I. Activity objectives
1. Love the rivers and mountains of the motherland, feel the civilization of the Yellow River, and understand how the Yellow River, as the "mother river", is deeply and comprehensively accumulated in Chinese culture.
2. Pay attention to the mother river and strengthen environmental awareness.
3. Cultivate students' ability to collect, sort out and screen data according to the theme, and guide students to master the basic methods of analyzing and using the obtained data.
4. Cultivate students' sense of cooperation and guide them to learn to cooperate.
5. Exercise students' listening, speaking, reading and writing skills, and pay attention to cultivating students' innovative consciousness and creativity in comprehensive activities.
Two. Activity guidance and suggestions
In the comprehensive study of this unit, teachers should make corresponding activity plans according to teaching practice on the basis of grasping the design intention as a whole, and also add, delete and adjust some contents according to local and school conditions.
This unit takes "exploring the Yellow River civilization" as the core of the activity, and takes learning the text of Ode to the Yellow River as an opportunity to naturally lead into the whole activity. The four parts are closely connected and take care of each other: the first part focuses on understanding the influence of the Yellow River on the formation of Chinese civilization, so the theme is "Yellow River, you are the cradle of the Chinese nation"; The second part focuses on collecting poems and songs, holding theme parties to arouse students' feelings about the Yellow River, which can be centered on "singing the Yellow River"; The third part is to collect information, screen information, understand the hardships of the Yellow River, arouse the awareness of caring for and protecting the Yellow River, and by extension, cultivate environmental awareness; The fourth part, on the basis of the first three links, requires students to express their feelings and understanding in written form, and summarize their gains from participating in the activities as self-evaluation.
In the teaching process, teachers should pay attention to the following aspects:
First, break the whole into parts and arrange activities alternately.
This unit has a lot of content, and the class hours are tense. When teaching, we should pay attention to the decomposition of many activities and insert them into the teaching activities inside and outside the class within two weeks. This comprehensive activity plan takes up two class hours of classroom teaching time, one class hour is used to arrange and guide students' activities, and the other class hour is used to show and evaluate students' activities. The rest of the activities are basically divided into several parts, which are carried out in class and after class.
Some contents (such as Ode to the Yellow River Part I) can be integrated into classroom teaching; Common sense and words about the Yellow River can be displayed by handwritten newspapers, blackboard newspapers and other forms; You can teach stories and legends related to the Yellow River three minutes before class to exercise students' oral expression ability; As for the ballads and poems collected by students about the Yellow River, let them sort them out and perform them at class meetings or literary evenings. Of course, students can also design public service advertisements in their spare time, and their achievements can also be displayed in classrooms or campuses.
This arrangement can solve the problem of insufficient class hours.
Second, arrange activities in groups.
Faced with the eight tasks in the four parts of this unit, even if the teacher makes a breakdown arrangement, the students will feel exhausted. Therefore, teachers should help students divide into several groups, so that each group can undertake a task, and there is a specific division of labor within the groups, so as to give full play to students' subjective consciousness and cooperative spirit. Finally, the above-mentioned division of labor will be integrated by means of results display and evaluation activities to realize resource sharing and benefit students from each other.
However, it is still necessary to keep one or two activities (the teacher is advised to choose the fourth part) as * * * activities for everyone to participate in, and ask students to write a composition and summary after each group exchange, so as to ensure that the activities are comprehensive, divided and combined.
Explain the design intent and specific guidance and suggestions of various activities.
The first part of the activity:
1. Review the lesson Ode to the Yellow River, find relevant information and discuss the following questions (see the textbook).
This activity aims to deepen the understanding of poetry and fill the "blank" of poetry language with more knowledge, which is a typical reading method; At the same time, it is natural to introduce it into this activity, which is easy to arouse students' interest. Teachers can ask students to finish it by themselves after class and communicate with each other before or after class. Don't take too much time. The specific explanation is as follows:
The first question is in the appendix after class. The second question-the historical facts of the capitals in the Yellow River valley are as follows: Yangcheng was the capital of xia Dynasty (now Dengfeng, Henan Province), Bo was the capital of Shang Dynasty (now Shangqiu, Henan Province), then moved to Yin (now Anyang, Henan Province), Haojiang was the capital of Zhou Dynasty (now Xi 'an, Shaanxi Province), Xianyang was the capital of Qin Dynasty, Chang 'an was the capital of Western Han Dynasty, Luoyang was the capital of Eastern Han Dynasty, and Wei Jin was the capital.
