Ozymandias in the desert: irrigation in Saudi Arabia

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Acknowledgements

I am grateful to my friends Chris Perry and David Dent for reviewing the paper. I benefited from their expert comments, but I assume full responsibility for the contents.

Disclosure statement

No potential conflict of interest was reported by the author.

Notes

1. Between 1968 and 1973, the average price for crude oil was US$3.64 per barrel. Between 1974 and 1980, the price rose to US$19.53 per barrel (InflationData.com, 2021).

2. Central Bank Yearly Statistics (2020): Table 19: Cultivated area size; and Table 20: Agricultural production (https://www.sama.gov.sa/en-US/EconomicReports/Pages/YearlyStatistics.aspx).

3. 300 bcm/20 years = 15 bcm/year.

4. Since 153 million tons of produce between 1980 and 1999 consumed 300 bcm water, then 203 million tons of produce between 2000 and 2018 could have consumed 398 bcm (300 bcm/153 million tons = 1960 m³/ton × 203 million tons = 398 bcm) and the total water extraction for the 39 years is 698 bcm (about 700 bcm).

5. 698 bcm/39 years = 17.9 bcm, about 18 bcm.

6. Assuming that 1 ha of wheat uses a similar volume of water as the rest of the cultivated area (476,000 ha × 14,000 m³/ha = 6.7 bcm). In 1992, cereals occupied 72% of the cultivated area and wheat production was 88% of all-cereal production (Elhadj, 2004a, tab. 1, p. 2; tab. 2, p. 11).

7. In 2018, the Saudi cultivated area was 1.004 million ha and the Riyadh and Qassim regions comprised 40%, that is, around 400,000 ha. With an average annual water use of 14,000 m³/ha, the two regions’ use of irrigation water would have been around 5.6 bcm. In 2018, Riyadh’s use of drinking and household water was 1.08 bcm and Qassim’s was 167,000 m³, for a total of about 1.25 bcm (Saudi Arabian General Authority for Statistics, 2019).

8. In 2018, total agricultural production was 14,905 million tons – fodder 9134 million tons, fruits 2311 million tons, vegetables 1748 million tons and grain 1440 million tons (Central Bank Yearly Statistics, 2020, tab. 20).