Flood plains are surveyed in a number of ways and which method is used will depend on the required accuracy. Lidar data and photogrammery can provide level information over vast areas of land, as aircraft are used for data capture. Airborne survey techniques can also be deployed from a small unmanned aircraft (SUA) for smaller areas. Storm Geomatics can provide ground control for this type of survey, ensuring consistency between air and ground based survey.
Our teams work collaboratively with aerial survey companies and often join as partners in a project to ensure that our clients get the maximum benefit out of technology and knowledge.
Storm Geomatics can check the integrity of third party data by using real-time kinematic (RTK) GNSS survey techniques to survey parcels of land for comparison purposes. RTK techniques are also used for capturing flood plain levels using vehicle mounted GNSS on a 4x4 vehicle or quad bike. This method has proved to be a cost effective alternative to aerial based surveys for smaller projects. Digital terrain models (DTM) can be created from the data captured to provide river modellers with compatible information to work with. RTK GNSS on foot can also be utilised, and is often used to produce flood plain cross sections for river modelling purposes – this method is particularly beneficial if a channel survey is being carried out in parallel.
There are many different ways to survey a flood plain, they all have their own advantages and disadvantages. It is worth speaking to a surveying professional about your project to understand the possibilities and limitations of different techniques, this will allow you to make the right decision in obtaining the data you need.