(2) The Yellow River originates from the northern foot of Bayan Kara on the Qinghai-Tibet Plateau and flows into the Bohai Sea, with a total length of 5,464 kilometers, and flows through Qinghai, Sichuan, Gansu, Ningxia, Inner Mongolia, Shaanxi, Shanxi, Henan and Shandong provinces.
3 ellipsis.
2. Folk stories related to the Yellow River.
This activity aims to train students' generalization ability and oral and written expression ability. In the process of collecting stories, students should be asked not to copy the original text as much as possible, but to cut or polish the stories appropriately.
Stories compiled by students can be published in handwritten newspapers and blackboard newspapers, and students can also use the speaking time a few minutes before class to tell stories and practice oral expression.
(1) the legend of the source of the Yellow River.
② Myths and legends related to the Yellow River.
③ Stories of historical figures related to the Yellow River.
A. Jiang Taigong went fishing.
B. Zheng Guoqu.
(For the above answers, please refer to Yellow River, edited by CCTV, China Youth Publishing House, 1989 edition).
3. Activities about collecting proverbs, proverbs and idioms.
This activity provides students with the opportunity to accumulate vocabulary and cultural knowledge, so as to feel the profound cultural accumulation of the Yellow River in national culture. Teachers should take this opportunity to emphasize the importance of vocabulary learning, so that students can feel the joy of vocabulary accumulation and master one or two ways to learn vocabulary.
Teachers should grasp three links in guiding this activity: collecting vocabulary-understanding meaning-learning to use it. For example, "He Qing Hai Yan" is the ideal peace and prosperity of China people; "Characteristic" is the cultural reflection of two tributaries of the Yellow River (clear water and muddy water). Ask the students to copy examples so as to fully understand the meaning of words from the situation, and ask them to make sentences with words.
The second part of the activity-collecting poems and songs about the Yellow River.
This activity can be carried out in cooperation with music teachers and can be regarded as an interdisciplinary comprehensive learning activity. You can ask the music teacher to recommend songs and ballads related to teaching and singing, which can be done in music class or after class, or in class meetings or even school cultural activities. The Chinese teacher is mainly trying to embody the China characteristics of the activity, asking students to copy the lyrics and guide students to evaluate. Students should be required to recite these poems and introduce them to their classmates.
Part III Activities-Protecting the Yellow River.
The theme of this section is "environmental protection". Among them, the first focuses on understanding the current situation of the Yellow River, and the second focuses on propaganda and appeal, but the ultimate goal is the same. Students may wish to undertake various tasks in groups. First, students collect information or conduct surveys to communicate with each other, and then guide students to design and display public service advertisements, so that the two activities can echo each other and enhance the effect of the activities. If the local conditions are limited, teachers can also organize students to investigate and collect in other rivers or local rivers, without forcing unity.
The organization, hosting and teaching of investigation and exchange activities should be undertaken by students themselves, so as to fully train students.
The design of public service advertisements should be ingenious, vivid and creative, but the characteristics of Chinese subject should still be highlighted. If students have no drawing ability, they can only describe their ideas in words. Of course, students from different majors can also be organized into several groups to design together to reflect the characteristics of cooperative learning.
The fourth part of the activity content-comprehensive writing.
This part is based on the first three parts. Through the above activities, students have a certain understanding of all aspects of the Yellow River. At this time, the process of writing and accumulating materials has been basically completed. The key lies in how to determine the topic angle and how to express one's views and feelings appropriately. 1 and 2 are regular compositions, so it is suggested that the teacher assign students to complete one of them. The writing of "Zhou Ji" in question 3 can be used as students' self-evaluation of this large-scale activity. Teachers should guide students to seriously sum up the gains, experiences and their own shortcomings in activities as an important reference for activity evaluation.
