Change search
ReferencesLink to record
Permanent link

Direct link
Dryspell frequency and trends over time in semi-arid and dry sub-humid sub-Saharan Africa: Implictions for smallholder farmers
Stockholm University, Faculty of Science, Department of Systems Ecology. (Natural resource management)
Stockholm University, interfaculty units, Stockholm Resilience Centre, Stockholm Environment Institute.
Stockholm University, interfaculty units, Stockholm Resilience Centre.
(English)Manuscript (Other academic)
Abstract [en]

Small-scale farmers in semi-arid and dry sub-humid sub-Saharan Africa (SSA) are vulnerable to dryspells, a primary reason for agricultural droughts. We used large-scale publicly available datasets to analyze frequency and trends over time in dryspells of critical length for farmers. 54 rainfall stations across the croplands of semi-arid and dry sub-humid SSA were included. Results show that stations with long-term seasonal rainfall averages below 600 mm experience critical dryspells in more than 60% of their seasons, whereas the corresponding figure for stations with averages above 600 mm is 40% or less. Almost every season is affected by dryspells for stations below 400 mm. Further, dryspell seasons are often affected by multiple dryspells. Most stations do not show any trends of changing dryspell frequency. Among the 21 stations that do exhibit changes over time, 19 have been subjected to an increasing trend, and only 2 to a decreasing trend. For six stations the increase is statistically significant. We conclude that frequent dryspell seasons with multiple dryspells, is a reality of rainfed farming systems, especially in semi-arid SSA. Efforts to increase productivity in these systems must include strategies to manage dryspells to be effective. The publicly available data contains large gaps that restrict the analysis. This is highly problematic, particularly given the fundamental importance of rainfall dynamics for livelihoods in the poorest regions of the world.

Keyword [en]
rainfall variability, dryspells, agricultural droughts, growing season, smallholder farmers, yield impact
URN: urn:nbn:se:su:diva-26827OAI: diva2:211490
Available from: 2009-04-15 Created: 2009-04-15 Last updated: 2010-01-14Bibliographically approved
In thesis
1. Traps and transformations: Exploring the potential of water system innovations in dryland sub-Saharan Africa
Open this publication in new window or tab >>Traps and transformations: Exploring the potential of water system innovations in dryland sub-Saharan Africa
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In semi-arid and dry sub-humid sub-Saharan Africa (SSA), high poverty levels and a heavy reliance on small-scale rainfed agriculture make rural livelihoods difficult. Upgrading current farming systems, in a way that safeguards productivity beyond field-scale, is urgent. This thesis builds on a case study of the Makanya catchment in Tanzania, and focuses on the potential of small-scale water system innovations (SWSIs), such as rainwater harvesting and conservation tillage, for increasing on-farm productivity while supporting multi-functional landscapes. The thesis consists of five papers that approach questions of alternative development trajectories for smallholder agro-ecosystems, and effects of SWSIs on key system variables, from varying perspectives. Paper I presents a conceptual model for interpreting multi-equilibrium dynamics in dryland agro-ecosystems, and analyzes Makanya's development over the past 50 years. Paper II investigates farmers' strategies to deal with drought and the impact of a local supplemental irrigation system on coping capacity. Paper III studies the effects of conservation tillage on yields and soil properties. Paper IV explores a set of future scenarios for the catchment. Paper V maps dryspell frequency and trends over time in a drylands-in-SSA perspective. The results show that smallholder farmers in agro-ecosystems such as Makanya depend on a wide array of on- and off-farm ecosystem services. The productivity of the surrounding landscape is especially important when crops fail. Furthermore, dryspells are a major constraint in these systems. In Makanya long dry-spells have become twice as common over the past 50 years, and frequently cause crop failures. This is a driver for land degradation, and maintains a climate-related poverty trap. SWSIs provide opportunities for dryland farmers to shift their agro-ecosystems to more productive trajectories through a number of mechanisms, including lowered crop failure frequency, altered on-farm water balances, and improved soil quality. Although this is promising, the task of transforming these systems is complex. For SWSIs to be effective, prerequisites are farming system solutions that integrate water- and nutrient management, and broad-based investments that focus on a much wider range of issues than only the water management technology. Moreover, given the uncertain future, investments in small-scale farming should be designed so that they benefit local communities across a range of pathways. Participatory scenario planning is useful both for identifying robust investment strategies and for navigating towards desirable development trajectories.

Place, publisher, year, edition, pages
Stockholm: Department of Systems Ecology, Stockholm University, 2009. 58 p.
smallholder farming, water system innovations, agricultural droughts, multi-functional landscapes, development trajectories, uncertainty
National Category
Natural Sciences
Research subject
Natural Resources Management
urn:nbn:se:su:diva-26833 (URN)978-91-7155-863-3 (ISBN)
Public defence
2009-05-15, De Geersalen, Geovetenskapens hus, Svante Arrhenius väg 8 A, Stockholm, 13:00 (English)
Available from: 2009-04-24 Created: 2009-04-15 Last updated: 2009-04-16Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Enfors, ElinBarron, JennieGordon, Line
By organisation
Department of Systems EcologyStockholm Environment InstituteStockholm Resilience Centre

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 86 hits
ReferencesLink to record
Permanent link

Direct link