Implementation and application of an urban pollutant load modelling tool within an ecosystem services assessment modelling framework to assess water purification capabilities of blue-green infrastructure under climate change

Abstract

ABSTRACT Ecosystem service (ES) assessment tools do not yet consider some of the most common urban pollutants and this study contributes to filling this gap. The methodology employed in the Modelled Estimates of Discharges for Urban Stormwater Assessments (MEDUSA) was implemented within the Land Utilisation and Capability Indicator (LUCI) to allow urban pollutant issues to be considered within a broader ES assessment context. Two land use change scenarios for the Ōtākaro/Avon River in Christchurch, New Zealand, were assessed for 2011–2020 and 2041–2050. Implementation of a limited set of blue-green infrastructure for 2011–2020 resulted in a reduction of TSS by 5–12%, of Zn by 2–5%, and of Cu by 4–7%. The simulated pollutant load values for future climate change scenarios clearly reflected the uncertainty in climate change predictions. The expanded LUCI can be employed for strategic planning of the implementation of treatment methods and types to protect waterways.