Upstream Basin Rainfall – Major Rivers of Cambodia

Water in Cambodia rarely comes from local rain. Only about 20% of the Mekong catchment lies inside Cambodia; the rest runs through China, Myanmar, Laos and Thailand. The level at Kratie is the consequence of rain that fell in southern Laos five days earlier.

So each river here is sampled for rainfall inside its own upstream catchment — the past 72 hours and the next 72. Those figures exist before the river level moves.

This is not river level. Official levels and discharge come from the Mekong River Commission (MRC) gauge network. Upstream rainfall is what causes the level, and it is visible days earlier.