Answer:
Densely populated regions with little vegetation.
Step-by-step explanation:
Flooding refers to a longer event in comparison to flash flooding, it may take a few days or weeks. On the other hand, flash floods are generally featured by intense fast-moving water post heavy rains, which gashes through urban streets, river beds, or mountain canyons sweeping everything coming in their way. They can take place within minutes or a few hours of extreme rainfall. In such cases, the regions with heavy population and comprising little vegetation would be the one that would be most affected.