Hazards and risks are two sides of the same coin in discussing natural disasters. Hurricanes, for example, are a hazard just because they exist. The same goes for earthquakes, volcanoes, etc. However, when these disasters occur near people and have the potential to cause deaths, destruction, and damages, they become risks. The first image shows the aftermath of an earthquake. Clearly, this event caused damages to buildings, and could have caused some deaths. Cities located in high-risk areas for earthquakes (like the Ring of Fire) can attempt to mitigate the risk in a few different ways. One of the most important ways to mitigate earthquake risk is to develop a monitoring system so that people can be warned before the earthquake begins. An additional way to mitigate the risk is to develop building codes that ensure structures will not fail when an earthquake strikes. Some other ways to mitigate the risk include not building nuclear power plants or emergency services near fault lines and limiting building height.
The second image shows the immediate aftermath of the meltdown at the Chernobyl nuclear reactor in Ukraine. Initially, the Soviet Union denied that anything had occurred at Chernobyl, and people from nearby towns were not evacuated until the following days, after symptoms of radiation sickness had already set in. Radiation quickly spread across much of Eastern Europe. The radiation contaminated the water, air, and land surrounding Chernobyl. A concrete containment structure was built around the affected reactor after the disaster in an attempt to reduce the spread of radiation. However, much of the surrounding area must remain depopulated for the foreseeable future because of the extremely high radiation levels.
The third image shows a tsunami reaching a coastline with many structures built near the water. Tsunamis are often caused by earthquakes, but can also be caused by water displacement, like from a landslide going into a body of water. Some people believe that there is an increased risk of tsunamis today, because there is more construction among the coastlines than ever before, especially in areas that might not have the best mitigation systems. The main (and essentially only) method of mitigation for tsunamis is a warning system. Additionally, educating the public about tsunamis can help them recognize warning signs, like a quickly receding tide.
The fourth image shows a wildfire near some homes. In desert and Mediterranean climates, fire is essential as part of a natural cycle. Fires clear dry brush often enough that there is never enough fuel to let the fire become very large. However, when people move into areas with these climates (especially in the western and southwestern United States), they want all of the fires extinguished. This allows lots of fuel to accumulate, causing large and very destructive wildfires. Lately, some areas have started using controlled burns to try to replicate the natural fire cycle, thus preventing too much fuel from accumulating. Many homeowners are still strongly against controlled burns, however. Unfortunately, in most wildfires, it is the firefighters who die.