William Fisher | Geology Reports

USGS2013

Current status, issues and applications of GIS to inland fisheries

This chapter is concerned with GIS applications made to inland fisheries. These include fisheries in freshwater rivers, lakes and reservoirs. Although these GIS applications have increased rapidly since the late 1980s, this area of fish production receives less attention than either aquaculture or marine fisheries. This is probably because inland fisheries are often practised in remote areas, at a semi-subsistence level, or are recreational in many developed countries, and data on most aspects of the fisheries are scattered, fragmented and frequently unsuited for use as inputs to GIS. The GIS-based inland fisheries work has concentrated on mapping the distribution and abundance of fish species and mapping and modelling habitats in rivers, reservoirs and lakes, and relating the two. Much of the material included in the chapter on inland fisheries comes from either Fisher and Rahel (2004) or from the series of symposium proceedings published by the Fishery-Aquatic GIS Research Group (Nishida and Caton, 2010).

Book chapter↗

USGS2011

Watershed morphology of highland and mountain ecoregions in eastern Oklahoma

The fluvial system represents a nested hierarchy that reflects the relationship among different spatial and temporal scales. Within the hierarchy, larger scale variables influence the characteristics of the next lower nested scale. Ecoregions represent one of the largest scales in the fluvial hierarchy and are defined by recurring patterns of geology, climate, land use, soils, and potential natural vegetation. Watersheds, the next largest scale, are often nested into a single ecoregion and therefore have properties that are indicative of a given ecoregion. Differences in watershed morphology (relief, drainage density, circularity ratio, relief ratio, and ruggedness number) were evaluated among three ecoregions in eastern Oklahoma: Ozark Highlands, Boston Mountains, and Ouachita Mountains. These ecoregions were selected because of their high-quality stream resources and diverse aquatic communities and are of special management interest to the Oklahoma Department of Wildlife Conservation. One hundred thirty-four watersheds in first- through fourth-order streams were compared. Using a nonparametric, two-factor analysis of variance (α= 0.05) we concluded that the relief, drainage density, relief ratio, and ruggedness number all changed among ecoregion and stream order, whereas circularity ratio only changed with stream order. Our study shows that ecoregions can be used as a broad-scale framework for watershed management.

Oklahoma↗