By Jim Albert
Managing a landfill is a complicated process that requires a large amount of preparation, planning, and adhering to government regulations such as meeting airspace requirements and assuring that the landfill is being built as designed. A well-planned landfill works in conjunction with its surroundings, assuring that the leachate that is produced from the decomposing trash does not enter streams and aquifers.
Drones have been commonly used in the solid waste industry for aerial photos or videos. The use of unmanned aerial vehicles (UAVs) – otherwise known as drones – can be an even greater resource for landfill managers. UAVs can be used to help landfill operators maximize airspace, assess slope stability and monitor their facility’s operations for erosion, standing liquids and hot spots. Currently this information is gathered by ground surveying methods; it’s done on foot and over rough terrain. Using a UAV and structure from motion (SfM) techniques offers a better alternative to capture that data by providing a less labor intensive, accurate depiction of the topography. SfM is a photogrammetric imaging technique that is used to estimate three-dimensional structures from two-dimensional images that creates an accurate model.
In exploring the potential uses of UAVs for landfill management, LDA conducted a study in early spring of 2018 at the Hamblen County, Tennessee landfill to (1) compare the output surface to the highly accurate LiDAR data collected by the state of Tennessee and (2) perform a comparative cost and accuracy analysis of a topographic survey vs. data collected using a UAV.
The study occurred in the Class 1 area at the site of the active area of the landfill, which is approximately six acres. It has been in operation for approximately 25 years and receives solid waste from all of Hamblen County and many other surrounding communities. A DJ1 Phantom 4 Pro was used to conduct the two flights and gather the imagery.
We found that surveying from the air provided more efficient and accurate topographical and volume data than conventional surveying. The accuracy of the data was nearly identical to LiDAR bare earth data collected in the same area. Most importantly, volume calculations performed between the two flights nearly matched the volume of the weight calculated at the landfill scales.
The conclusions of the research were compelling and will be beneficial to future operations of Hamblen County and other landfills. Utilizing UAVs provides a safer data collection environment, more accurate and timely data, and will reduce overall operating costs.
Jim Albert, GISP, is the Geomatics Manager at LDA Engineering. He is currently pursuing a master’s degree in Geospatial Information Science & Technology at North Carolina State University. Jim is also a FAA Part 107 certified commercial drone pilot. Jim will be presenting on UAVs at the 2018 Water Professionals Conference and the 2018 TCAPWA / SWANA Conference.