Measuring the world's rivers with videos from Space

Area of Science:

• Hydrology
• Remote Sensing
• Geospatial Analysis

Background:

• Accurate river discharge measurement is vital for water resource management, ecological health, and industrial use, particularly with climate change impacts.
• Existing global river monitoring networks are often insufficient and deteriorating.
• Current satellite methods lack water flow speed data, limiting accurate discharge calculations.

Purpose of the Study:

• To introduce a novel satellite-based method for accurately measuring river water flow speed.
• To enable high-resolution river monitoring, even in narrow channels.
• To validate the method through extensive ground-based measurements.

Main Methods:

• Utilizing high-resolution video imagery from a constellation of low-earth-orbit satellites.
• Developing algorithms to determine water flow speed from satellite video data.
• Conducting ground-based validation measurements at diverse river sites globally.

Main Results:

• Demonstrated accurate determination of water flow speed using satellite video.
• Successfully observed rivers as narrow as 70 meters wide.
• Achieved discharge measurement agreement better than 5% compared to ground-based data.

Conclusions:

• This satellite-based method represents a significant advancement in global river measurement capabilities.
• Enables monitoring of remote rivers and extreme events like floods without on-site presence.
• Offers a crucial tool for enhanced hydrological monitoring in a changing climate.