams can be used to:
The package includes a series of 'Games' that require the user to correctly select and rank the sections in terms of their relative suitability for particular management objectives. For example, the user may be asked to rank the sections in terms of their relative suitability for rehabilitation, for stocking with fish or as priority sites for conservation. The user has to try to correctly rank the sections according to their relative suitability for the defined purpose for the game. The outcome of the game is scored by comparing the ratings produced with the perfect scores for the game stored in a database. The results are shown as scores out of 1000. The outcome for each attempt for a game is also displayed on maps, in terms of how close the ratings produced for each section match those stored for each game. An overall score is also recorded for each session of using the game, which is the average of all the various attempts at the games during a session with the software.
Sets of 'Easy', 'Harder' and 'Challenge' games are provided. Tutorials and step-by-step demonstrations are provided to teach the user how to play the games.
This package can be used as a stand alone system to teach individuals or groups about urban streams and the ways in which they can be classified and rated in terms of current condition and potential for rehabilitation or restoration. The 'game' concept provides a challenge and a 'learn by doing' approach that generates interest and maximizes the educational value of the package. The package can also be used to demonstrate what data and ratings are produced by implementing the 'Decision Support System for Urban Streams' package and how it can be used to manage urban streams.
This report describes the outcomes of a research project conducted under the Urban Research and Development sub-program of the National River Health Program (NRHP).
The NRHP is an on-going national program established in 1993, managed by the Land and Water Resources Research and Development Corporation (LWRRDC) and Environment Australia. Its mission is to improve the management of Australia's rivers and floodplains for their long-term health and ecological sustainability, through the following goals:
Urban streams and estuaries (i.e. those affected by runoff and discharges from urban areas) are an important subset of Australia's waterways. Most are degraded biologically, physically and chemically and therefore require appropriate methods to be developed for health assessment and management. The Urban R&D Sub-program, managed by the Water Services Association of Australia, comprises 8 research projects which were developed to meet research priorities for urban streams and estuaries within the goals of the NRHP and to complement existing NRHP projects on non-urban rivers. Thus, research focuses on development of standardised methods for assessing the ecological health of urban streams and estuaries which can be linked with data on water and sediment quality. The urban R&D projects commenced in 1996.
The definition of health in urban waterways used is "the ability to support and maintain a balanced, integrative, adaptive community of organisms having a species composition, diversity and functional organisation as comparable as practicable to that of natural habitats of the region".
The eight projects of the Urban Sub-Program are:
| Decision support system for management of urban streams | Dr John Anderson Southern Cross University, Lismore |
| RIVPACS (River InVertebrate Prediction and Classification System) for urban streams | Dr Peter Breen CRC for Freshwater Ecology, Monash University, Melbourne |
| DIPACS (Diatom Prediction and Classification System) for urban streams | Dr Jacob John
Curtin University, Perth |
| Sediment chemistry- macroinvertebrate fauna relationships in urban streams | Dr Nick O'Connor Water EcoScience, Melbourne |
| Classification of estuaries | Dr Peter Saenger Southern Cross University,Lismore |
| Literature review of ecological health assessment in estuaries | Mr David Deeley
Murdoch University, Perth |
| Estuarine health assessment using benthic macrofauna | Dr Gary Poore
Museum of Victoria, Melbourne |
| Estuarine eutrophication models | Dr John Parslow CSIRO Marine Laboratories, Hobart |
Basic Decision Support System for Management of Urban Streams. Report No. 4.
Demonstration Game – Lets Fix Urban Streams
Dr. John R. Anderson
LWRRDC Occasional Paper 11/99 (Urban Subprogram, Report No. 4)
December 1999
ISSN: 1320-0992
ISBN: 0-642-26761-8
Published by:
Land and Water Resources Research and Development Corporation
GPO Box 2182 Canberra ACT 2601
Telephone: (02) 6257 3379
Facsimile: (02) 6257 3420
Email: public@Iwwrrdc.gov.au
WebSite: www.lwrrdc.gov.au
© LWRRDC
Published Electronically on au.riversinfo.org by the Environmental Information Association (Incorporated) with the permission of LWRRDC and Environment Australia. Environment Australia assisted by providing copies of the manuscript for electronic publication. The Natural Heritage Trust provided project funds which were used to assist in publishing this material. In the case of variation between this document and the hard copy original the original takes precedence. (Bryan Hall).
The information contained in this publication has been published by LWRRDC to assist public knowledge and discussion and to help improve the sustainable management of land, water and vegetation. Where technical information has been prepared by or contributed by authors external to the Corporation, readers should contact the author(s), and conduct their own enquiries, before making use of that information.
The development of the basic 'Decision Support System for Management of Urban Streams' is described by Anderson (1999a), the software system by Anderson (1999b) and the pilot studies for the project by Anderson (1999c). The final requirement for the project was a demonstration package in the form of a 'game' to illustrate how the decision support system could be used to manage or 'fix' urban streams. This package was also designed to provide information on the type of data collected for the 'Decision Support System for Urban Streams' and the ratings produced from these data. It also shows how the multi-faceted classification system can be used to manage urban streams using the various ratings either singly or combined with the other ratings in various formulae.
