What are the climatic resources and their utilization prospects?
Types of climatic resources (1) Light energy resources mainly refer to radiant energy from the sun. The amount of light energy resources in a region first depends on its geographical latitude. The quantity and availability of light energy resources in a year are usually expressed by sunshine hours and total solar radiation. China is rich in light energy resources.
Irreplaceable Climate Resources It is estimated that the total amount of solar radiation received by the land surface in China every year is 5× 10 19 kJ. However, due to the influence of geographical latitude, altitude and topographic and meteorological conditions, the distribution of light energy resources in China is quite different. The Qinghai-Tibet Plateau is the richest in light energy resources, followed by Northwest China and Sichuan Basin. The economic value of light energy resources is mainly manifested in two aspects: ① direct use of solar energy, such as solar power generation and heating; ② Photosynthetically effective radiation in solar energy is transformed into organic matter through photosynthesis of plants, such as forests, grasslands and food crops. To make it available to people. Photosynthetic effective radiation generally accounts for about 50% of the total solar radiation energy.
(2) Heat resources Heat resources refer to the heat that can be provided by a certain area under specific climatic conditions. It is the comprehensive result of solar radiation and various physical processes on the surface and in the atmosphere. The most intuitive description of thermal condition is temperature. The heat status of an area directly determines its crop planting type, growth status and yield. In order to describe heat resources, the accumulated temperature is generally used, that is, the accumulated value of daily average temperature within a certain temperature range.
According to the different heat demand of different crops, people also define effective accumulated temperature, active accumulated temperature and so on. Due to the great difference in topography and the influence of monsoon climate, the geographical distribution and temporal variability of heat resources in China are great, and its general law is gradually increasing from north to south. China is rich in heat resources, which can be divided into tropical, subtropical and temperate climate types from south to north. The best heat condition is south of Nanling, where crops can grow all year round and rice can be harvested three times a year. The worst hot conditions are the Qinghai-Tibet Plateau and Northeast China, where only one crop can be planted a year.
(3) Water resources Water resources are also an important part of climate resources. According to different climates in different regions, the distribution of water resources is also obviously different.
Take China as an example, the monsoon climate in China is very obvious, so summer is also the time with the most rainfall. Because of the different topography, latitude and distance from the ocean, the distribution of precipitation is very different, and the interannual variation is also great, and the frequency of drought and flood is high. Therefore, although China is rich in water resources, it is changeable and difficult to grasp. Generally speaking, the precipitation concentration season in most parts of China is consistent with the high temperature growth period, that is, the water and heat are synchronized, which is beneficial to agricultural production. On the other hand, due to the influence of monsoon climate, the seasonal distribution of precipitation is uneven, which makes it difficult for crops to get the required water at different growth stages. The distribution of precipitation in the whole country gradually decreases from southeast to northwest.
Utilization of wind energy resources (4) Wind energy resources Wind energy is energy generated by atmospheric movement and converted from solar radiation energy. According to the calculation, the wind power converted from solar energy reaching the earth is about 7W/m2. The utilization of wind energy has long been recognized by human beings, and it has been used to drive sailboats and drain water for thousands of years.
19 10, Denmark first started to use wind power generation, and then some developed countries in the west carried out research work on large wind turbines. China is also one of the earliest countries in the world to use wind energy. Since 1970s, China has installed wind turbines in the southeast coastal areas, and is currently engaged in the research of large-scale wind turbines. China belongs to monsoon climate, and the windy area of wind energy utilization ranks third in the world. The southeast coast is the region with the best utilization of wind energy resources in China, followed by Bohai coast, Inner Mongolia, northern Gansu and Alashankou area in Xinjiang. In addition, the distribution of wind energy is also of great significance to the layout and design of cities and industries.
(5) Carbon dioxide is one of the most important atmospheric component resources. The content, distribution and seasonal variation of carbon dioxide in the atmosphere not only affect the climate, but also play an important role in crop photosynthesis. Carbon dioxide is the carbon source for photosynthesis of terrestrial plants.
When the concentration of carbon dioxide in the surrounding air is different, it will affect the absorption of carbon dioxide by group crops, thus directly affecting the photosynthetic rate of plants, so the concentration of carbon dioxide directly affects the photosynthetic rate, growth and yield of crops. Effectively controlling the concentration of carbon dioxide in the atmosphere is of great significance to agricultural ecology and crop growth.
