An estimate of 61,000 people have been killed by natural disasters this year and 60% of these were caused by tsunami in the Indian Ocean. Reports show that there is a rise in reports of natural disasters due to better media reports and communication advancements. Two thirds of this increase is real and is a result of a rise in hydro-meteorological disasters that include typhoons, tsunamis floods, and drought.
Some people still doubt that human beings contribute to the occurrence of natural disasters. Human emissions are estimated to influence drought, and storm surges. In the long term, it is certain that human activities influence natural disasters. Humans also trigger occurrence of sudden natural disasters. Some of the natural disasters caused by human beings include;
Lake Peigneur in Louisiana was sucked into the ground on November 1980. It is believed that a Texaco oil rig that drilled into the salt mine beneath the lake pulled the lake’s plug and this caused water to pour into the mine. The water filled the shafts and dissolved the salt while the oil rig was sucked down. There were no casualties in this incident but the ecosystem was permanently affected. The lake disappeared as water flowed backwards from the Gulf of Mexico to Lake Peigneur. There are several other lakes in the world that have disappeared because of irresponsible human activities. Waste pollution is also one of the main contributing factors to destroying water bodies. Factory emissions are disposed into water bodies making then dirty and unfit for human consumption. In Africa, there are many reported cases of water hyacinth infestation of the water bodies due to the carelessness of human beings.
According to geologists, people cannot trigger the occurrence of real volcanoes. However, we have the capability of making the ground shake tremendously. Activities such as drilling oil make tremors common. Mining operations also increase the frequency of occurrence of tremors. These activities redistribute the normal stress that is present in rocks thus triggering movement.
Dams that are manmade water bodies are also triggers of earthquakes as per the report of the British Geological Survey. Artificial holding of a large volume of water in a single location causes increased pressure on the surface beneath. The lubricating effect of water also makes it easier for the faults to slip. An example of an earthquake caused by a dam was the one that occurred in Koyna India on 11th December 1967. A quake occurred in the area shortly after a large dam was built killing at least two hundred people with thousands injured. The region has always experienced frequent earthquakes since then. An area that was not prone to earthquakes is now earthquake prone as a result of destructive human activity.
Human activities can have an impact on natural disasters like flooding
Scientist’s activities can also cause flooding as experienced in the past. Cloud seeding is a well-known form of weather modification but a question to ask is if it can result in flooding. In cloud seeding, the skies are peppered with silver iodide that draws moisture from clouds by providing something for water to condense on. It is not easy to determine how much rainfall can be caused by cloud seeding. A flood that occurred in Rapid City on June 9th 1972 is assumed to have been caused by cloud seeding.
Human activities can have an impact on natural disasters through floods following these activities;
- Urban development
- Urban development causes water to flow into streams when it rains heavily causing higher flood peaks
- Natural wetlands destruction
The destruction of natural wetlands causes devastating floods during peak floods along river basins.
Hard surfaces such as sewers, parking lots, and concrete surfaces causes water to move faster as compared to natural channels. Cutting down natural vegetation and trees leaves land bare resulting in more erosion when water flows. More natural wetlands lower water level during heavy rains.
Urban development has an impact on natural disasters. It destructs the natural system of waterways. Draining over wetlands increases chances of spill over and raises the levels of the river’s ‘crest. Failure of one of the levees results in destruction of property and fatalities.
Large scale practise of agriculture can result in the depletion of top soils causing weakening of vegetation and inability to protect against flooding.