00:02 Good day, everyone.

00:12 I am Mr. Ife.

00:14 The basic science is so tough.

00:16 And our lesson topic for today is

00:19 environmental hazards one.

00:21 A quick run through to the objectives.

00:25 At the end of the class,

00:26 students should be able to explain soil erosion.

00:29 And identify human activities that causes erosion.

00:34 Number two, student should be able to describe

00:37 methods of controlling erosion.

00:41 Number three, student should be able to describe

00:45 practical methods of preventing erosion

00:49 on a given farmland.

00:52 Number four, student should be able to describe

00:54 different types of drainage patterns in their community

00:58 and state the causes of flooding.

01:01 Number five, student should be able to describe

01:03 how flooding can be prevented

01:05 and discuss the effect of flooding environmental hazard.

01:10 Environmental hazard is a time used for any situation

01:15 or state of event which poses a threat to the surrounding,

01:20 to the surrounding environment and adversely affect

01:24 the plant and animals.

01:26 So in summary, environmental hazard is anything

01:30 that poses a threat to the environment

01:32 which includes the plant and animals.

01:35 Soil erosion, soil erosion is a washing away

01:41 of the soil, either by every rainfall or by wind

01:46 resulting to the formation of golly and landslides.

01:51 And so living behind suits on which plants can no longer

01:56 grow.

01:57 The picture above shows in land

02:01 that has experienced soil erosion.

02:04 You can see this landslide and on this kind of land,

02:07 planting can not take place.

02:10 Soil erosion can also be defined as the removal

02:15 of top soil faster than the soil forming processes.

02:20 Can replace it due to the natural animal

02:25 and human activities.

02:27 So there are animal activities, there are human activities.

02:33 One of the animal activities that causes soil erosion

02:36 is over grazing.

02:37 Because of this class, we will learn what over grazing is.

02:41 Over cultivation, forest clearing,

02:46 mechanized farming, ETC.

02:49 Now soil erosion results in land infertility.

02:55 That is the land who will not be fatally north

02:58 for the production of plants.

03:00 It will lead to desertification

03:04 and devastating flooding.

03:07 Now, the causes of soil erosion

03:11 what are the causes of soil erosion.

03:16 Number one, one of the major cause of soil erosion

03:23 is excessive rainfall.

03:25 And less excessive rainfall due to excessive rainfall,

03:29 soil fatally soil is washed away.

03:33 The soil for planting,

03:36 the part of the soil that is responsible for nutrients

03:41 of the plant is washed away.

03:43 Number two, human activities.

03:46 Human activities accelerates disappearance

03:50 of protective cover of natural vegetation.

03:53 When human activities are too much

03:57 on the particular land,

03:58 it removes the cover and thereby exposes the land

04:03 to soil erosion.

04:05 Number three, over grazing in the picture below,

04:09 you can see cuttles.

04:11 It's in from the grasses in the soil.

04:18 And when there's too much of over grazing,

04:21 it leads to the absence of ground vegetation

04:25 and causes gradual depletion of soil,

04:29 of soil organisms and soil erosion.

04:31 Number four, the land use.

04:34 Human play a major role in soil erosion

04:38 through their use and abuse of natural resources.

04:41 For example, deforestation,

04:44 caught in down of trees,

04:48 grazing, that's the animals,

04:49 eating the grasses on the field,

04:52 arable land use,

04:54 faulty farming system,

04:56 eye crop intensity, construction, mining,

05:01 all these are human rules on the farmland

05:05 and they can cause soil erosion.

05:08 Climate, the two most important climate factors

05:13 are being a direct effect on the erosion,

05:17 are precipitation and wind velocity.

05:19 Presipitation is rainfall and wind velocity.

05:23 The amount of rain and the amount of wind

05:27 can determine how the edge crust or the soil

05:32 is eroded out of the land.

05:35 Bush burning, burning or bush.

05:38 Types of erosion, what are the types of erosion?

05:43 What are erosion?

05:47 Water erosion is the removal and carrying the wheel of soil

05:50 particles by rain.

05:52 The running of water, the melting of highs,

05:56 the running rapidly over and exposed soil surface.

06:01 When you have running water on the soil surface,

06:06 it's exposed the land and thereby causing soil erosion.

06:13 Here, the picture below can see the landslide.

06:18 The land is not leveled.

06:20 Why? Because of constant water flow.

06:24 So water is a factor for erosion.

06:30 Number two, wind erosion.

06:34 This is the blowing away of the soil particles

06:39 or the top soil by wind.

06:42 Wind erosion is common in arid, ground, dry land.

06:47 We age as little or no rainfall.

06:50 Now, when there is no rainfall in a place

06:54 and there is every wind,

06:57 it blows away the soil particles

07:02 and thereby causing an unleavened ground.

07:07 And so planting cannot occur on such a land.

07:13 Effect of soil erosion.

07:16 What are the effects of soil erosion?

07:18 Number one, reduction in soil quality,

07:22 which results from the loss of the nutrient

07:25 rich upper liars of the soil.

07:28 One of the effects of soil erosion

07:30 is that I'm going to cause the reduction of the quality of the soil.