The demonstration package uses a set of data collected during the pilot studies and various hypothetical 'skeleton maps' to establish a simulated set of sections in a drainage network. The ratings for various habitat components in these sections can be displayed and applied in various combinations using formulae and selection criteria to address management issues. The derived ratings for each of the 'homogeneous section' in the hypothetical drainage network are displayed in data boxes. A hypothetical map of the drainage network is also displayed. Various colours are used to display the category values produced for each section from the ratings. The ranking of the sections for various purposes is shown by the colours displayed on the maps.
The package includes a series of 'games' that require the user to correctly select and rank the sections in terms of their relative suitability for a particular management objective. For example, the user may be asked to rank the sections in terms of their relative suitability for rehabilitation, or for stocking with fish. Or the user may be asked to find the best sections for use as designated reference sections or for conservation. Sets of 'Demonstration', 'Easy', 'Harder' and 'Challenge' games are provided. The results of various attempts by the user to play the designated games in response to the questions posed are scored out of 1000. The outcome for each attempt is shown on the maps, in terms of how close the ratings produced match those stored for each game. An overall score is recorded for each session of using the game. This overall score is the average of all the various attempts at the games.
A 'Demonstration' game provides tutorial information and a step by step guide for running a set of demonstration games. There is also a glossary of terms and other information and hints for playing the games and running the package.
This package can be used as a stand alone system to teach individuals or groups about urban streams and the ways in which they can be classified and rated in terms of current condition and potential for rehabilitation or restoration. The 'game' concept provides a challenge and a 'learn by doing' approach that generates interest and maximizes the educational value of the package. The package can also be used to demonstrate what data and ratings are produced by implementing the 'Decision Support System for Urban Streams' package and how it can be used to manage urban streams.
The aims of this report are:
The software is available on CD-ROM from Dr. John Anderson
The package can be provided as an application for Visual FoxPro Version 6, or as a stand-alone application which includes the run-time version of Visual FoxPro. Please indicate which form is required. A postage and handling payment of $20 is required.
The installation of the software is described in the 'Read Me' file on the CD-ROM The stand-alone' version requires that the 'Runtime' version of Visual Foxpro, used to develop the software, be installed on the host machine along with a series of supporting system and library files. This runtime version of Visual FoxPro is included in the installation software. These files must be installed correctly using the installation programs for the package to run correctly. Visual FoxPro (version 5 or later) must be installed on the host computer to run the program as an application of this software.
The hardware requirements are:
The application is run by
OR
The stand-alone application is run by double-clicking on the game.exe file.
The package is organised as a series of 'screens' or pages within a form linked with a database that contains the ratings and the category allocations for the various games. The 'screens' or pages can be accessed via buttons on the 'Home' page or by selecting the 'Page Tabs' displayed at the top of each screen. The 'screens' or 'forms' for the package are:
Six games can be run without assistance, or as full step-by-step demonstrations for successfully running each game.
This part of the report describes the basic operation of the package in simple terms. Later sections provide more detailed explanations of the various parts. The user is encouraged to learn how to operate the various parts by operating the package itself. It is easier to 'learn by doing', rather than simply reading the instructions.
The software package has been developed as a simple database system with various forms and programs being used to display derived condition ratings and various other attributes for various stream sections on simple maps ('Skeleton Maps; see Anderson 1999a). The data used is a compilation of the data collected in the pilot surveys, which has been modified in various ways and linked to sections displayed on fictitious maps. There is a range of condition ratings and other information stored in a database for a set of 'homogeneous stream sections'. The type of information available is shown in Table 1.
| Table 1. Type of ratings and data summaries available in the package. | ||||
|---|---|---|---|---|
| Habitat Condition And Value Ratings | Habitat Classification Indices | Depth Parameters | Sediment Particle Size Parameters | Waterway Classification Indices |
| Riparian Vegetation | Channel Habitat Diversity | Pool | Pools | Average Buffer Naturalness |
| Environs | Riparian Zone Width | 'Flowing section' | 'Flowing section' | Pollution Source Index |
| Aquatic Habitat | Riffle | Suitability for Natural Design | ||
| Bank Stability | Cascade | Constraints and Opportunities for Rehabilitation | ||
| Bed and Bar Stability | Buffer to Bankfull Ration | |||
| Aquatic Vegetation | Modification Index | |||
| Conservation Value | ||||
| Overall Condition | ||||
Detailed descriptions of each attribute are provided in Section 3.6. All of the habitat condition ratings are stored as percentages, with 100% representing virtually pristine condition and full value, and 0% representing total loss of condition value and function. For example a value of 80% for riparian vegetation signifies that 80% of the original value or function of the riparian zone has been retained (20% of the value of the pristine original zone has been lost). Likewise a value of 30% means that more than 70% of the original value or function has been lost. Other attributes relate to the depth of pools and other habitat types and the size of the dominant sediment particles in these areas. There are also a series of other indices for classifying the sections in terms of the extent and type of modifications to the waterway and corridor and their suitability for rehabilitation.
The ratings scores assigned to each of the sections can displayed on 'skeleton maps' in data boxes beside the sections displayed as lines on the maps. A standard set of 10 categories (0-9) is used to rank the ratings for the sections. A standard set of colours and categories is used to display the section rankings on the maps. This system of colour-coded categories provides a simple way of ranking the sections according to their ratings for the various attributes. Each of the component attributes can be displayed by pressing a button for each attribute. Formulae and selection criteria can be used to derive new ratings that can also be categorized and displayed on the maps.
