Since uplift and erosion are more or less in equilibrium in the Himalaya, at least where the climate is humid, rapid uplift must be balanced out by annual increments of millions tonnes of sediments washing down from the mountains; then on the plains settling out of suspension on vast alluvial fans over which rivers meander and change course at least every few decades, causing some experts to question whether manmade embankments can contain the problem of flooding. Traditional Mithila culture along the lower Koshi in Nepal and Bihar celebrated the river as the giver of life for its fertile alluvial soil, yet also the taker of life through its catastrophic floods.