How does the Mekong River compare with the Irrawaddy and Salween rivers?

The Mekong, Irrawaddy, and Salween rivers are the three largest river systems in mainland Southeast Asia, all originating in the Plateau of Tibet. Despite this shared origin, they exhibit distinct characteristics:1

• Scale and Basin: The Mekong is the longest river of mainland Southeast Asia and possesses the largest drainage basin. In contrast, the Irrawaddy is shorter but features more extensive lowland areas and a large, rapidly expanding delta. The Salween has a highly restricted drainage basin with few tributaries and a small delta area.123
• Topography: While all three are somewhat atypical due to their narrow, confined upper and middle valleys, the Salween is characterized as a highlands river throughout nearly its entire course. The Irrawaddy flows through diverse terrain, including defiles and a broad alluvial dry zone, before reaching its delta. The Mekong transitions from a rugged, narrow upper valley in China to a more gentle lower course that drains plateaus and plains across Laos, Thailand, Cambodia, and Vietnam.124
• Navigation and Use: The Salween is largely impeded by dangerous rapids, limiting its use primarily to floating timber. The Irrawaddy supports seasonal and year-round navigation in various sections. The Mekong’s lower reaches are vital for regional agriculture, supporting extensive rice cultivation and water management projects.325