The condition ratings and the various other indices provide simple ways of finding the stream sections most suited for various management purposes, and ranking their relative suitability. The Decision Support System for Urban Streams (Anderson 1999a) provides a hierarchical array of data types that can be used to make various decisions about managing urban streams (Table 2). The user can move between the various levels in order to refine the selection or ranking process to locate the sections that best suit the desired outcome. Initially the user may be focus on the individual ratings or indices. The next step may be to examine various combinations of the ratings to further refine the selection criteria and ranking system. Finally the user may move to the raw data to help understand why the rankings have been produced and to further refine the selection process. The raw data attributes can also be individually displayed on the 'skeleton maps'. The power of this decision support system lies in the ability to move between the data levels to display all sorts of data in all sorts of combinations. The availability of the raw data as well as the derived data increases the power of the package. The user can also examine the relationship between all the available attributes or components in the database system. Users can also build their own formulae and selection criteria in a very flexible and explicit way.
The demonstration package described in this report does not include the raw data, or the external data, but it does show how the ratings can be used individually and in various combinations to develop formulae and selection criteria. The focus of the package is on developing ways of choosing sections that best satisfy a set of criteria and then ranking the suitability of the sections that meet the selection criteria. The decision support function is provided in terms of this selection and ranking process and audit functions built into the system.
| Table 2. Hierarchical data levels and their availability in the database and mapping system for the DSS package. | |||
|---|---|---|---|
| Level | Data Type | Included in Database? | Can be Mapped? |
| 1 | Raw Data | x | x |
| 2 | Condition Ratings and Indices | x | x |
| 3 | External Data Sources | x | x |
| 4 | Derived Ratings Produced using Formulae to combine the ratings | x | |
| 5 | Selections using formulae | x | |
A simple audit function is produced by quantifying the number of sections that fall within the various category ranges that describe their condition. In simple terms category '9' (coloured 'red' on the maps) includes the sections in the best condition (condition score >88%), and category '1' shows the sections in worse condition (condition score 1-11%). This audit function is fully developed in the main software system (Anderson 1999a), but is also readily seen in the demonstration package. The system also provides an 'action plan' by showing the location of various problem areas ('where are the worst bits'), or sections that should be conserved ('where are the best bits'). The category system and the simultaneous access to a wide variety of ratings and indices also allow this action plan to be further refined. For example, it may be better to focus on the partially degraded sections, rather than on the worst cases. Also it may be useful to consider various other attributes and their interrelationships when making decisions. For example it may be better to plant trees to improve riparian zones in areas where the banks are relatively stable and not prone to frequent disturbances. Likewise there may be benefits in planting trees in areas where there is a diversity of channel habitat types present (pools, runs, riffles, etc.) in order to maximize the benefits to the stream ecosystems.
The ratings are 'indicators' but they are linked to clearly defined features of the stream and are easily translated into a plan of action to shift the ratings to higher values and so improve the condition of the stream. For example the bank condition rating is simply derived from the estimated percentage of the length of bank on both sides of the stream that is stable, that is neither eroding nor aggrading. The simple response to a low score for this indicator is to address the cause of the instability (i.e. find the cause of the erosion or slumping and fix the banks). Many indicators produced from other projects, such as biodiversity score for macroinvertebrates may not immediately suggest why the problem has occurred and how to fix it. Most of the ratings in the present study are explicitly linked to targets and suggest obvious outcomes and monitoring targets, and so are readily translated into action plans provided the sources of the problems and processes involved can be properly understood. The capacity of the package to instantly show a wide range of habitat components ratings and various indices, and to combine them in formulae to produce various derived ratings which can also be mapped adds to the power or the package. The user retains control and the choices are made in response to the various layers of data available.
The games focus on the process of selecting sections for various purposes and ranking them in terms of their relative suitability for the identified purpose or function. The use has to find the sections that are best suited for various management purposes and to rank them in terms of the category system. The games are scored in terms of how well the sections are allocated to the suitability categories compared with a stored pre-determined outcome. A perfect score occurs when all the sections on the map have been correctly allocated to the predetermined category for that game.
The following sections describe the elements of the system in more detail.
The fundamental element in terms of the sample design, map displays and outputs is the 'homogeneous stream section' (Anderson 1999a). The streams and waterways in the drainage network are divided into these 'homogeneous stream sections' using a wide variety of available information and reconnaissance surveys. The sections defined by this stratification process have varying lengths. The concept is to identify 'bits' of stream or waterway that share the same physical and ecological features and condition in terms of the parameters used for the surveys. Key attributes are used to successively add more and more boundaries to better define the sections. As more boundaries are added, and more information is used, the sections become more clearly defined as 'homogeneous'. The process continues until the test of 'homogeneity' can be satisfied in terms of overall physical and ecological type and condition of the waterway and its corridor. The section boundaries are confirmed and further refined by conducting reconnaissance surveys. As an example, boundaries may be defined where the riparian vegetation changes from natural to cleared or exotic species. Boundaries are also added at each of the nodes in the drainage network. Likewise additional boundaries may be applied at the start and end of a section of stream that has severe bank erosion. In urban streams boundaries are also added for various types of channel modifications that may be present such as concrete linings, channelisation and channel realignment or for areas where bed or bank protection measures have been applied. The idea is to continue to add more and more boundaries until the user is satisfied that the length of stream between the boundaries is reasonably homogeneous in terms of the scale and key issues for the study.
