The Devastating Effects of Drought on Agriculture and Water Resources

Drought is one of the most destructive natural hazards on Earth – not because it strikes suddenly, but because it creeps in slowly, draining rivers, drying out soils, and collapsing livelihoods over months or even years. According to the International Rescue Committee, drought has affected more people in the last 40 years than any other natural disaster. Unlike earthquakes or floods, there is no single moment when drought “hits.” By the time communities recognise it, the damage is already deep – in the ground, in the crops, and in the economy.

What causes drought? 🔗

Drought rarely has a single cause. It results from a combination of atmospheric conditions, land use decisions, and long-term climate shifts. Three key drivers stand out.

Climate change and rising temperatures 🔗

As global temperatures rise, evaporation from soil and water bodies increases. This means that even when rainfall occurs at normal levels, more moisture is pulled out of the ground before plants and rivers can use it. Global warming makes land drier by accelerating evaporation, and when soil becomes severely parched, it forms an impermeable crust – so when rain does eventually fall, it runs off the surface rather than soaking in. This creates a damaging cycle where droughts become longer and more severe with each passing decade.

Deforestation and its role in disrupting rainfall 🔗

Forests are not just carbon sinks – they are active participants in the water cycle. Trees absorb groundwater through their roots and release it as water vapour through their leaves, a process called transpiration. This moisture feeds cloud formation and triggers rainfall. As more trees are cut down, evaporation levels are disrupted, drying out moisture in the air and throwing off the balance of the water cycle – eventually leading to a drought-prone, desert-like climate.

The effect goes far beyond local areas. A growing body of research suggests that the destruction of tropical forests is disrupting the movement of water in the atmosphere, causing major shifts in precipitation that could threaten key agricultural areas in China, India, and the US Midwest. A peer-reviewed study published in Nature found that crop yields decline by 0.5% for every percentage point reduction in precipitation caused by forest loss – a staggering figure when considered at scale.

Human activity and overuse of water 🔗

Intensive agriculture depletes groundwater faster than it can be replenished. Overgrazing compacts soil, reducing its ability to absorb water. High water demand from upstream dams and irrigation canals can cause drought-like conditions in downstream communities. When water demand outweighs supply – whether from population growth, intensive agriculture, or upstream diversions – the result functions like a drought even in areas with normal rainfall.

Types of drought 🔗

Scientists and policymakers use specific categories to define drought, because the type of drought determines what is affected and how to respond. The National Drought Mitigation Center classifies drought into four primary types – meteorological, hydrological, agricultural, and socioeconomic – each representing a different stage in the cascade of impacts.

Meteorological drought 🔗

This is the starting point. Meteorological drought is defined by the degree of dryness or rainfall deficit and the length of the dry period. It is region-specific – what counts as a drought in a tropical rainforest may be normal conditions in an arid zone. Meteorological drought sets off all other drought types, but its presence alone does not mean crops will fail or rivers will run dry. It simply marks the beginning of a prolonged rainfall deficiency.

Hydrological drought 🔗

Hydrological drought becomes evident when low water supply appears in the broader water system – rivers, lakes, reservoirs, and groundwater aquifers. It typically lags behind meteorological drought because it takes time for surface and underground water stores to be drawn down. Hydrological droughts are usually out of phase with meteorological droughts – it takes longer for precipitation deficiencies to show up in rivers and groundwater, which means communities can be caught off guard even after rains return.

Agricultural drought 🔗

Agricultural drought occurs when soil moisture falls below the level needed for healthy crop growth. It focuses on precipitation deficits, differences between actual and potential evapotranspiration, soil water deficits, and reduced water availability for irrigation. Critically, agricultural drought can develop even without a meteorological drought if soil conditions are poor or if water-intensive crops are planted in the wrong region. Deficient topsoil moisture at the planting stage can prevent germination entirely, while subsoil moisture shortages later in the season can reduce yields dramatically even when plants appear to be growing normally.

Economic and social impact of drought 🔗

Drought does not affect all communities equally. Its impact is sharpest in regions where agriculture is rain-fed, groundwater is limited, and economies offer few alternatives to farming. The consequences ripple outward from individual farms to national economies, food systems, and entire ecosystems.

The scale of the problem 🔗

The FAO estimates that the agricultural sector absorbs over 65 percent of the economic impacts of droughts globally. Beyond farm losses, drought drives food price increases, infrastructure stress, public health crises, and mass migration. Subsistence farmers are particularly vulnerable because they lack alternative food sources and have no financial buffer against failed harvests, making displacement far more likely when drought strikes.

Case study: India 🔗

India’s agricultural system is deeply tied to the annual monsoon. Only about 35% of India’s agricultural land is irrigated – the remaining two-thirds of cultivated land is entirely dependent on rainfall. When the monsoon fails or weakens, the consequences are immediate and severe across states such as Maharashtra, Karnataka, Andhra Pradesh, and Rajasthan.

