People on their society were tasked with measuring the floods. Doing this made it possible to predict the next flood, with enough data of course. They used Nilometers to measure this. A well with stairs built into the Nile. If it was high, they knew trouble was on the way, same thing if it was low. They had a sweet spot that produced the best harvests. Really cool stuff.

The Yangtze likely played a big role (In my poorly educated opinion). It's far more reliable than the yellow river and likely provided a more stable ecosystem from which early people would learn to live with, and make use of, the yellow river despite its volitility.