About the severe drought in Yunnan

Water

Recently, meteorological drought in Yunnan Province has developed rapidly and severely, resulting in insufficient soil surface moisture, severe agricultural damage, and continued high forest fire risk meteorological levels. The main characteristics of meteorological drought occurrence and development in Yunnan Province include early onset of drought, long duration, wide range of influence, and severe drought severity.

Deng Yiying from the Songhuaba Water Conservancy Project Management Bureau said: "The water level has now dropped to 169.93 meters, which is the lowest water level in the same period in previous years." As of March 5, the province's reservoir storage capacity was only 1.1 billion cubic meters, less than half of previous years and 1.5 billion cubic meters less than the same period last year. 64 small and medium-sized rivers in the province have stopped flowing, and 934 small reservoirs and mountain ponds have dried up... The drought-stricken area in the province has expanded from 27.52 million acres at the end of last year to 34.35 million acres, and the number of people with temporary drinking water difficulties has increased sharply from more than 2 million people. to 6.63 million people.

Water crisis. We rise up to fight against disasters. However, how much do we know about the water crisis? How much preparation is there in thought and action? As the source of all things, water is not only related to the quality of human life, but also affects human survival ability. Do we truly cherish water? Are we really saving water? Are we really protecting water resources? Seek water, cherish water, and benefit Yunnan! Everyone, start with yourself!

Drought is raging, Yunnan is in emergency!

Once a province with major water resources

Yunnan Province is very rich in water resources. The lake area is 311.388 square kilometers, the drainage area is 2920 square kilometers, the average water depth is 5.12 meters, and the deepest is 11.3 meters. The water storage capacity is 1.5931 billion cubic meters. The per capita water resource exceeds 10,000 cubic meters, which is four times the national average. "Usually, Yunnan is a province rich in water resources, but now, Yunnan is too thirsty... We urgently need rain to save the drought."

The once-in-a-hundred-year drought has made it difficult for the country to boast of rich natural resources. A heavy blow to Yunnan. Perhaps in the near future, rain will return to this dry land, but no matter what, it cannot dilute the imprint left by this drought on the hearts of Yunnan people.

From a scientific perspective, we can summarize this century-old drought as a "probabilistic event": an extreme weather event that occurs randomly in history. However, as we step closer to the answer to this drought, we find that the problem is not that simple. In addition to science, we still have many things worth exploring and reflecting on.

According to data provided by the Yunnan Provincial Department of Water Resources, the current water storage capacity of reservoirs in Yunnan Province is only 1.1 billion cubic meters, less than half of previous years, and 1.5 billion cubic meters less than the same period last year; 64 Small and medium-sized rivers have dried up, and 934 small reservoirs and mountain ponds have dried up. "Reservoirs in Yunnan mainly rely on rainfall during the rainy season to store water. Once this opportunity is missed, the reservoirs can only rest on their laurels." However, no rain fell after September last year, and the temperature in autumn was high and evaporation was large. Basically, no reservoirs could Escape the fate of dryness.

Even for several main streams and several large lakes with relatively abundant water resources in Yunnan, the current situation is not optimistic. In February, in Diqing Shangri-La, the river surface of many waters of the Jinsha River in the upper reaches of the Yangtze River has been greatly reduced. The river surface, which is usually 200 to 500 meters wide, is currently less than 50 to 100 meters; while in previous years, the river surface was as deep as 40 to 50 meters. The water level in the Pearl River source has also dropped by several meters due to reasons such as high evaporation, and some river sections have dried up and bottomed out.

So, what is the condition of Yunnan’s water conservancy facilities? A relevant person in charge of the Provincial Department of Water Resources said that for a long time in the past, Yunnan's water conservancy facilities were resting on their laurels. A very important aspect is that there have been almost no repairs on small reservoirs in Yunnan. As a result, one-quarter of township government residents in Yunnan currently have difficulty drinking water. This is not the worst part. Some local reservoirs, which are smaller than small reservoirs, not only lack funds for repairs, but also lack corresponding scientific management, causing them to dry up faster than small reservoirs when drought strikes. And for those small water cellars dug by the masses voluntarily, they have no ability to withstand drought without replenishing water sources.

