Change detection and monitoring has been a very useful tool and now with drone technology, more and more in industries and governmental operations.

Aerial surveillance by using drone has been used extensively in the industrial line of businesses. Surveillance by drones is proven efficient to cut down the time cost and provide more insights and details.

One of the current use of drone surveillance is to use it to monitor changes of a same site over a specific time period. This can be roughly called as time-based aerial monitoring. 

The main purpose of using drone to monitor changes over time varies by industries. In this article, we will discuss further the application and uses of time-based aerial monitoring that is currently being used across different industries.

Agriculture

Agriculture industry utilises time-based drone surveying as a tool to comprehend agricultural data such as plant health, crops growth, soil condition and irrigation. In the case of plant health, farmers will often fly drones in a specific interval of time (especially after a treatment) to determine if treatment such as fertiliser and pesticide is effective to the plant. 

This also can be done to get the general trend of crops growth in order to determine if more fertiliser or treatment is needed.

When it comes to soil condition or soil moisture index, it is relatively important as it directly affects the condition which the crops grow in. Soil moisture normally refers to the amount of water that is contained int he first 5 – 10 cm layer of land from the surface. 

Image via Esri

Soil moisture plays a very important role in controlling and regulating the interaction between the land surface and atmosphere. Soil moisture index does not only give insights to agricultural perspective of things, but it also gave us other data such as ecosystem. Soil moisture level can serve as an early warning of land erosion or land condition near/in a river that could give clues to soil movement such as soil erosion, infiltration and runoff.

This alone has made clear that UAV change detection can be used not only in agriculture, but also in forestry and environmental management, which brings us to the next point.

Forestry

Deforestation rate around the world is increasing at a quite alarming rise right now despite the many efforts of different parties to decrease the deforestation rate in order to address the severity of global warming.

Few parties all around the world such as government agencies have started to incorporate drone into their conservation operations to widen the surveillance assets and range. Using changes over time from drone reference can help enforcers to monitor the forest reserve more closely.

By using this method, not only the enforcers can see which area is at risk of deforestation and other further damages, they will also be able to calculate accurately the affected area with high accuracy thanks to help of RTK and PPK technology.

Other application would be identifying the habitat loss or upset ecological imbalance due to deforestation as well as threats of natural disasters such as landslide, flooding, soil erosion and so on.

Water Management (Dam, river, sea level increase)

As mentioned previously, the deforestation rate around the world has increased these past few decades which continually contributed to the global warming effects. The obvious effects of global warming would be the rise of sea level which threatens islands and coastal cities.

One way in which drones come in to monitor the rise in the sea levels which is expected to increase over time. Drones also are useful in monitoring beach erosion as the results of rising sea levels.

This will help authorities to plan out the contingency plans where some areas are predicted to be submerged when sea levels rose up.

Case study

Water management is crucial to society, as we use water in our daily activities. Improper use of water has lead to water scarcity and shortage in some areas. While you might think your area or country has no problems with water supply, the truth is, there’s a high chance the clean water provider is struggling to find more sources of water.

Drones can be used to monitor the water supply in major areas such as rainforest, lakes and rivers to see if there are any major changes that would lead to inevitable water shortage. Authorities then can plan to take measures to prevent the water supply shortage and thus, avoiding water supply issues to the public.

This is also applicable to monitoring a dam water level and the overall condition of the dam. 

Construction

In the construction industry, drones are being used commercially to monitor the progress of the construction. This application can be stepped up to another level by the visualisation of the changes of the construction in over time.

By doing this, project managers will be able to do reporting in a much more convenient way by visualising changes of the infrastructure progress in one window rather than showing a series of pictures as a replacement of time-lapse images.

You can view a sample of construction site change detection done by Hivemapper here.
How to read the map:

  • Blue is new — blue means the object is new.
  • Red is fled — red means the object is no longer there.
  • Gray is unchanged — no changed were detected

Urban Planning

Local councils are normally involved in the city planning in the area of their jurisdiction. As such, drones can help in planning for the development projects in the area. This is done by capturing the changes over time in the proposed site to see if there are any major changes from the past (for example, opening of residential areas) that would be suitable for a new development project (for example, shopping mall or parks).

The proposed site can be measure accurately just from the aerial imagery captured by the UAV which later can be utilised for the construction purposes.

Other than that, an aerial view of changes can be used to determine the traffic flow or behavioural changes. This will, in turn, enable landscape architects and planners to examine the existing social and environmental conditions of sites in far more detail than before and planning further development such as highways, upgrading roads, adding traffic lights and so on.

Example of vegetation management for urban planning purposes.