The Mekong is one of the world’s great rivers — a 5,000-kilometer waterway threading from China through Laos, Thailand, Cambodia and Vietnam. However, dams have subverted the ecosystem, bringing drought during the monsoon season and high waters when it should be dry. That has forever changed the lives of those who depend on the river for food and work in northeastern Thailand, a poor region bordering Laos and Cambodia. Vijitra Duangdee reports for VOA news, from Nong Khai, Thailand. VOA Khmer's Vathana Seourn narrates.