Multi-period optimization of water planning for a sustainable agriculture: carbon footprint and water footprint assessment

Abstract

The State of Qatar has undergone significant changes impacting water resources in recent years, with rapid population growth being a significant factor. The government has implemented several policies and initiatives to manage water resources effectively, including introducing a water conservation strategy investing in desalination plants and wastewater treatment facilities. However, the expansion of the agricultural sector has driven up demand for water resources, placing additional pressure on limited supplies. Effective decision-making processes are crucial to sustainable water resource management, particularly in water-scarce countries, and multi-period optimization is an important tool for such decision-making. This study presents a five-year period for multi-period optimization of water planning in the agricultural sector to consider short-term and medium-term dynamics. The aim is to minimize the carbon footprint associated with agricultural water allocation, and assess water pollution using the Water Quality Index grey water footprint indicator. The water budget considered includes desalinated water, brackish groundwater, and treated sewage effluent, while the agricultural sector comprises dairy, egg and poultry, red meat production, outdoor farming, and indoor farming. Considering the water conservation importance in the State of Qatar, the three levels of water stress that were considered are 0%, 25% and a base scenario carbon footprint-based water stress. The latter is calculated such that the improved scenario’s carbon footprint is lower than that of the base scenario while keeping a safe annual water stress. Results show that it possible to reduce the water stress from an unsafe average to as little as 13.7%. Similarly, the water pollution estimated using the grey water footprint method is significantly lower compared to the base scenario.