Climate Change in Southern Africa - Limpopo River Awareness Kit

Climate change is predicted to bring increased weather-related catastrophic events, with estimates putting increases at three times greater than the number non-weather related events (McMullen and Jabbour 2009).

The information provided below is part of a study undertaken by CESR at the University of Kassel, Germany. The study aimed to model and assess the impact that climate change will have on water availability as the climate changes and population increases (increasing demand). The modelling team conducted an assessment of the current situation, based upon historical records from 1961 - 1995, then two additional time steps, 2055 and 2075.

The assessment includes the following analysis:

Water availability (km³/yr) - Long term average potential water availability of the river basin calculated under consideration of the 1961-90 climate normal and the IPCC SRES A2 climate scenarios for 2055 and 2075. Here, surface runoff and groundwater recharge are combined.
Total water demand (km³/yr) - 1995 and future total water withdrawals includes the withdrawals for the domestic, industry, irrigation, and livestock sectors. The water requirements for irrigation are computed using the climate normal 1961-90 period and the A2 climate scenarios for 2055 and 2075.
Ratio of Water Availability to Demand (%) - divides total annual water withdrawals (water abstracted from surface or groundwater sources) by total annual water availability on a river basin scale. This water stress indicator describes the intensity of pressure put on water resources and aquatic ecosystems by external drivers of change. The larger the volume of water withdrawn, used and discharged back into a river, the more it is degraded or depleted, and the higher the water stress.

More information on the IPCC SRES A2 climate scenario can be found at the UNEP GRID website. The CESR team also conducted assessments using the B2 climate scenario, but in the interests of space only 1 assessment is shown here.

As can be seen from these time series data, the water availability reduces, as water demand increases, resulting in an intensification of water scarcity over time.