One or more representative sites (reaches) are then surveyed within each section, and the information and ratings produced for these sites is then applied to the entire section. This sampling procedure means that a real audit of the condition of the waterways can be produced and quantified in terms of length of stream classified in various ways. This includes classification into various types and also into various categories of severity of degradation or extent of modification. In this way the entire length of stream within the drainage network of a catchment can be characterised and rated in terms of various condition attributes such as riparian vegetation, bed and bank stability and also classified into various types. Their interrelationship can also be examined via their connection through the drainage network. Also the relationship between the various components for a single section can also be examined. The concept of the 'Homogeneous Stream Section' is used in the demonstration package (Fig. 1).
|
| Figure 1. Definition of 'Homogeneous Stream Sections' with representative survey sites (reaches). |
 |
| Figure 2. 'Skeleton Map' of 'Homogeneous Stream Sections' |
'Skeleton Maps' are simplified sketch maps that are used to display information about the sections using the database system (Anderson 1999a). These maps provide a simple and cheap way of generating map output without having to involve a Geographic Information System (GIS) (Anderson 1999a). These maps are not meant to replace the GIS as the final way of displaying the information, but they provide draft map outputs and allow exploratory analyses using various combinations of ratings without incurring the expense and complexity of a GIS. Maps of entire catchments can be displayed on single 'A4' or 'A3' sheets, rather than on large maps produced by GIS. The 'homogeneous stream sections' on the 'Skeleton Maps' are presented as straight lines with uniform length. The 'Skeleton Map' concept has been used in the 'Demonstration Package'(Fig.2), though the sections have not been reduced to straight lines on the screens to provide more realistic displays.
The basic display elements for the package are shown in Figure 3. Each element consists of:
| Table 3. Categories used for various parameters | |||||
|---|---|---|---|---|---|
| Rating Category | Percentage Ratings (Condition) (%) | Riparian Zone Width (x2) (m) | Depth (m) | Sediment Particle Size (mm) | Modification Index |
| 0 | 0 | 0 | 0 | 0 | 0 |
| 1 | 1-11 | 1-11 | 0.1-0.3 | Silt (<0.05 mm) | <31111 |
| 2 | 12-22 | 12-22 | 0.4-0.7 | Very Fine sand (0.05-0.5 mm) | 31111 -36666 |
| 3 | 23-33 | 23-33 | 0.8-1.1 | Fine sand (0.6-1.0 mm) | 51111-56666 |
| 4 | 34-44 | 34-44 | 1.2-1.6 | Coarse sand (1.1-2.0 mm) | 61111-65666 |
| 5 | 45-55 | 45-55 | 1.7-2.2 | Fine gravel (2.0-5.0 mm) | 66111-66466 |
| 6 | 56-66 | 56-66 | 2.3-3.0 | Medium gravel (5.1-20 mm) | 66511-66566 |
| 7 | 67-77 | 67-77 | 3.1-4.0 | Coarse gravel (20-60 mm) | 66611-66656 |
| 8 | 78-88 | 78-88 | 4.1-5.4 | Cobble (61-300 mm) | 66661-66664 |
| 9 | 89-100 | 89-100 | >5.4 | Rock (>300 mm) | >66664 |
| Not measured or no pool present | -99 | -99 | -99 | -99 | -99 |
There are five groups of component attributes (Table 1). Figures 4-7 provide summarizes of the derivation of the ratings for these attributes. This information is also displayed on the 'Data Types' screen in the package.
There are nine habitat condition ratings that are derived from the Decision Support System for management of urban streams (Anderson 1999a). The ratings for all of these attributes are expressed as percentages of the pristine condition or value with 100% representing original condition and no loss of original value or function, and 0% representing total loss of original condition and function. The derivation of each of these ratings is described by Anderson (1999a) and summarized later in Section 6. The categories used are the percentage categories (Table 3.).
The condition of the vegetation in the riparian zone (Fig. 4) is assessed from the width of the remnant riparian zone and the diversity of structural vegetation types within it (Trees, shrubs, herbs, grasses, etc.). High percentages only occur for sections with relatively wide remnant zones and a diversity of structural types present (trees, shrubs, herbs, grasses).
The environs rating (Fig. 4) refers to the overall condition of the stream side areas including both the riparian zone and the valley flat and floodplain areas. This rating is produced by assessing the extent of clearing and modification to these zones and the invasion of the areas by exotic plants.
The condition of the aquatic habitat (Fig.4) is assessed primarily as a cover rating. The rating is derived from the canopy cover and the extent and diversity of bank and instream cover available in the channel. Bank cover includes vegetation, bank and root overhang. Instream cover includes logs and log jams, branches and branch piles, aquatic macrophytes, emergent vegetation and various other forms of organic debris cover in the stream. It also includes cover available under or near boulders, rock and cobbles and also permanent deep pool habitats. High ratings only occur when the percentage cover of the bed and banks by these types is relatively high and there is wide variety of types present. The rating system recognises that excessive cover may represent degraded condition. For example a section of stream completely choked with floating or emergent vegetation may not represent ideal habitat. Various other ratings provide other ways of classifying the type and relative value and condition of the aquatic habitats present (e.g. the channel habitat diversity index, and the summaries of the depth and sediment particle sizes in pools and other habitat types).
