These wranglers double as tour guides, leading horseback rides through the surrounding arid lands, with views of the red rock mountains of nearby Sedona.

BBC: Touring the American Southwest in a cowboy��s boots

The programme, which provides a UNESCO Global Network on Water and Development Information for Arid Lands was established in 2004 to strengthen the global capacity for management of water resources in arid and semi-arid regions.

UNESCO: In Memoriam: Professor W. Mike Edmunds

In the vast, arid lands of the north, even most Western armies with all their modern technology might struggle to find small bands of rebel and Islamist forces who can simply disappear into the landscape.

BBC: Can France achieve its goals in Mali?