China has thousands of rivers and lakes across the whole country, and flood disaster has been always a threat during raining season, especially when unusual weather often happen in those few years. As most of the lakes and rivers are far away from residential area, where is wired network is hard to get, besides, the coverage range is so large that sending people there to monitor is not efficient enough. So the national disaster prevention center has been looking for an advanced monitoring and alarm system to monitor the rivers and lakes, and easy to install, cost-saving and can cover area easily.