Severity of Drought

Yunnan has distinct dry and wet seasons, and precipitation is extremely unevenly distributed seasonally. The winter and spring months from November to April each year are the dry season in Yunnan. The precipitation only accounts for 10% to 20% of the whole year. Droughts are common in winter and spring. Especially since 2002, Yunnan has been under a climate background of less precipitation and higher temperatures in summer and autumn, which has also provided a dry and warm climate background for the occurrence of drought since the autumn of 2009.

Meteorological experts analyzed that the main reasons for the meteorological drought in Yunnan are the continued low precipitation, continued high temperatures, large water vapor evaporation, and early end of the rainy season. From July 1, 2009 to February 23, 2010, the average precipitation in Yunnan Province was 521.6 mm, breaking the record for the fewest rainfall days in the same period since 1959.

If the hundred-year drought is really a simple matter of probability, does that mean that such a situation is simply unavoidable? Regarding this question, Xu Jianchu, a climate expert at the Kunming Institute of Botany, Chinese Academy of Sciences, gave an intriguing answer: "The hundred-year drought in Yunnan is an inevitable accident."

As for the cause of the drought in Yunnan, the academic community has given a The general conclusion: Global climate warming and the intensification of the Pacific El Ni?o phenomenon have damaged the atmospheric structure, causing the ocean monsoon to be unable to land and form rainfall. Xu Jianchu supports this view, but the difference is that he focuses his research on "global warming", the premise that causes drought.

Data provided by the Yunnan Meteorological Bureau: Since the 1980s, the average temperature in Yunnan has generally shown a clear warming trend, especially from 2001 to 2006, when the temperature in Yunnan increased by 0.64°C. , the magnitude of warming is greater than the global and northern hemisphere averages. Correspondingly, since 1961, annual precipitation in Yunnan has generally shown a decreasing trend, and at the same time, extreme precipitation events have begun to increase. If divided according to time periods, Yunnan has shown signs of warming since the mid-to-late 1980s, with the most obvious warming in the late 1990s. Central Yunnan has been the area with the most obvious warming in the province in the past 10 years. In terms of precipitation, in the past 50 years, summer and autumn precipitation in Yunnan has decreased, especially in summer.

In addition, by calculating the relationship between the global and northern hemisphere average temperatures and the four-season precipitation in Yunnan, it was found that the increase in global and northern hemisphere average temperatures is not conducive to the increase in summer, autumn and annual precipitation. This is consistent with the above-mentioned actual precipitation. The evolution trends are basically the same. In order to further study the changes in precipitation in Yunnan, Xu Jianchu selected the global cold period from 1961 to 1976 and the global warm period from 1987 to 2006. After calculating Yunnan's average annual precipitation and four-season precipitation in these two periods, he found that , the autumn, summer and annual precipitation in the cold period is more than that in the warm period, and this difference is very obvious. "These studies have proven without exception that warming temperatures have reduced rainfall in Yunnan."

Not only climatologists, but also villagers in Shuitang Village, Chenggong County, have experienced this personally. "It's getting hotter and hotter, and the hotter and drier it gets," is how Shuitang Village villager Zhou Hui summed up climate change in recent years. "It has never been as hot as last year and this year. I didn't even wear a sweater all winter. I didn't expect that even the water was hot." Like Zhou Hui, in the eyes of many villagers, the century-old drought and Rising temperatures are inextricably linked. As early as a few years ago, someone in the village discovered this "law" and subsequently replaced the paddy fields with dry land cultivation. Currently, Shuitang Village is all dry land.

In the view of Luo Yinhui, deputy director of the Yunnan Provincial Institute of Geology and Mineral Exploration, whether it is the water that disappears in ponds or the water that disappears in rivers and lakes, “most of it flows away in vain.” Yunnan has always existed A contradictory phenomenon: As a province rich in water resources, its total water resources rank third in the country. However, due to the special terrain environment and climatic conditions, the dam area, which accounts for 6% of the province's land area, concentrates two-thirds of the population and one-third of the cultivated land, but only accounts for 5% of the province's water resources. At present, the water resources development and utilization rate in Yunnan is only 6.9%. These characteristics have largely led to Yunnan becoming a water-poor province.

