Monsoons and Floods: Best Friends of Water By: Vivian Ooi
Monsoons: Rain and Wind A monsoon is comprised of heavy rain and constant wind. Monsoon comes from the word mausim, the Arabic word for season. They follow the weather and also change their direction based on where the weather is. A monsoon happens because of the uneven heating of the Earth’s surface. Floods, typhoons, and hurricanes can be caused by monsoons. Monsoon clouds over crops.
There are two types of monsoons: summer and winter. During the summer monsoon, the land heats up faster than the ocean, causing the air on the land to rise, creating low air pressure. When the water vapor is high in the atmosphere, it condenses back into water droplets,
forming clouds. The ocean is cooler than the land, which means that it has high air pressure because the molecules are more densely packed. Since the air over the land has evaporated, this cool ocean water comes onto the land (creating wind), only to be heated up again. Air with high-pressure move to areas with low pressure. This process repeats until the clouds get so heavy with the water droplets that rain starts to fall. Winter monsoons are the opposite of summer monsoons. Instead of bringing wet weather, it brings dry weather. This is because, during the winter, the ocean is warmer than the land, causing the air above the ocean to evaporate and form into clouds (low-pressure). The cooler air (high-pressure) above the land then blows into the ocean, only to heat up again and evaporate. The clouds form above the ocean, so when it starts to rain, it will rain over the ocean, not the land. The wind in a monsoon usually blows in patterns. When someone says monsoon, they usually mean a summer monsoon. In this report, we will be talking about summer monsoons. Pollution slows down the coming of monsoons because pollution creates more cloud cover, therefore reducing evaporation.
Monsoons? Important? Even though monsoons do not sound like a good thing, people around the world, especially India, need monsoons in order to survive. This is because of the water monsoons bring.
India has two different categories of crops: summer monsoon crops (kharif crops) and winter monsoons crops (rabi crops). Kharif crops include rice, millet, peas, and corn. Rabi crops include barley, wheat, and oats. In India, monsoons keep crops and animals alive, and they also keep the soil moist, since India is very hot. There aren’t many farmlands in India, so farmers usually have to adapt to when the monsoons come so that the monsoon doesn’t wash seeds or young crops away. If there is no monsoon, the crops (the kharif crops) die from not having enough water, causing people to starve to death. In 1770, over 10 million people perished due to the lack of food that was produced when a monsoon did not arrive.
The Gharial Crocodile
Animals also depend on monsoons, like the gharial crocodile. During a monsoon, the riverbanks get sandy. During the start of the next hot season, the females dig holes in the sand for their eggs. After 3 months, the sand gets warm, helping the eggs to hatch. If there was no monsoon during that season, the eggs might not hatch in time since there are no sandy riverbanks, and they might be carried away by the next monsoon. Indian elephants and lion-tailed macaques also depend on the monsoon season to live. The rain enables trees to grow and produce food. The Indian elephants eat the trees, and the macaques eat the food produced by the trees. There are special trees in monsoon forests that lose their leaves during the hot season so that they can store water, and the monsoon season helps the trees to grow and produce food.
Floods: Water Everywhere!
As you can see, there is a trapped woman on the roof of a car during a flash flood in Toowoomba
Floods can cause during monsoons due to heavy rainfall. They are also caused because of tsunamis. To the left is a picture of a flood in Mumbai. Melted snow can also cause floods if they melt too rapidly. They happen when bodies of water are filled with too much water and overflow, flowing inland. There are three main types of floods. Alluvial floods happen when rivers overflow, and they are common in the Midwest of US. Coastal floods usually occur in low-lying areas by the coast, and seawater flows inland. Both alluvial and coastal floods take time to happen. However, flash floods occur very quickly, usually after heavy rain. Flash floods can also happen when dry desert ground can’t absorb the rainwater from a storm, and when a dam breaks. When there is a severe flood, people evacuate from their homes and the police and firefighters save trapped people.
What You Can Do to Stay Safe During a Flood In order to stay safe during a flood, here are some things that you can do: ● Ensure that your family has an emergency kit with the necessities like a flashlight, canned food, first aid kit, and drinkable water in it. ● Listen to the weather reports and alerts. ● Have an evacuation plan and somewhere to find shelter if your house gets severely flooded. ● Stay away from places that are likely to flood when there is bad or rainy weather. ● Never try to get through floodwaters ● Build levees out of concrete or sandbags around your house to prevent the waters from flowing onto your property (of course, this can only block shallow waters) You should also donate to aid flood victims since that is what you would want other people to do for you if you ever become a victim of a flood.
Destructive Monsoons and Floods Monsoons can be destructive. They destroy buildings, roads, and the houses near a water source (like a lake, river, or the ocean) could flood. Most people who live in Mumbai are poor, so they don’t have very secure housing to protect them from the harsh weather. Many people in India make a living by selling products from carts on the side of the streets. Monsoons keep the people indoors with nowhere to sell their goods. The people can’t earn money. During a monsoon, drinking water becomes unclean, and diseases could be passed to citizens from the unclean water that they drink. About 1,000 people die in India due to unclean drinking water. Severe floods destroy anything that is in their way. They damage homes, ceilings, floors, and parts of buildings. There is usually mud and debris left when the water in the building has gone. Electrical systems are damaged, and mold, which is harmful to breathe in and can cause sickness, will start to grow on the damp walls. People are usually killed because they drown in the water, they are hit by debris, or they are swept away by the strong currents. The picture on the left is of a volunteer helping to clean up a house after a flood damaged it.