The bank stability rating (Fig. 5) is simply the average percentage of the length of bank in the section that is regarded as stable, that is neither aggrading, eroding or slumping (active current process).
The bed and bar stability rating (Fig.5) is simply the average percentage of the bed area in the section which is regarded as stable, that is neither eroding, or aggrading leading to the development of bars and sediment build-up in the channel (active current process).
The aquatic vegetation rating (Fig. 5) is derived from the percentage of the submerged bed that is covered by either emergent, submerged or floating aquatic vegetation.
This subjective rating (Fig. 6) is assessed from the known occurrence of rare and endangered species, or their habitats and the general estimated value of the instream areas as aquatic habitat and riparian zones as wildlife corridors for conservation purposes.
The overall condition rating (Fig. 6) is simply the average of the percentage ratings for the various components (bank, bed, riparian vegetation, aquatic habitat, etc.). The riparian vegetation and aquatic habitat are doubly weighted.
The Channel Habitat Diversity Index (Fig. 6) is derived from the percentage of the length of stream that is classified into the various channel habitat types (pools, riffles, runs, glides, cascades etc.). High values as percentages are only produced when two or more types are present in relatively equal proportions. The diversity of channel habitat types present is an important way of classifying and assessing the relative value of the section as habitat.
The width of the remnant riparian zone (Fig. 5) is also included as it provides additional information for examining the rehabilitation potential of the stream section. If the remnant zones are relatively wide, but the riparian vegetation condition is low, it indicates that there is a low diversity of vegetation types present. It is relatively easy to improve that riparian vegetation condition if the remnant zones are relatively wide. Once these zones have been lost, or extensively modified, it is much more difficult to reclaim these areas.
Various channel dimension and sediment particle size parameters (Fig. 7) are provided to classify the waterway sections. Pool depths, and depths in the higher flow areas such as riffles and runs, and the type of sediments present may determine the potential value of the habitat for fish and macroinvertebrates. For example, when trying to rate the potential of the sections for stocking with fish, the presence of relatively deep permanent pools with a variety of habitat types (pools, runs, and riffles) may be important. Fish passage is also affected by minimum depths.
The pool depth rating (Fig. 7) refers to the maximum depth of pools in the section. The depths are standardized using the 'water mark' that occurs at the 'normal' or most frequent water level in the section. The depth categories are shown in Table 3.
The riffle/run depth rating (Fig. 7) refers to the maximum depth in 'flowing' habitat types such as riffles, runs, cascades etc. The depths are standardized using the 'water mark' that occurs at the 'normal' or most frequent water level in the section. The depth categories are shown in Table 3.
The pool sediment size rating (Fig. 7) refers to the dominant or more frequent particle size for sediments in pools. Sediments vary at different locations and there is often a range of sizes at a single site. This parameter refers to the more dominant particle size in terms of relative abundance and distribution throughout the pools in the section. The categories used are shown in Table 3.
The 'flowing section' rating (Fig. 7) refers to the dominant or more frequent particle size for sediments in 'flowing' habitat types (i.e. runs, riffles, glides, cascades and rapids) present in the section. Sediments will vary at different locations and there is often a range of sizes at a single site. This parameter refers to the more dominant particle size in terms of relative abundance and distribution throughout all the 'flowing' habitat types present in the section. The categories used are shown in Table 3. Sediment particle sizes are also provided for riffles and cascades.
This rating refers to the dominant or more frequent particle size for sediments in riffles. The categories used are shown in Table 3.
This rating refers to the dominant or more frequent particle size for sediments in cascades. The categories used are shown in Table 3.
These parameters are used to classify the waterway in the section in terms of the extent of modification to the bed, banks and buffer zones, and for rehabilitation potential and various constraints and limitations that may apply.
This index is constructed by assessing the extent of modification to the bed, banks and three buffer zones: shoreline zone, middle zone and upper zone (Fig. 9). These five scores are then combined into a single '5 digit' number or index. The first number in the index is derived from the bed modification score, the second from the bank score, the third from the 'shoreline zone' etc. The '5 digit' index that is produced is used as a modification index, with relative weightings applied according to the position of the scores from the different zones. The modifications to the bed are the most important, then the banks, then the shoreline zone etc.
The scores for the three buffer zones are further modified to reflect the adequacy of the width of the remnant zones in relation to that required for the full buffer function to be realised. The modification index provides a simple overall index of the extent of modification of the waterway corridor and also the limited capacity of the section for rehabilitation or restoration, with and without addressing the major modifications and width limitations built into the index.
Building an Index
The index is constructed by assessing the Modification/Adequate Width Score for each of the five zones as a number from 1 to 6. These numbers are then used to produce a 5-digit number.
Four examples are provided to illustrate how the indices are produced.
Example 1. Index = 66432 – This section has unmodified bed and banks but extensively modified or narrow buffer zones. The bed and banks can be rehabilitated but what can be achieved will always be limited by the modifications to the buffer zones. Restoring the full value of the section can only be achieved by addressing these modification issues, if that is feasible. It may not be possible to increase the width of the modified zones.