Luo Yinhui said that this contradiction often creates the illusion that Yunnan has inexhaustible water, but in fact it is not enough at all. "Many areas in Yunnan are dominated by karst landforms and mountainous areas. There is no water on the slopes, only in the ravines. So when drought occurs, it becomes more difficult to obtain water." What worries Luo Yinhui even more is the rocky deserts in Yunnan's karst areas. change. This kind of rocky desertification is similar to the desertification in northwest my country and is one of the extreme forms of land degradation. As people continued to clear wasteland for farming, destroying the original vegetation, the soil layer that took tens of millions of years to form was rapidly lost, and finally only stones on the surface that could not grow any plants were left.

A latest survey shows that within the 740,000 square kilometers of the karst rock mountain area in southwest China, the rocky desertification area reaches 105,000 square kilometers, accounting for 14.2% of the surveyed area. Among them, Yunnan Province The area of ??rocky desertification is 28,000 square kilometers, with an annual growth rate of 2%. "It can be said that the current situation of Yunnan's surface water is not optimistic. Once rocky desertification intensifies, the surface will completely lose its original water storage function. The result is that more places will begin to lack water." Luo Yinhui said.

What factors lead to the continued drought in Yunnan?

Wang Xuefeng, deputy director and senior engineer of the Yunnan Provincial Climate Center, is drawing a monsoon weather cloud map in front of the computer. "Because Yunnan has a monsoon climate, once the monsoon cannot reach it, it is very likely to cause drought." Wang Xuefeng gave this explanation for the cause of the drought.

Wang Xuefeng said that Yunnan is in the southwest monsoon zone in summer, and most of its precipitation is related to water vapor in the Bay of Bengal and the Indian Ocean. Because the Tibetan High is too strong this year and extends downward and eastward, the water vapor in the Bay of Bengal cannot be transported to Yunnan. Coupled with the mountainous nature of Yunnan, the foehn effect intensifies the drought. "Yunnan's climate is also characterized by an obvious alternation of dry and wet seasons. The dry season is from November to April of the following year, and the wet season is from May to October. Generally speaking, the wet season accounts for the annual rainfall. More than 80% of the total amount, so once the rainfall in the rainy season is insufficient, it may lead to a drought throughout the year. "Last year, the rainfall in the rainy season ended one month earlier than normal, which is also one of the reasons for the severe drought.

Monitoring shows that from July 1, 2009 to February 23, 2010, the average precipitation in Yunnan Province was 521.6 mm, 30% less than the multi-year average, breaking the average precipitation for the same period since 1959 The average maximum temperature was 23.7℃, which was 2.0℃ higher than the average for the same period in many years, breaking the record for the average maximum temperature for the same period since 1959. From July to December 2009, the average water vapor evaporation in Yunnan Province was 822.5 mm. It is 12% more than the average for the same period in many years; from September 1, 2009 to February 23 this year, the average number of rainy days in Yunnan Province was 31 days, 44% less than the average for the same period in many years, breaking the minimum number of rainy days in the same period since 1959 record.

Drought is only one of the reasons for heavy crop losses this year; on the other hand, the serious waste of irrigation water must not be ignored. "Agriculture is a large user of water in Yunnan, with annual water consumption of up to 11 billion cubic meters, and the water utilization rate is only about 40%." Some scientists have calculated that according to China's current irrigation method, 1 kilogram of rice will "eat" 1 ton water! Currently, 1/2 of the irrigation channels in Yunnan are earthen channels. This traditional and backward irrigation method has a large amount of leakage. In addition, due to various constraints during the construction period, most of the reservoirs in the irrigation area are seriously aged and degraded, and the field projects are not supported. The reservoir irrigation area only has main canals and a small number of branch canals. The backward irrigation methods, coupled with the barren land, have led to the loss of water, soil, and water. Fat loss is serious.

