hi cool geographers welcome back we are gonna talk about water today so we need to talk about fresh water on the planet where fresh water is I'm gonna review a couple of things that we've already talked about with water and once we talk about fresh water then we're gonna launch into landforms that are made by water so landforms that are made by fresh water landforms that are made by ocean water and yeah and we're gonna keep going into landforms so let's take a look at water and I'm I posted a couple really good videos um on water like are we running out of water and you know something else about how fantastic water is water is fantastic obviously it's it's what we all need to survive and we share water with every single other living organism on the planet so how we use our water if you think about all the different things that that we do and how we impact our environment how we use our water is one of the most essential when it comes to us being able to live on this planet peacefully well that we live on it very peacefully right now but you know let's hope and dream but the way that we treat our water is one of the most essential parts of how we are able to survive so um I think this week I have extra credit as planet Earth you can watch any two planet Earth videos I really encourage you to watch that the freshwater one it's about fresh water because it's it's just an incredible the massive amount of ecosystems riparian communities all the incredible I don't know life sources of water that's kind of cliche to say because obviously water is a life source but all of the different ecosystems that adapt to water different types of water the way that water carves away our landscape the way that water is such a huge part of our survival okay so I have two coats for you both on guess what water nothing is softer or more flexible than water yet nothing can resist it right and water water everywhere all the board's did shrink clutter water everywhere not a drop to drink it's kind of where we are on our planet 70% of our planet is covered in water only 1% of that water is easily accessible fresh water that we have to share with every other freshwater living organism on the planet so we have water everywhere but not a drop to drink okay so just to remind you of the hydrologic cycle here is the hydrologic cycle we have water a lot of it's in the ocean so when we look at our ocean water that's where most of our evaporated water is going to come from water heats up it turns from liquid to vapor when it becomes vapor it leaves behind any of its minerals that's why we don't have salty water being absorbed up into the atmosphere the salt stays behind in the ocean that should tell you something about water around the tropics - do you think it's gonna be saltier it's salty than it would be here in the mid-latitudes because there's more evaporation happening so there's gonna be more density of salt and then it's saltier close to the Arctic as well because there's more ice and ice when it freezes just like when it evaporates leaves behind the salt so when the only time that water kind of holds its minerals is when it's liquid when it's frozen it leaves behind its minerals when it turns into vapor it leaves behind its minerals so anytime you have like more vapor or more vaporization or more sublimation more freezing then you're going to have a higher concentration of minerals and the surrounding water okay so it evaporates turns to vapor it condenses when it goes up to in the atmosphere remember you need a condensation nuclei for a cloud to form and then it moves sideways affectionally tell that wind rains down and now when it rains down this is what we're concerned with today so we are concerned with what where it rains down to how it gets absorbed how much of it is ground surface how much of it is underneath subsurface water that's what we're looking at today and just to remind you so many percent of the Earth's water is covered for sorry 70 percent of the earth's surface is covered in water ninety seven percent of that is ocean water is saltwater another two percent of that is frozen and just that one percent makes them all the water all over the like the fresh water all over the planet and we have massive amounts of fresh water you know if it's only one percent of all the water that should give you an idea of how much freakin salt water we have out there for one and how much of our water is locked in ice but just think of the Great Lakes and I've posted a video on the Great Lakes just think about the Amazon River the Amazon River is the biggest river in the world people sometimes used to think it was the Nile but with remote sensing one of our main GIS tools we found that the Amazon River is a little bit longer than the Nile but really it has so much more volume than the Nile so the Amazon River the Amazon River the river that runs through the Amazon has it's the biggest river in the world and it has ten so for the okay so for the next ten biggest rivers all of them would fit inside the Amazon that's how big it is so it's the biggest river in the world but the volume of water in the Amazon is so great that the next 10 biggest rivers would fit inside the Amazon that's how freakin big it is the Nile fits inside it the ninety River said that fits inside it the Congo River fits inside it the Zambezi fits inside at the Mississippi fits inside it it is a massive River and that still isn't even like a like a percent like a full percent of the amount of water on the planet I'm going to go through a lot of different terms and I'm going to go through these kind of quickly knowing that you can pause so that you can write down the definition so I'm gonna go through these quickly so you can but you can pause and write down the definition so groundwater that's term that you've probably heard before and what it means it's the subsurface water so it's all the water that gets saturated into the surface and it's stored in several different places it's an important part of the hydrologic cycle the groundwater can be found in many different places in the soil and aquifers I'll go over what that means in just a minute it is what's being stored in the subsurface so not in a lake right not in a river but underneath that hmm here's another picture of our hydrologic cycle shouldn't a solana done and so the groundwater would be all under here this is groundwater our infiltration that's how water absorbs into the soil into the regolith so so infiltration of water is very very important for a hydrologic cycle meaning that the ability for water to rain down so the ability for water to vaporize for one to condense and to precipitate rain back down those things are all very important but so is the ability for that water to infiltrate into the ground so some of that water gets stored into channels and into lakes that water has conveniently carved out for itself so we'll get into rivers and lakes later when we start to talk about how water carves out the landscape but water makes its way into like already established channels for itself channels being rivers channels being lakes but then it gets absorbed and like infiltrates through the soil and goes into what's called