Awarded the status of the driest continent on Earth. The climate and topography of the continent are quite monotonous, which cannot be said about the animals and flora. The bulk of Australia receives a large number of atmospheric precipitation, and the main watershed is located east of the center of the continent. This explains strange shape drainage systems.
Climate of Australia
The main part of the continent is located on the Australian Plate. The relief was formed during the Archean folding. For this reason, there are almost no mountain ranges here. Climatic conditions resemble those African continent. While there is snow in Eurasia, Australia is in the grip of a hot summer. average temperature in the center of the continent - about 35 ºC. The winter period begins in June and lasts until September. The average air temperature is about 10 ºC. Frosts are possible at night. Most of the territory receives no more than 250 mm of precipitation throughout the year.
The Australian continent is located in three natural areas: tropical, subtropical and subequatorial. About 44% of the area is occupied by deserts, of which there are 8. South part The continent is characterized by hot and dry summers, and winters, on the contrary, are rainy. Northern Australia is influenced by the South Trade Wind Current. In summer there is heavy rain, and in winter it is clear and dry.
Tectonics
Most of the continent's mountain systems disappeared as a result of weathering processes over several billion years. highest peak Australia - Mount Kosciuszko. The main part of the hills has a height of less than 200 m. About 40 million years ago, the Great Dividing Range was formed. It is significantly deformed mountain system, and also the only one here.
The continent is located far from the contact points of tectonic plates. This circumstance explains the fact that there are no volcanoes in Australia. The junction is located in Oceania. There is high volcanic activity in this place.
Australia's inland waters: at a glance
On the continent small indicator Basic quantity water arteries dries out. The rivers, starting on the eastern slopes of the Dividing Range and located in Tasmania, are year-round. Australia's inland waters in the west dry up during the summer heat. Most of the territory has streams and rivers flowing inland. The boundaries of the basins collecting water are poorly defined.
Rivers
The inland waters of Australia, photos of which are in the article, are presented main river- Murray. It has three large tributaries that collect moisture from an area of over 1 thousand km 2. The sources of the main tributaries are located 200 km from the eastern coast of the continent. As the current flows, they unite into large watercourses flowing along winding channels towards the sea. The length of the Murray is 2575 km. The lower reaches are navigable for 970 km from the mouth.
Sandbanks are an obstacle for large water transport. Due to their location near the mouth, seagoing vessels cannot navigate the Murray. Murrumbidgee - a tributary of the large river continent. Its length is about 1690 km, the river originates in the Kuma region. " Snowy mountains"- a hydroelectric power station that regulates the joint flow of these two rivers.
The Darling is the second major tributary of the Murray, collecting water from the western slopes of the Dividing Range. The length of this river is 2740 km. In its bed and on some tributaries there are dams that regulate the flow all the time, except for severe droughts.
Water mode
The features of Australia's inland waters are not limited to this. The main part of the continent's territory has a separate drainage or belongs to internal basins. An example of such a zone is the Western Plateau. In numerous channels, water appears rarely and for a short period of time. The drains lead to dry lakes or wetlands.
A huge territory, the area of which is 1143.7 thousand km 2, belongs to the lake basin. Air, one of the ten largest on Earth. The basin includes the Cooper Creek, Diamantina and Georgina streams. Their angle of incidence is very small, the channels are winding and intersect in places.
Studying inland waters Australia 7th grade secondary school. From curriculum It is known that the river beds of the basin are almost always dry, and flows of water appear in them only after heavy rainfall. At this time the width water flows reaches several kilometers. However, they almost always disappear before reaching the lake basin. Water appeared in it for the first time only in 1950, during the entire period of observation by Europeans who arrived on the mainland.
Australia's climate and inland waters are interconnected. The consequence of low rainfall was the instability of most of the continent's rivers. For this reason, they cannot be used for human benefit. There are few areas suitable for the construction of dams, especially in the central part of the mainland, where the problem of water supply is very acute. To solve it, many full-flowing reservoirs are needed.
