Evaluating catchment response to artificial rainfall from four weather generators for present and future climate

Area of Science:

• Urban water management
• Climate change adaptation
• Hydrological modeling

Background:

• Urban water infrastructure requires long-term planning considering climate change.
• Complex urban water models increasingly include decentralized stormwater controls.
• Evaluating these systems requires near-real condition simulations.

Purpose of the Study:

• To assess the suitability of weather generator (WG) products for long-term statistics (LTS) modeling of urban water systems under present and future climate conditions.
• To evaluate catchment responses using different WG products for both current and projected climate scenarios.

Main Methods:

• Long-term statistics (LTS) simulations were performed on two catchments.
• Four different weather generator (WG) products were used to generate artificial rainfall time series.
• Simulations were conducted for both present and future climate conditions.

Main Results:

• For present conditions, WG products yielded realistic catchment responses regarding pipe flow and combined sewer overflows (CSOs).
• For future conditions, significant differences emerged between WG products in representing climate change expectations.
• All future scenarios indicated an increased frequency of events stressing drainage system capacity.

Conclusions:

• Weather generator products are relevant tools for planning future alterations to urban sewer systems.
• Simulations highlight the necessity of adapting urban water infrastructure to anticipated climate change impacts.
• The study validates the use of WG-derived rainfall data for robust future-state assessments.