Water resources in Saudi Arabia: trends in rainfall, water consumption, and analysis of agricultural water footprint

Abstract

Saudi Arabia is one of the most arid countries in the world. Thus, freshwater availability and consumption are of crucial importance for the fast-growing population subjected to an escalating heat stress from climate change. We provide an overarching view of water resources in Saudi Arabia, in terms of supply, demand, vulnerabilities, and the associated implications on food supply and security. To estimate the effects of climate change on natural water supply, we use ERA5 for the reliable and complete statistics of the long term-precipitation (1950-2021) trends across the Kingdom’s territory. ERA5 is the latest generation of the reanalysis of global climate from the European Centre for Medium-Range Weather Forecasts. The average annual precipitation is about 50 mm/year and does not satisfy the freshwater needs of the country. Energy-intensive desalination, driven by fossil fuels, meets two thirds of municipal freshwater requirements, while non-renewable “fossil” groundwater addresses most of agricultural consumption needs. Total freshwater use has decreased in recent years due to a significant reduction of water use by agricultural sector. Nevertheless, this sector still accounts for 67% of the total freshwater consumption and provides a third of the country’s food supply. To understand efficiency of freshwater use in the agricultural sector, we have developed a novel methodology that allowed us to estimate the country-scale water consumption associated with crop production. Results indicate that water requirements for crop cultivation in Saudi Arabia are up to three times the global average. Date and cereal production consumes almost two thirds of the total freshwater supply, while mass production is dominated by forage crops.