Three. Activity evaluation
1. Emphasize process evaluation.
The purpose of comprehensive activities is to provide students with an opportunity to exercise their abilities and promote their development. The purpose of student research is not only to produce results, but also to evaluate the process. Teachers should first evaluate whether students are actively involved, whether they are seriously organized, and whether they are trying to organize materials to express their views. As long as students have made efforts in the above one or two links, teachers should give affirmation. As for whether the conclusion of students' homework results is complete and rigorous and whether the design is novel and creative, it can only be used as a reference factor for evaluation. Even if students' activities fail, as long as students actively participate, they will use all kinds of knowledge, exercise all kinds of abilities and accumulate all kinds of experience in practical operation. These are extremely valuable things and an important basis for comprehensive evaluation.
2. Don't ask for perfection, don't ask for perfection.
Don't expect to cultivate all-round ability in one activity. Teachers can make overall planning and macro-control on the cultivation of students' all-round ability by establishing students' learning files. Gradually guide students to cultivate and develop their abilities in an all-round way through various activities. Therefore, after each activity, it is only necessary to evaluate students' best performance (such as students' oral expression, writing, material arrangement, cooperation with others, etc.). ), and nothing is required.
3. Various evaluation methods are combined with each other.
When evaluating, students' self-evaluation and mutual evaluation should be combined with teachers' evaluation, so that evaluation can become a means to encourage and motivate students and a means for students to know themselves and others. At the same time, teachers should also strive to create conditions for school evaluation and social evaluation, so that the results of students' activities can be recognized by the campus and society, and this evaluation can get excellent educational results.
Four. relevant information
1. Ancient geological movements and the formation of the Yellow River (Chen,,)
In the constant movement of the earth's lithosphere, the North China platform uplifted about 654.38+0.7 billion years ago. Then it continued to rise, forming the earliest and largest ancient land in China. In the long time since then, the North China Platform sank twice and was soaked in seawater, and then rose again and reappeared in Permian (285 million to 230 million years ago). In this process of repeated uplift and subsidence, a large number of biological remains are accumulated in the subsidence area, forming rich coal, oil and natural gas resources.
Then a orogenic movement called Yanshan Movement took place in Jurassic (1950,000 years ago to1370,000 years ago) and Cretaceous (1370,000 years ago to 67 million years ago). The North China Plain, which was originally integrated with the Shanxi Plateau, turned to subsidence, first formed a basin, and then gradually developed into a great plain, while the Cenozoic Shanxi (. This orogenic movement was more intense than Yanshan movement, which not only caused the Himalayas to rise from the seabed and the Qinghai-Tibet Plateau to rise sharply, but also affected the whole of China, causing some plots to rise into mountains and some plots to sink into basins. For example, affected by this orogeny, Shanxi Plateau formed two almost parallel fault zones, which ran through the central part of the plateau from north to south, and the fault blocks of the fault zones fell down to varying degrees, forming a long and narrow valley. The southern end of the trough is connected with the subsidence zone where Guanzhong lies, forming the Wei Fen Basin. Later, some uplifted mountains were weathered and denuded, gradually flattened and became plateaus; The sunken basin accumulated water to form a lake. Since then, this area has experienced two large-scale glacial activities, and the climate has become cold and dry. Those big lakes are gradually shrinking or divided into many small lakes, and several big lake basins and many small lakes and wetlands have appeared in the whole area. From high to low, the flowing water on the ground gradually converged into an ancient lake basin and developed into several independent inland lake water systems. At the northern foot of Bayan Kara in Qinghai Plateau, a flowing water flows from here to the southeast. Because the Jishi Mountain, that is, the Animaqing Mountain, is bounded by the north and south of Bayan Kara, it flows to the now sinking Zoige grassland area, where it accumulates and forms the ancient Zoige Lake. Another flowing water, originating from Xiqing Mountain and Qingshan Mountain in Anima, flows from southeast to northwest in the valleys of the two mountains and gathers in the ancient basin of * * * county in Qinghai Province today. In the east of the ancient * * and the basin, there was another flowing water, which flowed eastward into today's Gansu along the canyon at the southern foot of Laji Mountain. After passing through today's Lanzhou, it turned to the north and flowed to today's Ningxia region, and gathered in the Yinchuan Basin formed by the collapse of the fault beside Helan Mountain, forming the ancient Yinchuan Lake. On the eastern edge of East Ordos Plateau, another river flows into Wei Fen Basin through a series of small lakes, forming the ancient Weifen Lake. In the east of Wei Fen Basin, stands a towering Zhongtiao Mountain. Due to the blocking of Shandong hills, the flowing water on the Shandong side flows eastward into the sea from different rivers in the north and south of the hills. In this way, from the Qinghai-Tibet Plateau in the west to the Shandong hills in the east, four unconnected rivers have gradually formed. The ancient Yellow River gradually evolved on the basis of these independent water systems.