Since 2015, India has experienced widespread drought conditions, with some 600 million people facing high to extreme water stress. In the Marathwada region of Maharashtra, increasing water scarcity and depleting groundwater levels have worsened an agrarian crisis linked to rising rates of farmer suicides. The shift toward water-intensive cash crops like sugarcane and cotton in drought-prone zones has accelerated groundwater depletion and made farmers more economically exposed when rains fail.

A study in Karnataka found that over 60% of wells had dried up in drought-affected rural areas, with farmers showing no capacity to adapt their cultivation practices in response to the water shortage. Young adults in affected households were increasingly being pulled from school to seek off-farm employment – a short-term survival strategy with significant long-term costs for education and rural development.

Case study: the Sahel region 🔗

The Sahel – a semi-arid belt stretching across West and Central Africa between the Sahara Desert and the Sudanian Savanna – is one of the most drought-vulnerable regions on Earth. Agriculture in the Sahel employs the majority of the region’s workforce and contributes up to 45% of GDP in some countries, yet it operates on a near-total dependency on three to four months of annual rainfall.

From the late 1960s to the early 1980s, drought-driven famine killed approximately 100,000 people, left 750,000 dependent on food aid, and affected most of the Sahel’s 50 million people. The economies and livestock populations of Mauritania, Mali, Chad, Niger, and Burkina Faso were devastated. Food production across the region dropped by an estimated 600,000 tonnes of grain crops per year – a 15% annual loss for the duration of the drought, and the Sahara Desert expanded into over 20 million hectares of previously fertile land annually.

Between 1970 and 2022, approximately 125 million people in the Sahel were affected by drought – an average of 2.5 million people per year. More than 80% of the region’s population relies on agriculture for survival, and the majority practice small-scale rain-fed farming. A single poor rainy season can collapse household food security, reduce access to healthcare and education, and force large-scale migration. The Sahel has shifted up to 200 kilometres southward over the past three decades, with far-reaching social consequences including conflict between nomadic and sedentary communities, and the disproportionate burden falling on women and girls responsible for fetching water.

The link between drought, water resources, and food security 🔗

When drought depletes surface water, communities turn to groundwater. But aquifer depletion is a slow-building crisis that cannot be easily reversed. Once wells run dry, entire farming systems collapse. By 2050, 40% more rain-fed crops will face unreliable water supplies than in 2020, with the greatest increases occurring in India, the United States, Australia, Niger, and China. Agriculture is already the world’s largest driver of water stress, responsible for 70% of global freshwater withdrawals.

The interplay between drought and food security is direct. Crop failures drive food price spikes that hurt the poorest first. Livestock die without pasture or water. Rivers that serve as both drinking water sources and irrigation supplies slow to a trickle or stop altogether. The World Health Organization warns that up to 700 million people are at risk of displacement as a result of drought by 2030 – a figure that underscores how this slow-onset hazard will reshape human geography in the decades ahead.

What do you think? Given that drought is intensified by both climate change and human land-use decisions, which area of intervention – reducing deforestation, changing crop choices, or improving water storage – do you think would have the greatest impact on drought resilience in vulnerable regions like the Sahel or southern India? And how should governments balance short-term food security needs with the long-term water management reforms that drought demands?

References

1. https://www.rescue.org/article/what-drought-causes-impact-countries-most-affected
2. https://www.earthday.org/how-deforestation-affects-the-water-cycle/
3. https://e360.yale.edu/features/how-deforestation-affecting-global-water-cycles-climate-change
4. https://pmc.ncbi.nlm.nih.gov/articles/PMC9995269/
5. https://drought.unl.edu/Education/DroughtIn-depth/TypesofDrought.aspx
6. https://www.weather.gov/safety/drought-types
7. https://www.drought.gov/what-is-drought/drought-basics
8. https://www.drought.gov/topics/agriculture
9. https://www.frontiersin.org/journals/climate/articles/10.3389/fclim.2024.1347519/full
10. https://en.wikipedia.org/wiki/Drought
11. https://en.wikipedia.org/wiki/Drought_in_India
12. https://www.lowyinstitute.org/the-interpreter/india-s-latest-crisis-600-million-people-struggle-drought
13. https://www.mdpi.com/2225-1154/11/5/93
14. https://voxdev.org/topic/agriculture/impacts-water-loss-low-income-farmers-india
15. https://www.un.org/africarenewal/magazine/december-2013/sahel-one-region-many-crises
16. https://en.wikipedia.org/wiki/Droughts_in_the_Sahel
17. https://www.ebsco.com/research-starters/environmental-sciences/drought-extends-reach-sahara-desert
18. https://www.ifad.org/en/w/explainers/dry-planet-drought-and-desertification-region-by-region
19. https://www.wri.org/insights/growing-water-risks-food-crops