our groundwater and the ability for water to infiltrate the soil is very important and think about the things that we might do as humans to inhibit that infiltration the way that we build things remember I said that cement only absorbs about a foot of water every hundred years meaning that it really doesn't absorb any water at all so the more cement we have the less ability that water has to infiltrate and this is very important because we rely on this router and the ability to infiltrate has to do with the ability for the hydrologic cycle to stay uniform so if we cover and we kind of like literally blocking one of the significant parts of the hydrologic cycle it's going to directly affect us and you might think like well doesn't it just I'll run off and collect in a patch of soil that's not covered yes but the ability for it to infiltrate at a certain rate before it before it becomes Overland flow so let's say you have a whole bunch of roads and that blocks the water from infiltrating so then that water cruises off to the side and finds open soil and you think like well why can't it all infiltrate there because it can only take a certain amount and it like it doesn't just talk suck it up right it's not like a vortex so it would take time and then you have flooding and then you have Overland flow so we are inhibiting our ability to to to to continue to rely on the hydrologic cycle and the amount of water that we have underneath us and that water goes to our lakes it goes to our rivers it resupplies the river channel it resupplies the the lakes and here in California our aquifers are really important because we have these long very dry very hot summers and the way that we keep water basically in our lakes and our rivers is mostly reliant on groundwater and that groundwater is fed through the infiltration of water and that groundwater is fed through our Sierra snowpack and our Sierra snowpack that is a permanent pact of ice that lines the spine of the Sierra it's constantly flowing so like you have this frozen basically just imagine like a collection of glaciers along the top of the Sierra Nevada during our long hot summers what happens is those glaciers because they're there year-round they melt and they make their way down they infiltrate the soil they get into the groundwater that groundwater replaces our lakes and our rivers so our long hot summers we have this huge part of our economy that's agriculture and it relies on the ability for water one to come from the snow-packed which by the way is being reduced and reduced every year and to to infiltrate into the soil so if we inhibit our ability to to have water infiltrate the soil we are really really hurting ourselves evapotranspiration that is all of the water vapor that's going into the air so whether it's coming off of like and whether it's like straight-up evaporation so lake water ocean water turning into vapor or whether it's transpiring if you remember I said the word transpire transpire earlier in the semester it's we have pores that let out sweat right water vapor plants do - they're called stomata so if evapotranspiration is all of that together it's the water that's a big that's like turning from water to vapor from a pool of water and it's also the water vapor that's coming from us coming from plants coming from the soil so evapotranspiration is the amount of water that's it's like the total sum of water that's going into the atmosphere and then our soil water belt that's where you have infiltration of water and then you then you have soil many of regolith then there's gonna be part of our soil where you have a little more water and it's like a good mixture of soil and water and then eventually it gets down to what we call an aquifer down here come back to an aquifer in a minute runoff I keep saying that word it's the flow of water that's leaving an area as opposed to Overland flow which is the movement of water over land down a slope so runoff is when you have a collection of water in a place that can't infiltrate that then runs off whereas Overland flow is a more general term of water that's like cruising over the surface trying to infiltrate the soil but there's too much water so it's flowing outwards then over that inflow is going to come in when we talk about flood plains just a minute so you can pause this and get those definitions down percolation again that has to do with like the infiltration of the water through the soil the water table so I mentioned the water table earlier in a different lecture and I'm sure you've heard that term before water table that's that's once you get through basically so you have water that's infiltrating through the soil you have soil you have biomass up here you have soil you have regolith and then eventually you're gonna get to a point down like inside the earth so just not not lithosphere inside the earth but like from where we are going on down to bedrock you should get to a point where there is more water than soil so when it's generally at sea level it depends on there's different base levels for where that water table is gonna take place but here in Santa Barbara it would be at sea level so once you have that water and filtrate down for the soil makes its way down and then eventually you get to a point where there's more water than soil the one of the ways that you have more water than soils you have a concentration of waters that water gets pulled down by gravity but a water table is generally so water table is the upper limit of what's called an aquifer so the water table is the upper limit of where we now have more water than soil and then we get into what's called the saturated zone the saturated zone is what's referred to when we talk about groundwater so when we talk about groundwater when we talk about our aquifers we're talking about excuse me the point where there's now more water than soil and the water table is right on top of that so our saturated zone also called groundwater aquifer is a term that I keep using that is where we see again more water than soil aquifer groundwater and an aquifer also called an underground rivers sometimes it's referred to as an underground river is where again you have more of a concentration of water than soil but in order for an aquifer to exist you have to have something that okay so the water gets pulled down through the soil through the regolith because of gravity and then when you have an aquifer a concentration like an underground river essentially it's sitting on top of what's called an occlude so in occlude right there is a solid impermeable area that's that's under an aquifer so it could be over an aquifer as well but basically it is it's a solid layer of bedrock or it's something that the water can't penetrate so if the water can't penetrate this occlude this layer of rock that's why you get a collection of water so you can have an occluded underneath an aquifer you might have an include underneath and over an aquifer and I have this little concentration right here that's when you really start to see underground rivers but that's gonna include it so and include is the park the water can't get through the aquifer is the collection of water so it gets pulled