The relationship between rain, dust, sun, trees and human life

The relationship between rain, snow, clouds, fog, dew, frost and hail and human life

It is difficult to clearly explain the relationship between these natural phenomena and human life. For example, drought has a great impact on human life: drought lacks Water is a global problem. In the early 1990s, southern Africa experienced four consecutive years of drought and lack of rain. Farmland was parched and reservoirs were depleted. The drought caused the already weakened economic security of some countries to lose their vitality. my country's agricultural drought and water shortage are also serious. In the 1970s, 170 million acres of farmland were affected by drought every year. By the 1990s, the number increased to 400 million acres. The annual water shortage in irrigated areas across the country is about 30 billion cubic meters. Drought and water shortage have affected the steady development of agriculture and the secure supply of food. .Drought affects both rural areas and cities. In 1995, there was a water shortage in Xi'an, so the university had to stop final exams and start summer vacations in advance. This shows how important rain is to human life. But it rained too much, and floods Flooding can also cause floods, posing a threat to human life and property.

Another example is snow. In the vast areas of northern my country, if there are a few deep snowfalls in winter, the melted snow water in spring can Irrigating crops once is beneficial to the growth of crops, but like the winter snowstorm in Inner Mongolia, the temperature drops to minus 30-40 degrees, which will cause a snowstorm that will freeze a large number of sheep to death, causing great losses to local herdsmen.

Another example is fog. For mountainous areas where tea is produced, the famous "Cloud Tea" can be baked due to the fog. However, for highways, fog will cause traffic accidents and bring losses to people's lives and property. Loss.

As for hail, it is of absolutely no benefit to mankind and will only bring disasters to mankind:

Hail is a common disastrous weather in our country, especially in our province. Hail-prone areas. Large hail often destroys crops and injures people and animals, causing disasters. Hail also has varying degrees of harm to transportation, housing construction, industry, etc. Therefore, how to reduce hail disasters is to develop the national economy. It is especially an important issue in agricultural production.

Hail is very harmful to crops and can cause mechanical damage to crops. The damage of hail depends on the size, duration, crop type and its During the development stage, if large hail strikes violently or the hail lasts for a long time, crops will suffer more damage. Dicotyledonous crops such as beans and cotton will suffer more damage than gramineous crops. Crops in the flowering or mature stage will suffer more damage than those in the seedling stage. Severe damage can even cause devastating damage. If fruit trees are hit by hail, their growth in the current year and in the future will be affected. They are also prone to diseases and insect pests due to trauma. Various crops have different abilities to resist hail damage, and the same crop has different resistance to hail damage at different growth stages. The abilities are also different. Graminous crops have strong resistance to damage in the early stage of growth, but weak resistance to damage in the later stage of growth. For example, wheat is broken by hail before heading, and as long as root stubble is left, it can still resume growth and obtain a certain yield, but If the stems and ears are broken during the late heading period, the yield will be low and the maturity will be late, affecting the sowing of the next crop