Some people say that soil is the most precious resource on the earth. How do we explain this view? Tell your reasons and share your opinions with your classmates.
2. Show pictures and written materials for teachers to explain and students to read and learn.
3. Talk about the relationship between soil and human beings.
4. summary.
Fourth, extracurricular activities.
Read Gao Shiqi's poem Mother in Our Soil.
Blackboard design:
Postscript of teaching:
Lesson 5 Erosion of Land by Rain
Teaching objectives
Scientific concept:
Rain and runoff will take away the soil on the surface and erode the land.
Erosion changed the topography of the surface.
Process and method:
Through simulation experiments, the erosion of rain on land is discussed.
Record the experimental results with words, pictures and symbols, and describe the phenomena in the experiment with oral and written language.
Explain the experimental results by yourself and exchange the results and ideas in the group.
Design a simulation experiment to explore the factors affecting the degree of soil erosion.
Emotions, attitudes and values:
Pay attention to the erosion phenomenon in nature.
Teaching focuses on understanding the erosion of land by rain.
Teaching difficulties: design simulation experiments to explore the factors affecting the degree of soil erosion.
Teaching preparation
Grouping equipment: wet soil mixed with a small amount of sand and gravel, rectangular plastic sink with a hole on one side, newspaper, plastic film, small shovel, rain collector (beverage bottle with a hole in the cap) and water.
Teacher demonstration: pictures or videos of rain eroding land, and courseware introducing experimental operation.
teaching process
First of all, introduce.
1. Rain is a common weather phenomenon. When it rains, the rain falls on the land. Will rain affect the land? What will happen to the land? What will the rain be like?
2. Students discuss and communicate.
3, good! Today, in this class, we will discuss these problems.
Second, how does rain affect the land?
1, let's look at two pictures first. (Showing pictures of rain eroding the land)
Can you tell me what you see?
Have you ever seen a similar scene?
What do you think is the reason for this scene?
2. Simulation experiment: It rains.
Students observe the experimental device and understand its significance.
The teacher's courseware shows the basic operation method of the experiment, and students learn while watching.
Students experiment in groups. Requirements: carefully observe the shape of the land on the slope before the experiment; During the experiment, pay attention to the situation of the land in the process of "rainfall", as well as "rainwater" and "runoff", and make records; After the experiment, the phenomena in the experiment are described and analyzed according to the experimental results.
Group communication and report.
3. Summarize and expand.
Will rain affect the land?
Teachers show pictures, students observe and think: How do these many small gullies on the slope come from, and how will the water collected in these small gullies change the terrain?
Three. Factors affecting erosion
1. What will happen if the land we just experimented with is not a slope but a flat land, if the slope is covered with trees, and if it rains heavily? Why?
2. Students answer.
3. Next, let's study "factors affecting erosion". Can we design experiments for research?
4. Students choose a research question and discuss it before the experiment design.
The student group tried to write an experimental scheme, and the teacher suggested that it was a comparative experiment. In the scheme, we should pay attention to the selection of experimental equipment and the design of experimental devices under different and the same conditions.
Fourth, extracurricular activities.
What other factors affect erosion? I hope you can continue to observe and study after class.
Blackboard design:
Postscript of teaching:
Lesson 6 What kind of land is easy to be eroded
Teaching objectives
Scientific concept:
Slope, vegetation coverage and rainfall will all affect the degree of land erosion.
Erosion is constantly changing the topography of the surface, and it will also cause land loss and affect our production and life.
Protecting forests and returning farmland to forests can reduce soil erosion.
Process and method:
In the process of communication, reflect and modify the unreasonable places in the experimental scheme.
Carry out the experimental operation according to the established experimental scheme and observe the experimental phenomena carefully.
According to the test results, the effects of "land slope size", "presence of vegetation" and "rainfall size" on soil erosion were analyzed.
Use the experimental results to infer the situation of nature, and use the learned knowledge to think about the causes and preventive measures of flood disasters.
Emotions, attitudes and values:
Recognize the importance of protecting the ecological environment.
Pay attention to the disaster caused by flood and what measures people take to prevent it.
The focus of teaching is to communicate the experimental design and operation as planned.
The further improvement of the experimental scheme of teaching difficulties makes it more scientific and reasonable.