Example 2. Index = 23665 – This section has highly modified bed and banks but essentially natural buffer zones of adequate width. The modifications to the bed and banks will greatly restrict the rehabilitation that can be achieved, despite the adequate buffer zones. Restoring the full value of the section can only be achieved by addressing these modification issues. If the bed and banks are lined with concrete for example, then rehabilitation will be severely limited unless the concrete can be removed, and the natural channel restored. The index defines the current capacity or capability for rehabilitating or restoring the section.
Example 3. Index = 66655 – This section has unmodified bed and banks and essentially natural buffer zones with adequate width. This section can be rehabilitated to its full potential without being limited by modifications or width limitations.
Example 4. Index = 23434 – This section has all zones extensively modified. The rehabilitation of this section would be severely limited by these modifications.
The use of a number as a combined rating or index makes it easier to select a range of waterway types and to use the index in developing formulae. The position of the various scores in the combined index recognises their relative importance for the value and rehabilitation potential of the section. The bed has highest ranking, followed by the banks, shoreline zone and then the middle and upper zones. The combined index provides an instant assessment of the ranked modification and capability of the section for rehabilitation. For the examples provided above the ranking are Example 3> Example 1> Example 2> Example 4, which is their same order as numbers 66655>66432>23665>23434.
Using this index rehabilitation can be regarded as achieving the maximum possible improvement without major structural works (that is within the limits implied by the index). Restoration involves major works to address the limitations described by the index. Restoration can only be achieved by addressing the modifications present or the inadequate buffer zone widths. This would change the relative ranking given to the section in terms of overall condition, but the index values would also be changed.
The modification index provides a very useful way of quickly rating the sections in terms of the extent of modification to the waterway corridor and their capability for rehabilitation. The following example shows how the modification index can be used to help manage urban streams.
Example Rate the sections in terms of their relative capacity for rehabilitation without major structural change or works to the channel.
The modification index itself provides this rating or ranking. The overall condition index rates the sections in terms of their overall condition and so these two indexes provide information on current condition and potential for rehabilitation. The modification index can be used to select a group of sites worth considering. For example, a test for sections with indices greater then 55,000 will select sections with essentially natural bed and banks. Likewise a test for indices greater than 55,500 will select sections with natural shoreline zones of adequate width, as well as natural bed and banks. Ranking the sections selected in this way in the reverse order for overall condition (by applying a negative contribution to the formula) will produce a relative ranking of the sections with low overall condition but good rehabilitation potential.
The modification index is difficult to use in the formulae because it is a five-figure number, and most of the other ratings are percentages. However, when the modification index is used in a formula the category value, times 10, is used, rather than the index itself. The modification index can therefore be used in the formulae. Developing a formula with a positive contribution from the modification index and a negative contribution from the overall condition rating would produce a similar result to that described previously using the selection test. The results of the two procedures would be a relative ranking of the sections in terms of the desired requirement, because the outputs are always displayed using the nine suitability categories built into the display system.
The average buffer naturalness index (Fig. 8) is another way of summarizing the modification scores for the bed, bank and three buffer zones. In this case the percent naturalness scores have been given various rankings reflecting their relative importance for the stream ecosystems.
| Average % Naturalness rating = | 0.40 *(bed naturalness) |
| + 0.25 * (bank slope naturalness) | |
| + 0.20 *(streamside zone naturalness) | |
| + 0.10 *(middle zone naturalness) | |
| + 0.05 *(upper zone naturalness) |
This is the ratio of the buffer width to the bankfull width multiplied by 10 and expressed as a percentage score (100% for a buffer 10 times the bankfull width) (Fig. 8). This parameter is used to classify streams in terms of the remnant buffer width. It is useful for assessing the suitability of the site for natural design. It is normally assumed that meander wavelengths are about 10 to 14 times the bankfull width for natural streams in various positions in the drainage network (varying with channel gradient). Also it is assumed and that the spacing between riffle/pool sequences is half this at 5 to 7 times the bankfull width (Rosgen 1996) and also related to channel gradient. The ratio of meander width (belt width to bankfull widths) for natural streams ranges from 1-40 depending on the sinuosity (Rosgen 1996), but is generally less than 10 for less sinuous streams. It has been suggested that a minimum buffer width of 35m(100ft) was necessary for urban streams or about 25 times the bankfull width for the middle buffer zone (about the 100 year floodplain width)(Schueler 1995). Obviously the space needed to allow a stream to meander naturally across its floodplain, and to interface with its floodplain will depend on the natural sinuosity and floodplain width for the channel. These parameters will in turn be affected by valley widths, channel and valley gradients, sediment particle sizes and discharge patterns and other parameters. The width requirements will also vary in different parts of the drainage network and will be affected by changes in runoff dynamics associated with changes in imperviousness of urban catchments. Nevertheless the ratio of the buffer width to bankfull width is a useful parameter to classify streams in terms of the space available for implementing natural design concepts and re-installing a more natural meander patterns and riffle/pool sequences, as linked objectives.
A number of indices have been included that directly relate to the potential of the section for rehabilitation and to the constraints and opportunities that may be available.
