Using a Geospatial Model to Relate Fluvial Geomorphology to Macroinvertebrate Habitat in a Prairie River—Part 1: Genus-Level Relationships with Geomorphic Typologies

Abstract

Abstract:Modern river ecosystems undergo constant stress from disturbances such as bank stabilization, channelization, dams, and municipal, agricultural, and industrial water use. As these anthropogenic water requirements persist, more efficient methods of characterizing river reaches are essential. Benthic macroinvertebrates are helpful when evaluating fluvial health, because they are often the first group to react to contaminants that can then be transferred through them to other trophic levels. Hence, the purpose of this research is to use a geospatial model to differentiate instream macroinvertebrate habitats, and determine if the model is a viable method for stream evaluation. Through the use of ArcGIS and digital elevation models, the fluvial geomorphology of the Qu'Appelle River in Saskatchewan (SK) was assessed. Four geomorphological characteristics of the river were isolated (sinuosity, slope, fractal dimension, and stream width) and clustered through Principle Component Analysis (PCA), yielding sets of river reaches with similar geomorphological characteristics, called typologies. These typologies were mapped to form a geospatial model of the river. Macroinvertebrate data were aligned to the locations of the typologies, revealing several relationships with the fluvial geomorphology. A Kruskal-Wallis analysis and post hoc pairwise multiple comparisons were completed with the macroinvertebrate data to pinpoint significant genera, as related to the geospatial model.

Using a Geospatial Model to Relate Fluvial Geomorphology to Macroinvertebrate Habitat in a Prairie River—Part 2: Matching Family-Level Indices to Geomorphological Response Units (GRUs)

“…Our objective is to show the usefulness of the GRU model as a means of gathering important data, as applied to fluvial macroinvertebrate habitats. Part 1 revealed several significant relationships between geomorphic typologies and certain macroinvertebrate genera [17]. By further categorizing the typologies into GRUs, and comparing them to the broader family classification of macroinvertebrates, we hope to find additional significant relationships.…”

Geospatial Modeling of River Systems

“…Multivariate-derived geomorphic response units (GRU) that categorized reaches along river systems that exhibit similar geomorphic structures were established, thus providing a link between the hydrological regime and species habitat preference. Meissner et al [76] focused on macro-invertebrate genus groupings as the ecological indicator, whereas the better-performing macroinvertebrate species groups are described in Meissner et al [77].…”

“…[76,77] papers, Doll et al [78] also used macroinvertebrate community metrics, but extended their correlation with in-stream geomorphological features (e.g., bankfull channel cross-sectional area, width-to-depth ratio, channel sinuosity and channel slope) to include morphological features in the river basin (e.g., width of the flood prone area, valley width, valley slope, and substrate). They, too, used principal component analyses to determine correlations between landscape features with macroinvertebrate indices.…”

“…Hosseini et al [75] and Meissner et al [76,77] used different modelling approaches to determine the effects of spatial variability and indicators on aquatic ecology. Hosseini et al [75] applied a deterministic water quality model to determine the impact of location along a river on the sensitivity of ecological parameters (e.g., oxygen demand and growth rate) to water-quality variables (e.g., dissolved oxygen and chlorophyll-a concentrations).…”

“…Meissner et al [76,77] developed a geospatial model to easily identify fish and invertebrate habitat along another Prairie river to assist water and wildlife managers to rapidly identify fisheries habitat in need of protection. The study concentrated on fluvial geomorphology (metrics included channel sinuosity, width and slope and fractal dimension) and examining the hydrological and geological processes that shape certain fluvial geomorphological structures and patterns, as developed by Lindenschmidt and Long [66].…”