Considering human factors, the main reasons for drought caused by human activities are the following four points:

1. The massive increase in population has led to an increasing shortage of limited water resources.

2. Forest vegetation has been destroyed by humans, and the water storage function of plants has been lost, resulting in a decrease in groundwater and soil water.

3. Human activities have caused large amounts of water pollution, reducing available water resources.

4. Water wastage is serious, especially in agricultural irrigation water, which is alarming in our country, leading to water shortages.

Drought has seriously affected the lives of residents in Yunnan

Since the autumn of 2009, precipitation in the southwest has continued to be low, and Yunnan has suffered a severe drought that has not happened in a century. The drought has had a serious impact on the lives of people in Yunnan.

Looking through the information, we found that this year is not the only year that drought has had a serious impact on Yunnan’s social and economic life. In 2005, Yunnan suffered the most serious early summer drought in the past 50 years. The drought caused agricultural economic losses of more than 4.2 billion yuan and industrial economic losses of nearly 8 billion yuan.

Judging from the impact of the current drought, farmland crops mainly affect small spring grains, sugar cane and natural rubber. If the drought continues to develop, it will affect spring sowing, and the agricultural production throughout the year will be greatly affected, and even trigger Price trends in the second half of the year. It is now the sugarcane crushing season, and severe drought will lead to the emergence of new sugarcane plantings at a lower sugarcane yield. The drought is expected to reduce Yunnan's sugar production this season by about 15% year-on-year.

Since Yunnan is China's main sugar-producing area, if the drought continues, sugar production in the next crushing season will also have a very large impact, and sugar prices may continue to rise in the future.

The ongoing drought also affects the production of fruits and vegetables. According to the Planting Industry Management Office of the Yunnan Provincial Department of Agriculture, the area affected by crops sown in autumn and winter reaches 2.12 million hectares (accounting for 85% of the area sown), of which the area affected by vegetables reaches 2.12 million hectares (85% of the sown area). 262,000 hectares, 163,000 hectares were affected by disasters, and 61,000 hectares were affected by no harvest; 452,000 hectares of five economic fruit trees, tea, sericulture, rubber, and coffee were affected by drought in the province, 140,000 hectares were affected by disasters, and 14,700 hectares were affected by no harvest, of which : The affected area of ??fruit reached 157,000 hectares, with 54,000 hectares suffering damage and 5,000 hectares experiencing no harvest. Therefore, it will have a greater impact on fruits, vegetables, etc. in the short term. If the drought continues, then even later replanting will lead to a significant decline in the annual fruit and vegetable production in Yunnan and Guizhou provinces.

Residents go to the provincial capital to take a bath

Residents in Yiliang, Xundian, Songming, Chuxiong and other cities have had water difficulties for several months. In addition to relying on fire trucks to provide water over long distances, Urgently build canals to divert water to areas with water. Many urban residents in Xundian have been without water for bathing for more than a month. Some residents even went to Kunming to bathe. Sticking to the bottom line of people's livelihood is the bottom line of Yunnan's drought relief work. To achieve this, urban industrial water use has mostly been at a standstill.

Residents haven’t had soup for months

Li Shaorong and his wife in Kunming last had soup three or four months ago. They only eat simple rice, pickles and a few small slices of radish for every meal every day. Li's hometown is Shiyanzi Village, Xundian County, Yunnan Province, which has suffered the worst drought in a century. The broad beans and rapeseed in the fields have withered, and the food is almost exhausted. Since January, the local government has provided water to each household according to quotas, but the amount of water is only enough to survive. None of them could remember the last time they took a shower.

Villagers eat wild vegetables to satisfy their hunger

Drought has made it unprecedentedly difficult for residents in Jinning, Yunnan to drink water. There is no running water, and villagers can only rely on external supplies for drinking water. The villagers' vegetable baskets are facing unprecedented difficulties. Villager He Zhongcai began to pick wild vegetables from the mountains to eat. He soaked a kind of wild vegetables called "hungry sheep vegetables" in a pot. This is a plant that sheep usually only eat when they are hungry. There was an obvious astringent taste in my mouth that went straight to the top of my head. My throat started to tighten and I couldn't help but cough. In the vegetable field behind He Zhongcai's house, several blooming green onions are still growing tenaciously. He Zhongcai said: "You can also eat some chopped green onion if you pour it with washing water."

