The influence of irrigation on water resources globally is substantial, affecting water availability, quality, and ecosystems.
Here are six key points and associated statistics that BWI has noticed about the impact of agriculture on continental freshwater:
- Water Usage: Irrigation accounts for a significant portion of global water usage. According to the Food and Agriculture Organization (FAO), agriculture consumes about 70% of the world’s freshwater withdrawals. Source: FAO – AQUASTAT
- Water Stress: Irrigation can exacerbate water stress in regions where water resources are already limited. Approximately 20% of cultivated land globally is irrigated, but this land contributes around 40% of total food production. Source: World Water Assessment Programme
- Depletion of Aquifers: In many regions, excessive irrigation leads to the depletion of underground aquifers faster than they can recharge. For example, in India, one of the world’s largest users of groundwater for irrigation, aquifer depletion is a significant concern. Studies suggest that India is over-extracting groundwater by 56%. Source: Nature – “Groundwater depletion in India”
- Salinization: Poor practices can lead to soil salinization, where salt accumulates in the soil over time, rendering it unsuitable for agriculture. It’s estimated that around 20% of the world’s irrigated lands suffer from salinization to some extent. Source: FAO – “Status of the world’s soil resources”
- Ecosystem Impact: Over-irrigation can also impact local ecosystems by altering water flows in rivers and wetlands, leading to habitat loss and biodiversity decline. For example, the Aral Sea in Central Asia has significantly shrunk due to excessive irrigation diversion from the rivers that feed it. Source: NASA Earth Observatory – “Shrinking Aral Sea”
- Climate Change: Climate change adds further complexity with altered precipitation patterns and increased temperatures affecting water availability and irrigation demands in many regions. Predictions suggest that climate change will likely exacerbate water scarcity issues in areas already facing water stress. Source: IPCC – Special Report on Climate Change and Land
In a nutshell, while irrigation is essential for global food production, its unsustainable practices can have significant negative impacts on water resources, including water stress, aquifer depletion, soil salinization, ecosystem degradation, and exacerbation of climate change effects. Sustainable practices are crucial to mitigate these impacts and ensure long-term water security for both agricultural and environmental needs.
