Wastewater resources, agricultural practices management strategies, soil salinity predictions and artificial recharge in the Middle East-Saudi Arabia: A review

Abstract

Water scarcity threatens agriculture, domestic, industrial, and food security in the land of Saudi Arabia. The nation produces significant quantities of municipal wastewater, which, with adequate treatment (nanotechnology), could serve as an alternative water source for irrigation, thereby reducing reliance on fossil groundwater and/or surface water. This study assessed the management of water resources for irrigation in KSA. A multi-criteria approach was applied to evaluate the water suitability for domestic and irrigation, including complying with Saudi Standards and the potential salinity (PS) indices. The application of treated wastewater (TWW) irrigation has successfully maintained groundwater sustainability in the study area, as evidenced by increased groundwater levels up to 2 min some aquifers and the equilibrium for other deep aquifers. Although TWW contributes to crop productivity and soil fertility, long-term agricultural sustainability could be enhanced by improving effluent quality, regulating irrigation practices, implementing buffer zones, and monitoring shallow groundwater. Agricultural activities in KSA mixed with return flow irrigation water to deep groundwater increase total dissolved solids (TDS), sodium adsorption ratio (SAR), nitrate (NO₃), pesticides, and radionuclide element (⁴⁰K and ²²⁶Ra) concentrations. In intensive agricultural areas (Tabuk, Al Jouf, Al-Qassim, Hail, Riyadh, Al Kharej, Wadi Dawaser, Jazen…), the nitrate levels exceeded 200 mg/l, ²²⁶Ra, ²³²Th, and ⁴⁰K radioactivity is of the order of 35 Bq/l, 41 Bq/l and 730 Bq/l respectively.

The best methodology plan should orient to improve the management practices and the protection of the water resources and to orient to the unconventional water sources (TWW, collection of drainwater, seawater…) and thirdly move towards rainwater (liquid and vapor) harvesting and the fourth direction is logical sharing between sectors and law enforcement. Water, soil and human health protection are the principal goals of this study.