Water Cycle PDF

WATER CYCLE Water is constantly on the move. From rivers to oceans, from rain to the roots of plants, and even from the ground into the air, water can be found all around us. In fact, we’re made of mostly water too! We drink water, sweat it out, and use it to clean ourselves and our homes. We play i...

WATER CYCLE Water is constantly on the move. From rivers to oceans, from rain to the roots of plants, and even from the ground into the air, water can be found all around us. In fact, we’re made of mostly water too! We drink water, sweat it out, and use it to clean ourselves and our homes. We play in it and build snowmen out of it. We search for it on other planets. There’s no doubt that water is one of the most important compounds to all life. In order to fully understand how water moves, though, we need to first take a look at water’s different forms. States of Matter Matter (anything you can feel or touch) has 3 main forms: solid, liquid, and gas. All matter can change in any of the three forms, but for most materials it’s quite hard. For example, while it wouldn’t take too much heat to melt plastic, can you imagine how much it would take in order to turn plastic into a gas? Even rocks change form! Think volcanoes! Water, however, is unlike any other substance because it can change form very easily. It doesn’t take much heat to turn water into a gas. It also doesn’t have to be very cold for water to turn into a solid. Because water changes form so easily, it’s able to move around a lot more than most other materials. Let’s take a look at some of the ways water moves. Precipitation The first and perhaps most obvious way water moves is through precipitation. Precipitation is when water falls from the sky in any form. Rain, snow, sleet, and hail are all considered forms of precipitation. Condensation Of course, though, there wouldn’t be precipitation without condensation. Condensation is the process of water vapor (gas) turning into liquid water. This happens whenever the water vapor is cooled off enough. You have most likely witnessed condensation on the outside of your cold cup. Water vapor floating in the air around you changes form before your eyes as it clings to the outside of your glass. Condensation happens in clouds too, which is how rain forms. Evaporation Evaporation is the process of water being heated so much that it’s molecules eventually defy gravity and break away from one another. In other words, water changes from a liquid to a gas called water vapor. Evaporation happens whenever there’s liquid water around. I’d be willing to bet you’ve even relied on evaporation to clean up a mess or two! Transpiration Just like we sweat and water leaves our body, the same thing happens with plants. The process of transpiration is when water that was absorbed by the roots of plants evaporates directly out of their leaves. This is a completely normal process for the plant, and is actually an important part of the photosynthesis reaction.. Runoff As you have seen around you plenty of times before, water is affected by gravity just like any other matter. When rain falls or snow melts, water moves downwards. This process is known as runoff. Runoff water may form rivers and eventually lakes or even soak directly into the ground. Plant Uptake Another way that water moves is when it is absorbed by the roots of plants. This process is known as plant uptake. Percolation Percolation is the process by which water sinks into the ground to become groundwater. Groundwater is a collection of freshwater that is trapped underground. This is still a major source of clean drinking water for many communities around the world. You may be familiar with the concept of a well, which is one way to access groundwater. Groundwater isn’t like an underground lake though, usually. Many rocks are porous, which means that water can flow through them. The groundwater will be contained within these porous rocks. River Discharge and Collection After water has moved as far downwards as it can through runoff, it will often collect at the lowest point. This is how we get our lakes and oceans. Here, the water becomes a major source for evaporation to collect huge amounts of water into the air. These molecules will condense to form clouds, and later go on to create major weather patterns across the globe! Things like hurricanes, thunderstorms, and even many temperature patterns are a direct result of water’s constant movement in the water cycle.