A Method for Easy and Low-Cost Monitoring of Agricultural Land Use in Burkina Faso by Matching Small Scale Amateur Aerial Photogrphy

摘要

The Kou watershed, situated in the Southwestern part of Burkina Faso, has succumbed since a couple of decades in a typical theater of anarchical water management. In spite of the abundance of water most water users are regularly faced with water shortages due to an intensification of irrigated agriculture coupled to low irrigation efficiencies. Local stakeholders are hence in need of a low-cost and easy to use tool for the monitoring and mapping of these irrigated zones. The aim of this study was to develop a fast and low-cost procedure for the mosaicking and georeferencing of amateur small-scale aerial photography for land use surveys. Sets of tens and hundreds of low altitude aerial photographs, having a resolution of respectively 0.4 m and 0.8 m, were used for a detailed mapping of the typical African small-parcel irrigated agriculture. A commercially available stitching tool and a GIS allowed the construction of georeferenced 'mono-images', with a horizontal root mean square error of ± 11 m. The approach is also less sensitive to atmospheric conditions non-predictable in the programming of satellite imagery. The high-resolution mono-images yielded more than satisfying result for the monitoring and surveying of small irrigated plots.