Assessment of LID-BMPs for Urban Runoff Control in Newly Developing Zones: the Case of Yanming Lake Residential District, China

The best management practices for low impact development (LID-BMPs) have been widely applied to control stormwater runoff. LID-BMPs using bio-retention and bio-filtration swales were planned to control the urban runoff in the studied case of the Yanming Lake Residential District which is a developing urban zone. The control of runoff by the LID-BMPs was simulated and assessed by applying the following methods of scenario analysis, SCS-CN model and GIS tool. The three scenarios studied were the existing background (EB), a conventional stormwater drainage system (CSD) and an ecologically designed stormwater system (EDS). We found that the land use types affected rainfall-runoff, with the runoff depth decreasing in the following land use types: road > commercial land > residential land > arable land > woodland > green/grassland. The different stormwater controlling systems, in the same land use type, also affected the runoff amount, with the runoff from EDS being 77.2% to 87.7% less than CSD. EDS had a "system-wide" reduction of runoff volume. The runoff volume of EDS (3.50 x 10(6) m(3)) was 25% less than EB (4.69 x 10(6) m(3)) and 36% less than CSD (5.49 x 10(6) m(3)). EDS showed the best performance on flood control, the submerged area was reduced by (1.84 x 10(6) m(2)) (24.0%) and (2.09 x 10(6) m(2)) (25.5%) compared to EB and CSD respectively.