Flood defense refers to the various methods and structures designed to protect areas from the damaging effects of flooding. This can include building dikes and levees to hold back water, creating retention basins to store excess rainwater, and implementing drainage systems to redirect water away from vulnerable areas. These measures help safeguard homes, businesses, and infrastructure from flood damage. In addition to physical structures, flood defense also involves planning and preparedness. Communities often develop emergency response plans and conduct public awareness campaigns to educate residents about flood risks. By combining engineering solutions with community engagement, flood defense aims to minimize the impact of floods on people's lives and property.