VTechWorks staff will be away for the winter holidays starting Tuesday, December 24, 2024, through Wednesday, January 1, 2025, and will not be replying to requests during this time. Thank you for your patience, and happy holidays!

Browsing by Author "Alsmadi, Mohammad"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Effectiveness of stormwater management practices in protecting stream channel stability
    Alsmadi, Mohammad; Sample, David J.; Thompson, Theresa M.; Miller, Andrew (2021-06-16)
    Hypotheses
    1. Channel instability in Minebank Run is caused by high shear stresses generated during even relatively frequent storm events.
    2. Retrofitting the Minebank Run watershed with additional watershed stormwater controls will reduce channel incision and bank failure (will compare environmental site design (ESD) only, traditional downstream controls only, and combination of both).
    3. Had Minebank Run been developed with ESD channel incision and degradation would have 1) been prevented, or 2) been reduced.
    4. Current channel degradation in tributaries to Little Seneca Creek are the result of recent large magnitude storm events, which are typically not well controlled by ESD.
    5. Had the Clarksburg watershed been developed using traditional stormwater control measures (SCMs), more extensive channel degradation would have occurred.
    6. A combination of ESD controlling small storms and SCMs controlling larger events is necessary to protect stream channels against erosion.
  • Thumbnail Image
    Efficacy of environmental site design in protecting channel stability under changing climate
    Towsif Khan, Sami; Thompson, Theresa M.; Alsmadi, Mohammad; Sample, David J. (American Ecological Engineering Society, 2023-06-06)
    Research on the impacts of climate change (CC) on water resources has received much attention during the past decade. However, little research has been done on how future climate will likely impact sediment transport and channel stability of first-order streams, particularly in urban environments which utilize Nature-based Solutions (NbS) for stormwater management. This study aimed to assess whether the current stormwater regulations in the state of Maryland, USA, which require the use of environmental site design (ESD), are protective of channel stability when CC is considered. ESD relies on the combination of the concepts of NbS for enhanced infiltration and evapotranspiration with the utilization of storage-based gray infrastructure. To achieve this goal, a coupled hierarchical modeling approach was developed and applied to examine projected changes in bedload transport and channel geometry for a first-order riffle-pool, gravel-bed channel draining an urban watershed equipped with the extensive implementation of ESD. The modeling approach was based on discharge from a watershed-scale hydrologic model driven by a range of spatiotemporally downscaled CC scenarios. Changes in sedimentary responses of the modeled reach were estimated using the Hydrologic Engineering Center River Analysis System 6.3 (HEC-RAS). Ensemble simulation results showed that even with the extensive implementation of ESD, the studied reach is expected to degrade over many decades developing alternate regions of aggradation and degradation due to the changes in watershed hydrology caused by urbanization under both current and future climate conditions. Mobilization of larger particles during high-magnitude storm events and their subsequent deposition upstream of narrower sections of the reach leads to the formation of several steep riffles. Results from this study show that the current stormwater regulations in the State of Maryland are not protective of channel stability and that changes in climate will likely accelerate channel degradation.