The head of the United Nations Environment Program (UNEP) said Wednesday that the recent Indian Ocean tsunami could have serious impact on the environment of the countries affected.

Although it was too early to make a detailed assessment, early indications from the UNEP's work on the tsunami were that the direct damage to the environment, including water supplies, forests and other natural resources will likely be high in many ofthe countries affected, said Klaus Toepfer, executive director of the UNEP.

"Beyond the immediate concerns of threat to human health and livelihoods, there is increasing evidence of serious impacts on the natural environment, such as damage to coral reefs and protective forest in a number of countries," he said at the World Conference on Disaster Reduction which started here Tuesday.

He stressed the importance of the environment in disaster reduction. "Without the environmental dimension firmly in the equation, there will be no long term disaster risk reduction," he said.

To highlight the role played by sound environment protection inreducing damages by natural disasters, he said the Hurricane Jeanne last year killed up to 3,000 people in Haiti, because deforestation made flood rush down unchecked from hills, while theneighboring Dominican Republic saw few casualties partly thanks togood protection of forest.

Toepfer called for increasing investment in environmental protection and putting a disaster prevention value on the natural ecosystems.

More than 4,000 participants from about 150 countries and organizations are attending the five-day to map out a disaster reduction guideline for the decade to come.