Teaching preparation
Grouping equipment: wet soil mixed with a small amount of sand and gravel, soil with plants growing, rectangular plastic sink with holes on one side, newspaper, plastic film, small shovel, rain collector (beverage bottle with big holes and small holes on the bottle cap), water and water receiving container.
Teacher demonstration: pictures or videos about soil erosion, loess plateau and Yellow River water.
teaching process
First of all, introduce.
Last class, our group made a research plan on the degree of rain erosion of soil and the related factors. Let's talk about it today. See if our design is scientific and reasonable.
Second, exchange and discuss the experimental scheme.
1, group exchange demonstration experiment scheme.
2. The whole class discusses, evaluates, modifies or improves the experimental scheme.
3. Thinking: What problems should we pay attention to in the experiment?
4. summary.
Third, explore erosion experiments.
1. Pre-experiment preparation: make clear the experimental scheme and matters needing attention, and teachers should pay special attention to the fairness and standardization of the operation in the experiment; Prepare the experimental device.
2. Students experiment in groups, and teachers tour to guide them.
It is required to catch the "runoff" with a container, and carefully observe and record the phenomenon in the experiment.
3. Group communication: What phenomena did we see in the experiment and what did these phenomena show?
4, the whole class exchange report.
5. Summary: What are the factors related to the degree of land erosion?
Fourth, expand and extend.
1. Just now we did an experiment to explore erosion, from which we can infer where the land in nature is most vulnerable to erosion.
Students discuss and communicate, and the teacher shows pictures and videos about "Yellow River Water" and "Soil Erosion".
2. What will happen to the terrain during the process of land erosion?
Students discuss and exchange, and the teacher shows relevant pictures and videos such as Loess Plateau.
3. Thinking: What kind of disaster will erosion bring us?
Students exchange and discuss.
Verb (abbreviation for verb) homework after class
Everything has two sides. What does erosion bring us when it brings us disaster? Please think about it after class and look for relevant information.
Blackboard design:
Postscript of teaching:
Lesson 7 the role of rivers on land
Teaching objectives
Scientific concept:
Rivers are also formed by running water eroding land.
Rivers will erode river beds and banks, taking away soil, which will be deposited in places with slow water flow.
The erosion and deposition of rivers have formed many different landforms.
Process and method:
Do river experiments to explore the role of rivers on land.
Predict where the river flows fast, where it flows slowly, where it will be eroded and where it will be deposited.
Observe the phenomena in the river engineering experiment, record and express the results of the river engineering experiment with words and different symbols, and make your own explanation of the experimental results.
Try to explain the reasons for the formation of the impact plain.
Emotions, attitudes and values:
Recognize that the topography of the surface is constantly changing.
Cultivate feelings for the soil and understand the importance of protecting cultivated land from destruction.
Weathering, erosion and deposition have both advantages and disadvantages for human beings.
Teaching focuses on river experiments and explores the role of rivers on land.
Difficulties in teaching: Observe the phenomena in the river engineering experiment, record and express the results of the river engineering experiment with words and different symbols, and make your own interpretation of the experimental results.
Teaching preparation
Grouping equipment: wet soil mixed with a small amount of sand, rectangular plastic water tank (a liter milk box can be cut and butted into a river device), newspaper, plastic film, small shovel, large beverage bottle, plastic cup (with holes punched at the bottom side of the cup), water, ruler and bucket.
Teacher's demonstration: pictures or courseware of river formation, river erosion, sediment deposition on both sides of river bed and plain formation in the lower reaches of river.
teaching process
First of all, introduce.
1. What are the big rivers in China? What rivers are there in my hometown? What do these rivers have to do with our life and production? Do you know the reasons for the formation of the Yangtze River and the Yellow River?
2. Students answer, and the teacher explains after summing up: Rivers are generally streams formed by melting ice and snow, or mountain streams. When flowing water overflows the surface, small streams and gullies will be formed, which will gradually form streams and merge into rivers, while gullies will gradually develop into large gullies and gullies and form river beds in the continuous erosion of flowing water.
3. The formation of rivers is also the result of flowing water eroding the land. So what effect will this river have on the land?
Students discuss and communicate.
Today, let's explore the influence of rivers on land.
Second, explore the influence of rivers on land.
1. Will rivers erode the land on both sides?
2. If a river flows from a rugged mountain to a flat place, what happens to the sediment carried by the river?
Recall the sedimentation experiment and look at the pictures of "big stones-pebbles-fine sand".
