Hello there pre-meticulants, welcome to Educate. Let us talk about geomorphology, particularly the topography associated with horizontal strata. So first of all, what is topography?
Basically topography is just the relief or the shape of the land. If the land looks like this, that is topography. If the land looks flat, that is topography. It's all about the build of the area and how the land looks like in general. And then when we are talking about the strata, we are talking about the layer of rock.
It's just layer of rocks. So whenever we're talking about topography associated with horizontal strata We just want to see the landforms or the shape of the land when we have got horizontally layered rocks So where does it start? It starts here when we have got lava that is erupting from underground. This is known as lava Basically, it's just a volcano.
It is actually coming from molten magma that is found deep down under the earth's surface So when a volcano erupts in this case the lava or this fire liquid, the one that is actually the molten magma, the one that is erupting, it will actually solidify. It will actually become solid and it actually forms a mountainous like shape and we say this is known as a basaltic plateau. So this is known as a basaltic plateau which just results as a result of the solidification of this lava. So this liquid-like type of thing here, this liquid-like type of thing that you are seeing erupting from the ground, it will eventually be exposed to the air and it will solidify or it will become solid or is a cleaner if you want to use this as well.
But basically it's going to be rigid and it's going to form a mountainous-like shape. So this is known as a basaltic plateau. So a basaltic plateau, to write it in words, we say that lava pours out through the cracks from the ground So basically for the lava to actually come out and erupt here from the ground, it is actually moving or it's pouring out through the cracks of the ground. So basically the ground has got smaller cracks and those cracks allow the lava to erupt from under the ground.
And then over millions of years, there will be continuous eruption of lava and then it will eventually flood out the landscape. So as this lava is pouring out here from the ground, it will eventually fill out the entire place. And when it fills out the entire base, this lava will solidify or the lava will become a solid basically because you can see that the lava here it looks like it's liquid this thing that looks like fire. It's actually a liquid, it's a molten molten magma actually. So it actually solidifies, it becomes a thicker or it becomes a rigid and then it forms thick layers of basaltic rock.
So basically we say that basaltic rock is formed by this erupting lava and then this basaltic rock will lay horizontally of course and when it lays horizontally this will form a basaltic plateau with uniform resistance to erosion so basically a basaltic plateau is formed due to lava that erupts from under the earth's surface or underground so this basaltic plateau has got uniform resistance to erosion Meaning that whenever there are some agents which want to wash away the type of rock, it is uniformly resistant to that erosion. It's able to resist erosion in all parts of it. Are all able to resist erosion in an equal manner in a sense.
So that's basically where we start. We start with the basaltic plateau. Okay, we start from the lava that is pouring out from the ground or that is erupting from the ground.
Then it becomes solid. or it solidifies and then it forms a thick layers of basaltic rock and they lie horizontally and then this will lead to a basaltic plateau. So remember this is all about the shapes of the land or the topography or the relief of the land which is associated with horizontally laying rocks. That's why we say here the basaltic rock lies horizontally.
So now the plateau actually becomes a canyon. So a plateau can become a canyon. So how is that? Look at this.
This is a plateau and it's known as Colorado Plateau. So this Colorado Plateau is basically, we can see that it is just a layer of rock, a big space of basaltic rock that is filling out the land. So this is actually the Colorado Plateau. So now look at this. This is now known as a canyon.
So what do you see as the difference between the first and the second image? You can see that at this first image, you have got just layers of rock okay you have got just layers of rock that is known as a plateau it's just a a huge piece of rock um which is forming from lava right so this one is a colorado plateau that's the name of the plateau but now you can see here At the canyon we have got a river that is in between the plateau. So in a basic sense for us to form a canyon from a plateau, what's basically happened? The river actually cuts down into the what? Into the plateau.
So in a sense, this river here, the river will actually cut down into the lower layers of the plateau. So the river actually erodes. We say it is eroding. Remember that water has got a...
an ability to just wash away things. So in this particular sense, the water from the river here, it is cutting down vertically on this plateau to make it a canyon. So this is known as Colorado Plateau, but when it is like this, it's now known as a canyon.
