What is convective rain?
The phenomenon of precipitation caused by atmospheric convection is also called convective rain. When the air near the surface layer is heated or the air in the upper layer is strongly cooled, the air in the lower layer rises, and the water vapor cools and condenses, which will form convective rain. Before convective rain comes, there are often strong winds, which can pull up trees with a diameter of 5 cm, accompanied by lightning and thunder, and sometimes hail.
Convective rain is mainly produced in cumulonimbus clouds, where ice crystals and water droplets exist. The vertical thickness and water vapor content of the clouds are particularly large, and the airflow rises and falls strongly, up to 2 ~ 3m/s, and the clouds are charged. Therefore, cumulonimbus clouds often develop into strong convective weather and produce heavy rain. Lightning strikes, strong winds and heavy rains often occur in this kind of thunderstorm.
light cumulus clouds are thin and have low water content, so rain usually falls to the ground. Cumulus clouds rarely precipitation in the middle and high latitudes, but in the low latitudes, because of the rich water content and strong convection, sometimes precipitation can be produced.
The convective rain is most frequent at low latitudes, and the precipitation time is generally in the afternoon, especially in the equatorial region, and the precipitation time is very accurate. In the morning, the sky was clear. As the sun rose, the sky cumulonimbus gradually formed and developed rapidly, and it became thicker and thicker. In the afternoon, the cumulonimbus surged, the weather was sultry and unbearable, the wind passed, the thunder and lightning were mixed, and the rainstorm poured down. The precipitation continued until dusk, and it was fine after the rain, and the weather was slightly cool, but the next day, there were repeated thunderstorms. In the middle and high latitudes, convective rain mainly appears in the summer half year, and it is extremely rare in the winter half year
The application of extracurricular information in the teaching geography class
Yangmude in Aoxi Middle School, Tongan, Xiamen
Geography is a comprehensive subject that studies the geographical environment of human existence and the relationship between human beings and geographical environment, and its research content is extensive, including geographical location, natural economy, society, history and other aspects, and these contents are changeable. Compared with this, the content capacity of geography textbooks is limited, and the updating speed is slow, which requires us to fully grasp extracurricular geographical information, constantly update geographical knowledge, and build a more reasonable content structure of geography textbooks, so as to fully maintain the characteristics of geography application and practicality, and gradually realize the transformation of geography teaching from exam-oriented education to quality education.
1. The significance of extracurricular information in teaching geography class:
1. It is beneficial for students to integrate theory with practice. Some geographical knowledge learned by students in textbooks is abstract and difficult to understand. What information reflects is the real thing, the latest domestic and international events, and the natural phenomena produced in nature anytime and anywhere. Teachers' purposeful selection and application in teaching can help students analyze geographical knowledge that is difficult to understand in textbooks, solve geographical problems and understand geographical phenomena. For example, when talking about "convective rain", it is difficult for students to understand what convective rain is, and the reasons, time and characteristics of convective rain are difficult. Teachers feed back the information captured in their lives to students, telling them that the so-called "convective rain" is what we call "northwest rain" and "thunderstorm" in daily life, so that students can think about it in combination with reality, and then teachers can give appropriate guidance. Therefore, teachers link information with knowledge in class through teaching, which is beneficial for students to integrate theory with practice.
2. It is beneficial to stimulate students' interest in learning geography. Due to the influence of abnormal entrance education, students generally think that geography is a minor course in the middle school curriculum, and they don't pay attention to geography learning, so the quality of geography teaching is difficult to guarantee. Therefore, how to improve students' interest in learning, make students have a psychological tendency to learn geography and cultivate their consciousness of learning geography is the key to geography teaching, and the application of extracurricular information can play a very important role. Geographical information is close to life, close to the times, closely linked to real life, interesting, fresh and interesting. For example, when talking about "South Asia", add the issue of India and Pakistan; When it comes to West Asia and North Africa, it introduces the dispute between Palestine and Israel and the sanctions imposed by the United States and Britain on Iraq. Proper selection of teachers in teaching can arouse students' attention, arouse students' exploration of geography knowledge, improve classroom atmosphere and stimulate students' interest in learning geography.
3. It is beneficial to update the subject knowledge. The information reflects the latest domestic and international problems, especially some major problems faced by today's society: population growth, food shortage, resource utilization, ecological destruction, climate change, environmental protection and so on. For example, at the report meeting of the relevant departments of the Fourth Session of the Ninth National People's Congress on March 12, it was reported that the forest coverage rate in China has increased from 12.7% to 16.55%, and desertification land accounts for 26.3% of the national territory. Teachers collect and sort out this information and use it when talking about forest resources in China. In this way, we can show the latest knowledge to students, understand the efforts and achievements made in environmental protection in China in recent years, and also understand the problems existing in environmental protection in China, so as to train students to start from me, protect and beautify our homeland, and be a natural administrator.
4. It is conducive to enhancing students' sense of social responsibility. The information fed back from the society can best reflect social life and reflect the rhythm of the times, which is the epitome of society. Information reflects people's behavior and thinking habits, such as unreasonable utilization of natural resources, deforestation, indiscriminate hunting and killing of wild animals, destruction of the ecological balance of nature, land desertification caused by indiscriminate reclamation of grasslands, resource destruction and environmental pollution caused by indiscriminate exploitation of mineral resources, etc., many of which are caused by human factors. Environmental governance is actually human governance, and environmental protection is closely related to each of us. Students think and analyze the information given by teachers, establish correct thinking habits and behaviors, and enhance their sense of social responsibility.