In the early Quaternary geological age (from 2.5 million years ago), that is, about 6.5438 million years ago, the glaciers in this area melted, the climate became warm and humid, the precipitation was abundant, the river surged, and the erosion and undercutting of running water intensified. The erosion of flowing water makes the riverbed gradually change from shallow to deep, resulting in traceable erosion, which makes the source position move in the opposite direction of the river flow and makes the upstream continuously extend upward. The downward cut of flowing water impacts the mountain that blocks its progress, opening a channel for itself and making the downstream extend downward day by day. At this time, the plateau in the central and western regions of China continues to be in the rising stage, further strengthening this downward erosion of flowing water. Traceability erosion and undercutting erosion of flowing water finally opened the watershed between the two rivers, making each closed lake basin have an outlet and connecting their independent river sections. At this point, the ancient Yellow River began to emerge. However, at this time, the ancient Yellow River was still an inland river, and its eastern end ended in the vast Sanmen ancient lake, because Zhongtiao Mountain in the east still blocked its way to the sea. However, the ancient Yellow River continues to play its function of tracing the source and cutting erosion with tenacious perseverance. When a large amount of upstream water enters Sanmen Ancient Lake, the water level rises, exceeding the height of Sanmen horst, and the lake overflows eastward and keeps cutting down. After a long time, she finally crossed Sanmenxia, flowed into the North China Plain, joined the flowing water on the east side of Zhongtiao Mountain, ran eastward and threw herself into the embrace of the sea. A great life was born!
Scholars have different opinions on the specific time when the Yellow River finally crosses Sanmenxia and runs through the whole line, but one thing should be certain, that is, when Beijingers who lived 700,000 to 200,000 years ago appeared in Zhoukoudian, this great river originating from the Qinghai-Tibet Plateau has connected all the river sections from west to east, and entered the ocean, never to return. However, at this time, her downstream flows into the sea around the southern part of Shandong hills. There have been several changes and migrations in the lower reaches, but the upper reaches are basically stereotyped. Moreover, due to the traceability, erosion and extension of running water, its upstream and downstream continued to extend, and finally formed today's face.
Today, the Yellow River, with a total length of 5,464 kilometers, is the second longest river in China after the Yangtze River. She flows eastward from the source, passes through Qinghai, Sichuan, Gansu, Ningxia, Inner Mongolia, Shaanxi, Shanxi, Henan and Shandong, and flows into the Bohai Sea in Lijin County, Shandong Province, with a drainage area of 75? 24.43 million square kilometers. If you add the area of Ordos inner flow area, it is 794,000 square kilometers. Including the areas along the Yellow River in Henan and Shandong provinces, which are closely related to the Yellow River, there are 300 million mu of cultivated land and a population of 654.38+0.2 billion. Historically, the Yellow River also flowed through Hebei, Tianjin, Anhui and Jiangsu provinces and cities, and the alluvial plain in the lower reaches of the Yellow River was about 250,000 square kilometers. According to the latest statistics released at the beginning of 2000, the average annual runoff of the Yellow River for many years is 58 billion cubic meters, which is only 2% of the annual runoff of rivers in China. However, these Yellow River waters, together with the limited groundwater in the basin, undertake the water supply tasks of 15% of the country's cultivated land, 12% of the population and more than 50 large and medium-sized cities, and transfer water to the outside of the basin for a long time, and undertake some water supply tasks outside the basin. From this figure alone, we can see the great contribution of the Yellow River to the economic, historical and cultural development of the Chinese nation.
