The four-year CGA project for the WRC, An Earth Observation Approach towards Mapping Irrigated Areas and Quantifying Water Use by Irrigated Crops in South Africa, has been published by the WRC and is now available online.
Various assessments since 1990 have documented area of the irrigated crops in South Africa. However the estimations of the area of irrigated crops are both outdated and vary greatly, with figures ranging between 1.21 to 1.58 million ha and the most recent estimate undertaken in 2001.
In 2013, the Water Research Commission (WRC), with co-funding by the Department of Agriculture, Forestry and Fisheries (DAFF), initiated a research project to address this knowledge gap. Led by Professor Adriaan van Niekerk of the Centre for Geographical Analysis (CGA), Stellenbosch University, and in collaboration with several local and international partners the project used Earth observation (EO) techniques to update the existing estimations of the area and amount of water used by irrigated agriculture in South Africa.
The results of the project indicate that 1 334 562 ha of SA’s land surface was actively irrigated during 2014/15, with a total consumptive water use from irrigated agriculture of 10 221 million m3 for that period. The project also demonstrates how EO can be used to accurately and cost-effectively provide an overview of the status quo of irrigated agriculture water use in manner that can be easily replicated in future.
Based on the findings of this research, it was recommended that:
- Since the irrigated area mapping procedure is automated, funding for future implementation of the procedure by DAFF be prioritised;
- The irrigated area map be continuously updated (i.e. on a monthly or quarterly basis);
- The consumptive water use of irrigated crops is revised on a continuous (seasonal) basis at national scale; and
- The water accounting framework is applied on primary catchment level, preferably in all catchments of SA.
~ Official press release by the WRC titled “An Earth Observation Approach towards Mapping Irrigated Areas and Quantifying Water Use by Irrigated Crops in South Africa, WRC Report TT 745/17”
For the official press release, including a more detailed summary of the project, published by the WRC, click here.
To see the full report, “An Earth Observation Approach towards Mapping Irrigated Areas and Quantifying Water Use by Irrigated Crops in South Africa, WRC Report TT 745/17”, click here.
