1.1. Types of Floods and Earthquakes

Now, coming another important feature is the speed of onset like, if we consider a flood, it is a flash flood, it is very sudden without warning, very quick or is it a kind of slow process like in case of cyclone, we have much time to predict so, we have; we can prepare our self, we have better early warning system and we can take time but in case of earthquake, we do not have any time, it is very sudden or in case of flash flood, we have less time also consider to other kind of a flood. Speed of onset is very important and when you are considering the hazards in disaster risk management and the spatial dispersion; area likely to be affected by particular event.

The speed of onset refers to how quickly a disaster occurs after the initial warning. For floods, there are different types: flash floods happen suddenly and without warning, while other floods may develop slowly, giving people time to prepare. In contrast, earthquakes occur suddenly; there typically isn’t any warning beforehand. Understanding the speed at which these events occur is crucial for disaster risk management, including planning and preparedness strategies. This involves knowing where the disasters are likely to strike and how quickly they can happen.

Imagine a surprise fire drill at school where you only have two minutes to exit the building versus a planned fire drill where you have a full hour to prepare. The sudden fire drill represents an earthquake, while the planned drill parallels a slow-developing flood event, showing the importance of time in disaster preparedness.

In case of just for an example, maybe we can see that in case of earthquake; earthquake occurs along the boundaries of the tectonic plates of the earth crust. this is one hazard and when this is the source of the hazards and when this happen and this happens, we can see that these plates come in contact with each other and the pressure builds up an earthquake occurs.

Earthquakes are caused when tectonic plates, which make up the Earth’s crust, interact with each other. They are usually found along the boundaries of these plates. When the plates push against each other, stress builds up until it’s released in the form of an earthquake. This process explains why earthquakes frequently occur along these boundaries.

Think of a rubber band being stretched. As you pull it more and more, it builds up tension. Once the tension is too much, it snaps. The snapping of the rubber band is similar to how energy is released during an earthquake when tectonic plates move suddenly.

Now, this is just simply a physical event, this is you can see some of the distribution of the tectonic plates in some places and this hazard; this earthquake hazard, we have 3 processes; physical process that can trigger this hazard. One is that convergent boundaries; when two plates collide together this created the Himalayan mountain so, one way of the event of earthquake that can happen when two plates are colliding each other. Another was is the subductions; there is when one oceanic plate goes under the land plate and created the this kind of earthquake. And another one is the divergent one, when two plates are moving apart, this can also cause earthquake.

There are three main types of tectonic plate boundaries that can trigger earthquakes. First, convergent boundaries occur when two plates collide, often creating mountains, like the Himalayas. Second, subduction happens when an oceanic plate sinks beneath a continental plate, which can lead to powerful earthquakes. Third, divergent boundaries occur when two plates move apart, allowing magma to rise and form new crust, which can also result in earthquakes. Understanding these processes helps explain where and why some earthquakes happen.

Imagine two cars crashing together in a traffic accident (convergent), a car driving off a ramp and landing on a lower level (subduction), and two cars driving side by side in opposite directions (divergent). Each scenario depicts different interactions similar to those of tectonic plates.

Now when we are talking about hazards, can we avoid hazard? No, historically hazards were there, it is there and it will remain. So, we cannot avoid hazard basically.

Hazards like floods and earthquakes are natural occurrences that have always been part of our environment. They cannot be completely avoided; rather, we can only prepare for them, manage their impact, and reduce their risk. Historically, these events have consistently affected humans, and they will continue to do so in the future.

Consider the weather; we cannot stop a storm from forming but we can prepare for it by securing our homes, stocking supplies, and evacuating if necessary. This preparedness is crucial for managing hazards.

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