The pollution source index (Fig. 8) summarizes the number of potential water pollution sources that occur within the section or in areas immediately upstream. These potential water quality problems represent a constraint for rehabilitation. They would obviously threaten the success of rehabilitation efforts in relation to the re-establishment of aquatic, amphibian and terrestial fauna and possibly riparian flora as well. The rating is developed as a percentage score from the number of potential water quality sources that have been identified. It should be noted that the values obtained are the reverse of what applies for most other attributes. In this case the higher the score the worse the problems. This means that this rating has to be used as a negative in various formulae to rate the sites in terms of the low number of such sources in the sections.
This index (Fig. 8) provides a preliminary subjective assessment of the overall suitability of the section for applying natural design concepts. The percentage rating is based on the average score for four components assessed during the surveys
The values produced generally conformed to the following descriptions of the suitability for natural design:
This rating (Fig. 7) is produced by summing the positive (+1) and negative (-1) answers to a series of questions concerning potential constraints and opportunities for rehabilitating the sections. The results were expressed as a percentage of the highest possible score of 22. The questions concerned the viability of immediately installing artificial habitats, and planting trees to improve riparian zones. Other questions related to weed problems, the general suitability of the area for biota and links with upstream communities. The stability and frequency of disturbance of the habitats are also considered as well as buffer widths and whether minimum effective riparian zones can be restored. Once again the size of the rating is the reverse of the condition ratings, that is the higher the score the worse the constraints and lower the opportunities. This means that this rating will have to be applied as a negative when building various formulae to rank the sections in terms of the low number of constraints that apply to a particular section.
The software package is operated as a form with multiple pages or screens. The user can select the various screens from buttons on the 'Home' page or by simply 'clicking' on the screen 'tabs' at the top of each page. The software package is 'button-driven' rather than 'menu-driven' to simplify the interface and make it easy to understand. This means that all options are displayed all the time and so the choices available are always explicit.
Figure 10. illustrates the key set of buttons used to display the individual attributes and to build the formulae and selection criteria. Figure 11. shows the basic page layout for running the games. Pressing the individual attribute buttons (e.g. Riparian Vegetation, Environs, Aquatic Habitat, etc.) applies the ratings for the attribute to the sections on the maps (as in Fig. 3). The values for the attributes are displayed and the categories allocated are shown in boxes next to the stream sections. The lines representing the sections on the maps are coloured according to the categories. No score is recorded because at this stage no game is being played. Pressing one of the other attribute buttons shows the ratings or values for that attribute.
Pressing 'New Game', one of the 'Game' buttons, or opening one of the other screens for the first time, changes the data linked to the sections displayed on the maps. A random process is used to link new data to the sections. Every time you run the game the data will be different. However the data used is derived from real surveys and so the set of attributes is reasonable rather than arbitrary.
A total of 13 sections shown on the maps for the 'Easy' games and 45 for the 'Harder' and 'Challenge' games. The data for these sections are randomly chosen from a database of 405 sets of data stored in the database. Only the category values are shown on the maps for the 'Harder' and 'Challenge' game sets.
The sections are allocated to the categories using programs linked with each button. For the individual attributes, the allocation is made in terms of nine equal size categories with fixed maxima and minima. The value of '-99' signifies that the section was excluded using the selection criteria or there was no relevant data for the attribute selected. For the formulae there are also nine equal size categories but the category ranges vary according to the maximum and minimum for all sections in the database. In both cases not all the categories will necessarily occur on any one map. Some of the attributes such as depth, sediment particle size etc. have designated non-continuous category ranges (Table 3). For these attributes the category values (times 10) is used in formulae rather than the attribute value.
The formulae are built by pressing the '+' and '-' buttons next to the desired attribute for a positive or negative contribution to the formula, respectively (Figs 10, 11 and 12). Formulae have to be constructed via the buttons. Entering letters into the formula field will produce an error. When the button is pressed a word will appear in the 'formula' field. Figure 12 shows a formula built from 'Bank Condition' plus 'Riparian Zone Width'. The 'Clear' button can be used to clear the formula field and start again. Pressing the 'OK =>' button calculates the derived rating for each section using the formula and displays the values obtained and the categories to which each section is allocated.
Pressing the '-' button for each attribute simply applies the negative of the rating to the formula. For example, pressing '+' for 'Bank Condition' and '-' for 'Riparian Zone Width' would produce a formula that subtracted the 'Riparian Zone Width' from the 'Bank Condition' rating (i.e. Bank Condition – Riparian Zone Width'). In some circumstances this may produce a negative result, but this does not matter as it is the relative relationship between the sections, rather than the absolute values that are important. Negative values can be displayed in the value boxes. The category values are always positive. The category ranges will be determined from the maximum and minimum values found for the formula for all 405 data sets in the database, divided into the nine categories.
The information displayed on the maps when the 'OK=>' button is pressed will reflect the derived values produced by the formula displayed in the formula field. Pressing one of the individual attribute buttons will display the ratings for that attribute. The ratings from the formula will only be produced when the 'OK=>' button is pressed. If there is no formula in the formula field when the 'OK=>' button is pressed, there will be no change to the display.
Multiple weights for a particular attribute, both negative and positive, can be applied simply by adding the attribute to the formula field as a '+' or '-' twice or more times. Multiplication, division and other mathematical functions can not be used in the formulae, only addition and subtraction.
