APPLICATION OF DRONE TECHNOLOGY (UAV) IN VISUAL INSPECTION OF DAMS
Dams are critical systems serving a wide variety of important uses – storage of water for drinking and industries, land irrigation, electricity generation and flood control. There are more than 5200 large dams in the country as per official statistics, and it is estimated that a significant number of these dams have shortcomings because of ageing and sub-optimal designs.
Safety of dams is high priority due to not only their critical functions, but also the endangering of lives on a mass scale that a damaged dam can entail. It is imperative that dams are assessed on a regular basis for their fitness and optimal functioning – and visual inspections provide crucial pointers on the current state and risk levels to dams.
Visual Inspections – Limitation of traditional methods
Inspections of dams are performed with the following key objectives in consideration – evaluating the performance of the dam system, identification of shortcomings that need repair or monitoring, assessment of the soundness of the dam and observation of any changes – in order to ensure optimal functioning and collating information for undertaking suitable remedial measures.
Traditional methods for visual inspection of dams are largely manual in nature – setting the cameras / binoculars on the banks of the river or at suitable vantage points, or inspection personnel lowered in either harness or baskets onto exterior wall sides of the dam to observe and create detailed drawings in paper. This method has multiple challenges of not just accessibility and human safety, but also lead to a manifold increase in costs, efforts and time required. Inaccessible areas of the dam have to be observed from the ground, leading to lower quality of inspection.
Drone Technology provides the edge
Drone, the popular name for Unmanned Aerial Vehicle (UAV), is beginning to proliferate the Indian market with its varied range of applications. From its early beginning in military uses, the gamut of its application has spread widely to encompass civil and commercial activities.
For visual inspection of dams, drones provide an effective solution to the many challenges encountered. The inspections can be carried out at a fraction of cost, requiring minimal manual efforts and manpower on the field. The earlier time requirement of many hours or days can be reduced by as much as 90%. Inaccessible areas of the dam walls can be duly captured with this technology. High resolution 4K cameras on the drones capture the footage while beaming it live to the UAV operator on the ground. These miniature sized-devices have the ability to fly hundreds of feet high in air and cover up to a distance of 2kms in one go. These can be maneuvered in air easily by a skilled operator, providing a round – field view, while also remaining stationary mid-air for effective photo and footage capture. The information captured enables detailed analysis and tracking, aided by software solutions for a comprehensive inspection. Thus, the applications and advantages of drone technology in dam engineering are numerous and are increasing by the day.
Methodology adopted for Dam Inspection using Drone
Based on the Guidelines for Safety Inspection of Dam, Following Dam Types are to be inspected.
- Embankment Dams
- Concrete Dams
- Composite Dams
Based on the checklist provided in the Manual for Dam Inspections, the activities for Unmanned Aerial Vehicle will be dovetailed to cover the entire aspects related to Dam inspections which are scheduled as under.
1) Comprehensive evaluation inspections
2) Scheduled inspections
3) Special (unscheduled) inspections
4) Informal inspections
Players in the Drone Technology space
Today, there exist only few private companies in the country that provide high quality services leveraging drone technology. Highly skilled Drone operation personnel and quality post processing of data collected are the differentiators for the service providers in this space.
Among such players, ICON Group – a national service provider based in Bangalore, has carved a niche for itself with a plethora of projects for both government and commercial clients using drone technology. One of their current projects on the inspection of the important Alamatti dam approved by Krishna Bhagya Jala Nigama Limited adds another feather to their cap among the many projects of high impact and value undertaken by them.
The way ahead
The Central Water Commission document on guidelines for safety inspection of dams released last year highlights the importance and advantages of Drone technology for dam inspections, and recommends its usage. This technology will soon be the mainstream inspection method of the dams across the country.
ICON CADSOFT & SURVEYORS (I) PVT. LTD
|D GIRIDHAR SHARMA
M.Tech (IIT Kanpur), FIE Civil Engineering Professional(Hydraulics, Structural, Geo-technical and Rock Mechanics) Technical Advisor