Trees act as a natural barrier that descend the flow speed of flood. Protecting residential areas from flood can be possible by afforesting them. Besides, the roots of the trees can also hold the ground tightly. For this reason, to prevent landslides stemming from flood and soil erosion it is required to afforest the land. With this statement it is emphasized that trees are natural protection both for preventing the formation of flood and decreasing the negative effects of flood.