Why More Rain Does Not Necessarily Mean Less Drought for West African Smallholders

Rainfed farmers across parts of Burkina Faso and Ghana are confronting a drought risk that cannot be captured by annual rainfall totals alone. Dry spells are appearing during the rainy season, warming is increasing atmospheric demand for water, and recurring drought cycles are exposing rural households to repeated production shocks.

These findings come from the study "Drought Variability and Cycles in Smallholder Farming Systems of the Sudano-Sahelian Region of Burkina Faso and Ghana," authored by Meron Lakew Tefera of the University of Sassari and the Desertification Research Centre. Published in Meteorology, the research analyses climate conditions between 1981 and 2021 across Burkina Faso's Centre-Est and Centre-Sud regions and Ghana's Upper East Region.

Using the Standardized Precipitation–Evapotranspiration Index (SPEI), the study assesses drought across short, seasonal and longer accumulation periods. It also applies Continuous Wavelet Transform analysis to identify recurring drought patterns. The results reveal that drought frequency varies sharply by location, wet-season droughts can strike during crucial crop-growth stages, and recurrent cycles extend from several months to more than five years.

A Warmer Climate Can Produce Greater Water Stress Without More Drought Months

The study recorded a significant warming trend across the study area. Mean annual temperature increased by approximately 0.89°C between 1981 and 2021, while annual rainfall showed a statistically significant increase of about 3.24 millimetres per year.

Higher rainfall totals might appear to offer some relief to farming communities. Yet the research warns that rising temperatures increase atmospheric evaporative demand, allowing heat to draw moisture more rapidly from soils and plants. Rainfall recovery therefore does not automatically translate into lower agricultural risk.

Annual drought frequency did not show a statistically significant long-term increase during the study period. Instead, drought conditions were concentrated in particular periods, especially the early 2000s and the years after 2010. The study recorded especially high drought frequencies in 2000, 2001 and 2002, when drought conditions affected 62.78%, 64.44% and 74.44% of the observations respectively.

The pattern suggests that farmers are not necessarily facing a steady rise in the number of drought months. They are dealing with a more volatile combination of heat, rainfall variability, timing and persistence. A climate can deliver occasional wetter years while still producing severe stress during critical agricultural windows.

Drought During the Rainy Season Threatens the Harvest at Its Most Vulnerable Stage

The research found that drought occurred during both wet and dry seasons, with the wet-season occurrence slightly higher. Drought affected 31.25% of wet-season observations, compared with 29.85% during the dry season.

Moderate-to-extreme drought conditions were also more common during the wet season, occurring in 18.12% of observations compared with 15.76% in the dry season. Severe wet-season droughts were identified in years including 2002 and 2014.

For smallholder farmers, the timing of a moisture deficit can be as consequential as its overall intensity. A dry spell during planting can prevent germination or force households to re-sow. Moisture shortages during flowering and grain filling can reduce yields even when the wider season records a near-normal amount of rainfall.

Shorter drought indicators are therefore essential for agricultural decision-making. A 12-month measure can reveal accumulated water stress, but it may not adequately capture a dry spell that arrives suddenly during crop establishment. The study's use of one-, three-, six- and 12-month SPEI periods provides a more detailed picture of how drought develops and affects farming conditions.

Early-warning systems built around end-of-season assessments risk missing these crop-stage shocks. Useful climate services must communicate not only whether a season is likely to be dry, but also when moisture deficits may emerge and how long they could last.

Drought Exposure Is Uneven Across the Burkina Faso–Ghana Corridor

The study identified strong spatial differences in drought frequency and persistence across the transboundary region. The northern and western parts of the study area, including portions of Burkina Faso's Zoundweogo and Boulgou provinces, experienced the highest drought frequencies. Some locations recorded more than 19 drought events over the study period.

Locations in Ghana's Upper East Region, including Talensi and Pusiga, recorded lower annual drought frequencies of approximately seven to 11 events. The regional contrast reflects the study area's north-to-south rainfall gradient. Annual precipitation rises from around 700–800 millimetres in the north to more than 1,100 millimetres farther south.

