Author(s): Xiaoyu Zhang; Shereif H. Mahmoud; Wenming Zhang

Linked Author(s): Wenming Zhang

Keywords: Nitrogen; Mike Urban; Climate change; Urban stormwater; Rainfall characteristics

Abstract: Evaluating build-up and wash-off models on simulating nitrogen loading in urban stormwater is important but less. We developed a mike urban model to assess climate change impact on the loading of nitrogen species in stormwater runoff of an urban catchment in Canada. The model was calibrated and validated against the observed data of nitrogen loadings and event mean concentration (EMCs) from 2010 to 2016. we used the model to evaluate the factors that affect nitrogen loadings (tkn, nox-n and nh4-n), and important ones are rainfall intensity, rainfall duration and antecedent dry days. First flush effect of the storm events from 2010 to 2016 were examined, which showed that 32.1% to 59.8% of the three nitrogen species loadings were transported by the first 30% of runoff volume. Based on projection of future climate, we further used the model to predict the nitrogen loadings in the future (2044 - 2050) and found that the average total loadings of TKN, NOx-N and NH4- N will increase by 18.7%, 17.4% and 22.9%, respectively, compared to the historical data of 2010 - 2016. the largest increase was found in June and July due to more heavy rainfall events (i. e., higher maximum one-day precipitation and maximum five-day precipitation) in 2044 - 2050.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0666-cd

Year: 2023