A selection test for a group of sections can be produced by pressing the 'S' button next to each of the attributes (Figs. 10 & 11). A test is then built by pressing the '>', '<' or '=' buttons and entering the value in the data box. More complicated tests can be devised by using the 'and', 'or' and brackets buttons. The test can only be built using the buttons, not by directly entering text into the box. The selection test only works if there is an attribute entered into the formula field, either as a single attribute or as a formula. The selection test therefore allows a group of sections to be selected before the formula is applied. The categories are allocated using the maximum and minimum values for the formula applied. For example in ranking the sections as suitable sites for stocking of fish the first test may be to select sites with relatively deep pools. Applying the test 'Pool depth >0.5' will select sections with pools deeper than 0.5m. This test will also eliminate sections that do not have pools present because the pool depths for these sections will be have pool depths of –99. If 'Aquatic Habitat' is selected for the formula, pressing the 'OK=>' button will rank the sections with pools deeper than 0.5m in terms of the condition of the aquatic habitat. The remaining sections will be labeled as '-99' and coloured Grey on the maps.
The '?' buttons next to the game buttons activates a message showing what is required for each game. The user tries to meet the game requirements using one of the individual attributes or using a formula with, or without, a selection test. Once the test is applied, pressing the 'Game' button invokes a comparison of each of the section ratings with stored values. This changes the display in accordance with the category match for each section. A score is also produced for the match for all the sections on the map.
When the 'Game' button is pressed, the category values boxes are colour-coded according to the match between the category values produced by the test and the stored values for the game. For the correct matches the value boxes are coloured 'Green' and a 'tick' is shown beside the section button. When the category values are within one or two from the required value the boxes are coloured 'Yellow'. The remaining boxes are coloured 'Pink'.
Figure 12 shows an example of a demonstration game to rank the section in terms of the best use of tree planting to improve riparian vegetation and instream habitat values. The formula using Bank Condition plus Riparian Zone Width only produces two perfect matches (sections S4 and S8). The score for this attempt is 587 (Figure 12). The colours applied to the value boxes show how closely the section ratings match those required for the game. Adding Riparian Vegetation Condition as a negative rating, produces the perfect score (Fig. 13). In this case the game required sections with relatively stable banks (plantings not washed away), relatively wide riparian zones remnants (adequate space for trees), but with low current condition ratings for riparian vegetation (trees or shrubs absent or sparsely distributed).
The score is produced by summing the errors between the category values produced by the ratings and the stored values for each of the sections on the map. The score is the average error expressed as a score out of 1000. For example, an average error of one for each section will produce a score of 500. A separate score is shown for each attempt at a game. An overall score for the session is also produced. This is the running average score for all attempts for all games during a session.
The session must be completed by pressing the 'QUIT' button.
The 'Home' page provides a simple introduction to the package and it also allows the various other pages to be selected. The other pages can be selected using the set of buttons on this page. The various pages can also be selected by 'clicking' on the 'Page Tabs' at the top of each page. 'Home' buttons on each of the other pages allow the user to return to this home page.
The 'Introduction' page provides a basic introduction to the screen display, the map elements, the attribute buttons and the methods used to build formulae and selection criteria. It also shows how the games are run and how to get information about the games. The information is similar to that shown in Figs. 3 & 10.
This page provides access to a series of figures that explain how the various ratings and indices are produced. The information is identical to that shown in Figs 4-9.
The 'Demonstration' page provides information on the scoring, ratings, categories, formulae, selection methods, running the games and information about the display. The six games provided can be run without assistance or using step-by-step instructions (buttons Demo1-Demo-6). These demonstrations provide an easy structured way of learning how to run the package.
This includes six games played for 13 sections. The games are relatively easy requiring single attributes or simple formulae. Many hints are provided to help the user.
This includes six games played for 45 sections. The games are relatively harder requiring formulae and simple selection tests.
This includes six games played for 45 sections. The games are relatively hard requiring selection test and more complex formulae.
A glossary of terms is provided.
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| Figure 3 Display elements for maps used in the various groups |
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| Figure 4. Derivation of the Condition Ratings for Riparian Vegetation, Environs and Aquatic Habitat |
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| Figure 5. Derivation of the Condition Ratings for Banks, Bed and Bar and Aquatic Vegetation |
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| Figure 6. Derivation of the Condition Ratings for Conservation Value, Overall Condition and Channel Habitat Diversity Index |
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| Figure 7. Derivation of the Condition Ratings for Constraints and Opportunities, Depths and Sediment Particle Sizes, and Remnant Riparian Zone Widths |
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| Figure 8. Derivation of the Condition Ratings for Average Buffer Naturalness, Pollution Source Index and Suitability for Natural Design |
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| Figure 9. Derivation of the Modification Index |
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| Figure 10. Buttons and tools used to display component ratings and to build formulae and selection tests |
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| Figure 11. Screen layout for the 'Easy Set of Games |
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| Figure 12. Outcome for Game 1 using a formula with Bank and Riparian Vegetation Condition Ratings |
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| Figure 13. Outcome for Game 1 with Bank and Riparian Zone Width added and Riparian Vegetation Condition applied as a negative. |
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