down by the high gravity it hits an include and that's why it starts to accumulate and pretty soon you have more of a concentration of water and you do of soil so here's our occlude um and again you can pause those so you can see the definitions for longer so groundwater and our water table depending on what we're doing up here the amount of cement that we're building how much water we're using and how wisely we're using that water all of that can affect our water table so when we build a well what we're doing is we're digging down into the earth and getting to the water table so the water table being the top of the aquifer and then we are going down even further than the water table so that we can take water directly out of that underground river alright so if we do that and water continues to recharge meaning that you know it goes to the whole hydrologic cycle it rains down it infiltrates to the soil so then we have this cycle even though we're taking water out through the well it's being recharged the problem is is when we start to take too much water out of the water table and it's not being replenished and it could not be replenished because of drought it could not be replenished because we are using it unwisely like we are you know in a pretty dry place and we're growing almonds almonds are hugely water intensive crop it takes about a gallon of water for each almond to grow so if we are growing something highly water intensive in a place that's prone to drought what gonna see pretty soon is over drawing of that well an over drawing of the groundwater and so what can happen then is a whole depression so I'll get into depressions in just a minute ah the other thing that can happen is you run out of water you run out of fresh water in your local area this is an issue that we see all through California because we we have a we have an incredible agricultural economy here California has three growing seasons because of its unique climate and its multiple multiple different microclimates but we grow these really water intensive crops here like almonds like alfalfa and we grow them in places that get like three inches of rain a year so we're drawing from these from these aquifers these underground aquifers that in a lot of them for example in Southern California in the Imperial Valley there's a huge ancient underground aquifer that's there in part because of the Sierra snowpack and also in part of a long time ago geologic time wise there was a huge Inland Sea in California so Bakersfield would have been covered a lot of the Central Valley would have been covered in an inland sea a lot of that water is still stored underneath California but we are rapidly drawing it out because of our water intensive plants so that's one way that we strongly we can still grow stuff here it's just not watering it just shouldn't be so water intensive other things like in Mexico City for example Mexico City is famously built in a valley on top of a lake and there's a whole aquifer underneath it and as that city has increased in size and urban covering so that you have more cement less water has been able to go and recharge that underground aquifer and what's happening in Mexico City is it's literally sinking it's literally sunk several inches there are some statues that used to be flush with the ground but now you have to build they had to build steps up to because the ground has sunk around those statues and they're now like above-ground so there are some of the issues that we have little hot springs okay so if you remember back to when you watch that video on super volcanoes super volcanoes should tell you the same kind of information that would go into hot springs basically you have that's this is one of the reasons that Yellowstone for example is famous for its hot springs in fact if you've noticed my little picture it's like the icon on my classes and stuff and at Yellowstone in that picture and there's all these like steam coming up behind me that is from these geysers and so you have this super volcano you have this like plume of magma active magma sitting underneath Idaho sitting underneath like all the way to Montana uh and so the Idaho batholith and then you have this you have the super volcano basically that Yellowstone is sitting on top of and as you know from that video super volcano is where you've had a collapsed caldera but so no outlet but you still have this magma underneath and that magma is heating the earth it's geothermal heating the earth so any water that gets trapped down inside Yellowstone gets heated up and what happens when water gets warm enough it turns from its liquid to its vapor State and that paper comes out in the form of geysers and that leads to things like hot springs we have some hot springs here in Santa Barbara and hot springs all over the world and that's that's why they're happening it's basically geothermal heating that's heating the groundwater below us so much to a point where it turns straight to vapor and then that gas makes its way out of the soil and burns you sometimes in Yellowstone it would burn you rotorua is this town in new zealand and there's just like a whole underground the geothermal heat is is very active under rotorua and whatever is a Maori name and you have these like like if you ever go to rotorua there's like you can see steam like coming out of the vents in them in the street and stuff super cool it doesn't smell great just warning so remember I was talking about Lyme stone and how limestone is particularly vulnerable to carbonic acid so limestone if you happen to be sitting on top of limestone if your ground is basically the foundation of it is limestone then what you have probably is a piece of ground that is like being carved away underneath you so if we have limestone and limestone is sedimentary rock that's formed under water so if you have limestone above ground that means that it formed underwater and then uplifted or it formed underwater when there was maybe an inland sea and then that england sea went away so you have water that rains down goes through the soil the soil stores carbon remember plants are doing that for us all the time so nicely we don't even pay them to do that and they're just sucking up all the co2 removing the carbon from the oxygen releasing the oxygen so we can breathe it in thank you very much and then storing that carbon in the soil or in their plant bodies so now we have all this carbon stored in the soil not in the atmosphere would be heating up our climate and water runs through goes through the soil water love it's like it just absorbs that carbon just freakin loves it right it's just like and then it hits the limestone and it carves away the limestone and it creates these huge underground caverns so these caverns lead to what we call karst topography karst topography is a landscape that has limestone underneath it so that limestone is gonna erode and dissolve and now you're going to have caves you might have some stalactites and stalagmites and you might have whole underground tunnels of water I know I've seen very excited about this but this is what geography is you all geography is when stuff starts to connect you know you learn the