A natural disaster is an unforeseen occurrence that causes the environment and society.

A natural disaster is an unforeseen occurrence that causes the environment and society. Many people lost their lives in the natural disaster. Moreover, these disasters are happened by mankind activities and some of them have occurred naturally and this natural disaster is unpredictable. Some natural disasters are earthquakes, Tsunami, Landslides, Avalanches, Volcanic eruptions, and many more. Sometimes these disasters cause the environments largely and sometimes less. This is measured with the help of spatial measures. This spatial measure is further classified into three categories. Small scale measure, it causes the natural environment and it covers the ranges of 50km to 100km. These kinds of causes are affecting less. More or like, we can easily survive from these kinds of natural effects. Medium-scale measure, it causes the natural environment and it covers the ranges between 100 km to 500 km. This kind of cause affect more and damage many lives, shelters, etc. , To survive this natural disaster is quite difficult when we compare it with small-scale measures. Large scale measure, it causes the natural environment and it covers the ranges of more than 100 km. This kind of caused affect and destroy the whole country. This rarely happened also wiping out of dinosaurs was happened due to the large-scale causes. The natural disaster is classified into the following categories, Internal disaster: Internal disasters happen inside the core of the earth. This is due to the displacement or movement of changes inside the earth. Some of these natural disasters are earthquakes, and this creates a path or way to other causes such as Tsunami. External disaster: The external disaster happens above the earth, it causes landslides, volcanos, avalanches, etc. This is due to soil erosion, sometimes mankind activities like deforestation, etc. , These external disasters destroy the hill stations, slopes, valleys, forests. Hydrometeorological disaster: The hydro-meteorological disaster are happens in the oceans and seas. The Major disasters are cyclones, floods. This is due to climate changes in terms of heat and pollution. Biological disaster: The biological disaster causes are spreading through viruses and diseases. Many peoples and animals got suffered due to the virus spreading like Flu, Yellow virus, malaria, etc. , Some of these viruses are spreading from animals to human beings and some are of these are from mosquitoes. In recent years, the COVID-19 virus has also been a biological disaster that spread across the world. Earthquake: The earthquake is mostly happened due to the displacement inside the earth. Some earthquakes are less affected and it is unnoticeable. Some of these earthquakes are high and even it has the ability to destroy the whole city. Many peoples lost their families and lives due to the large effect. Many developed and developing countries created innovative technology to sense the earthquake waves and alert the people to move to other places. Tsunami: The tsunami happens due to the shakes in the earth and it generates a large wave in the ocean. The speed of tsunami outcome is faster, it can reach the seashore quickly after the tsunami generates. Many countries, islands, coaster areas were destroyed completely over the years. To come out of the situation to normal is quite tough for the people and governments. Landslides: The landslides are happened due to soil erosion, digging, etc. As technology changes people are starting urbanizing from one place to another place. Due to the necessity of mankind's basic needs people are starting doing deforestation, mining, and other activities. Also, not all landslides are happened due to human activities and some of these are happened due to climatic changes and increased rainfall. This causes soil erosion easily because the soil does not have the strength to handle this landslide, rocks rolling. Avalanche: Avalanche is more or similar to landslides, instead of that, it happens in the snows. Many peoples in the snowy areas are free from the avalanche. To survive from the avalanche is difficult for human beings.