What did the sandstorm in the grasslands of southern Canada say?
Canada is the second largest country in the world, with an area of about 1 million square kilometers, second only to the Russian Federation. Due to the bad climate in the north, only 12% of the land is suitable for developing agriculture. For this reason, 3 million Canadians have to rely on the 3-kilometer narrow strip between the Atlantic Ocean and the Pacific Ocean on the southern border with the United States.
The Canadian Prairie is located in the northern edge of the North American Great Plains, in a half circle from the Rocky Mountains to the Red River Basin, including the southern areas of Alberta, Saskatchewan and Manitoba, with a total area of about 196 million hectares, accounting for 19.6% of the total land area.
The prairie region is Canada's grain bag, settlement and development zone.
Developed agriculture covers an area of 37.7 million hectares, and the three prairie provinces account for 8% of Canada's agricultural base. Agriculture is the pillar industry here and the main wheat producing area in Canada. In fact, the three prairie provinces are among the regions with the highest grain yield in the world. Therefore, it has won the reputation of "world granary".
in p>1818, within 5 years after the boundary between Canada and the United States was determined, Canada officially exercised its sovereignty in 1867 according to the British North America Act. The federal government has promulgated many policies to encourage settlement and develop western grasslands, invested in the construction of the Canadian Pacific Railway, and implemented special transportation price concessions for settlers. Thousands of square kilometers of territory, once considered worthless by people, have been developed into settlements. However, until 1881, the western plain was still uninhabited.
The temperature and precipitation of "American Desert in vast expanse" are different from place to place, and the frequency of natural disasters such as sandstorm and drought is very high, especially in prairie areas.
after the construction of settlement areas began in the second half of the 19th century, droughts occurred in 186-1862, 187-1873, 1886-1889 and 1893-1895, accompanied by frost, crops suffered serious losses, which led to the phenomenon of settlers' "emigration". At the same time, various dry farming measures were accepted and adopted by some farmers, and early-maturing wheat varieties were developed. At the end of 19th century, farming methods in dry land were improved, which triggered a second wave of immigrants to settle and develop prairie areas.
the climate, vegetation and soil productivity of the whole area are ever-changing. Typical landforms include flat and broad plains and gently undulating plateaus, continuous hilly areas, canyons, mobile sand dunes, large reservoirs, lush wetlands, dense valley forests and exposed sandy bedrock.
Due to the barrier of the western Rocky Mountains, the prairie area is far from the ocean, which makes it a grassland area with continental climate. It is extremely hot in summer and extremely cold in winter, with the highest temperature of 4℃ and the lowest temperature of-4℃. The precipitation is low, with an average annual precipitation of 25~75 mm, which belongs to arid and semi-arid areas. The annual precipitation in the red river basin of Manitoba with high humidity is about 5 mm. Strong wind is also a unique weather in the prairie area. Strong wind dries the soil and dries up plants, which is more serious in the south. There are no large water bodies in the upwind and prevailing wind directions, droughts are frequent, and sandstorms often occur in dry seasons.
since 188, the biggest change is to reclaim the Canadian prairie area from the original natural grassland into an agricultural farming area. A large number of natural vegetation has been destroyed. In order to meet the population's demand for food and livestock feed, the original rich topsoil was reclaimed for farmland to grow crops. At the beginning of the 2th century, the speed of reclamation in prairie areas was further increased due to human factors. Many people question the practice of reclaiming southern grassland and developing agriculture, because early farmers didn't realize that they destroyed grassland and also caused soil erosion. However, Gray argued that as a country, Canada could not exist today without the settlement and agricultural development in the prairie area.
Arid land is often subject to sandstorm activities, in which strong wind is an important factor of erosion. Wind erosion has been a long-standing problem in western Canada since the beginning of agricultural reclamation. In the southernmost part of the prairie, westerly winds prevail, including southwest winds and northwest winds. The prevailing wind carries the warm and humid air current of the Pacific Ocean eastward across the mountain system, and the air becomes cold, and the humid air current drifts down in the form of precipitation or snowfall. The more the airflow moves eastward, the more moisture falls in the form of snowfall. The mountain system here runs from north to south, so there is no barrier to stop the Arctic cold current from the north, and the cold winter permeates the whole prairie area. Similarly, there is no obstacle to the warm and dry air mass from the southwest of America pushing northward. Therefore, the atmosphere here is bumpy, clouds are deep, strong winds are everywhere, and precipitation is soaring. When strong winds prevail in spring and heavy rains pour down in summer, they are often accompanied by strong winds. At this time, the arid and loose surface and the field plots without vegetation cover are extremely vulnerable to wind erosion. At this time, sandstorms occurred rapidly, and the black waves of dust rolled up by strong winds could be seen thousands of meters away. Dust storm is like a black wall, rolling and pressing to the ground. Locally dubbed it God's "blackout".