climate you learn the lithosphere and then you start to see how everything starts to connect and build our entire landscape if limestone wasn't particularly vulnerable to carbonic acid then you wouldn't have these huge underground caverns and those huge underground caverns store water and so now we have these huge freshwater storage units all over the world and guess what those freshwater storage units led to some of our oldest civilizations like the Mayan civilization and the Yucatan Peninsula the Mayan civilization is the only civilization of the first five so of our first five civilizations sewn on our first five cultures we have cultures that are older than our civilizations civilizations that's a it's a term that really relates to economy not to culture it has to do with when you have an economy based on agriculture and then trade that's when civilization starts mmm I like to make I like to point that out because a lot of times people think civilization equals like superior culture doesn't have anything to do with culture so culture comes out as a result of it it has to do with the economy so of our first five civilizations the Mayan civilization is the only one to develop around in the tropics our other first five civilizations they all developed in the mid latitudes in flood plains so Mesopotamia in between the Tigris and the Euphrates the Indus River Valley in modern-day Pakistan the Yellow River Valley Yellow River Valley in China Mesopotamia by the way is modern-day Iraq and then the Inca in the Andes again in the mid-latitudes and the Aztec later but before the Aztec and they're like further up in Mexico before the Aztec we have the Maya and here come the Maya in the lowlands in the tropics now if you've taken human geography from me or economic geography from me or you want to take them in the future we talk all about how civilizations grow around plants that you can domesticate and there aren't a lot of domesticated well plants in the lowlands in the tropics there's a lot of domesticated plants outside of the tropics but the domesticated will plants in the tropics are a lot fewer than the millions billions of plants that aren't domesticated in the tropics so the fact that the the Maya developed a civilization for one in the tropics had to do with their ability to farm maize corn and - it had to do with these huge underground caverns because of the limestone so because of the limestone you have these huge underground caverns of water that the Maya were able to build their entire civilization on away from a river every other civilization had to be formed on a river away from a floodplain they were able to form their civilizations multiple civilizations and multiple like all through the Yucatan Peninsula down into modern-day Guatemala even down into El Salvador Honduras Belize all of those countries because of this because limestone has a particular vulnerability to carbonic acid without that physical geography without that chemical reaction where would the Maya be I'm asking also does anything else live in caves think about it think about it what do we need for life we need the Sun interestingly enough the Sun burns the crap out of me the Sun kills me right it's coming along - just give me skin cancer but everything else you gives life - mm-hmm think about that in our evolutionary code uh so when you're in a cave you don't have life I mean sorry you don't have Sun so does life exist in a cave it does it basically lives off of recycled sunlight so if plants absorb Sun turn it into carbohydrates take carbon and hydrogen together and turn that into food and then other little animals come along and eat those plants and then other animals come along and eat those animals and etc etc etc if you don't have the Sun lights the things that live in the caves live off of recycled sunlight and what I mean by recycled sunlight is literally poo or dead animals so if you think about bats for example bats live in caves and then they come out to where the Sun is and the evening living off the Sun and then they fly back into their caves and there are caves in the world that are full of bat poo bat guano is the nice way to say it and there's entire ecosystems that live off of the recycled protein and carbohydrates of that bat guano it's freaking amazing I know it's hard to take in and talk about poo but like once you realize it's basically recycled sunlight and that we have these crafty creatures all over the planet that have learned to adapt to that recycled sunlight it's just amazing okay so our current karst landscape while it's doing a whole lot underground is also gonna change the what the landscape looks like right do you have if you once upon a time had a block of limestone and then that limestone has a big hole in it what's gonna happen is your your land might sink and so here this is Vietnam Vietnam has a lot of limestone Borneo Southeast Asia all those places have a lot of limestone where you have this sedimentary rock that was formed underwater a long long time ago and is now outside of some of it is now like outside of the water so in Vietnam in Borneo you have these like cliffs that are so sharp because they are basically limestone and the water has rained down on them and left these just like little spikes literally just like spikes of limestone or you can have a limestone cavern which means that your entire landscape collapses so you have these weird little mountains these mountains are not a result of uplifts like most mountains are uplift you're gonna see like dormant cinder cone volcanoes you're going to see something that like was compressed and popped up you know where as what's happening here is basically the land sunk around it so that's what these little holes come from I really strongly encourage you to watch planet Earth caves I gave you the option to watch Planet Earth this week for your extra credit and the caves and the freshwater those are like the ones you should really watch and Jack maybe I'll just make that yeah I think I'm gonna go back and make that say extra credit caves and freshwater mmm because it's one thing to see me talk about it and for you all to think like who is this crazy lady and does she have an outlet for this energy not really one and two it's just because I've seen it all in action and I think it's amazing so it's one thing for me to say it it's another thing for you to go watch it so yeah extra credit cabe's and fresh water made that decision there's a big old hole people jump into that hole they jump in it's so big that they jump into it and they have on parachutes and they like freakin parachute into that that's how freaking gigantic that thing is why because of limestone and also there there's a cave there's a limestone cavern in Borneo that is so big a jet can fly through it now if I could remember the kind of jet that would make a big difference because there's a difference between like a little Learjet and a 747 right let's say it's a 747 I don't think it is that big but it's like in that class can fly through this cavern why because of limestone because sedimentary rock that is limestone is particularly vulnerable to carbonic acid and then you get a hole big enough to