Power cuts in some provinces and cities

The severe drought in southwest China has continued to strain the supply of thermal coal, and power cuts have already occurred in some provinces and cities. A severe drought has caused cracks to appear on the runway in Kunming, the capital of Yunnan province, and the runway will be closed for repairs at 7:30 am every morning until next month.

Why does the drought persist?

Perhaps the results of a latest study can give Yunnan people who have been without rain for a long time a little relief. Xu Jianchu pointed out in a study titled "Climate Change Facts in Yunnan" that rainfall in Yunnan will generally increase in the next 30 to 40 years. The study also pointed out that Yunnan has entered a new warm period since the 1990s. In the next 10 to 20 years, the temperature in Yunnan will still maintain a high trend, and in the next 30 to 40 years, the temperature in Yunnan will mainly be high. "If the impact of human factors on climate change is taken into account, the temperature rise in Yunnan will increase and there will be more precipitation."

The problem is that this is not consistent with the previous conclusion that rising temperatures cause precipitation to decrease. Contradictory? Xu Jianchu explained that this is because in the next few decades, the temperature increase in Yunnan will be slightly lower than the national average. From a national perspective, the temperature in Yunnan is still declining, which is why rainfall in Yunnan will increase. reason. "At the same time, according to the rainfall cycle, Yunnan will be in a very long period of increasing rainfall in the next 30 to 40 years."

Coincidentally, the National Meteorological Center uses the atmospheric model developed by the Climate Center and the atmospheric physics of the Chinese Academy of Sciences The results of future temperature changes simulated by a model integrated with the ocean model developed by the institute prove Xu Jianchu's inference. Simulation results show that the annual average temperature in Yunnan is likely to increase by about 3.5°C by the end of the 21st century, and precipitation is mainly in the excessive phase.

“In other words, the possibility of another severe drought in Yunnan will decrease for a long time to come.

"Xu Jianchu said that many people were excited when they heard the news because in the context of a century-old drought, this is somewhat like "once bitten by a snake, ten years afraid of well ropes." If you think about it calmly, you will find that The challenges Yunnan faces have not really diminished. “As long as the probability of extreme weather does not decrease, Yunnan’s future will be full of uncertainty. Once there is too much precipitation in the future, the possibility of floods in Yunnan will greatly increase. According to the current conditions of Yunnan's water conservancy facilities, it still does not have the ability to compete with nature. ”

Such a view may sound too pessimistic, but Xu Jianchu said that this does not mean giving up efforts. Xu Jianchu said that the government has adopted various measures to combat drought and disaster relief, but in fact the most fundamental The method is to establish the concept of water conservation. “Although drought is inevitable, we can at least live a better life through our own efforts. ”

Tips for saving water:

1. When taking a bath, try to use a shower instead of a bath.

2. Wash your hands with a small amount of water in a short time.

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3. When washing vegetables, dishes, utensils, etc., do not rinse for a long time and try to use a small amount of water for washing.

4. Put a plastic bottle of water in the bathroom toilet tank. Each time you use water, you can save 500 ml of water.

5. When flushing the squatting pit, reducing the valve pressing time can save more than 1 liter of water (the lower the floor, the less pressure should be used). 6. Wash clothes: Use the waste water from rinsing clothes to flush the bathroom, mop the floor, rinse mops, and flush the corridors. You can also connect two plastic buckets for backup, which can save more than 100 liters of water per week (prepare two plastic buckets). p>

7. Proper use of cold water in front of the solar system. The lower the floor, the more cold water there is. It is also a good method to connect the cold water to the container for backup.

8. Comprehensive utilization of waste water. p>

9. Use the waste water from bathing to flush toilets and pits, which can save more than 80 liters of water each time.

10. Vegetable washing water can be used to water flowers.

11 Showing with a shower head saves 80% of the water than using a bathtub. Therefore, it is recommended that you use showers more and use less or no bathtubs. You should avoid taking long showers and turn off the water in time when scrubbing; do not use the water from the shower head. Leave it open at all times, and should not be left open.

