Using Large Climate Ensembles to Plan for the Hydrological Impact of Climate Change in the Freshwater Environment

Fai Fung, Glenn Watts, Ana Lopez, Harriet G. Orr, Mark New, Chris Extence

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

We explore the use of large ensembles of climate scenarios to inform climate change adaptation in response to hydrological impacts on the freshwater environment, using a sensitive chalk river in south east England to illustrate the approach. The climateprediction.net experiment provides large ensembles of transient climate series from 1920 to 2080. We use 246 transient climate series in the CATCHMOD rainfall-run-off model to develop large ensembles of plausible river flows for the River Itchen. This transient ensemble allows the exploration of how flows may change through the twenty-first century, and demonstrates the range of possible consequences for freshwater ecosystems, based on invertebrate community impacts. Hydrological modelling of flow sequences including abstraction allows the continued effectiveness of river support from groundwater to be assessed. A new environmental impact matrix considers the response of the freshwater ecosystem in the Itchen, concentrating particularly on macro-invertebrates. Through the century increasing numbers of models fail the flow targets, with a minority of models suggesting flows that would lead to irreversible change to the invertebrate community. The large ensemble provides a richer picture of the range of possible change, allowing managers to explore a range of different responses. The approach used is illustrative, but demonstrates that large ensembles may be of great value in improving the understanding of the possible impact of climate change, provided that they can be communicated effectively to decision-makers.

Original languageEnglish
Pages (from-to)1063-1084
Number of pages22
JournalWater Resources Management
Volume27
Issue number4
DOIs
Publication statusPublished - Mar 2013

Keywords

  • Climate change
  • Uncertainty
  • River ecosystems
  • Macro-invertebrate response
  • Water resources
  • Decision making
  • Modelling
  • Large ensembles
  • MACROINVERTEBRATE COMMUNITY RESPONSE
  • MODEL PARAMETERS
  • FLOW VARIABILITY
  • UNITED-STATES
  • RIVER
  • MANAGEMENT
  • CATCHMENT
  • UK
  • UNCERTAINTY
  • FRAMEWORK

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