throw fly a freaking jet through so we over draw our water like I said and we can get a cone of depression where again the land sinks because water used to be holding it up just like limestone was holding up the previous landscapes we saw Wow water was holding up the landscape and if you take out too much water you're gonna get a cone of depression so cone of depression means that you have this drawdown of the landscape it's cuz you're withdrawing too much groundwater and it's a real problem it's a real problem if you don't have aquifers if you don't have some no sorry if you don't have aqueducts if you don't have a system of water that brings in water from somewhere else here we live in Santa Barbara and you look at other people in the world and you know they're drawing out of wells more like oh that's too bad for them but they shouldn't live there so that's what I hear students say I don't think that um but what I like to point out to people when they say like well people should live there they should move is that we live in a place that doesn't have any water the only reason we don't feel it is because we have these immense systems of infrastructure that bring water in from wet places so we have these systems that infrastructure that bring water in from Northern California Northern California is full of water and not people Southern California has no water and a ton of people seventy percent of our population lives in Southern California and 20 percent of our water is in Southern California how does that work it works because we've built infrastructure around it other people who don't live in places that have built infrastructure around it or dealing with it in a more present way we are we have like the ability to kind of ignore it because we have built this infrastructure around us but that doesn't mean that we're not gonna have to deal with it eventually when you remove water from a wet place you're removing it from that hydrologic cycle so pretty soon instead of having one desert you'll have two deserts instead of having two wet places you will just have two deserts and remember earlier in the semester what I said we do with our freshwater we straight-up in it so I think we should rethink some of the ways that we use our water mm-hmm also I'm we're infiltrating our water in different ways besides blocking water that can be absorbed incident into the water table we're also putting a whole lot of trash in the ground what we do is our trash is we bury it and we have miners around our are what are they called place where we bury the trash what's it called um yeah they only work my head right now with aquifer limestone and the Maya and bat guano a you know a tip trash dump hell are they called Oh second landfill so our landfill has lining but that lining breaks down over time so we when we first started building landfills the first landfill wasn't in the US was in Fresno or maybe this was just California it was in Fresno in the 1940s and in the 1940s we hadn't yet created plastics and we hadn't yet created this entire economy based on disposable plastics so the thing about plastics is they don't break down we've never actually seen plastic break down if it's based on oil it's estimated to break down in about a thousand years but that's just an estimate so that means every plastic product that you've ever used unless it was made out of corn oil is still sitting somewhere in the ground and so what happens when you build landfills before you have a technology that doesn't break down is you line it but that liner is going to break down before what we have in the landfill so as liners break down all the leachate all the garbage juice that we have in our landfills they make their way into our groundwater as well I know I'm painting a super sad picture right now Overland flow remember that is that's gonna come up more with them with flood plains which I'll talk about in a minute and then sheet flow as well both of these things have to do with our drainage systems so how does our water drain hmm water drains in a couple of different ways it depends on what the physical geography looks like essentially the topography looks like so a drainage system is a system just it's like streams its rivers channels it's basically it's basically rain has fallen here before for a long time and that rain has found its way into the ground and out to the ocean or to a lake so the way that rainwater has found its way into the soil into a lake into the ocean is by carving out channels for itself depending on what how much rain you have how wet is the place you live in is going to make a difference with what you're I look like so sometimes we have channels that are only wet part of the air and sometimes we have like river systems or streams that always have water in them these these are all different types of drainage so a drainage basin is a whole collection of these things and I'm going to show you a picture of a drainage basin in just a minute but it's a collection so if we think about here in santa barbara we get most of our fresh water from Lake Cachuma Lake Cachuma is at a higher elevation in the Santa Ynez Mountains we use gravity basically to bring that water down to us but from Lake ahjumma to the Pacific Ocean that's a drainage basin so all the streams all the aquifer all the lakes all the all of the places that water is stored between Lake Cachuma and the ocean that's our drainage basin so a drainage it's a system of like streams lakes channels rivers now these different drainage patterns will again they they have to do with streams or lakes or whatever and like what they might look like so what those patterns of how water gets from a high elevation to a lower elevation depending on what that topography looks like that drainage pattern is gonna be a little bit different so a dendritic pattern that develops when you have a uniform Rock basically when you have something that doesn't have like severe slopes or anything like this you have a uniform rock it looks like a tree branch don't your tree branches right there a trellis is a pattern that's gonna follow in a valley so you have water that makes its way downhill now it's in a flat valley and see the way it's gonna kind of flow you can imagine that's a valley and it's gonna kind of flow like straight through that valley they're also gonna have little branches of where that water might go if there is excess water or yeah and then our annular pattern that's if you have an eroded dome so notice how it kind of like goes in circles imagine you have this eroded um so it's not like sharp its eroded down and that water is gonna kind of like make its path least of resistance right so like it's coming down this eroded dome and like here comes the water it's like what's going on here it's like making its way down so like imagine that's the top of the dome and it's like makes its way and there and then it goes around in a circle it's kind of like what you would hike basically and then this is gonna be a large volcano something that's a lot basically a lot steeper so an eroded dome you've eroded away kind of the tip where is that let's imagine a stratovolcano how's the water gonna run off a stratovolcano