Title: Investigation of the Relationship between the LIFE Index and RIVPACS: Putting LIFE into RIVPACS
Author: R T Clarke
Author: P D Armitage
Author: D Hornby
Author: P Scarlett
Author: J Davy-Bowker
Author: Environment Agency
Document Type: Monograph
Annotation: Environment Agency Project ID:EAPRJOUT_1263, Representation ID: 423, Object ID: 2473
Abstract:
In the UK, there are competing demands for both surface and groundwater resources. Sustained or repeated periods of low flows and/or slow flows are expected to impact on the plant and animal communities within rivers. To assess the potential impact of flow-related stresses on lotic macroinvertebrate communities, Chris Extence and colleagues from Anglian Region of the Environment Agency developed the Lotic-invertebrate Index for Flow Evaluation (LIFE). Extence et al. (1999) showed that for several individual sites, temporal variation in LIFE could be correlated with recent and preceding flow conditions. RIVPACS (River InVertebrate Prediction And Classification System), developed by CEH, the Environment Agency and their predecessors, is the principal methodology currently used by the UK government environment agencies to assess the biological condition of UK rivers. RIVPACS assesses biological condition at a site by comparing the observed macroinvertebrate fauna with the fauna expected at the site if it is unstressed and unpolluted, as predicted from its environmental characteristics. Biological condition is estimated currently using two Ecological Quality Indices (EQI) represented by the ratio (O/E) or observed (O) to expected (E) values of the number of Biological Monitoring Working Party (BMWP) taxa present and the ASPT (Average Score Per Taxon), denoted by EQITAXA and EQIASPT respectively. LIFE is based on the same macroinvertebrate sampling procedures as RIVPACS. In this R&D project an assessment was made of the potential to use the RIVPACS reference sites and methodology to standardise LIFE across all physical types of site, as a ratio of observed to expected LIFE, denoted LIFE O/E. LIFE O/E then provides a standardised estimate of the severity of the impacts of any flow-related stress on the macroinvertebrate fauna at a site. CEH have derived a numerical algorithm to provide predictions of the expected LIFE for any river site based on its values for the standard RIVPACS environmental predictor variables. This algorithm is compatible with the derivation of expected ASPT, gives appropriate lower weighting to taxa with lower expected probabilities of occurrence and hence should be used in preference to the current LIFECALCULATOR method. It is recommended that this new algorithm is incorporated into an updated Windows version of the RIVPACS software system to provide automatic calculation of observed LIFE, expected LIFE and hence LIFE O/E for any macroinvertebrate sample and river site.
Publisher: Environment Agency
Subject Keywords: Flow rate; Monitoring; RIVPACS; Macroinvertebrates; Methodology; Catchment Abstraction Management Strategies; Resource management; Freshwater ecology
Extent: 182
Permalink: http://www.environmentdata.org/archive/ealit:4702
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