Exploring the Omchhu River Basin: A High-Tech Journey

By Bhutan Flying Labs

On March 25, 2025, the team at Bhutan Flying Labs undertook a landmark mission in the Omchhu River Basin, Phuentsholing. In partnership with Phuentsholing Thromde and the Asian Development Bank (ADB), we carried out a high-resolution aerial LiDAR survey as part of the Climate-Resilient Omchhu River Basin Project. Our objective was clear: to produce detailed and reliable maps and models that will support sustainable urban planning and flood risk management for the region.

Our Mission and Its Importance

Utilizing advanced drones equipped with LiDAR sensors and high-precision positioning systems (RTK/PPK), we captured comprehensive 3D data of the Omchhu corridor. This project was about gathering critical data to inform urban development, enhance flood resilience, and support sustainable growth in Phuentsholing. From dense forests to dynamic riverbeds, every detail was mapped with precision to support future-proof planning efforts.

Deliverables at a Glance

Through this mission, we produced a suite of high-value outputs:

• LiDAR Point Clouds: High-resolution 3D models capturing every tree, structure, and terrain feature, essential for infrastructure planning, environmental management, and land analysis.
• Digital Orthomosaic Maps: High-accuracy, high-resolution aerial imagery for monitoring land use, tracking environmental changes, and supporting development planning.
• Digital Surface Models (DSM) and Digital Terrain Models (DTM): Detailed 3D surfaces and bare-earth models critical for hydrological modeling, flood risk prediction, and engineering projects.
• Contour Maps: Precise topographic representations to aid in urban design, slope analysis, and landscape planning.

Precision Matters

To ensure the highest levels of accuracy, we aligned our survey data with Bhutan’s DrukRef 03 framework and the EGM2008 Geoid Model. Rigorous spot height checkpoints were established, and a comprehensive Quality Assurance Report was prepared to validate the data's integrity and reliability.

Challenges and Solutions

Operating in the Omchhu Basin presented notable challenges:

• Challenging Terrain: Steep slopes and rugged valleys required advanced drone capabilities. We utilized ALT Terrain Follow Mode to ensure consistent, detailed data capture across varying elevations.
• Signal Connectivity: In areas with limited network access, we employed a hybrid approach using both RTK and PPK positioning techniques to maintain centimeter-level accuracy.

Final Deliverables

At the conclusion of the project, we delivered:

• High-density LiDAR point clouds
• High-resolution orthomosaic maps
• Detailed DSMs and DTMs
• Precision contour maps
• A complete Quality Assurance Report

Building a Resilient Future for Bhutan

This project is a vital step towards strengthening Phuentsholing’s resilience against climate risks. By delivering precise, actionable data, Bhutan Flying Labs is helping the community to plan smarter, build safer, and prepare for a sustainable future.

For more information on our drone and data services, contact us. We are proud to be at the forefront of innovation and resilience-building in Bhutan.