Main characteristics of climate resources
Climate resource is a very special resource. It is different from other resources, and the characteristics of climate resources are as follows:
(1) Climate is composed of light, temperature, humidity, precipitation, wind and other factors. Its resource quantity depends not only on the value of each factor and its mutual cooperation, but also on different customers and their cooperation with other natural conditions. Unlike gold, coal and other mineral resources, the more the better. For example, for crops, temperature is a resource within a certain range. Too high may cause heat damage, and too low may cause cold damage or freezing damage. Precipitation is a kind of resource in a certain range, too much may turn into flood disaster, too little may turn into drought. Although there are abundant photothermal resources in arid areas, the shortage of water resources limits the full utilization of photothermal resources and greatly reduces their value. For another example, rainy weather may be beneficial to the growth of some crops, but it may not only be unfavorable, but even harmful to tourism and salt drying; Covering with snow is beneficial to protect some crops from wintering, but it may be harmful, making it difficult for cattle and sheep to eat grass.
(2) Climate changes with time. Some of these changes are periodic; Some periodicity is not obvious, and the law of change is elusive. For example, the temperature changes day and night, seasonal changes, mostly day by day, year by year, cycle by cycle. But the weather is not like this on a certain day or season every year. As for the climate change in a certain period or years, although there is a certain range, the change is complex and it is difficult to predict accurately. Therefore, the utilization of climate resources must keep pace with the times. At the beginning of Taishengshu, the oldest agricultural book in China, it said: "The foundation of all farming lies in the interesting time", and Mencius also said: "If you don't go against the farming time, you can't beat grain." All these show that when planting crops, we should seize the opportunity. If we miss the opportunity, resources will be fleeting and wasted.
(3) There are regional differences in climate. (1) Every place in the world has its own unique climate, and the climate in other places cannot be exactly the same. Therefore, the utilization of climate resources must be adapted to local conditions. "The Book of Klang" says: "There is no time to grow grain, because the place is the time", which means that there is no fixed date for planting millet, and the time varies from place to place; In some parts of the world, although far apart, the climate is not exactly the same, but it is similar. Therefore, we can introduce crops, livestock and exchange experiences in using climate resources.
(4) Climate resources are renewable resources. Unlike gold, coal and other mineral resources, mining a little is a little less and will eventually dry up. In the final analysis, climate resources come from solar radiation. If properly used and protected, it will live like the sun and can be used repeatedly and permanently.
(5) Climate can be influenced by manpower. This influence can be divided into conscious and unconscious. Because climate conditions are closely related to other natural conditions, human beings often change climate conditions consciously or unconsciously in the process of transforming nature in production and life activities. For example, planting grass and trees and storing water for irrigation can make the climate better; Destroying forests and grasslands and draining lakes and swamps will make the climate worse. Urbanization and industrialization have polluted the atmosphere and increased the acidity and temperature of precipitation, which may lead to long-term and large-scale climate change and have a great impact on human survival. At present, human beings consciously improve the climate, mostly in a small range. For example, build a shelter forest and set up a wind barrier; Drainage and irrigation facilities, glass greenhouses, plastic greenhouses, etc. With the development of society and the progress of science and technology, there will be more and more aspects of human transformation, and even some unfavorable climatic conditions can be transformed into favorable climatic conditions, and some climatic disasters can be transformed into climatic resources.
World climate resources situation
In tropical rain forest areas (such as Congo basin, Amazon plain, Malay archipelago, etc. ), high temperature and rainy all year round, rich in water and heat resources, coffee, rubber, cocoa and other tropical cash crops are distributed here.
The interior of the mainland on both sides of the Tropic of Cancer has a tropical desert climate, which is most widely distributed in Sahara, southwest Asia and central and western Australia. The climate is hot and dry, with little precipitation. Drought threatens all activities here.
The temperate zone is located in the mid-latitude zone, and most parts of Eurasia and North America are in the temperate zone. The temperature and precipitation here are moderate and the four seasons are distinct, which provides good climatic conditions for agricultural development and is most suitable for human life. It is the most densely populated area in the world. The cold zone is located in the high latitude zone, and the cold climate limits human activities.
Tropical rain forest area is rich in water and heat resources.
China is also rich in climate resources. Most of China is located in the north temperate zone and subtropical zone. Because of its vast territory, complex terrain, great difference in distance from the sea and complex and diverse climate. For example, there is no summer in northern Heilongjiang Province, no winter in Hainan Island, four distinct seasons in Huaihe River Basin, four seasons like spring in southern Yunnan-Guizhou Plateau, snow all year round in western Qinghai-Tibet Plateau, hot summer and cold winter in northwest and inland areas, and large daily temperature difference.