Floods and Monsoons that Really Occurred The 2018 monsoon season in India has killed 774, and 27 people are reported to be missing. This monsoon is said to be the worst ever since 1924. Houses, crops, and other properties were damaged. The Yellow, Yangtze, and Huai rivers in China flooded in 1931. 4 million people died. The people in the picture are the flood victims.There were lots of snow during the year 1930,
and the following spring brought heavy rain, causing the water level to rise. At that time, China was a weak country, and there were many wars taking place. Since there were many wars and rebellions, the government couldn’t monitor the rivers well and they didn’t do their job, causing overused land near rivers, incorrectly constructed levees, and dams, and damaged forests and wetlands (forests and wetlands helped regulate the river, so this was a serious issue). When the rivers flooded, most of Central China was underwater, and 10,000 people perished during the floods. Survivors were homeless and had no food to eat. China was still underwater during the fall, so they weren’t able to plant crops. The government was still weak, so they weren’t able to gather the necessary resources and people to help with the situation. Due to the lack of resources, people were famished and soon died of hunger, and diseases spread. Lack of food led to the people becoming cannibals, eating the dead. On November 7, 2017, Penang experienced a flood where 7 people perished and thousands evacuated from their homes. Penang was still inundated by 4 meters of water after the storm that lasted 18 hours. Sherilyn Kang, a resident, said to the Straits Times at 10 am, “The water has still not subsided so we can’t clean up yet.” She also remarked, “This is the worst in Penang’s history”. In 2017, the heavy rains that the monsoon brought killed more than 1,200 people across India, Bangladesh, and Nepal. 18,000 schools were damaged, causing 1.8 million children nowhere to go to school. Landslides occurred, roads were destroyed, electrical towers were damaged, and homes and farmlands were swept away. 40 million people were affected by this devastating monsoon.
Where Monsoons and Floods Prefer
​The blue regions represent the summer monsoonal regions of the world. As you can see, India is mostly covered in blue, and so is Africa.
Monsoons mostly occur in eastern Asia because the elevated land masses create a bigger monsoon effect. Monsoons occur in India from June to September. The water that the monsoon brings can be more than 40 feet (12 meters) of rain for over 4 months. Most rain falls in northeastern India. Monsoons don’t just happen in India, though. They can also happen in other parts of Asia, like ​Vietnam, Thailand, Cambodia, Bangladesh, Laos, and Pakistan. Monsoons also happen in Mexico, also affecting US states like Arizona and Mexico. Africa also experiences monsoons. Alluvial and coastal floods need a river or the location needs to be somewhere near the coast in order for them to happen. However, flash floods can happen anytime, anywhere, as long as there is too much water that cannot be absorbed by the Earth or accumulate in a body of water. The water flows inland.
Monsoons/Floods: The Job of Predicting Them Meteorologists (scientists who study and predict the weather) use different methods to predict the location and the coming of a monsoon. They use satellites to predict and find where rain clouds and winds form. Another thing they do is track how fast the winds travel after rain starts to fall. Forecasters search for light winds that blow and when the clouds form. Information about the clouds tells them when the monsoon is going to happen because the warm, humid air is evaporating to form clouds.
For floods, meteorologists use radars (RAdio Detection And Ranging). It looks like a big golf ball, and it sends out electromagnetic waves that reflect on precipitation and sends the waves back. Sometimes the radar reflects insects, birds, aircrafts, ash, and smoke instead of precipitation. How long the waves take to get to the radar determines distance, and how strong the waves return is based on the type of precipitation. Radars give information about the amount of rain or snow in the air and
the speed a storm is moving. The range of a radar is in between 5-200 km.
Flood zone map, areas that are likely to flood.
Flood maps are created by analyzing the flooding history of an area, and scientists can predict where floods might happen and how to keep everyone safe and sound. Scientists issue a flood watch when there is more rainfall than usual, and they will issue a flood warning when it is certain that a flood is occurring or if it is already occurring. Weather forecasters can only predict the weather, which means that they are not always a hundred percent correct. The atmosphere and weather are constantly changing, so it is difficult to make an accurate prediction every time.
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Monsoons? Important? Flood: Water Everywhere Pic 1: T. (2011, January 10). Trapped woman on a car roof during flash flooding in Toowoomba [Digital image]. Retrieved November 15, 2018, from https://commons.wikimedia.org/wiki/File:Trapped_woman_on_a_car_roof_during_flash_flooding_in_Toow oomba_2.jpg Pic 2: T. (2017, August 31). Rain Paralysed Mumbai - People Slept In Offices, Homes of Colleagues [Digital image]. Retrieved November 15, 2018, from https://en.wikipedia.org/wiki/File:Rain_Paralysed_Mumbai_-_People_Slept_In_Offices,_Homes_of_Collea gues_(36515650870).jpg
Destructive Monsoons and Floods Valdez, D. (2011, July 27). A volunteer from All Hands Volunteers from Rolla, N. D. , helps clean up a house after recent flooding in Minot, North Dakota. FEMA is working with many partner organizations to assist in the recovery of North Dakota. [Digital image]. Retrieved November 15, 2018, from https://picryl.com/media/flooding-minot-n-d-july-27-2011-a-volunteer-from-all-hands-volunteers-from-184 432
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