(Excerpted from Biography of the Yellow River, Hebei University Press 200 1 Edition)
2. Loess Plateau
The Yellow River runs from Longyangxia in the east of Qinghai Province to Sanmenxia in the west of Henan Province, passing through the world-famous loess area. This vast loess area generally starts from Sun Moon Mountain in the west, reaches Taihang Mountain in the east, Qinling Mountain in the south and Yinshan Mountain in the north, with an area of about 580,000 square kilometers and an altitude of1000 ~ 2,000 meters, which is called the Loess Plateau. Due to soil erosion, a large amount of sediment is transported to the Yellow River every year. The famous "Yellow River" is actually a gift from the Loess Plateau.
Loess Plateau is the most typical area of loess development in China. When you enter the Loess Plateau, you suddenly see golden yellow loess covering the earth. Nowadays, the loess plateau is almost naked with a broad chest, cut into pieces by rolling mountains and criss-crossing gullies, which constitutes a unique natural landscape of the loess plateau.
In fact, the ancient Loess Plateau is not what it is now. The mild climate and fertile soil provide a good natural environment for the growth of everything. During the period of 1973, archaeologists in China excavated a relatively complete ancient elephant fossil in Heshui County on the Ma Lian River in the upper reaches of Jinghe River in the gully region of the Loess Plateau. According to archaeological identification, this is the "Yellow River Saber-toothed Elephant" that lived on the Loess Plateau 2 million years ago. This ancient elephant fossil showed people the natural features of the Loess Plateau at that time: forests, wilderness and lakes were everywhere; On the vast Yuan Ye, wild horses gallop, antelopes baa, ostriches stroll, zokor forages, and ancient elephants flock ... The Loess Plateau is like a natural animal and plant park.
According to the excavations of archaeologists, primitive humans of Paleolithic age, Lantian ape-man, Ding Cun ape-man and Hetao ape-man, lived on the Loess Plateau in the Yellow River basin. In modern times, many Neolithic Yangshao cultural sites have been found here. For hundreds of thousands of years, human beings have developed fertile land here with hard-working hands and created splendid ancient culture.
Emperor Yan was a tribal leader in ancient China. Emperor Yan lives in Jiang Shui because he thinks his family name is his. Jiang Shui is located in the east of Qishan County, Shaanxi Province, and belongs to the Weihe River Basin on the Loess Plateau. Legend has it that he tried a hundred herbs to cure the disease, "according to the time, divide the land, make crops and teach the people to plow." So Emperor Yan is also called Shennong. The ancestors of Yan Di tribe were the first people to explore the Weihe River basin. In the long-term production practice, with the collective wisdom and hard work, artificially planted crops have grown on fertile loess, making the Weihe River Basin on the Loess Plateau the birthplace of primitive agriculture in China.
The emergence of agriculture marks the beginning of human settlement. From Xia, Shang to Qin and Han dynasties, the Loess Plateau was gradually reclaimed, and there was a prosperous scene of "a hundred grains and a hundred vegetables". Xia Shu Yugong is the earliest geographical work in the history of China. It is said that this book was cast in Jiuding, describing the geography and products of all parts of China at that time. According to Yu Gong, today's loess plateau areas in Shaanxi Province and Gansu Province, north of Qinling Mountains, are "lost in the yellow land" and "in the fields". Up, up, is the best of the nine grades. The Loess Plateau in Dayu period was indeed a place with rich products and wealth. During the Western Zhou Dynasty, a large number of agricultural products such as rice, sorghum, millet, wheat, millet, mulberry, hemp, melons and fruits were planted here, and horses, cattle, sheep, chickens, dogs, tapirs and other livestock and poultry were domesticated. According to the statistics of the second year of Emperor Pingdi of the Western Han Dynasty (AD 2), there are more than 2.4 million people living in three auxiliary areas around Chang 'an, the capital of the Western Han Dynasty (now Huayin, Gaoling and Meixian). During the Han and Tang dynasties, the animal husbandry here was very developed. There were more than 1,000 livestock/kloc-0 in Han dynasty. There were more in the Northern and Southern Dynasties, with 6 million in northern Shaanxi alone.
