REVIVING URBAN STREAMS: LAND USE, HYDROLOGY, BIOLOGY, AND HUMAN BEHAVIOR¹

Abstract

Successful stream rehabilitation requires a shift from narrow analysis and management to integrated understanding of the links between human actions and changing river health. At study sites in the Puget Sound lowlands of western Washington State, landscape, hydrological, and biological conditions were evaluated for streams flowing through watersheds with varying levels of urban development. At all spatial scales, stream biological condition measured by the benthic index of biological integrity (B‐IBI) declined as impervious area increased. Impervious area alone, however, is a flawed surrogate of river health. Hydrologic metrics that reflect chronic altered streamflows, for example, provide a direct mechanistic link between the changes associated with urban development and declines in stream biological condition. These measures provide a more sensitive understanding of stream basin response to urban development than do treatment of each increment of impervious area equally. Land use in residential backyards adjacent to streams also heavily influences stream condition. Successful stream rehabilitation thus requires coordinated diagnosis of the causes of degradation and integrative management to treat the range of ecological stressors within each urban area, and it depends on remedies appropriate at scales from backyards to regional storm water systems.

A Model Approach for Estimating Colony Size, Trends, and Habitat Associations of Burrow-Nesting Seabirds

“…They attribute these shifts to heightened runoff resulting from increased imperviousness, leading to both higher water flow rates and volumes and increased mobilization of contaminants relative to levels observed in watersheds dominated by rural residential and forested areas (Bilby and Mollot 2008). Benthic indices of biotic integrity (Morley and Karr 2002;Booth et al 2004;Alberti et al 2007;Shandas and Alberti 2009) and fish (Matzen and Berge 2008) have declined as a consequence of the percent imperviousness within watersheds.…”

“…Expanding on a previous study of urban land use impacts on biotic integrity (Booth et al 2004), Alberti et al (2007) examined relationships between landscape composition (directly related to vegetation amount) and configuration (including levels of fragmentation and edge contrasts) in the central Puget Sound and benthic indices of biotic integrity. They found a strong negative relationships between benthic indices of biotic integrity and contiguity of urban land cover, a somewhat weaker negative relationship with overall imperviousness, and still weaker but significant negative relationships with road density and road crossings.…”

“…Construction of transportation corridors frequently disrupts connectivity within and among shoreline ecosystems, particularly in the form of overpasses through or over river deltas and embayments. Lastly, increased contaminant loadings occur as a result of nearshore transportation structures, both directly deposited by automobiles and trains and indirectly mobilized via surface water runoff across impervious surfaces (Booth et al 2002(Booth et al , 2004Kaye et al 2006;Krahn et al 2007;Schlenger et al, in review).…”

Developments in water quality monitoring and management in large river catchments using the Danube River as an example

“…For example, in riverine monitoring, it is generally accepted that sampling sites should be situated at the mouth of principal tributaries (Sharp, 1971). However, river reaches between tributary confluences can be subject to numerous influences, including structures for hydropower generation (Kovács et al, 2015a,b), and urban (Booth et al, 2004;Konrad and Booth, 2005), industrial (Vignati et al, 2013) and agricultural effluent (Lenat, 1984). Therefore, increasing the number of monitoring sites in "uncovered" sections of the basin would be logical.…”

An Ecological Flow Assessment Framework: Building a Bridge to Implementation in Canada

“…Streamflow has direct effects on aquatic ecosystem integrity through its influence on hydraulic parameters such as current velocity and depth. It also indirectly affects aquatic ecosystem integrity through its influences on: physical habitat (i.e., fluvial geomorphology); connectivity, along the channel and with riparian areas, which is important to energy sources, nutrient dynamics and the ability of aquatic species to access habitats; water quality (e.g., dissolved oxygen concentrations, water temperature); and biotic interactions (e.g., predation, disease) (Booth et al, 2004;Poff et al, 1997).…”