Professor Meyer and his colleagues came to realise that what they were studying was not a desert, but rather an arid steppe, with underground grass roots that keep rain from sinking into the soil. Rainwater collects in intermittent creeks and rivers called wadi by the Arabs.
The archaeologists gathered evidence that residents of ancient Palmyra [Roman times AD] and the nearby villages collected the rainwater using dams and cisterns. This gave the surrounding villages water for crops and enabled them to provide the city with food; the collection system ensured a stable supply of agricultural products and averted catastrophe during droughts.
Trade Routes In Ancient Arabia
Recent scientific research is giving more information about trade routes in Arabia. Here are links to some of that research.