Floods and land erosion are two of the most devastating natural disasters that affect millions of people worldwide each year. They cause immense damage to infrastructure, homes, and farmland, resulting in a loss of life, property, and livelihoods. But what causes these disasters, and what can be done to prevent them or mitigate their impact? In this article, we’ll explore the causes and effects of floods and land erosion, as well as the measures that can be taken to minimize their impact. So, buckle up and get ready to learn about these destructive forces and how we can protect ourselves from their wrath.
Floods are a common disaster occurring due to natural or human-made reasons. A flood is overflowing water that submerges an area that is usually dry. The natural calamity of floods is an area of study in the discipline of hydrology. Floods are the most widespread severe weather event. According to the Organization for Economic Cooperation and Development, floods cause over $40 billion in yearly damage worldwide.
There are several types of floods. They can look different as flooding covers everything from a few inches of water to many feet. Floods can also occur very quickly or gradually. According to the National Severe Storms Laboratory, there are five different types of floods. They include Coastal, River, Storm, Flash, and Inland flooding.
What is Land Erosion?
Land erosion is the process by which soil from the earth’s surface is displaced and moved due to natural or human-made factors. Land erosion often becomes a water quality stressor as the displaced soil reaches surface water. In this case, the sediments themselves are a pollutant. Today, around 33 percent of the soil on the earth is damaged and degraded, and more than 90 per cent of soil could get degraded by 2050. Every five seconds, the equivalent of one soccer pitch of soil is eroded.
Land or soil erosion reduces soil fertility, severely affecting crop yields. Land erosion also sends soil-laden water downstream- this can lead to heavy layers of sediments that prevent rivers and streams from flowing smoothly. It could eventually lead to flooding. Thus, flood and land erosion are connected.
Floods and Land Erosion: Causes
Why do floods occur? There are several natural and human causes of floods. The simplest cause of floods is heavy rains. Most urban areas and cities are installed with systems and infrastructures designed to take rainwater into reservoirs or the sea. During heavy rains or cloudbursts, these infrastructures are overwhelmed, and the rainwater does not drain as fast as it needs to. In these situations, the drainage systems fail, and the water rises. Thus, cities, towns, houses, and markets get flooded.
Floods also occur due to the overflowing of rivers. People living near rivers can experience several flooding events during heavy rains. Floods also occur due to broken dams. During heavy rains, the water level rises, causing ageing dams to break and flooding an entire neighbourhood.
Most urban areas are made of concrete and other waterproof materials. Areas with an urban drainage basin made of concrete do not let water seep into the ground. When drains fill up during rains, floods occur in low-lying areas.
Lack of vegetation is another cause of floods. Vegetation helps stop water from running off, thus preventing floods. Winter months of heavy snowfall and precipitation can lead to a spring of flooding. An unusually heavy winter of precipitation is bad for low-lying areas around mountains when the spring hits.
Land erosion mostly occurs due to human activities. Developed lands cause land erosion as it generates more runoff than undeveloped land. They prevent precipitation from entering the ground and produce runoff that erodes the soil and other materials.
Construction activities lead to land erosion as they generally result in the loss of vegetation. These activities produce high rates of soil loss. Further, changing an area’s topography could lead to significant erosion. Agricultural activities such as poorly managed pasturing, land disturbance associated with the planting and harvesting of crops, overgrazing, and more lead to land erosion. Agricultural practices reduce vegetative cover and, in turn, cause land erosions.
The constriction of skidder trails, logging roads, log landings, log transport activities, and more that expose the soil to precipitation can result in land erosion.
Floods and Land Erosion: Effects
The immediate effects of flooding include damage to property, loss of human life, loss of livestock, and deterioration of health conditions. Floods are the most expensive natural calamity in Australia, with costs estimated between 1967 to 2005 averaging $377 million per year. Floods damage communication links and infrastructures such as roads, bridges, power plants, etc. Several economic activities are put on halt, people are forced to leave their homes, and normal life is disrupted.
Industries are also disrupted and can lead to loss of livelihood. Destruction of infrastructure causes several long-term impacts like disruptions to wastewater treatment, electricity, clean water supply, communication, transport, health care, and education.
Floods also traumatize victims and their families for a long time. Losing family members and friends can have deep impacts, particularly on children. Loss of property, home displacement, and disruption of livelihoods, business, and social affairs can cause anxiety and stress. Thus, there can be several psychological impacts as well.
Land erosion can significantly reduce the fertility and quality of the soil. However, soil or land erosion impacts beyond the loss of fertile land. Land erosion has led to an increase in pollution and sedimentation in rivers and streams. It has clogged waterways and caused a decline in fish and other species populations.
Not to mention one of its prominent effects- flooding. As land erodes, it is less likely to hold onto water, which can worsen flooding events. Land erosion also increases the amount of particles and dust the wind carries- these air pollutants can carry around 20 human infectious diseases like tuberculosis and anthrax.
Measures Against Floods and Land Erosion
Creating a sponge city- a city that can clean, hold, and drain water using ecological approaches. Instead of channelling rainwater away, a sponge city retains the water for its use.
Green roofs can help absorb rainwater and tackle floods. It has several benefits, such as preventing combined sewer overflow, removing nitrogen pollution from rainwater, and neutralizing acid rain effects.
Overflow areas for rivers and flood plains play a significant role in flood protection, nature conservation, and water management. They retain and absorb rainwater.
Separating rainwater from the sewer system can prevent floods by enabling wastewater treatment plants to function efficiently without overburdening them with stormwater.
Installing attenuation systems, sustainable drains, water infiltration systems, and keeping sewer systems clean are other measures to prevent flooding.
For Land Erosions
Maintaining large vegetation covers or healthy perennial plant covers around cities, towns, and neighborhoods can prevent land erosion. Maintaining large forest covers around agricultural lands and rivers can also prevent land erosion.