Lower rainfall is only one part of the vulnerability equation. Rainfall variability, shorter effective growing seasons, limited irrigation and soil degradation can magnify the effects of individual dry spells. Even locations with lower annual drought frequency may face serious crop risks when rainfall becomes irregular within the wet season.

The geographic pattern has direct implications for public policy. National or regional adaptation programmes that distribute resources evenly may fail to match actual exposure. Areas facing persistent moisture deficits may require greater investment in water harvesting, soil conservation, drought-tolerant varieties and irrigation. Locations with lower overall drought exposure may benefit more from measures designed to manage short intra-seasonal dry spells.

Cross-border coordination also deserves greater attention. Burkina Faso and Ghana share climatic conditions and agricultural systems across this corridor, while drought impacts can affect food markets, livestock movements and household mobility beyond administrative boundaries.

Recurrent Drought Cycles Demand Longer-Term Planning

Continuous Wavelet Transform analysis revealed drought periodicities at both short and multi-annual scales. Short-term cycles ranged from approximately one to nine months. Dominant multi-annual patterns generally appeared around 31 to 50 months at individual locations, with regional signals extending towards approximately 64 months.

Short cycles are directly relevant to farm operations. They can influence planting dates, crop selection, re-sowing and decisions about allocating scarce labour and inputs. Longer cycles create a different type of pressure by increasing the likelihood of repeated drought exposure before households have recovered from previous losses.

Repeated shocks can reduce livestock holdings, deplete savings, weaken soil fertility and discourage investment in fertiliser, improved seed or equipment. Households may respond by adopting less risky but less productive strategies, which can reinforce low agricultural productivity over time.

The study identifies possible links between the observed recurrence patterns and large-scale climate variability, including the Atlantic Multidecadal Variability and El Niño–Southern Oscillation. It does not establish a causal connection between those climate modes and the drought cycles. The periodicities should therefore inform preparedness rather than be treated as precise forecasts.

The policy opportunity lies in combining different layers of information. Short-term indicators can support immediate farm decisions. Seasonal forecasts can guide crop and water planning. Multi-annual signals can help governments, development agencies and insurers prepare financing, seed distribution, safety nets and recovery programmes before repeated drought pressure becomes a humanitarian crisis.

From Climate Monitoring to Agricultural Resilience

The study demonstrates that drought is not a single, uniform hazard. It changes across timescales and locations, and its consequences depend heavily on when moisture deficits occur. A farmer experiencing a short dry spell during germination faces a different problem from a community dealing with several successive seasons of accumulated water stress.

Governments can use multi-timescale drought information to improve agricultural advisories, climate-risk financing and index-based insurance. Extension services should translate technical indicators into practical guidance on planting windows, crop diversification, water harvesting and soil-moisture conservation.

Development agencies and international organisations could use recurrence information to support anticipatory action. Financing released before a drought intensifies can help households protect livestock, secure seed and maintain food access. Such systems will require transparent thresholds, reliable local data and safeguards against excluding farmers who lack formal records or access to digital services.

Businesses may find opportunities in climate-resilient seeds, decentralised irrigation, water-storage systems, agricultural data services and rural insurance. Investment strategies will need to account for affordability, maintenance capacity and unequal access to finance. Technologies that are unsuitable for small farms or dependent on unreliable infrastructure could deepen existing inequalities.

Notably, the study relies on gridded climate datasets because long-term station observations are incomplete across the region. Potential evapotranspiration was estimated through a temperature-based method that does not include humidity, wind speed or actual radiation. The analysis also does not directly measure crop yields, soil moisture, food prices or household welfare.

Future research should connect drought indicators with farm-level production, livelihood and market data. Additional work could test how identified cycles perform in operational early-warning systems and whether they improve decisions on insurance, public spending and agricultural support. Downscaled climate projections could also clarify how continued warming may alter drought intensity, duration and recurrence.