Climate impact indicators
Global essential climate variables/indicators used

Climate forcing data from the climate data store (CDS) will be used to produce CIIs for historical and future periods representing

- mean and extreme temperature changes
- monthly and extreme rainfall changes
- changes in rainfall seasonality

Regional/local indicators used and produced

The ACRU agrohydrological model and HYPE model will be configured for the uMgneni catchment. Using the global CII together with future climate scenarios and regional climate, land use and soils data, regional CII will be produced such as change in streamflow, changes in high flow (amount and timing), and nutrient loading.

Global data to regional/local scale

Step 1: Data collection and model configuration: Using local sources of available data (mean and extreme temperature changes, monthly and extreme rainfall changes and changes in rainfall seasonality), update the existing configurations for the ACRU model for the uMngeni and Thukela catchments. Working together with SMHI, configure the HYPE model for the two catchments. Investigate linkages between ACRU and HYPE to address the need for simple but robust nutrient and pathogen modelling within the ACRU model. Undertake the baseline historical simulations.

Step 2: Defining scenarios and CIIs: From the available ensemble of climate change scenarios, evaluate the suitability and resolution of the downscaling of the GCMs to the region and decide on the scenarios to be selected. Undertake bias correction of the selected future climate scenarios. Define the relevant CIIs for the two catchments.

Step 3: Scenario modeling and analysis: Using the defined future climate scenarios as input to the ACRU and HYPE model configuration, produce modeled results which will cover the potential impacts on the nutrient and pathogen loadings, agricultural production and water security. These will include rainfall, stream flow, low flow and high flow events, primary production, crop yield, irrigation demand, percolation to groundwater and yield. Additional analyses to determine the heat units, growing season lengths, and frost season.

Step 4: Development of showcase: Once the analysis of results has been completed, develop a showcase which will demonstrate the relevance and potential uses of the CIIs for either the uMngeni or Thukela catchments. The showcase will take one of the more severe potential impacts.

Step 5: Dissemination of results/findings: The dissemination of the findings to the stakeholders through presentations at local conferences and meetings; distribution of links to the showcase to the relevant stakeholders; distribution of a popular article on the findings and results to the relevant stakeholders; a scientific paper.

Centre for Water Resources Research, University of KwaZulu-Natal
Umgeni Water

Poster displayed at the Kick–Off meeting, 7/8 September 2017, Norrköping, Sweden