Utilization of climatic resources
Rational utilization and correct development of climate resources is an important subject of climatology.
(1) Utilization rate comes first, and promotion comes second.
The utilization of climate resources should first go with the flow and guide the situation. "The Book of Qi Yaomin" said: "The terrain is good and thin, and the mountains and rivers are different. When the weather is fine, if you measure soil fertility, you will achieve more success with less effort. If you rebel, you will get nothing. " The climate can be improved to a certain extent within a certain range. But improving the climate needs manpower and material resources, and it needs to measure the economic gains and losses. In addition, we should also consider social and ecological benefits, and must not cause long-term, overall and irreparable losses for immediate and local interests. Nevertheless, human beings should try their best to continuously improve climate conditions, otherwise society will not progress.
(2) Strive to create conditions and make the best use of them.
China has a large population and a small land, and it is a common phenomenon that climate resources are overloaded. For example, in the absence of conditions and measures, tropical perennial woody crops moved northward to subtropical areas, and subtropical perennial woody crops moved northward to temperate areas. When they encounter severe cold damage, the fruits that have been cultivated hard for several years or even longer will often be destroyed. Another example is the compulsory implementation of two-year triple cropping system in two-year triple cropping system areas and three-year triple cropping system in one-year double cropping system areas. Either insufficient heat or insufficient water will often aggravate and aggravate the drought, frost and cold damage of crops, so the loss outweighs the gain. However, as mentioned earlier, the climate can be improved, and the climate resources are not static. People should not take advantage of the godsend opportunity, but should use new technologies, new tools and new methods to maximize the use of climate resources, and constantly expand and explore. For example, if you choose a microclimate environment that is sheltered from the wind and take some cold-proof measures, crops may move northward up the mountain; We can also cultivate crop varieties with early maturity, high yield and strong stress resistance, and take measures such as seedling raising, transplanting, intercropping and mixed planting to improve the multiple cropping index.
(3) Reducing disasters means increasing profits.
Climate disasters consume and waste climate resources, so that the value of climate resources is greatly reduced or even completely lost. Therefore, it is not reliable to use climate resources and ignore climate disasters. The so-called rational utilization of climate resources should include reducing and mitigating climate disasters as effectively as possible.
It is better to fight climate disasters than to prevent them, and it is better to avoid them. Take crop frost prevention as an example. After the frost comes, after-care measures such as supporting seedlings, pruning, loosening soil and fertilizing can also reduce some losses, but it is better to smoke, cover and irrigate again before the frost comes, or set up wind barriers in advance to create shelter forests, which is more economical and effective. According to the agricultural climate zoning, it is the most economical and effective to plant crops in areas and seasons where frost is not easy to occur.
(4) Give full play to the advantages of climate resources.
Climate resources have regional differences and temporal changes. Therefore, in the utilization of climate resources, if we can foster strengths and avoid weaknesses, we can get twice the result with half the effort. For example, in arid areas, abundant sunshine, dry air, high temperature in summer and large temperature difference between day and night are its strengths, while insufficient water is its weakness. For example, planting crops with drought tolerance and high transpiration efficiency, such as wheat, millet, cotton, melons and fruits, not only has high yield, but also has good quality. Plateau area, sunny, low temperature; The winter in North China is also sunny and the temperature is low, which makes the light resources unusable. If greenhouse cultivation is developed in these areas, light resources can be used. For another example, in the double-cropping or triple-cropping areas in Central China and South China, it is often the time when the climate resources such as crop changing season, heat and water are the richest in a year. At this time, the previous crop is mature, and the latter crop is in seedling stage, so there is little demand for light, heat and water resources, which wastes a lot of climate resources. If perennial woody crops are replanted, measures such as seedling raising and transplanting, changing planting system and mode are taken, and climate resources are used as much as possible, agricultural output will be greatly improved.
(5) Make full use of the regional and seasonal differences of climate resources.
People like to go to South China in winter and to the Northeast for meetings, recuperation and tourism in summer. In agricultural production, we can also make use of the differences of climate resources between the north and the south, the plains and the mountainous areas, and the climate distribution law that the southern season is earlier than the north and the plain season is earlier than the mountainous areas to provide unique and fresh agricultural products for some big cities. For example, the continuous production of fresh fruits and vegetables in Beijing in recent years is to make good use of the climate differences between suburban plains and remote mountainous areas, as well as between the north and the south, so that these places can adjust the off-season in Beijing and supplement the agricultural products that Beijing cannot produce.