RT Journal Article
SR Electronic
T1 “Retro-Greening” Suburban Calgary
JF Landscape Journal
FD University of Wisconsin Press
SP 124
OP 143
DO 10.3368/lj.29.2.124
VO 29
IS 2
A1 Roehr, Daniel
A1 Kong, Yuewei
YR 2010
UL http://lj.uwpress.org/content/29/2/124.abstract
AB Green-factor systems, rating the “ecological value” of a site and the green factors for landscape elements according to their positive effects on the ecosystem, are adaptable and applicable to many cities. The “positive effects” of landscape elements, however, vary with climatic and geographic conditions. One method of evaluating elements such as green roofs, permeable pavement, vegetated walls, rain gardens, and bioswales considers their contribution to stormwater management. In this study, runoff depth, volume, peak-flow rate, and the mass loading of contaminants, determined through analysis of a typical Calgary residential site using climatic data and simulation tools (NRCS-CN, crop coefficient, and Rational Methods), are compared with those of two green-intervention scenarios with differing landscape elements achieving a Seattle Green Factor of 0.3. Calculated results show that Scenario 1—with green roofs and vegetated walls—could reduce total annual runoff volume by 31 percent, peak-flow runoff by 17 percent, mass loading of total suspended solids by 8 percent, and nutrient content to 36 percent. Scenario 2—with green roofs, permeable pavement, rain garden and bioswales—could reduce total annual runoff volume by 96 percent, peak-flow runoff by 28 percent, mass loading by 90 percent, and nutrient content to 96 percent.