5. It is conducive to the education of "three emotions" for students. The so-called three feelings are nostalgia, national conditions and world conditions. The major events at home and abroad in information are rich in content and knowledge, and some major events at home and abroad often have their background and reasons, which are strong in story, vivid and varied in speaking. It is of great significance to quote relevant information in geography teaching for students to keep abreast of major events at home and abroad and correctly understand the causes and development trends of changes in the domestic and international situation.
Second, the application of extra-curricular information in teaching geography class:
1. Introducing new lessons: It is a common method to introduce new lessons by using extra-curricular information. For example, when talking about "Northwest China" and "Qinghai-Tibet Region" in China, it was just after the Fourth Session of the Ninth National People's Congress was held. On the basis of summing up the work of the Ninth Five-Year Plan, this meeting put forward the work plan of the Tenth Five-Year Plan. I arranged for students to go back and collect relevant information materials, and put forward the following questions: What are the contents related to the western region in the Tenth Five-Year Plan? The geographical location, development status, natural resources, traffic conditions, existing problems, the significance of the central government's adjustment of China's economic development strategy, and the future development prospects of the western region. Then the teacher summarized and introduced the explanations of "Northwest China" and "Qinghai-Tibet Region". Another example is to talk about "America", introduce the time and place of "9.11" incident, and let students discuss the reasons, the harm to the American people and the impact on the world. In this way, the introduction of new courses will make students feel fresh and interesting, and stimulate their enthusiasm for learning geography.
2. Classroom Essays: Teaching by combining the content of the textbook with relevant extracurricular information is helpful for students to deepen their understanding of the content of the textbook and apply what they have learned, which is also a frequently used method. For example, when talking about western Europe, students like to listen to this information and are very concerned about how to solve the aftermath left by the indiscriminate bombing of Yugoslavia in the Balkans by NATO led by the United States on May 8, 1999, especially when the flames of war broke out again in Macedonia. Under the influence of teachers, students also pay attention to watching TV when they go back. Newspapers ordered by classes and Semimonthly Talks have become magazines that students compete for, and they have developed the habit of reading newspapers. Students are no longer "deaf ears to things outside the window, but concentrate on reading sage books", but become good students who care about everything in the family, state affairs and the world. This has played a great role in broadening horizons and enriching knowledge, and can achieve the purpose of ideological education.
3. Summarize the whole class: Using news reports as the summary of a chapter or a class can deepen the teaching content and make the finishing point, and also deepen the ideological and political education for students. For example, after finishing the chapter "Humans live together on the same earth", the teacher brazenly attacked our embassy in Yugoslavia with five missiles on May 8, 1999 by the US-led NATO, and on April 1 this year, a US military plane invaded our airspace, deliberately crashed and damaged a military plane of our army and landed at Lingshui Airport in Hainan Province of China without permission, and recently, the US government violated Three Joint Communiqués despite the strong protest of the China government. The Taiwan Province issue has stirred up trouble again, openly decided to sell military weapons to Taiwan Province, grossly interfered in China's internal affairs, and undermined China's sovereignty and territorial integrity. I combine the current affairs materials and the collected information to educate students with the theme of "condemning the United States, strengthening China, opposing hegemony and maintaining peace"; There is only one earth for mankind, but this earth is not peaceful, hegemonism and power politics still exist, and the cloud of war always hangs over the whole earth, destroying the geographical environment for human survival and creating "humanitarian disasters" and "ecological disasters". We should love our motherland, study hard, make great efforts to revitalize China, persist in unity and stability, speed up economic development, improve comprehensive national strength, oppose hegemonism, safeguard world peace, and. Ending the whole class in this way is not only the best summary and summary of the last lesson of studying world geography, but also has a strong educational effect.
4. Special lectures: give special lectures by combining extracurricular information with teaching materials, broaden students' horizons, pay attention to social hotspots, care about major events at home and abroad, and establish a global concept. For example, after the lecture on "West Asia and North Africa", I gave students a supplementary introduction in the form of lectures: the historical background of the Palestinian-Israeli problem, the root causes of the Palestinian-Israeli conflict, and the ways to solve the Palestinian-Israeli problem. Why did the United States and Britain bomb Iraq for 1 years in a row, especially the war that broke out again after George W. Bush took office? The students listened with relish.
3. Matters needing attention in the application of extra-curricular information in the teaching geography class:
1. Information infiltration must be closely linked to the teaching materials, and through vivid factual materials, students can understand and master the abstract and tedious geographical science concepts and geographical problems in the textbooks in a relatively simple way, which is the main purpose of teaching with information materials. Therefore, when selecting information, we should give priority to the teaching materials.
2. Pay attention to newness and accuracy in information selection. Information selection must be accurate, scientific and logical. Because many materials are not obtained by personal experience, they often start from subjective wishes when choosing, and sometimes they backfire. In a scientific, rigorous and realistic attitude, it is generally not appropriate to choose materials that lack scientific basis and are inconclusive. Even if they are selected, they should point out the focus, reasons and development direction of the debate, so that students can know fairly well. The selection of some statistical materials, such as data and charts, must be "accurate" at the same time, and it is best to choose from the materials published by the National Bureau of Statistics, and at the same time, the year and month, the statistical scope and the source should be indicated.
3. The use of information should be precise and simple. Information sources are multi-channel. Therefore, when selecting, it must be reviewed, processed, edited, screened, simplified and simplified, in order to receive short, concise, just right, persuasive and effective. For example, when talking about the problems in the Middle East, there are many reports on the hot issues in the Middle East in ordinary newspapers, and students know a lot. This kind of information should be detailed and simple, so as to stimulate interest.