So in a basic sense, a canyon is just a plateau that has been eroded by a river. So to explain the formation of a canyon landscape, you have to say that this is your Grand Canyon. Okay, this river is known as Colorado River.
This is Colorado River. It is the one that actually erodes Colorado Plateau to make it the Grand Canyon. So this is Colorado River.
It's just an example of a plateau. So now the canyons, they form on rocks with varying resistance to erosion. So I might have told you that the basaltic plateau has got uniform resistance or the resistance to erosion.
It is the same at all points. But in a basic sense, a plateau becomes a canyon. Basically the canyons form on the rocks with varying resistance to erosion, meaning that some of the layers of the rock are less resistant to erosion.
They are easily washed away. Some of them are more resistant to erosion. They are not easy to wash away.
So now basically this is the first point. Now you mentioned that the rivers erode vertically into the land and they form deep valleys. So basically The river like here in this case you see that we had just a Colorado plateau but because we have a river that is eroding down, a river that is flowing washing away all this part of the rock that is eroding downwards or that is eroding vertically, they erode the plateau vertically.
So basically the rivers erode vertically and they will form deep valleys. You can see that this valley is very deep okay. So basically they form deep valleys because they're eroding downwards.
They're actually cutting deep down into the ground. So the rivers, as they erode, they cut deep down to the ground and we end up forming deep valleys. Basically, the valleys we are talking about the bottom parts of the mountain. So here, these bottom parts of the mountains, these bottom parts of the mountains, they're known as valleys.
So these valleys are going to be very deep because the rivers are eroding vertically or they're eroding downwards. they're actually washing away the ground and they are cutting deep into the ground. So basically here if we look at our landscape, our canyon landscape, here on top we'll just pretend that the top layers are more resistant so they will form cliffs.
We say they're known as cliffs and those cliffs are very steep. And then the less resistant layer is the one that I found at the bottom, at the bottom of the mountain. Those ones are less resistant and they will form gentle slopes. We are still going to do slope elements later on, but just so you know that the top layers, they are more resistant to erosion and then those top layers that are more resistant to erosion, when they eroded, they actually form steep cliffs. They are very steep, but the bottom layers, the ones that are found here at the bottom of the mountains or that are found at the valleys here, they form gentle slopes.
So this is how basically the Kenyans developed. So the canyons basically develop from the plateaus. So in a sense here, we start with lava. The lava solidifies to form a plateau. Then the plateau is eroded by the river.
Vertical erosion, of course. And then due to that vertical erosion, we end up forming the canyons, whereby more resistant layers will form steep cliffs when eroded, and less resistant layers will form some gentle slopes. I'm sure you know the difference between gentle and steep.
So now canyons are important because they've got several functions. We can build dams on canyons. So you can see that the valleys have got a lot of water and then the rivers actually cut deep. So we can actually build dams on canyons or we can build dams in canyons to generate hydroelectricity. Remember that we can generate electricity, basically hydroelectricity.
It is the one that is generated from the power of the water. So basically If we build a dam here on a canyon, for example this Grand Canyon, if we were to build a dam there we would be able to generate electricity using water. That is known as hydroelectricity. It is the one that is...
generated from water. So that's an economic advantage. Whenever they say what is the advantage of having canyon landscapes? The advantage of having canyon landscape is that you can be able to build dams and those dams since they are rivers the rivers are deep so you can be able to build dams and those dams can be used to generate hydroelectricity because the water flows fast with the force so we can create electricity from that.