The Loess Plateau is a golden land, which nurtures people on the plateau with rich resources and fertile soil. If the Yellow River is the cradle of the Chinese nation, isn't the Loess Plateau the Golden Baby?
(Excerpted from A Journey to the Yellow River, Shanghai Education Press, 1979 edition)
3. The Yellow River cut-off and the ecological environment construction in the basin.
The main stream of the Yellow River is 5,464 kilometers long, with a basin area of 796,000 square kilometers, cultivated land area of about 20 million hectares and a basin population of 65.438+0.2 billion. The Yellow River is an important water source in northwest and north China, the lifeline of economic development along the Yellow River, and the axis of inland economic development in China in the 2nd/kloc-0th century. For a long time, there have been serious problems such as flood threat, soil erosion and sediment deposition in the Yellow River. In recent years, there have been new problems such as increasing water shortage and serious water pollution. The interruption of the Yellow River is not a simple hydrological phenomenon, but a comprehensive reflection of the serious imbalance of ecological balance in the basin and the contradiction between human needs and fragile ecological environment. These problems have seriously affected the production and life of people along the Yellow River, and the cutoff of the Yellow River has become a major concern at home and abroad. This part focuses on the cutoff of the Yellow River and soil erosion in the Loess Plateau and its control.
The Yellow River was cut off from 1972, and it became more frequent in 1990s. The river closure time and distance are prolonged, and the lower reaches of the Yellow River are in danger of becoming an intermittent river.
(1) Current situation and trend of Yellow River cutoff
The Yellow River was cut off from Lijin, Shandong Province on 1972, and then it became more and more serious. During the 27 years from 1972 to 1998, there were 2 1 times of water cut-off in the downstream, especially in the 1990s, the first time of water cut-off was advanced, and the time and distance of water cut-off were continuously extended. 1997 Shandong Lijin Station stopped water 13 times, for a total of 226 days. No Yellow River water enters the sea for 330 days, and the starting point of cutoff extends to the vicinity of Liuyuankou in Kaifeng, with a total length of 704 kilometers, accounting for 90% of the length of the lower reaches of the Yellow River. Not only that, the main tributaries of the middle reaches of the Yellow River have also been cut off. The headwaters of the Yellow River began to cut off in 1997, and the first cut-off occurred in the spring of Zhaling Lake to Eling Lake 1999, with a completely exposed reach of 8 kilometers.
(2) The influence of the Yellow River cut off.
The cut-off of the Yellow River has caused the imbalance between supply and demand of water resources along the Yellow River, and the contradiction between industrial and agricultural production, urban life and ecological environment has become increasingly acute, which has greatly affected the social and economic development and ecological environment along the Yellow River and increased the hidden dangers of flood control in the downstream.
The production and life of industry and agriculture in the lower reaches of the Yellow River are seriously endangered 1972 ~ 1996. The total economic losses of industry and agriculture caused by water cut-off and insufficient water supply are about 26.8 billion yuan, with an average annual loss of more than 1 1 billion yuan. In the 1990s, due to the increasingly serious cut-off, the average annual loss has reached 3.6 billion yuan. The drought-affected area of farmland was 4.7 million hectares, and the grain output was reduced by 9.86 billion kilograms. Shengli oilfield has reduced its production by several hundred thousand tons due to the reduction of water injection. The Yellow River brings economic benefits of 654.38+000 billion yuan to Shandong every year, and its interruption affects Shandong's economic development. The longest interruption in the history of 654.38+0997 has caused tens of billions of direct economic losses to Shandong Province. During the seven years from 1992 to 1998 in Binzhou, the industrial and agricultural losses caused by water stoppage and pollution were 158 billion yuan, including 400 million yuan in agricultural losses and 350 million yuan in drought relief funds. The interruption of the Yellow River makes the delta face a serious water crisis, which will directly affect the implementation of the sustainable development strategy. The interruption of the Yellow River has also disturbed people's normal life and work order. Dongying, Binzhou, Dezhou and other cities in Shandong often adopt limited water supply because of insufficient water supply.
