Principal Investigators: M. Thoms and R. Norris
Research Officers: M. Parsons and G. Ransom
Cooperative Research Centre for Freshwater Ecology
Monitoring River Health Initiative Technical Report Number 23
Environment Australia, 2002
ISSN 1447 1280
ISBN 0 642 54889 7
To adopt a standardised protocol within AusRivAS for the assessment of river physical and chemical condition incorporating instream physical habitat, catchment geomorphology, riparian condition and water quality.
We have produced a comprehensive physical assessment protocol, which details a standardised rapid method for the collection of geomorphological, physical habitat, riparian and basic water quality data. It is intended that after the collection of data from reference sites, AusRivAS-style predictive models can be constructed. Subsequently, these models can then be used to assess the physical condition of test sites, and will be able to predict the local scale physical and habitat features that should occur at a test site.
The physical assessment protocol document is comprised of three main components:
Theoretical background
Sets out the philosophies underlying this approach to stream assessment, including predictive capability, hierarchical approach, use of rapid survey techniques and the reference condition concept.
Reference site selection procedure
Details a method for the selection of reference sites, based on the stratification of sampling sites across functional process zones.
Instructions for the collection of each variable
Gives instructions for the collection of each office and field based physical variable. The variables included in the protocol are generally derived from existing stream assessment methods. Variables were chosen to represent a range of physical factors, including planform channel features, catchment character, landuse, hydrology, physical morphology and bedform, substrate, bank character, riparian vegetation, instream habitat and floodplain character. Although water quality is included in the protocol, this aspect of the project was reduced because of concerns about the value of instantaneous chemical measurements and it was decided to concentrate on aspects of water quality that are directly related to geomorphology. To reflect the reduced focus on water chemistry, the name of the protocol was changed from "physical and chemical assessment" to "physical assessment".
To build software to incorporate the physical and chemical assessment module into the AusRivAS software platform, with relevant text resources and diagnostic outputs, integrated with the results of bioassessment.
We have produced software that reports test site physical data in relation to the physical character of AusRivAS reference sites. The user enters test site physical information into the package, and this information is compared against reference site information. The user can then examine whether the physical character of the test site lies outside the range of physical character that occurs at corresponding reference sites. The software was designed to utilise existing AusRivAS physical data and as such, it does not support the format of the physical assessment protocol (see Section 1.3 for a description of the recommendations made by the steering committee).
The software is available via the existing AusRivAS website and is accessed in the same manner as AusRivAS. Users download the software from the website and install the software onto their computer. Test site data is entered via the user's terminal, and is submitted for comparison against reference site data that are stored centrally on the AusRivAS server. The user receives graphical and categorical information that summarises the test site value in relation to reference sites. This summary information can be saved in a number of output formats. Access to the program is password controlled. The physical and chemical reporting software is also accompanied by a manual that gives detailed instructions on the use of the program.
The steering committee meeting of 22 March 2000 resolved that the overall aim of the project was not to construct predictive models from the existing AusRivAS data. Discussions at the Habitat Assessment Workshop (2-3 May 2000) and examination of existing data revealed that physical data collected for the AusRivAS biological models did not include the full array of geomorphological variables necessary to construct comprehensive and robust physical predictive models. Thus, the project proceeded to develop the physical assessment protocol, which is a 'ready to implement' method for the collection of data appropriate for the construction of AusRivAS-style models. Once data are collected and models constructed, it will be possible to predict the occurrence of physical features and assess the physical condition of test sites. Implementation of the physical assessment protocol is discussed further in Section 3.1.
The steering committee meeting of 22 March 2000 also resolved that it would be necessary for this project to develop software to report the existing AusRivAS physical and chemical data. Thus, the AusRivAS physical and chemical reporting software utilises existing AusRivAS data and reports the physical character of test sites, in relation to the physical character of reference sites. The software does not provide any quantitative assessment of 'condition', because it was not considered valid to assign ratings of condition to individual variables (e.g. what percentage of riparian vegetation cover is good and what percentage is bad?), or to sets of variables that contained different arrays of physical components.
Further, the software was designed to utilise existing AusRivAS physical data and subsequently, it does not support the format of the physical assessment protocol. That is, it is not software to construct and display physical predictive models. Instead, the software utilises existing AusRivAS data by reporting the physical character of test sites, in relation to the physical character of reference sites. Implementation of the software is discussed further in Section 3.2.