Desribe the major crops and flooding cycles of the yellow river?

The major crops include wheat, corn, peanut, and cotton.
The ice flood mainly happens in Ningxia, Inner Mongolia and lower reaches where the water runs from south to north; the water flood maninly happens in lower reaches. It is said that Kaifeng in Henan Province has been flooded six times in history and there are six cities buried under current Kaifeng.