It has a great impact on the ecological environment along the Yangtze River, especially in the estuary delta. This influence is mainly manifested in the following aspects: First, coastal erosion and retreat. Due to the decrease of sediment entering the sea, the coastline of the Yellow River Delta has been dominated by net erosion, which has led to the coast retreating. The second is the deterioration of groundwater environment. Due to the decrease of surface fresh water supply, the increase of underground fresh water consumption, the decline of groundwater level, seawater intrusion and salt water intrusion, the water quality deteriorated. Third, the environmental capacity of surface water is reduced and the pollution is aggravated. Due to the increase of sewage discharge and the decrease of surface water, the concentration of pollutants in major rivers not only exceeds the water quality standard of fishery water, but also reaches or exceeds the lethal concentration of fish in the middle and lower reaches of some tributaries, and many rivers are basically extinct. Fourthly, the salinization and desertification of the land in the estuary have degraded the wetland ecosystem. The surface vegetation in the Yellow River Delta is very fragile and easy to succession. The vegetation is mainly grassland, with grassland 2180,000 square kilometers, including natural grassland185,000 square kilometers. Due to the cut-off, not only the soil is salinized, the grassland degenerates into halophytes, but also the growth of artificial grassland is affected. Fifth, the biodiversity of estuaries and offshore waters decreased, and the biological population and genetic diversity were lost. Due to the interruption of water flow and the imbalance of water environment, the delta wetland seriously threatens the survival and reproduction of thousands of aquatic organisms, hundreds of wild plants and 180 birds in the wetland reserve, resulting in a decrease in the number of biological populations and a simple structure. Cut-off has deprived the Bohai Sea of important food sources, affected the reproduction of marine life, and made it impossible for more than ten kinds of fish to migrate.
The shrinkage of the river channel changes the scouring pattern of the river channel. Sediment deposition makes the river channel shrink, the riverbed rise, and the lower reaches of the Yellow River become a suspended river on the ground, which reduces the flood discharge capacity, increases the risk of breach diversion and threatens the safety of people's lives and property in the lower reaches.
(3) The main reason of the Yellow River cut off.
Hydrologically, the Yellow River cutoff belongs to seasonal variation of water quantity. But in essence, stopping water is a reflection of the contradiction between human needs and fragile ecological environment.
The sharp increase in water consumption is the fundamental reason for the interruption of the Yellow River. Most areas of the Yellow River Basin belong to arid and semi-arid areas. Especially since the 1990s, rainfall runoff is less, and the per capita and per mu water consumption is far below the national average. Drought is the natural cause of the interruption of the Yellow River.
The industrial and agricultural production in the Yellow River basin has developed rapidly, and the water consumption has increased sharply. 90% of the Yellow River water is used for agricultural irrigation, and the irrigation area of Yellow River diversion increased from 800,000 hectares in the early days of the People's Republic of China to 73 1 10,000 hectares in 1994. The water consumption of agriculture, industry and life in the whole basin has increased year by year:17.4 billion cubic meters in 1949, 124 billion cubic meters in 1950s and 29.6 billion cubic meters in 1990s. At present, the actual water consumption in the Yellow River Basin has exceeded 37 billion cubic meters, which can't guarantee the ecological water consumption for river scouring (265.438+0 billion cubic meters). At present, the development and utilization rate of the Yellow River runoff has exceeded 50% of the average natural runoff for many years, exceeding the utilization level of other rivers in China and developed countries such as the United States and Japan. It can be seen that the sharp increase in water consumption is the fundamental reason for the interruption of the Yellow River.
The deterioration of ecological environment in the headwaters and middle and upper reaches Qinghai is the largest runoff-producing area and water conservation area in the Yellow River basin, with the basin area accounting for 19.6% of the total basin area, while the runoff accounts for nearly 1/2 of the total runoff of the Yellow River. Vegetation destruction leads to grassland desertification and water conservation function decline. Since the mid-1980s, the runoff in the upper reaches of the Yellow River began to decrease year by year, and the decrease became more obvious after 1990s. 1997 from June to March, the runoff decreased by 23% to the lowest point in history, and it stopped flowing for the first time, and the downstream was the most serious in history. In the loess plateau area of the middle and upper reaches of the Yellow River, soil erosion is serious and sediment keeps falling. The annual sediment input into the Yellow River is 65.438+0.6 billion tons, and the annual sediment deposited in the downstream riverbed is 400 million tons. The riverbed is raised by 65.438+00 cm every year, which is 3 ~ 65.438+00 meters higher than the land on both sides of the river, forming a "suspended river" of nearly a thousand miles on the ground, and the downstream banks are becoming more and more dangerous.