3. Students' experiments.
Prepare the experimental device: pay attention to the 1/3 of the empty box, and do not fill it with soil.
Observe the "river channel" where no river flows, draw the shape of the river channel on the record paper, and mark its width and depth on the map.
Speculation: When a river is formed, where the velocity is high and where the velocity is low, where erosion will occur and where deposition will occur?
Write down your own speculation on the river and mark it with dotted lines.
Students do experiments. Note: When injecting water into the "river", be sure to check whether the outlet is facing the "river" and try to see if the water flowing out just flows into the "river". Only after confirmation is correct can the "river" be officially filled with water. At the beginning of water filling, always keep the water in the cup full. At the outlet of the experimental box, be sure to use a larger container to catch the water flowing down. In order to make the effect more obvious and the observation more clear, the experimental observation time can be longer, that is to say, after a bottle of water is used up, pour another bottle of water.
Observe the change of river velocity and pay attention to the place where the river is eroded. Where will the soil be stored?
4. Group communication and discussion.
5. The whole class exchanges and reports.
6. summary.
Three. Terrain formed by erosion and deposition
1. Thinking: Why are the lower reaches and estuaries of big rivers often plains?
Students discuss and answer.
2. Erosion and deposition occur all the time in nature. The teacher shows relevant pictures or courseware.
Fourth, extracurricular activities.
Besides flowing water, what other natural forces can cause land erosion and deposition? Please read the unit database after class to understand the erosion and deposition of land by wind, glaciers, waves and other natural forces.
Blackboard design:
Postscript of teaching:
Lesson 8 Reducing Soil Erosion
Teaching objectives
Scientific concept:
In the process of reshaping the surface morphology, various natural forces will also affect human production and life.
Human activities are also changing the shape of the earth's surface, and we should try our best to reduce the erosion of the land.
Process and method:
Through simulation experiments, we can test whether our home can withstand the attack of heavy rain.
Reflect on the experimental results and seek improvement methods.
Emotions, attitudes and values:
People realize that all kinds of forces have positive or negative effects on people's production and life when reshaping and changing the topography of the surface.
We agree that human activities should respect the laws of nature and reduce the negative effects caused by their own activities.
Recognize the significance of land to life and human production and life.
Pay attention to various measures taken by human beings to prevent soil erosion and protect the land from being destroyed.
The focus of teaching is to test whether your home can withstand the storm through simulation experiments.
Teaching difficulties reflect on the experimental results and seek improvement methods.
Teaching preparation
Grouping equipment: rectangular plastic sink (or large plate), soil, newspaper, plastic film, small shovel, rain shower, water, water receiving container, building materials, etc.
Teacher demonstration: pictures, videos or courseware to prevent and control soil erosion.
teaching process
First of all, introduce.
1, running water, wind, glaciers, waves and gravity will erode the land. Erosion causes soil erosion in some places, changes the topography, and has a great impact on human production and life. In order to protect their homes, people try to reduce erosion as much as possible. Show pictures, videos or courseware to prevent soil erosion.
Today, we will use what we have learned in this unit to build a terrain with mountains and plains in a big sink, and then choose a place to build a house in the terrain. If a rainstorm comes, can our home withstand the storm without being destroyed? Let's compare in groups.
Second, design and build our home.
1, what kind of terrain do we build and what materials do we use? Where to choose to build a house? Discuss and draw the design in groups.
2. The whole class exchanges and shows the design drawings, and describes why the terrain is built in this way, explaining why the location of the home is chosen in this way, the reasons for building the terrain and the materials needed for the house.
3. Assessment and summary.
4. What will happen to our home after the rainstorm?
3. What effect does the rainstorm have on our family?
1, Thinking: What conditions should each group keep unchanged in the competition experiment and why?
Students conduct a competition experiment: use a sprinkler to add water to simulate a rainstorm, and observe whether their homes can withstand the rainstorm.
3. Discuss and evaluate the experimental results of the competition.
4. Reflection: If we redesign and build our own home, what improvements will be made to the terrain? Are we still building the house in the same place? Why? Where will we build the house?
Fourth, summarize, expand and extend
1, we already know which forces will change the topography of the earth's surface?
2. What disasters will the various forces of the earth, including human beings, cause us when they change the topography of the surface?
3. Investigate what measures people have taken to prevent these disasters and minimize the harm caused by them.
Pick me.