title: Development of an integrated catchment model framework for climate change impacts assessment: The Nerang River catchment, Australia
Creators: name: Jahandideh-Tehrani, Mahsa
Publisher: name: Griffith University
Year: 2020
Subjects: subject: climate change
subject: sea level
subject: Nerang River catchment

description: Long lasting changes in all components of the climate system are expected to occur due to continuing greenhouse gas emissions and increasing human activities (IPCC, 2014). Extreme events, such as droughts and floods are predicted to be significantly affected by climate change. The vast and variable climate change impacts on hydrological regimes, water availability, floods, droughts, rainfall intensity and frequency confirm that current water resource planning and management must be adopted for efficient future planning, policy design, as well as sustainable water supply. Evaluating climate change impacts has been an important issue in Australia, particularly in Southeast Queensland (SEQ) as this region is regarded as a “hot spot” in Australia, which is significantly affected by climate change. Additionally, in Australia, 1% change in the mean annual rainfall leads to 2-3% change in the mean annual streamflow (Teng et al., 2012). Therefore, there is a fundamental need to understand and analyse the potential changes in rainfall under climate change in catchments located in SEQ, as small rainfall changes will considerably alter the resulting hydrologic response of these catchments. In order to properly consider uncertainty in the hydrological projections for catchments and to improve forecast accuracy under climate change scenarios, multi-model ensembles of General Circulation Models (GCMs) should be employed. Such an ensemble multi-model approach can potentially provide a range of possible future hydrological conditions, allowing water managers to consider integrated uncertainty and adaptation strategies. The overall aim of this study was to develop a holistic understanding of the ensemble impacts of climate change and sea level rise on the Nerang River catchment, SEQ, Australia. This includes the development of an integrated catchment modelling framework for the catchment, which has proved to be a robust tool for understanding climate change impacts in SEQ. Additionally, such integrated catchment modelling framework provides in-depth understanding of the interaction between separate parts of a river system and catchment behaviour. To achieve a holistic understanding of the catchment behaviour, the first part of this research was based on model establishment, including two hydrologic models (for both real-time and long-term river flow predictions), a reservoir operation model, and a hydrodynamic river model which were developed, calibrated and validated for the Nerang River catchment. After successful establishment of the stated models, the second part of this research focused on evaluating impacts of climate change on the hydrologic and hydraulic conditions of the Nerang River catchment using ensemble projections of eight GCMs and sea level rise. The outcomes of the developed integrated modelling framework in this research equip decision makers with an efficient and easy-to-apply tool for evaluating different climate change scenarios to investigate adaptation strategies.