Severe dust storms are sometimes called sandstorms or "dust devils" because they sound more vivid. However, there is a big gap between the two. Dust storms are often caused by strong winds that roll up powdery substances on the ground into the air, and the height is higher, while sandstorms are different. "Dust devil" is a small atmospheric vortex, and the rolling dust clouds are mixed with dust or dust impurities that can be seen by the naked eye. According to the frequency of long-term occurrence, dust storms strictly occur about five times a year in parts of Saskatchewan, but the strong wind with dust affects a wider area.
Desert-like landscapes can be seen everywhere in the prairie area. For example, in the Red Deer River Basin in Alberta, excessive water erosion and wind erosion have carved various grotesque shapes on the local sandstone, which is called "ominous objects" locally, and soil erosion has also caused mobile sand dunes. The land in southeast Alberta and southwest Saskatchewan is extremely vulnerable to wind erosion. Although there is no clear information, during the "black storm" in the 193s, the whole surface soil was swept away by strong winds, resulting in a loss of 2, tons of surface soil per hectare, which led to the erosion of nearly 2% of the fertile fields in various provinces in the prairie area during the black storm.
Up to now, the most disastrous sandstorm and drought occurred in the "evil dust" of the 193s, which made all three provinces in the prairie region suffer. From 1933 to 1937, the precipitation in this area decreased by almost half. As a result, the output of wheat and corn decreased by 32%~5% respectively, 2, farms went bankrupt, 3, people moved to other places, and 5, farmers depended on government relief. In the Palisade Delta alone, 1, families were forced to abandon their farming, and men carried simple bags on their shoulders and took railway wagons, far away from the prairie area. On August 1, 1931, the Canadian Red Cross launched a campaign to donate food and clothes to 125, poor farmers who suffered from cold and hunger for three consecutive years, which aroused the concern of the whole country about the seriousness of sandstorms and droughts.
throughout the 193s, wind erosion and drought were extremely serious. In this period of time, 25 cities and more than 7 million hectares of land in the prairie area have been affected by drought. There is no accurate record of how much farmland was destroyed by wind erosion. At that time, it was no exaggeration to describe the state that the topsoil of the land was denuded as "out of control". Ge Lei called building fences and leaving weeds as effective measures to preserve soil and sand. This measure is absolutely necessary, because in just one year, the barbed wire fence was completely buried by the sandy material carried by the wind and sand flow. The drought in the 193s also brought the locust disaster. In the first year of the occurrence of locusts in Alberta, the area severely attacked was about 4,1 square kilometers, and by 1939, the area attacked by locusts reached 155, square kilometers. The area under moderate attack in Saskatchewan increased from 4, square kilometers in 1931 to more than 26, square kilometers, accounting for more than 4% of the province's area.
it's a life-and-death struggle to survive on the land in the prairie area. Farmers have lost the fruits of their labor, and almost no grain has been harvested everywhere. Sandstorm and drought destroyed towns and farmers' fields, and brought immeasurable losses to people's property and food production.
Historians have recorded the long-term harm of dust storms to local residents. "Farmers are often blinded by dust storms and feel their way out of the fields to go home". Momativuko and Eastcott described it as follows: "People wrap their heads in shirts or shrink their heads into their coats to prevent dust from entering their noses." Older local residents still remember the "evil dust" in the 193s, when people really experienced a terrible disaster. All kinds of disasters that can be imagined have happened, such as sandstorm, ruthless drought, blazing high temperature and so on. What's more, "people have to buckle the dishes on the table, otherwise, the tableware is full of sand and dust, so they can't eat."
Gray described the dust storm that occurred in the Canadian prairie in 193s with the following vivid words: "The wind rolled up the topsoil, which filled Alberta's railways like heavy snow, and the dust storm eroded, transported and accumulated the topsoil on the barren land of Sakqiwan to the fertile land. Regina, Muscho and Swift Cullent are covered with a thick layer of dust inside and outside. Winnipeg's golden coat was baptized by dust. Snowfall in winter makes roads impassable, while summer monsoon sandstorms paralyze roads again. The sandstorm buried residents' courtyard walls and fences, blocked windbreaks and buried vegetable gardens, orchards and gardens. Sand overflowed the henhouse, tearing the windows, filling every room with dust and sand, and piling up yellow sand in front of the door, making people unable to go out, leave the village and walk. It can be said that it is difficult to get out of the house because of the sandstorm, and a sandstorm destroys the home. "