Recent rapid expansion of private small-scale irrigation provides an opportunity to improve livelihoods and food security, but requires knowledge of where it is happening, in order to sustainably manage water use. Concerns are rising regarding the negative impacts of unchecked expansion of irrigation on downstream water quality and availability, particularly when using sub-optimal practices (de Fraiture et al. 2014; Domenech and Ringler 2013; Shah 2007).
Therefore, for informed planning of potential sustainable irrigation expansion, policy makers and resource managers at the national level are interested in maps of the current extent of small-scale irrigation. Although several maps of irrigated areas have been produced for Burkina Faso, these maps, often of 250 meter (m), 300 m or 1 kilometer (km) resolution, are of too low resolution to account for scattered irrigation on areas smaller than 1 hae.
Therefore, in response to the need for an improved map, which captures small-scale irrigation on areas less than one hectare, a new methodology was developed and tested for mapping irrigation at high resolution throughout Burkina Faso. The method called Small-Scale Irrigation Mapping (SSIM) tool, uses a time series of 30-m Landsat 8 imagery combined with ground truthing data and local knowledge collected along a transect across three of the four agro-climatic zones in Burkina Faso.
The results of the mapping exercise are presented here, with reflections on the opportunities it provides for improving knowledge of small-scale irrigation in countries with incomplete irrigation inventories.