it does its radial pattern like basically like flowing straight down for a while and then it kind of branches off once you get less of less of an incline remember that stratovolcano had the really sharp sides steep sides okay and then we get into our stream channels so our stream channels you're gonna break it up in a couple different ways first we have the channel itself so that is that is that is a landform that's created by fresh water by the way water that makes its way from a high elevation to a low elevation carves a nice little channel for itself into the ground and you can tell the different different rivers have different ages one of the ways that you can tell their ages is does it have a V shape does it have a larger U shape right if it's a root it can as it erodes more away it's gonna have a wider and wider base but also if it's coming downhill you're gonna have a V shape because basically it's not carving into the land it's just making a path so it can like shoot down the hill so if you have a river coming down the hill it's gonna follow like a V pattern as it comes down the hill and then once it hits the lower elevation so it's coming down the hill it's got this nice little B hits lower elevation and then it's it's not like just racing down the hill it's gonna form more of a channel for itself which is how it then gets into this nice wide channel so um the gradient that's like is it coming down a hill is it flat is going to affect the velocity that's if it's coming down a hill the velocity is gonna be like right if it's going along a flat plain the velocity is gonna slow a whole lot so it's gonna grind more into the ground whereas if the velocity is shooting straight down it's not grinding so much into the earth it has a much shallower Channel once it gets down here to flat ground it's gonna have this nice white channel here is a drainage system in the US that is the Mississippi drainage basin so that so the Mississippi dismembered right here this isn't an old river by the way this is a middle-aged river and there's there's different ways of showing age four rivers I'll talk about in just a minute but what this Basin or drainage system is basin systems essentially the same thing as it goes from the highest point of elevation in the Rockies so here you have the highest point of elevation in the Rockies and the highest point of elevation and the Appalachians and in between those two highest point here highest point here you have all the water in the aquifers in channels in streams in rivers eventually making their way to the Mississippi or close to the Mississippi and then draining out into the Gulf of Mexico so we have all this water that's coming from the highest point of elevation on the Rockies and the Appalachians and everything in between that and basically New Orleans is the drainage system every single aquifer stream lake river all of it is connecting and eventually flowing out this Delta right here into the Gulf of Mexico now what's happening on the other side of this what's happening on the other side of this highest point is the Colorado River basically like all the water that drains from the Rockies into the Colorado River the Colorado River is so freakin powerful it carved out the Grand Canyon that's how much water is flowing through the Rockies that and some other stuff carved out the Grand Canyon I'll get to that later mmm but um but because this water is like making its way not just imagine like here it's coming through a pretty flat space this is the prairies right the prairies the Prairie so that water like once it comes down the hill now it kind of is like some of its going underground some of its finding its way into channels whereas this it's sharply coming off of mountains and and building this very deep amazing channel that we call the Colorado River that flows all the way from the Rockies through multiple different states carves out though freakin Grand Canyon and then makes its way between Arizona and California and then into Mexico excuse me if I would have thought if I could have paused that before I sneezed I would have um okay so drainage system our biggest drainage system in the u.s. is the Mississippi and notice like how this is light blue what does that mean that's aquifers so that's all the water that's being stored under the soil so what this is showing you is the overland flow of the channels and the rivers and the streams and the underground storage of water and not storage of water when we use water from the Mississippi when we use water from the Missouri that underground aquifer recharges and adds to those rivers and we really depend on these rivers why do we really depend on these rivers I don't know corn like we grow corn basically all through here I'm kind of exaggerating but not really we grow a lot of corn and a lot of soy and we feed most of it to animals that live over here and what we put in this soil makes a big difference because it doesn't just stay in that soil when we're growing enough corn in Iowa to feed the entire country what we're putting into the soil the ammonia the the synthetic pesticides synthetic herbicides synthetic fertilizers they make their way into this aquifer through the Mississippi and down into the Gulf of Mexico and what they've done to the Gulf of Mexico is they've destroyed basically the ability for other species to live here what we have here is what's called a dead zone that dead zone is because you're essentially I'm all these fertilizers coming from the Midwest down through the Pacific Mississippi and comes out here and those fertilizers fertilize the algae the algae blooms all the oxygen out of the Gulf of Mexico and everything else in the Gulf of Mexico basically dies so the shrimp the red snapper all the things that used to live down here that come to this incredible ecosystem along this Delta is mostly dead and so are the economies as well so the reason that I say all this is not because I want to just continue to bum you out is because we all have choices in this all of this exists because we buy into it so if we stop buying into it if we make smart choices we can't affect the environment around us the reason that we built an economy based on this kind of growths of corn that then gets into the aquifer and effects like entire ecosystems down here and economies down here is because we throw our money into it if we stop throwing our money into it it won't be profitable anymore okay so this is what I was saying about the velocity as it comes down the hill it's not gonna have nearly a steep of the channel deep deep of a channel it's gonna go down a very steep slope so it's not gonna be building a channel for itself it's gonna basically the water right here is concerned with getting down this hill it's not concerned with burrowing into the ground so it's just speeding down the hill and then see how it's dug out a deeper pool for itself it's eroded away a deeper pool so now you have more collection of water because there's a gentler slope basically when water is coming down a steep slope it's not eroding away at the landscape of that slope it's eroding the landscape once it gets to a gets to less of an elevation and now that