[Influence of Pervious/Impervious Pattern on Runoff and Pollution in Parcel-based Catchment]

Area of Science:

• Environmental Science
• Urban Hydrology
• Landscape Ecology

Background:

• Urbanization alters underlying surfaces, affecting surface runoff and pollution generation.
• Understanding the influence of pervious/impervious surface patterns is crucial for urban water management.
• Non-point source pollution and urban waterlogging are significant environmental challenges.

Purpose of the Study:

• To analyze the relationship between pervious/impervious surface patterns and surface runoff and pollution generation.
• To investigate how landscape metrics (fragmentation, complexity, vergence) influence runoff (Q) and pollutant loads (Ld, Lp).
• To provide insights for optimizing Low Impact Development (LID) facility allocation for better urban water management.

Main Methods:

• Utilized landscape metrics to quantify characteristics of pervious/impervious surface patterns.
• Analyzed correlations between landscape metrics and total runoff (Q), dissolved pollutant load (Ld), and particulate pollutant load (Lp).
• Statistical analysis including correlation coefficients (r) and significance levels (P) was performed.

Main Results:

• Patch density (PD) and split index (SPLIT) positively correlated with runoff and dissolved pollutant load (Ld).
• Largest patch index (LPI) and mean shape index (MSI) showed negative correlations with runoff and pollutant loads.
• Landscape shape index (LSI) positively correlated with runoff and particulate pollutant load (Lp).

Conclusions:

• Surface pattern characteristics significantly influence urban runoff and pollution generation.
• Transforming scattered, small pervious patches to larger, potentially irregular ones is recommended for small catchments.
• This study offers a novel approach to rainfall runoff and pollution control by considering the spatial patterns of LID facilities.