Influence analysis of different design conditions on urban runoff and nonpoint source pollution

Abstract

Urban waterlogging and nonpoint source (NPS) pollution caused by urbanization have considerably increased, and their control effects are affected by many factors. This study established a distribution model to analyze the influences of different rainfall conditions and rain garden layouts on runoff output and NPS pollution. Simulation results showed that (a) the reduction rates of the runoff and pollution load decreased from 45% to 23% and from 57% to 23% with increasing rainfall duration (1-24 hr). The flow and concentration peaks, total discharge amount and load increased, and the reduction rates of the runoff and pollution load decreased from 47% to 32% and from 60% to 21%, respectively, with increasing recurrence period (1-50 annual). The changes in the rain peak coefficient had minimal reduction effect on water quantity and quality. (b) Under different rain garden layouts, the reduction rates of the runoff and pollution load were 37%-52% and 13%-57%, respectively. The reduction effects of the runoff and pollution load improved, whereas amplitudes decreased with increasing rain garden layouts (0%-4%). (c) Rainfall duration and rain garden proportion greatly influenced the runoff and load reductions, respectively. © 2019 Water Environment Federation • Practitioner points• The reduction effects of runoff and pollution load under different rainfall conditions were simulated and analyzed. • The reduction effects of runoff and pollution load under different setting proportions of rain garden were simulated and analyzed. • The influence degrees of different design conditions on water quantity and quality reduction rates were evaluated.• Key words analytic hierarchy process; rain garden layout; rainfall condition; reduction effect; Stormwater Management Model

A Comprehensive Review of Machine Learning for Water Quality Prediction over the Past Five Years

“…Changes in water quality in coastal areas are influenced by both natural and anthropogenic factors [72][73][74][75][76]. Pollutants in the marine environment are not only from sewage discharge but also from natural activities, whereby water bodies transport pollutants through inherent circulation processes [77,78], including rainfall, runoff [79], seawater intrusion, and tidal intrusion, ultimately merging into the ocean. Water quality pollution encompasses a broad spectrum of sources and complex causes, rendering accurate results challenging through mechanistic analysis.…”

Urban stormwater characterization, control, and treatment

“…The study showed that the model did not predict water quality concentrations in the bioretention outflow well; however, pollutant concentration predictions emanating from the impervious area (bioretention influent) were well predicted. SWMM was also used to assess the impact of rainfall conditions and rain garden proportion on stormwater retention and water quality in Xi'an, China (Li, Ma, Ma, Li, & Zhang, 2019), and the impact of LID (vegetated swales and rain gardens) in Kuala Lumpur, Malaysia (Rezaei et al, 2019). Li et al (2019) found that rainfall intensity was the primary influencing factor for water quantity concerns while the rain garden proportion impacted water quality.…”

“…SWMM was also used to assess the impact of rainfall conditions and rain garden proportion on stormwater retention and water quality in Xi'an, China (Li, Ma, Ma, Li, & Zhang, 2019), and the impact of LID (vegetated swales and rain gardens) in Kuala Lumpur, Malaysia (Rezaei et al, 2019). Li et al (2019) found that rainfall intensity was the primary influencing factor for water quantity concerns while the rain garden proportion impacted water quality. Rezaei et al (2019) also saw a positive impact on water quality from the implementation of LID.…”