there's less elevation the water isn't being pulled down by gravity as much so now it starts dig out a channel for itself and then goes down deeper pull mmm floodplains okay so so we have water it has dug a channel for itself it comes down a mountain super fast velocities super fast and then it hits the valley slows down builds itself a nice deep channel but every once in a while that channel is going to overflow every once in a while that channel is gonna have too much water in it and when it has too much water in it that's what we call Overland flow so that that water is now gonna go out laterally and what its gonna bring with it is all the sediment all the wonderful things that are in that water rivers are amazing rivers are like our veins in our body so our veins in our body what do they do they transport so blood goes out from our heart and takes oxygen to all the different parts of our body and then that blood picks up all the dirty things that we have in our body and brings them back to our heart and our heart cleans that blood and then sends out the clean blood and oxygen back to our body that is what a river is doing for an ecosystem what it's doing is it's moving along the landscape it's delivering fresh water and oxygen to all the riparian communities all the plants and the animals that sort of riparian community is it's all the plants and animals that basically live next to that river it's delivering fresh water to all of those it also has its own ecosystem in itself meaning that there's fish and all kinds of things living in that in that in that river and those fish are pooing and dying and all of that is carbon that feeds the riparian community so that riparian community is both getting oxygen and nutrients from the water but it's also cleaning the water it's taking the waste out of the water that's what a river system does it's just it's just it's where geography comes together you know it's a you try to pull anything out from the universe and you find that it's connected to everything else you find that the fish who are living in the river are not just living off the river but they're also providing nutrients for all the plants along the river and that plants along the river are providing nutrients for the animals that live along the river and the animals eat other animals that live along the river I'm sorry but you know animals could eat each other and so when we have this overland flow in a floodplain what we're doing is we're taking the sediment and the nutrients and everything all the waste basically nature wastes nothing so all the waste from animal is just food for another community of plants so when we have this overland flow all that sediment all those nutrients they then come out to the soil that's normally not part of that river channel and they get saturated with this sediment and saturated with these nutrients and it makes the soil really really rich which is why we build our civilizations on floodplains because the soil is super rich you have this fresh water that comes through the landscape and that fresh water is delivering water as well as nutrients to the soil and then you also have the trade so if you're growing a whole bunch of stuff you're gonna trade the surplus and you need a water channel in order to get that surplus out but this river is bringing you the water you need for your agriculture but it's also replenishing the soil constantly the problem is is that if you live in a floodplain what's gonna happen every once in a while it's gonna flood and so if you build your house on the ground that can be a real problem that's why so many like Mesopotamia like in Mesopotamia for example or for civilization and modern-day Iraq the people who lived on the floodplains they grew plants on the floodplains but they usually put their houses back or they had migratory houses that they can pick up and move or they put them on stilts because they live in a flood channel alright and here is the Mississippi the Mississippi the Mississippi the lifeblood of the Midwest uh feeds all of these these farms all through the Midwest but we're also affecting it in the way that I said earlier where we're basically putting a bunch of ammonia synthetic fertilizer synthetic herbicides into that River but we're also growing like I said in an earlier lecture a lot of corn and that corn only grows from like summer to fall the rest of the year it's all open dirt and the problem with that is like I said earlier when that dirt basically when we have Overland flow when the Mississippi and all of its tributaries those are the rivers that feed into the Mississippi are called tributaries when that whole drainage basin has Overland flow because it's going to it's part of a floodplain you're gonna see flood plains all through here and when we just have when we don't have Prairie holdin down the soil when we just have soil exposed what are we gonna have increased flooding erosion basically like every time any of the tributaries of the Mississippi Flood it takes away half the soil of the Midwest and half the soil of the Midwest is really important to our survival because what we grow what we what we depend on our annual plants not perennial plants but plants that only live for a year and so if you only live for a year your roots when they get so deep perennial plants because they live for years and years and years and years their roots are way down here right but annual plants the ones that we live off of their roots are right here so the soil just at the very top what we call the topsoil the soil at the very top of everywhere is really important to our survival because if you have soil at this like top layer that is nutrient rich that is rich in houmous humans like he misses like the good biomass that feeds our soil if you have that top soil that's nice and rich and houmous rich and all that good stuff well it's gonna feed our annual plants but if we're doing things like leaving our topsoil just totally exposed for half the year so that it gets picked up and pushed away by friggin an overland flow then what we're gonna see is a degradation of our topsoil and that topsoil is is incredibly important to our survival our survival being highly dependent on the health of that topsoil and the health of our water and again I tell you all this not to depress you not because I want you to think like well everything is just screwed it's because you have a choice you are all the people who need to take over this world and start to do things right you know start to I mean we can so simply fix this issue in the Mississippi and in whole drainage basin if we just rotate crops I have a video on here that you're gonna watch on how if we rotated I think corn and oat and maybe soy throughout the year that we would reduce first of all the need for synthetic herbicides by like 30 percent and we would also reduce this flooding so a lot of the times these huge problems that we see in the world have really simple fixes we just need to do them we just need to do them okay and if we have the Mississippi flooding we also have towns that are flooding and those towns that are flooding are going to be upset hmm so yeah all right oh I need to uh I need to