Water Scarcity and Water Stress in Agriculture

Abstract

In the present era of human population growth and climate changes, water scarcity (insufficient hydro-resources with appropriate quality for long-term food and energy production) is recognised as the key environmental issue. In European countries, water scarcity has already affected a significant portion of the territory (>10 %) and population (>14 %). The most recent projections are that ~40 % of the world’s population would live in regions affected by water scarcity in the next 10 years. Agriculture, especially production of irrigated crops food/feed, is a predominant water “consumer” given that ~70 % (~3 trillion m³) of totally abstracted fresh hydro-resources are exploited by agri-sector and that irrigated agriculture produces ~40 % (~1.6 billion tonnes) of global food supply. In agriculture, water scarcity is often equalised with drought, i.e., water stress. However, while drought (agronomic, hydrological or meteorological) implies a temporary decrease in water availability (due to precipitation deficiency and/or reduced groundwater/soil moisture), water scarcity from an agricultural perspective assumes that consumption of finite fresh hydro-resources exceed their sustainable exploitation for food production, and thus appropriate long-term water/land management strategies (e.g., implementation of modern irrigation systems) are needed. Unfortunately, recent report indicated that the amount of food wasted annually due to inadequate (post)harvesting processes and relatively high-quality consumer/market standards (~2 billion tonnes) exceeds the annual food production in irrigated agriculture. Therefore, certain solutions to water and food crisis need not to be based on relatively expensive agricultural intensification (increasing land or water productivity), but can rather be based on (1) improved food storage/transport capacities (notably in low-income countries) and (2) changed market-consumer relations (principally in high-income countries).