In the driest areas, large amounts of water simply evaporate. Only in Tasmania do Australia's inland waters have stable year-round flows.
Lakes
Australia's topography, climate and inland waters have caused a large number of dry lakes. The bottom of these basins is covered with clay rich in salts. IN in some cases There are lakes filled with water. However, they are saturated with salts and silt at shallow depths. Most of them are in the western part of the continent, and the largest are in the southern part (Eyre, Frome, Torrens, etc.).
In the southeast of the mainland there are many lagoons with salt-rich water, which are separated from the sea by sand barriers. Tasmania is a region where you can find the most big lakes continent with hydroelectric power stations built on some.
The groundwater
Australia's groundwater inland water is a vital resource. Most rural settlements supplied from this source. The areas occupied by underground pools are huge (over 3240 thousand km 2). Most of them contain dissolved solids that are unsuitable for irrigation. However, this water can be used for livestock farms.
Under the ground of the continent is the largest on the planet, the Great Artesian Basin. Its area is 1751.5 thousand km 2. The waters located underground contain large amounts of salts. However, without this source of moisture, the mainland would be at risk. There are smaller artesian basins in other areas of the continent.
You already know that most of Australia is in tropical zone Therefore, a tropical dry climate prevails there. Only 1/3 of the territory receives sufficient or excessive rainfall. Australia experiences higher temperatures and less rainfall than South Africa. What explains this? The significant extent of the continent from west to east, due to which continental air masses are formed in Australia. The low altitude of the continent above ocean level is also important.
How is precipitation distributed on the mainland? To do this you can look at climate map and by conventional signs find out how much precipitation falls and where. But in order to explain the reasons for the distribution of precipitation, it is necessary to remember what air masses and what winds prevail in each climatic zone. Northern Australia is in subequatorial belt, here it is formed subequatorial climate, as well as a similar climate in Africa. Formation of dry tropical climate you know. In the east of the tropical and subtropical zones there are areas humid climate. The eastern slopes of the Great Dividing Range are under the influence of sea waters all year round. air masses, coming from Pacific Ocean. The saturation of air with moisture increases under the influence of warm ocean current. Therefore, heavy rainfall falls on the mountain slopes. The south of the mainland is in the subtropical zone.
There are no large deep rivers in Australia. More than half of the continent's area does not drain into the ocean. The internal desert and semi-desert parts of the continent are characterized by a network of temporary drying rivers - creeks. Full-flowing rivers throughout the year are found only in the east of Australia, where there is a lot of rainfall. Naturally, the rivers are fed only by rain and groundwater.
The biggest river system Australia - Murray s major influx Darling. These rivers originate on the Great Dividing Range. In the lower reaches of the Darling, during droughts it dries out and breaks up into separate reservoirs. Murray does not dry out, but its level changes dramatically. During rains, the river floods heavily across the flat plain. High water on the Murray usually comes quickly and does not last long.
Due to sharp fluctuations in water levels on the Murray and Darling, navigation on them is difficult. River waters are used to irrigate fertile but arid lands. For this purpose, reservoirs were built on them.
Most of Australia's lakes have no drainage and are saline. Many lakes are filled with water only during the wet season. The largest of them is Lake Eyre, which lies 12 m below sea level. During the rains, the cries flowing into the lake bring a lot of water, it overflows, and its area increases greatly. IN dry time years, Eyre breaks up into small bodies of water, the dried areas are covered with a crust of salt.
geography teacher
A lesson in problematic and
multi-level
training
Subject:Climate and inland waters of Australia
Goals:
1. Form in students comprehensive presentation about the climate and inland waters of the continent.
2. Develop logical thinking, skills of reasoned evidence, ability to identify cause-and-effect relationships.
3. Educate careful attitude to water resources.
Equipment: physical map of Australia, climate map of Australia, "chips".