talk to you about the age of rivers so our rivers here we go here's our white board again um a rivers like I said there there's different types of channels and those channels if you're going downhill it's gonna be more of a V if you're going if you're like in on like a plane you know a valley it's gonna be like it much deeper you but a river has a different age so you have an you know new collection of water making its way down a hill into a valley it's going to carve out a channel for itself as it carves out that channel for itself the longer it's carving that channel the different that channel is gonna look so basically rivers start out in like a real extreme just like right there just there finding like the easiest path to make their way from higher elevation to lower elevation so and a young River year it's just like it's just cruising through life it's just like I don't care what's gonna happen to me I'm gonna live forever I'm just going to do anything I want to and no consequences right bounce back what's a hangover that kind of thing and then you know you live a little bit longer you start to carve out more like you know you're going a little bit slower you don't bounce back nearly as much you really feel that hangover so your Manders that's the curve of a river it's following me under you're me and oh man Locke meanders start to UM they start to curve out right they start to smooth out a little bit yeah here your edges are all jagged you know they're just uh they just they're they're gonna live to see another day you know they're gonna live forever here you're kind of faced with mortality a little bit more you slow down start to smooth out your edges and then eventually you get into old age and you are just not in a hurry to get anywhere you have carved out a channel in life and you don't care whose way it gets into you've been here for a long time you deserve it right so that's when we're gonna get some wide meanders just slow running river that's an older river so along the way some of our early meanders from our young life we might find out don't really work that well in the long run so you start to carve out a different channel which is how a river like this look at this do you really think it's gonna continue on this meander forever or is it basically gonna flood a little bit and pretty soon you're gonna have a meander right here and this I just erase that whole thing can I not gonna go back all right well I'll just drive so now you have found a new path you know started out life you were like I'm gonna do finance and then after a while you're like you know and I'm like finance think I'm gonna be a I don't know accountant all right so now over here cuz you know you're still working in finance but it's not quite rough so you've got this old man door over here that's now cut off and remember this river use demand are all the way around but pretty soon it's found like kind of a shortcut for itself you know capital gains or whatever and now it finds a better path for itself but you have this old meander that's still hanging out we call that an oxbow lake so one of the signs that a river is older is that it has this oxbow lake just what used to be a connected meander is now this little crescent look in lake and so that oxbow lake is something that you're gonna see next to an older river a river that has defined itself longer has a there's a more clear path for itself understands there's sounds what it's doing a little bit more I don't know this analogy got away from me okay so going back over here are see notice that in this river which is older it has these broken off meanders those are oxbow lakes oxbow lakes when an oxbow lake dries up if it does dry up that's what we call a bog or it could be swampy right if you imagine a swamp it's like more mud and water but it's still got that a little swampy feel to it lake in case you weren't sure what I was talking about when I said lake is a body of standing water it's often it's generally part of a river system so you've got like a river feeding it and then you've also got an outlet that's why Lakes tend to stay so clean because they're basically constantly being replaced whereas a sea a sea is when you have just water coming in but no water going out and that's why seas can often have more minerals the Dead Sea for example they often have like more of accumulation of minerals they often don't have nearly as much alive in them because basically they are they have no so they're not they're not like in and then out it's just everything is coming in and so it doesn't allow for it has more of an accumulation of sediments and and it can inhibit some life it has its place in physical geography it's not like oh no we don't want to seize it that's just the difference one has the lake has the outlet the sea does not have the outlet ah body water standing with you you get it don't you know lake is mmm and then with sprawl if I was talking about earlier as we grow our cities with the type of cement that we grow our cities with right now we can grow our cities with permeable cements we can still continue to live on this planet in fact we can live very beautifully on this planet we have the technology to do so we just have to apply it so the more we are sprawling the more we have this runoff and not run off like I said doesn't get infiltrated into the groundwater it often runs off directly into the ocean so I'm never going into that groundwater never never I'm rehydrating the hydrologic cycle I'm looking around the world here's our water supply around the world look at North America has a lot of water the Mississippi drainage basin look at the Colorado right there the Columbia drainage basin Canada has 60% of the world's lakes so Canada has 60% of the world's freshwater lakes basically Canada used to all be frozen when I get into glaciers and periglacial environments I'm going to talk about how Canada was all frozen at one point there was just an ice sheet over all of it when that Ice Sheet retreated a dug out big old holes and then filled in with the water of the ice sheet that was melting look I just talked about it leaving a whole lot of a whole lot of lakes here is the so remember this is showing aquifers as well as rivers so there's the aquifer that is feeding the Amazon remember the Amazon is the biggest river in the world it is so big that the 10 biggest other rivers fit inside it Africa has a lot of water a lot of people are like Africa has no water that's not true Africa's tons of water it has the Niger aquifer right here it has the Congo River base it has water all through the East African Rift Yuja has a whole lotta water but all that water under Russia under China you know who doesn't have water in Australia has no water okay so water access and supply what else what point did I want to make you know take note that Australia has no water no water look at it look at the only water is coming here from the Appalachian the Australian Alps and that's where the water is concentrated that's where the people are concentrated to smartly enough there's really nobody who lives out here mmm okay I think that's it next time we will talk about how the water carves out the landscape