All right, here we are. My name is Mr. Chippen. I teach biology, AP Biology at Murray High School, Mary, Kentucky. And now I'm teaching also environmental science. Well, I'm not teaching it. I'm just making videos for it because I like this stuff. And we're looking at the hydraologic cycle 1.7. Uh, the water cycle. You've probably heard it called since third grade. A lot of this stuff's not going to be new. There's a couple of new terms that I sort of pulled out that I think may be some terms that you haven't touched on before. So, yeah, let's look at it. So, here's a nice picture. I just love these cycle pictures. There's so much going on. Somebody took some really real care to draw the clouds in this picture, but then sort of got less care as they went further down in the picture. This is the idea that water is moving through the ecosystem, right? Does that in various ways. All living things need water in order to survive. So moving water through the ecosystem is obviously going to be an important portion of that life. Water can exist in several forms. There's steam, there's ice, there's liquid water uh depending on temperature in the in the area, depending on pressure in the area as well depending, you know, there may be underground or something along or under way underwater, right? So very important. Let's look at a couple of the words here. Well, first of all, primary reservoirs for water are going to be um the water you like the oceans, fresh water. Now, this is interesting. Um obviously, salt water is not drinkable by animals. And so, um we have to figure out a way to have fresh water. Fresh water is very much more important than salt water as far as we're concerned if we want to live. Um but that isn't to say that water that's in the ocean isn't adding to the freshwater reservoirs in the world, right? because water evaporates and all that sort of thing. So, seeing those things as separate entities, but also understanding that all water is sort of the same water, you know what I mean? Let's go back here. Let's uh just talk about a couple of these terms just to make sure we're all on the same page. Then we'll pull out a couple of them to make sure we hit those. Um evaporation, obviously, liquid becoming vapor. This is happening everywhere. You don't see it. Water's coming up off all bodies of water adding itself to the atmosphere. Atmosphere is a certain percentage of water vapor most times. It's going to be different depending on where you're at. If you're where I'm from in West Kentucky, it's going to be a high percentage because of all the humidity here. If you're like Death Valley, there's almost zero water in the air there, right? Um transpiration, uh which is water being released from plants. So, uh it's different from evaporation, right? Water's coming off the plants. This act of transpiration actually pulls water through the plant which is very important and um the amount of transpiration that an a forest has usually is directly relation to its productivity because water's necessary for photosynthesis. Condensation this is water like condensing getting smaller right going from vapor to like a cloud or something like that. Precipitation then is that water coming out of the cloud. These are all terms you're familiar with. Then there's a couple that, you know, we weren't I wasn't familiar with anyway. Infiltration. So we have a couple words here, right? We have filtration. It's filtering. We have infiltration. So it's like going into filtering into something. So this is the idea that water is soaking into the soil. Uh a word that you often times see with this is the idea of percolating, right? sort of like dripping right into the soil. And there's a water there's water underneath the soil like a water table. It's where we get a lot of our drinking water from, right? And this is necessary for the things that live in the soil. Sort of keep the composition of the soil depending on where you're at. Very very important idea. Um then there's different places that water stored. Could be like the water table like I talked about. um could be stored in different areas because of like ditches like runoff or something like that. So when we're talking about reservoirs, don't just think oceans and big lakes or something like that, but literally anything that has is holding a standing water is an important concept. Oceans hold 97% of the Earth's water. And so uh there's a lot of evaporation happening off of oceans. Um, glaciers and ice caps store most of the Earth's fresh water and it's largely inaccessible of course because we can't eat ice and so we depend on this sort of cycling obviously to live or we we wouldn't be there very very quickly at all. Uh, the atmosphere is a very small reservoir. It's important to note very little um precipitation in the atmosphere but very critical obviously to the growth of plants and that sort of thing. So let's talk about this idea of a watershed. So you're going to see this term, you'll probably see it again as the year goes on. A watershed is this idea of all the water sort of like coming into a particular area. If you want to think of like a watershed, think of um all the areas are gathering water. Like you think of a river, where does a river gather water from? It's all these little tributaries and streams, right? That is the watershed. It's a word you're going to hear a lot that filtration is getting is not only filtering from the ground or from the like surface but also from the underground filtering into in those individual wersheds and moving into like these bigger areas of water. So very important idea this idea of watershed which brings us to the human impact because of this idea of infiltration and the water sort of percolating into back into the water system. Um what it goes through is obviously going to affect that water right and so uh there are several ways that humans can impact this. Obviously cities um water that coming from a city is going to be less desirable than water coming from a non city. I want to be careful that we don't make a distinction between like a farm because a farm is going to have different problems, right? It's going to um because of the animals and whatnot, it's going to cause some different sorts of things to be percolating into the soil. So that's very very important um idea as well. we have an impact on the water table just by sort of doing our normal life, right? Uh which is a a common theme that you're going to see in this class is that a lot of what we do is not natural, right? It takes away from the natural part of the environment. I think it's very important for us to consider that. Let's look at some practice questions. Pause the video if you need to. I'll read the question. Student exams diagram of water cycle showing an underground aquifer, a forested watershed and a nearby ocean. Which change most likely decrease infiltration and increase runoff? It's a good question. Recharging the aquifer by injecting the watershed planting native vegetation. So we're again we're decreasing infiltration. What's going to do that? Paving over the forest to build roads and commercial areas definitely going to decrease uh infiltration because the water's not getting into the soil, right? Um vegetation and that sort of thing is a normal natural sort of thing. But when as soon as you cover that, water's unable to penetrate um and it can cause an issue. Hopefully this was helpful. 1.7's in the books. We're going to be moving towards 1.8 night soon enough.