Allowing Citizens To Effortlessly Become Rainfall Sensors

Lack of data is one of the most common problems in water management. Although technologies to produce data with enough spatial and temporal resolution and acceptable quality and quantity are available, they are only affordable by a few countries in the world. In parallel, we are experiencing an exciting technological moment. There will soon be one smart-phone for every five people in the world and there are already more mobile phones subscriptions in use than humans alive. These developments make the concept of citizen observatories interesting to collect denser information in space and time, and to promote the participation of the public in a variety of different ways. We present the results of diverse experiments that aim to facilitate citizens using smart-phones. In the context of the WeSenseIt project, the use of arbitrary scales, textual descriptions, pictures and videos are explored, being the latter an interesting option that is effortless to a common citizen and might provide potentially acceptable information for scientific purposes.