8,255
edits
Changes
Jump to navigation
Jump to search
Line 29:
Line 29: + + − − Figure xx: Facility wide infiltration rates for different LID practices installed in the Greater Toronto Area
→Performance studies on fine textured soils
==Performance studies on fine textured soils==
==Performance studies on fine textured soils==
[[File:Infiltration_rates_studies.png|thumb|Facility wide infiltration rates for different LID practices installed in the Greater Toronto Area]]
A number of field studies of LID practices have been conducted in southern Ontario on fine textured soils. Several of these studies have yielded data that allow for calculation of the facility wide infiltration rate during natural rain events of varying sizes. These are summarized in Figure xx. Infiltration rates on silty clay, clayey silt and sandy silt textured soils had a median value of 3.3 mm/h and a range between 0.3 and 17.8 mm/h. Permeable pavements had lower values in part due to compaction of the subsoils to accommodate traffic loading.
A number of field studies of LID practices have been conducted in southern Ontario on fine textured soils. Several of these studies have yielded data that allow for calculation of the facility wide infiltration rate during natural rain events of varying sizes. These are summarized in Figure xx. Infiltration rates on silty clay, clayey silt and sandy silt textured soils had a median value of 3.3 mm/h and a range between 0.3 and 17.8 mm/h. Permeable pavements had lower values in part due to compaction of the subsoils to accommodate traffic loading.
Stormwater runoff volume reductions vary between sites, primarily due to factors other than the native soil infiltration rate. For instance, the infiltration trenches and chambers shown in the Figure xx had similar native soil infiltration rates (3.1 to 5.1 mm/h), but runoff reduction values varying from 16 to 90%, chiefly due to site to site differences in the I:P ratio (reference definition), which ranged from 10:1 to 155:1.
Stormwater runoff volume reductions vary between sites, primarily due to factors other than the native soil infiltration rate. For instance, the infiltration trenches and chambers shown in the Figure xx had similar native soil infiltration rates (3.1 to 5.1 mm/h), but runoff reduction values varying from 16 to 90%, chiefly due to site to site differences in the I:P ratio (reference definition), which ranged from 10:1 to 155:1.