Merging patterns and processes of diffuse pollution in urban watersheds: A connectivity assessment

Abstract

Urban diffuse pollution affects water resources as much as its rural counterpart does; however, it is considerably less studied. The full complexity of the urban landscape needs to be addressed to apprehend the diversity of surface layouts and covers, multiple pollution sources, and the diverse changes caused by different types of drainage systems. In this article, crucial patterns of pollution source areas are categorized, and current knowledge on their temporal and spatial variations are collated. Urban alterations of transport processes that enhance, delay, or inhibit diffuse pollution transport from source areas through the urban watershed are detailed. Current knowledge regarding diffuse pollution patterns and processes is conceptually merged by the simultaneous assessment of urban structural and functional connectivity relevant for pollutant transfer. Applying a more holistic approach is considered a prerequisite for identifying critical source areas of diffuse pollution within complex urban catchments, to minimize the transfer of particular harmful pollutants and to enhance future management of urban waters. This article is categorized under: Science of Water > Water Quality Engineering Water > Planning Water

Owing to the on‐going urban expansion accompanied by an anticipated increase of flash floods, diffuse water pollution in cities is likely to increase. The complexity of pollution patterns and their distribution mechanisms in cities are reviewed in the context of urban connectivity of pollution. Explicit handling of urban connectivity may guide the re‐design of urban drainage strategies toward more decentralized and sustainable management approaches of urban water resources.