12 Use water for multiple purposes. For example, rice washing water can be used to wash vegetables. It is also helpful for removing pesticides on the surface of vegetables, and vegetable washing water can also be used for flushing toilets. ; Bath water, laundry water, face (foot) water can be used for mopping the floor, and can also be used for flushing the toilet.

Do not turn on the tap for a long time to wash your hands, do laundry or wash vegetables. Change the flow rate of faucets to intermittent flushing. Repair leaking faucets and other water appliances promptly. Leaking faucets can consume 70 liters of water per day. People’s advice: Use water-saving appliances to effectively save water.

Key points of diseases that need to be prevented during droughts

Drought is a relatively common natural disaster that often lasts for a long time, has a wide scope, and is progressive. The human living environment gradually deteriorates, and health hazards continue to exist and increase. During the drought, prevention of these diseases should be done to maintain normal life and production activities.

1. Prevention of intestinal infectious diseases

Drought causes water shortage and high temperature. Weather. Pathogens multiply faster in polluted water sources and food, such as cholera, dysentery, typhoid, and hepatitis A. To prevent intestinal infectious diseases, remember to "eat cooked food, drink boiled water, and wash." "Hand cleansing" principles. Do not drink raw water or boiled water; food must be cooked thoroughly, leftover food must be thoroughly reheated before eating, and eaten while it is hot, and do not eat spoiled food

2. Popularity Prevention of Japanese encephalitis

Summer and autumn are the epidemic seasons of Japanese encephalitis, and mosquito bites can easily cause the occurrence and epidemic of Japanese encephalitis. It is even more necessary to do a good job in preventing and killing mosquitoes.

3. Prevention of food poisoning

During a drought, food is prone to spoilage, but the appearance may be normal, and the amount eaten is normal. Bacterial food poisoning often occurs suddenly and has a short incubation period. Although non-bacterial food poisoning is more sporadic, the mortality rate is high. Therefore, prevention efforts should be strengthened. First, do not eat livestock, poultry, aquatic products that died of illness or unknown causes of death, or foods with strange smells; second, the food must be cooked thoroughly; third, if you feel unwell after a meal, you should seek medical treatment in time.

4. Prevention of heat stroke

Exposure to sunlight and high temperature for a long time can cause heat stroke.

To prevent heat stroke, you need to: take personal protection. If heat stroke occurs, move the patient to a ventilated and cool place to lie down, loosen clothes, apply cold compress to the head or chest, give the patient cold salt water to drink, and take Rendan, Ten drops of water and apply cooling oil. Mild illness recovers faster,

Cherish every drop of water

Cherish resources and protect the environment. We can start from the small things around us, such as: don’t litter, pay attention to conservation Water and electricity resources, not using disposable items, etc. are all ways to cherish resources. As long as we have perseverance, we will definitely become small role models who cherish resources.

If most people destroy the environment, then the country will need to spend a lot of resources to control the environment. This requires not only a lot of manpower, but also a lot of material resources. However, if we all become messengers to protect the environment, then we will not only save resources, but also save manpower and material resources. If most people waste water resources, then there will be no water to drink in the future, even if there is water Drinking it will also be very precious. A newspaper once said: In about 70 years, water will be more expensive than oil.

Water, the basic substance on the earth, is so worthy of our praise! It is she who gave birth to all living beings in the world; it is she who provides energy for life so that life can survive; it is she who makes life continue to develop and become more and more prosperous and developed. So it is no exaggeration to say that "water is the source of life."

If people do not cherish water resources, then the last drop of water in the world will be human tears.

Is water inexhaustible? We can answer with certainty: no. Although 70.8% of the earth is covered by water, 97.55% of the water is seawater, which is neither directly drinkable nor irrigated. Among the remaining 2.5% of fresh water, the water that humans can actually utilize is less than 1% of the world's total fresh water. It is true that from the emergence of primitive life on the earth until now, water has been serving life, working hard and never stopping. But I wonder if you have ever thought about it: the endurance of water has its limit, and today’s water resources are already in short supply!