Effects of a Flood on the Ecosystem

Benefits to Plants

• On dry land, plant life can benefit from the sudden appearance of a large quantity of flood water. Water stored underground will be replenished by the floodwater, while the soil above ground will be able to soak up the water. Plants will be able to receive water as a result. The nutrients carried by the flood water can also revive deprived plants and aid in the germination of seeds.

  Over the long term, this flood water may provide a new lease on life for an area. The soil is likely to be more fertile, leading to a suitable area in which to grow crops. Some cultures have traditionally relied on yearly floods to replenish the land's nutrients.

Animal Breeding

• In areas where a flood has occurred, the environment becomes highly suitable for the reproduction of species of birds and other animals, as noted by the Skwirk educational website. Fish can breed and give birth in the areas where flood water stays for an extended duration.

Water-based Ecosystems Upset

• Ecosystems depend on a careful balance of factors, and the sudden impact of a flood can quickly disrupt this, with dramatic consequences. While the flood itself will affect mainly dry land, the ecosystems of deep water-based habitats, such as coral reefs, are particularly at risk from the runoff from the flood. This runoff will contain sediment and products such as pesticides and fertilizers, and will carry these into the ecosystem, as noted by a report from the Fitzroy Basin Association. These changes in the very nature of the water can affect every part of the ecosystem --- habitats may be destroyed, and animal and plant life is likely to suffer. For example, the sediment may obscure the sunlight which marine plants need to survive. As a result, these plants will not photosynthesize and may die.

Clear Pollution

• While water-based ecosystems may be adversely affected by flood water, they can also benefit. The sudden appearance of an overflow of water can wash away unneeded salt, alongside man-made products, such as waste chemicals, from these areas, allowing flora and fauna to survive and thrive. The flood water can also sweep away junk and debris which may have accumulated by the side of rivers.