21st Century Climate Change Impacts on Mokolo and Crocodile (West) River Flows South Africa

The analysis concludes that river flows in the Mokolo and Crocodile (West) catchments are very likely to decline due to a combination of projected precipitation decreases and increased evaporation driven by rising temperatures. Using the American Southwest as a semi-arid analog, the author argues that temperature-induced flow declines will occur even if modest precipitation increases happen. The report warns that these systems are already over-allocated and that further warming, potentially reaching 5°C under high-emissions scenarios, will exacerbate water shortages and increase the frequency of 'flash droughts'.

• Temperature increases in the Mokolo and Crocodile (West) catchments are virtually certain, with projections ranging from approximately 2°C to 5°C by the end of the century, depending on greenhouse gas emission levels.
• Annual precipitation is projected to decrease in both catchments, with the Mokolo basin showing consistent drying across all models and future periods. The Crocodile (West) basin may see modest increases by mid-century under some scenarios, but is projected to experience declines by the end of the century.
• River flows are very likely to decline because higher temperatures increase evaporation and evapapotranspiration, which can overwhelm any modest increases in precipitation.
• Based on data from the American Southwest analog, a 3°C warming could reduce river flows by about 20%, and a 5°C warming could reduce them by nearly 35%; counteracting these declines would require annual precipitation increases of 10% to 17%, which is deemed unlikely.
• Future precipitation is expected to occur on fewer days with greater intensity, leading to longer dry periods and an increased likelihood of 'flash droughts' in South Africa.

APA

Udall, B. (2018). 21st Century Climate Change Impacts on Mokolo and Crocodile (West) River Flows South Africa. Centre for Environmental Rights. https://cer.org.za/wp-content/uploads/2018/03/Udall-Mokolo-Crocodile-Rivers-Analysis-Notarized-.pdf?x21779

Chicago

Udall, Brad. 21st Century Climate Change Impacts on Mokolo and Crocodile (West) River Flows South Africa. Centre for Environmental Rights, 2018. https://cer.org.za/wp-content/uploads/2018/03/Udall-Mokolo-Crocodile-Rivers-Analysis-Notarized-.pdf?x21779.

Wikipedia

{{cite report |last1=Udall |first1=Brad |title=21st Century Climate Change Impacts on Mokolo and Crocodile (West) River Flows South Africa |publisher=Centre for Environmental Rights |date=26 February 2018 |url=https://cer.org.za/wp-content/uploads/2018/03/Udall-Mokolo-Crocodile-Rivers-Analysis-Notarized-.pdf?x21779 |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{udall201821st, author = {Udall, Brad}, title = {{21st Century Climate Change Impacts on Mokolo and Crocodile (West) River Flows South Africa}}, institution = {Centre for Environmental Rights}, year = {2018}, month = feb, url = {https://cer.org.za/wp-content/uploads/2018/03/Udall-Mokolo-Crocodile-Rivers-Analysis-Notarized-.pdf?x21779}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }