Wednesday, June 6, 2007 - 4:00 PM
314

Large Scale River Health Assessments: The Pros and Cons of Integrating and Aggregating Bioassessments across different Themes and Spatial Scales

Wayne A. Robinson, M., App., Sci., Faculty of Science Health and Education, Universityof the Sunshine Coast, Sippy Downs Drive, Sippy Downs, Australia

Integrated river health monitoring and assessment involves gathering data from various themes, e.g. fish, algae, habitat, vegetation and invertebrates, which are usually measured at small scales such as individual reaches.  However, management and funding agencies often desire an integrated or overall score for an entire watershed or even larger region.  This presentation will document several commonly used methods of integration (i.e. combining of assessments from different themes) and aggregation (i.e. reporting at larger spatial scales).  Some of the questions to consider before calculations are performed include whether to give equal weighting to different indicators when integrating and whether to weight the reach scores (e.g. by length of reach) when aggregating. The results are widely applicable but I primarily use case studies and data from two Australian programs, the Sustainable Rivers Audit and the Index of Stream Condition.  Emphasis will be on how assessments compare between integration using arithmetic weighted or unweighted averaging and summing, standardised Euclidean distance and expert rules.  The major focus will be on propagation of errors at the larger spatial scales, the effects of aggregating or integrating first and the effects of correlations among the sub-assessment indices.

See more of Bioassessment V
See more of Contributed Sessions

See more of The NABS 55th Annual Meeting