Lack of unified management, low utilization rate of water resources, the Yellow River backbone projects and large irrigation areas belong to different departments and regions, and the management system and operation mechanism of unified dispatching and hierarchical management of water resources in the Yellow River are not perfect, making it difficult to achieve overall consideration of the upper, middle and lower reaches of the whole river. The upstream irrigation area accounts for 27% of the whole basin, but the water consumption accounts for 44% of the whole basin irrigation water. The utilization rate of agricultural irrigation water is only 30%, and the repetition rate of industrial water is only 20% ~ 30%. The average water consumption per 10,000 yuan output value is more than 1 times higher than the national average, and more than 6 times higher than that of advanced countries. Extensive management and serious waste of water resources are the main reasons for the interruption of the Yellow River. In addition, the treatment rate of industrial wastewater in the whole basin is less than 2 1%, which further aggravates the shortage of water resources.
(4) Basic countermeasures to alleviate the interruption of the Yellow River.
The increasingly serious interruption of the lower reaches of the Yellow River has attracted the attention of all walks of life. Relevant departments organized experts and scholars to conduct on-the-spot investigation and discussion on the causes, effects and countermeasures of network disconnection, and put forward many opinions and suggestions.
The basic countermeasures to alleviate the interruption of the Yellow River can be summarized as the following four aspects:
A. Strengthen the unified management and protection of water resources in the basin and implement unified water dispatching in the whole basin;
B adhere to the water-saving policy, develop water-saving agriculture and establish water-saving industries;
C. strengthening the protection and construction of the ecological environment in the river basin;
D. accelerate the process of south-to-north water transfer.
4. Questions and answers about Yellow River knowledge
① "To despise the Yellow River is to despise our nation!" Which great man said this sentence?
This famous saying was said by Comrade Mao Zedong. After commanding the PLA to win a great victory in Yichuan, the CPC Central Committee decided to cross the Yellow River eastward into North China. March 23rd 1948 The central authorities crossed the river from Kawaguchi Village, wubu county. A dozen wooden boats boarded the first boat, and Ren boarded the second boat, and Hu Qiaomu boarded the third boat. When the boat reached midstream, huge waves roared with ice the size of a millstone, and the ice hit the wooden boat with a thrilling crash. The small wooden boat suddenly jumped on the waves and sank into the trough. In the face of this situation, Mao Zedong was deeply moved and pondered for a long time. He sighed deeply: "You can despise everything, but you can't despise the Yellow River. This is to despise our nation!"
There are many ancient battlefields in the Yellow River basin. Can you name a few?
Mu Ye Ancient Battlefield: In the north of Weihui City, Henan Province, it is a suburb of Chao Ge, the capital of Shang Dynasty. At the end of the Shang Dynasty, the crusade against Yin and Shi was sworn here, and they broke in at one fell swoop and forced themselves to commit suicide, ending the 600-year history of the Shang Dynasty. This is the famous battle of Makino in history.
Hill ancient battlefield: in the northwest of Luoning County, Henan Province. During the Spring and Autumn Period, Qin Jin, who was married, had been fighting with each other because both sides wanted to be the king. After his death, the conflict became public for Zheng. Duke Xiang of Jin laid an ambush on the only way to Qin Jun, and Qin Jun was wiped out with 300 chariots. This is the famous battle of Xiaoshan in history.
Julu Ancient Battlefield: Pingxiang County, Hebei Province. At the end of Qin Dynasty, Chen Sheng and the uprising were defeated by the Han army. Zhang Han then suppressed another rebel army led by Xiang Liang, then attacked Zhao and occupied Handan, the capital of Zhao. The prince of Zhao retreated to Julu and asked Qi, Yan, Chu and other countries for help. The King of Chu sent two military forces, one led by Liu Bang to attack Xianyang and Qin Dou directly. Yi Song rate of a route