Effects of Impervious Cover at Multiple Spatial Scales on Coastal Watershed Streams¹

Abstract

The spatial scale and location of land whose development has the strongest influence on aquatic ecosystems must be known to support land use decisions that protect water resources in urbanizing watersheds. We explored impacts of urbanization on streams in the West River watershed, New Haven, Connecticut, to identify the spatial scale of watershed imperviousness that was most strongly related to water chemistry, macroinvertebrates, and physical habitat. A multiparameter water quality index was used to characterize regional urban nonpoint source pollution levels. We identified a critical level of 5% impervious cover, above which stream health declined. Conditions declined with increasing imperviousness and leveled off in a constant state of impairment at 10%. Instream variables were most correlated (0.77 ≤ |r| ≤ 0.92, p < 0.0125) to total impervious area (TIA) in the 100‐m buffer of local contributing areas (∼5‐km2 drainage area immediately upstream of each study site). Water and habitat quality had a relatively consistent strong relationship with TIA across each of the spatial scales of investigation, whereas macroinvertebrate metrics produced noticeably weaker relationships at the larger scales. Our findings illustrate the need for multiscale watershed management of aquatic ecosystems in small streams flowing through the spatial hierarchies that comprise watersheds with forest‐urban land use gradients.

Hydrologic Effects of Urbanization and Climate Change on the Flint River Basin, Georgia

“…Applications of hydrological models that focus on the effect of urbanization on hydrology in the United States have been documented for a variety of geographic regions, such as the Piedmont (Hejazi and Moglen 2008), Midwest (Tang et al 2005;Choi and Deal 2008), coastal New England (Schiff and Benoit 2007), Pacific Northwest (Cuo et al 2008), and Southeast (Ferguson and Suckling 1990). Many of these have focused on water, habitat, and other ecological quality factors (e.g., Schueler et al 2009;Brabec 2009;Walsh et al 2009;Nelson et al 2009).…”

Urbanization and Quality of Stormwater Runoff: Remote Sensing Measurements of Land Cover in an Arid City

“…These echo the recommendations of Thurston et al (2003) who advocate a 'tradable allowance' for impervious surfaces; Brattebo and Booth (2003), Conway (2007), and Schiff and Benoit (2007) (Newman, 1999;Slavin, 2011), and the 'carrying capacity,' which is the population that a given habitat can support (Wedding and CrawfordBrown, 2007). Ultimately, the search is for a balance between quality of life, environmental habitat tolerance and economic progress (van Kamp et al, 2003).…”

The vulnerability analysis of catchment areas using rapid assessment method (case study in Universitas Indonesia, Depok)

“…Increasing number of impervious land covering strongly affected on the change of water quality and ecosystem especially for small scale catchment areas within 13 -77 km 2 [4,5]. Excessive impervious land covering brought bad impacts on the healthiness of catchment areas [6].…”