And then the other thing is that the canyons have got beautiful scenery or they've got aesthetic beauty. When you say that the scenery of canyon is beautiful, simply you can see that here this Grand Canyon is a tourist attraction. Many people who are interested in touring and looking at such great places, they will actually be happy to go to some place like the Grand Canyon and they will attract tourists. and this is an economic advantage because the more tourists come and they take pictures and they tour around this place and it actually benefits the economy okay it benefits the economy of that country just like this is just like a national park like your crook national parks and all of those parks that you can visit they help to generate econ um they actually help to generate money for the country so this beautiful scenery when you say beautiful scenario just talking about how beautiful the place is or they can say it is aesthetically pleasing They can say that canyons are aesthetically beautiful or they can say they are aesthetically pleasing.
This just simply means that they look beautiful to the eyes of a human being. So basically they will attract tourists. So now these are the disadvantages of canyons or these are the limitations of canyons.
Agriculture cannot be easily done on canyons okay. Agriculture in in general okay most of the times are talking about they they they clump up agriculture So the agriculture cannot be done easily due to the dry plateaus. So the plateaus are dry.
So you can see that here, we don't have any trees. And these canyons, they basically form on places that do not have trees. Okay.
There is low rainfall there. So basically, we can say that here, agriculture cannot be done easily because basically the place is dry. When the place is dry, you cannot plant any crops. Okay.
even if you were to bring livestock here, it is very difficult to even feed the livestock because where is the livestock gonna eat grass? There's no grass here so it's basically a dry place so agriculture cannot be easily done due to the dry plateaus. And then the rivers are also too deep to access water for irrigation.
Let's just say for example you want to do crop farming, maybe you want to plant some crops or maybe you want to plant some maize mill or what. You cannot do that because in a basic sense you can start it is dry number one. So if you try to to get water from the rivers the rivers are too deep so how would you actually be able to climb down the mountain you are climbing down the mountain so that you can access water at the bottom of the river since we have said that the valleys are deep due to vertical erosion or due to downward erosion it is not easy for you to be able to get to excess water for irrigation or to excess water for watering your plants so in a sense the canyons they've got rivers that are too deep or valleys that are too deep. You can say valleys or rivers, still the same context. So in this way, the rivers are too deep to access water for irrigation.
And also the steep slopes here, they act as barriers for building transport roads. So as we've already said that the more resistant a rock, they will form steep cliffs. So this is very steep.
You can see that if you were to stand here, you would easily fall down because the gradient is steep. So in our training about steepness, we just aim. asking ourselves would you fall if you were to stand on that place if it is gentle you wouldn't fall if it is steep you would fall so in a sense you can see that there are loads of steep slope there are loads of what of steep slopes on canyon landscapes so since there are loads of steep slopes on canyon landscape it will be easy for you to fall here so basically if you want to build let's just assume that you want to build the road here and you want to Maybe build a transport route or maybe you want to do some production using this land. It would be so difficult.
You can see that there are no roads around the Grand Canyon. It is basically because this steep slope acts as a barrier for us to build roads. We cannot actually build roads due to these steep slopes.
The roads are just going to fall off and then eventually they won't be able to work properly. So these are the things that you can look at canyons. But just to revise, remember everything starts here at lava. We have got lava or we have got a volcano that is erupting from deep underground. They can say it is known as molten magma.
It is still the same thing. And then this volcano will solidify. It will solidify or it will become thicker and it will form what you call a basaltic plateau.
So the plateau is just a piece of huge land, a huge rock. It is very thick. It's just a piece of thick rock.
and then now you explain how basaltic plateau forms and then the next thing this basaltic plateau is eroded by a river so the river cuts down the river erodes downwards or it erodes vertically on the what on the on the plateau and then when the river erodes successfully and enters the entire plateau we say it is known as a canyon landscape so a canyon is basically a plateau that has been vertically alluded by a river They are eroded by what? By a river. So a canyon just comes from a plateau. So we started the plateau, we go to the canyon. So now you also explain how the canyon forms due to this downright erosion.
You also proceed and explain also the importance of canyons. That's usually asked in the eight max paragraphs question. And then you also need to apply the disadvantages of canyon landscape. So thank you guys in the comment for watching this video.
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