Satellite Could Help Flood, Fishery Control fishery management

A satellite that uses radar to take images of the earth’s surface could be used in Cambodia to monitor flooding and rice crops and manage fisheries, a group of environmental consultants told government officials Thursday.

The satellite, known as Radar­sat, is owned and operated by the Canadian government. It was created to monitor ice flows in the Atlantic Ocean, but has since been used for research across the globe, including the lake Tonle Sap basin.

Unlike optical satellites, which rely on light from the sun to take pictures, radar satellites can record data at night. They can also penetrate clouds, smoke and haze, meaning images can be obtained during heavy rainfalls.

The technology can be used for anything from accurately mapping a country’s coastline to monitoring ships for illegal fishing or dumping. Data from the satellite can be processed within a few hours, meaning it could be used to monitor flooding. The detail is great enough to detect small channels of water or bamboo fishing traps in a lake.

Over the past nine months, Hatfield Consultants, Radarsat international and the Cambodian high-tech firm Aruna Technology worked with the Mekong River Com­mission to map the Tonle Sap lake at different periods of flooding.

Images were taken at three times during the year. When laid over each other, they show how far flooding extends during different seasons. Images from different years can help determine how rain and flooding patterns are changing.

The service is expensive; a package of 50 pictures, which can be taken any time over two or three years, costs $120,000. The Mekong River Commission project was funded through the Canadian Space Agency. Donor support would be sought for future projects, said Thomas Boivin, chief operating officer for Hatfield Consultants.

For Neou Bonheur, of the Ministry of Environment, Radar­sat would be most useful in monitoring land use changes, illegal logging and illegal fishing near the Tonle Sap lake.

But Neou Bonheur said he was not convinced by the Radarsat images he saw. On some traditional satellite pictures, he said, images are easier to distinguish.

The Radarsat system, Boivin emphasized, is not meant to be used alone but in conjunction with traditional satellite images, ground surveys and topographical maps. “It’s one piece of the puzzle,” he said. “It’s not the answer.”



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