07:34 The soil is supposed to be rich enough

07:38 for the plants to absorb its nutrients.

07:42 But the quality is wiped away.

07:44 Number two, reduces water-ordering capacity of the soil.

07:49 That's an effect to reduce the water-ordering capacity of what the soil.

07:55 Number three, displacement of people from their homes

08:00 to displaced people.

08:02 Destruction of farmland.

08:05 Colossal building.

08:07 Damage of soil surface and roots.

08:13 The picture you can see the collapse of building.

08:17 We move to the control of soil erosion.

08:20 How can we control soil erosion?

08:22 Number one, planting of vegetative cover

08:27 when you defolrest.

08:31 You plant again.

08:35 And you call down the tree, you plant.

08:38 So planting of vegetative cover.

08:42 Covas and shields the soil to shield the soil from the soil.

08:47 So cover crops such as tree, grasses, shrubs

08:52 can be planted to cover the soil surface.

08:55 This will reduce the effect of rainfall on the soil.

09:00 The picture below shows plants on the soil.

09:04 Number two, avoidance of indiscriminate bush burning.

09:11 We need to avoid indiscriminate bush burning.

09:16 Bush burning exposes the soil to erosion

09:19 because the vegetative covers are bonked.

09:23 When you burn the bush, the soil is exposed.

09:25 Number three, avoidance of overgrazing.

09:28 Overgrazing is when animals feed on their valuable plants that are on the soil.

09:41 So plants should not be overgrazed to prevent water erosion.

09:45 When the soil does not have any plant and water flows,

09:50 it washes the top soil.

09:53 Four, mulching.

09:55 This is the covering of ridges, beds and mounds in the farm with leaves.

10:01 So covering those ridges with leaves is called mulching.

10:09 Dry grasses and shrubs.

10:11 Mulching reduces the impact of rain drops on the soil

10:16 and thereby prevents erosion.

10:19 Crop rotation.

10:22 This is the growing of certain crops in an order

10:27 and rotating them every plant in season.

10:29 Crop rotation is having a land.

10:34 When you use a land for this year,

10:39 next year you leave it to get back its strength.

10:43 You don't plant the next year.

10:44 You rotate the crop by planting in another farmland.

10:52 So that the previous farmland that you use this year

10:55 can regenerate the nutrients back.

10:59 So that's crop rotation.

11:00 So this is the growing of certain crops in an order

11:02 and rotating them every plant in season.

11:05 In order to maintain soil fertility.

11:08 And also prevent water erosion.

11:11 Number six, application of organic manure.

11:14 Organic manure

11:15 are matters.

11:17 Prevent loss of water from the soil

11:20 and mix the soil moist at all times.

11:24 So when we have organic manure,

11:26 that's it in the picture.

11:27 We have organic manure.

11:29 It will prevent the loss of water

11:31 and will keep the soil moist all the time.

11:35 This makes the particles of the soil edgy.

11:38 For wind to blew away.

11:40 Number seven irrigation.

11:42 Artificial irrigation.

11:44 Artificial application of water to the soil

11:47 will make the soil moist.

11:50 Now the soil needs water.

11:52 So that it can be moist.

11:53 In the picture below,

11:54 you can see an irrigation process

11:58 where the water is sprinkled all over the place.

12:02 There by binding the soil particles together

12:06 and preventing the soil particles

12:08 from being blown away by the wind.

12:11 Flood.

12:12 The picture above shows

12:14 a community

12:16 where flooding took place.

12:19 Flooding can be defined

12:22 as an overflowing of water onto the land.

12:26 It also occurs when there is more water on the surface

12:32 or the land than it can take.

12:35 When there is too much of water on the land

12:37 than it can take.

12:38 And as a result of this,

12:40 a bad drainage system will cause

12:43 overflowing.

12:44 This may lead to river overflowing its bank.

12:47 This bay home was built on the cliff

12:51 that has undergone severe erosion.

12:55 The picture below shows a bay home

12:58 which has gone undergone severe erosion.

13:02 Many people battle erosion by planting grasses

13:05 and trees to form a strong root system

13:08 or lay down netting to keep rock

13:11 and soil from washing away.

13:14 We move to the causes of floods.

13:17 What are the causes of floods?

13:18 Number one, deforestation.

13:19 When large areas of forest

13:22 near the rivers are cleared,

13:24 the land may be used for settlements,

13:27 roads and farmland.

13:28 This raises the river bank.

13:31 So the river overflows its banks easily

13:33 and then flooding or cause.

13:36 Deforestation is one of the cause of floods flooding.

13:41 Number two, poor water management.

13:45 When the dams are poorly constructed

13:48 or maintained,

13:49 they can easily collapse

13:51 and this result

13:52 into flooding.

13:55 Number three, population pressure.

13:57 Because of large amount of people,

14:02 more food,

14:03 root and need aid for consumption.

14:06 Thereby leading to overconservation of lands

14:10 which leads to erosion

14:12 and increase in the risk of flooding.

14:14 When there are too many people

14:15 in your community,

14:16 you begin to source for food,

14:19 you begin to source for food and wealth,

14:22 root as a source of wealth.

