Nam et al. (2026) Everything Comes Down to Timing: Optimal Green Infrastructure Placement and the Effect of Within-Storm Variability

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Water
• Year: 2026
• Date: 2026-03-26
• Authors: Seonwoo Nam, Minseok Kim
• DOI: 10.3390/w18070790

Research Groups

Not explicitly stated in the provided text, but the research likely involves groups in hydrology, civil engineering, or environmental science focusing on urban water management.

Short Summary

This paper develops a timescale-based framework to understand how green infrastructure (GI) placement affects urban flood peak mitigation, revealing that optimal placement depends on the alignment of storm temporal structure, network response, and GI filling dynamics, quantifiable by two nondimensional ratios and storm descriptors.

Objective

• To develop a timescale-based framework that links urban flood peak reduction by green infrastructure (GI) to the alignment among within-storm temporal structure, network response, and GI filling dynamics.
• To provide a compact way to interpret when different network positions become most effective under a fixed GI design.
• To quantify how often realistic storm event structures alter the optimal GI location and the regret associated with adopting a uniform design storm.

Study Configuration

• Spatial Scale: Conceptual/generalized urban catchments, spanning fast to slow network responses.
• Temporal Scale: Within-storm dynamics, evaluated using 2351 observed hourly storm events.

Methodology and Data

• Models used: A general convolution representation of runoff generation, interception, and routing; a generic dispersive routing representation.
• Data sources: 2351 observed hourly storm events.

Main Results

• Peak reduction efficiency and location ranking are organized by two nondimensional ratios (comparing storm duration and network response time to a characteristic GI filling time) and simple descriptors of within-storm temporal structure.
• Under uniform rainfall, these ratios yield an interpretable regime diagram with analytical transition curves between downstream-, mid-network-, and upstream-optimal GI placement.
• Within-storm variability can substantially reorganize these regimes, with highly concentrated storms and storms with early internal peaks especially likely to reorder the ranking of candidate locations relative to the uniform-rainfall baseline.
• Realistic event structures frequently alter the optimal GI location, quantifying the regret associated with adopting a uniform design storm.

Contributions

• Development of a novel timescale-based framework for interpreting GI effectiveness and optimal placement for urban flood peak mitigation.
• Introduction of two nondimensional ratios and simple storm descriptors that organize peak reduction efficiency and location ranking.
• Quantification of the significant impact of realistic within-storm temporal variability on optimal GI placement, challenging the reliance on single design hyetographs.
• Motivation for robustness-oriented GI placement strategies based on ensembles of plausible storm temporal structures, organized within the proposed timescale diagram.

Funding

Not explicitly stated in the provided text.

Citation

@article{Nam2026Everything,
  author = {Nam, Seonwoo and Kim, Minseok},
  title = {Everything Comes Down to Timing: Optimal Green Infrastructure Placement and the Effect of Within-Storm Variability},
  journal = {Water},
  year = {2026},
  doi = {10.3390/w18070790},
  url = {https://doi.org/10.3390/w18070790}
}