1. When rain is falling on a concrete floor, the floor does not have the ability to soak up the water because of its cemented surface, so the water usually stay on the surface of the floor and build up. When rain is falling on a slanted roof, the water usually run off the surface of the roof. When rain is falling on the surface of a water body, it adds to the quantity of water in the water body.
2. During a long rainy season, the various body of water will receive more water from the rain and the level of water in them will increase. Depending on different operating factors, the water in the water bodies may overflow and leads to different degree of flooding.