14:23 And overconservation occurs in that community

14:28 and such the exposure of lands.

14:32 And when rain falls and when wind blows,

14:37 it washes away the top soil.

14:39 Number four,

14:41 I rainfall.

14:43 The amount and intensity of rainfall

14:47 determines the amount of runoff on the land.

14:50 And this will determine the amount of water

14:52 available for flooding to occur.

14:54 So I rainfall is another cause.

14:59 Number five, closeness to the sea or ocean.

15:02 Imagine a community that is close to the sea.

15:06 It's bound to have over flooding.

15:10 When the level of your water rises above the bank

15:13 of the sea or river,

15:15 flooding occurs in areas close to the sea or the river.

15:20 Number six, social habits.

15:23 What are social habits?

15:24 We have people tend to build structures

15:26 to block drainage system.

15:28 DMB blockage of water channels and free fuel of water

15:33 is in that which may lead towards to flooding.

15:36 Effects or consequences of flooding.

15:40 What are the effects or consequences of flooding?

15:43 Number one, it will result into the loss of human life.

15:48 You can see in the picture

15:51 the house as collapsed as a result of flooding.

15:55 Number two, the damage of properties.

15:58 Number three, deteriorating of health conditions

16:03 or into water-borne disease.

16:05 The people living in this environment in the picture

16:09 will be prone to water-borne diseases.

16:11 People are forced to leave their homes

16:14 and normal life is disrupted.

16:17 Number five, disruption of industry can lead to loss of livelihood.

16:24 When there is flow, the industry that are around

16:27 water goes into them and destroys the industry

16:31 and thereby people will lose

16:33 their jobs and their livelihood.

16:36 Number six, damage to infrastructure

16:40 also causes long-term impact

16:42 such as disruptions to supplies of clean water.

16:47 Effects of flooding on our farmland.

16:51 What are the effects of flooding on our farmlands?

16:53 Number one, widespread damage to crops and fencing.

16:57 The effects of flooding on farmland.

17:01 Number two, loss of livestock.

17:04 Number three, what are logged soils?

17:09 Number four, delaying our vest

17:12 are further intensified by transport problems

17:16 due to flooded roads and damage in our structure.

17:19 Number five, food prices increase

17:23 due to shortage, shortage in supply.

17:25 Providey is number six.

17:28 We move to prevention of flooding.

17:31 How do we prevent flooding?

17:34 Number one, constructions of dams

17:38 to take excess water that may lead to flooding.

17:42 Seeing the picture, there's a construction

17:46 there and it can't take as many as possible.

17:51 So the construction of dams will take

17:54 excess water.

17:56 Number two, construction of reservoir

17:59 that will hold excess water

18:02 which can be used for other purposes.

18:04 When there's a lot of flooding,

18:05 we need to construct reservoir.

18:07 Now we take in those water and store them

18:12 for other purposes.

18:14 Number three, claim of gutter or waste

18:18 that can prevent free flow of water.

18:22 This is why we observe environmental

18:24 and environmental sanitation.

18:26 We'll clear our gutters

18:27 for things that would block the drainage system.

18:32 Number four, prevention of construction of structures

18:37 are long river and sea bank.

18:39 Constructions of buildings are long

18:42 seaside should be prevented.

18:45 Number five, having adequate and proper time planning

18:50 which will bring about construction of adequate drainage system.

18:53 Every community asks their time planning

18:58 developers.

18:59 It is necessary that before

19:04 we plan our houses, we need to get to the time planers

19:09 and make sure that the construction of our houses

19:14 are in line with adequate drainage system.

19:18 Number six, education, proper education.

19:20 She'll be giving to the people

19:23 drainage patterns.

19:26 What are the drainage patterns that we have?

19:28 So, what exactly is drainage pattern?

19:32 drainage pattern is the process by which water

19:35 or liquid waste is emptied from an area.

19:38 The way the water is being drained out of an area

19:48 and what are the times of drainage patterns?

19:50 Number one, surface drainage system in the picture.

19:54 You can see

19:57 there's a building, there's a construction of holes there

20:05 such that when the water flows from the roads

20:09 it enters into those holes

20:15 and then the end time to the goters and flows.

20:18 The surface drainage system, this is type of drainage system,

20:21 is found in rural areas and it is not designed by qualified engineers.

20:26 So, when the drainage systems are not designed by qualified engineers,

20:29 it can cause erosion.

20:32 Number two, sub-sophage drainage system.

20:37 The sub-sophage system is covered with concrete

20:42 wild water flows on the ground then preventing overflow of the boundaries.

20:48 It is designed by qualified engineers.

20:51 This type of drainage is usually found in cities such as Abuja and Legos.

20:56 Evaluation.

20:58 Number one,

21:01 students are expected to explain two activities

21:05 of man that promotes erosion.

21:09 Number two, describe two methods of controlling erosion

21:13 and practical method of preventing erosion

21:16 and giving farmland.

21:19 Number three, states two causes of flooding in their community

21:25 and describe two ways of preventing flooding.

21:29 Also, mention the effect of flooding on the environment.

21:33 Thank you for watching.

21:36 I am Miss Saifere.

21:40 Till next time.