During the classes:
Org moment. Check of knowledge:Physico-geographical position of the continent (working with a map)
History of discovery and continental relief (frontal)
3. Motivating students’ activities:
You have already noticed that Australia is an unusual continent.
What component of nature should we talk to you about today, having studied the geographical location of the continent?
What time of year is it now in Australia?
“The gardens there bloom in October,
It's summer there in January, not in July,
Rivers flow there without water,
They got lost in the desert somewhere..."
4. Learning new material:
Climatic features of the mainland
You remember that Africa is the hottest continent. We haven’t studied Antarctica yet, but you can easily say that this continent is the ... coldest. What makes Australia special in this regard?
Let's take a close look at the climate map, especially the precipitation map. What conclusion comes to mind right away? (Students answer that there is little rainfall there, it is very dry).
Doesn't this conclusion seem strange to you? After all, Australia is a very small continent, surrounded on all sides by ocean waters, so perhaps it should be relatively humid there...? (problematic situation).
Let's try to solve this today "scientific problem"
We set ourselves a goal - prove, that Australia is the driest continent!
Where do we start? We haven't been to Australia... What clue can we rely on? ( Students point to the map. They notice main feature- Australia intersects almost in the middle with the Southern Tropics. This conclusion is associated with the distribution of pressure areas, etc.) In the course of reasoning, a logical chain:
Middle == High == Clear == Low ===DRY!
- Southern sky precipitation pressure
Tropic
(This chain represents cause-and-effect relationships. The teacher suggests “going through” this chain from the beginning, and then from the end.):
We go from left to right - we are looking for consequence. We reason: since Australia is crossed in the middle by the Southern Tropic, there will be an area of high pressure. Since it prevails high pressure, then... (etc.)
We go from right to left - we are looking for reason. Why is Australia dry? – Because there is very little rainfall there. Why is there so little rainfall there? Because.. etc.
Conclusion: thus, working on this “scientific problem” you and I conclusively showed that Australia is the driest continent.
Climate zones
(Students sign the names of the belts on the contour map, working with the atlas map - page 7.
Let us remember the climate features of each zone. One of the students places the “tiles” on the wall map. The chips are cardboard circles with an inscription on the back: for example, “Summer is humid and hot, and winter is hot but dry,” “Precipitation occurs here in winter,” etc.
Rivers and lakes
(The teacher only names and shows on the map three main hydrographic objects - the Murray and Darling rivers, Lake Eyre. Next comes independent work students with cards containing multi-level tasks. Sources of information: atlases, textbook text – pp. 151-152.)
Based on the personal assessment of the class, abilities and capabilities of the children, 3 levels are distinguished: low (weak), medium, high (strong).
Card 1.
1.Locate on the map which sea or bay the Murray River flows into.
2. Is the Darling River a left or right tributary of the Murray?
3.Name from which mountains these rivers begin.
4.What are “screams”?
5.What is the name of the lowland on which Lake Eyre is located?
Card 2.
1. What type of food do the rivers of Australia belong to?
2. At what time of year do they have high water?
3. How do Australians solve the water shortage problem?
4. Why is Lake Eyre shown lilac on the map?
5. Explain why there are no large deep rivers in Australia.
Card 3.
1. Compare the Murray and Darling rivers. Indicate the similarities and differences (in geographical location, mode, flow direction, etc.)
2. Explain why floods on the Murray River come quickly and do not last long.
3. Make a forecast: what changes will occur in the Central Lowlands if Australia's climate suddenly becomes wetter.
5. .Consolidation. Key issues of the topic.
:6. Summing up the lesson. Evaluation of student work.
7. Homework: paragraph 36, climatograms on page 152.
The smallest continent located in Southern Hemisphere meager surface waters, This is caused by the predominance of a subtropical and dry tropical climate on the Australian continent, the absence high mountains with snow caps and glaciers.
There are very few rivers and lakes in Australia. Almost 60% of the area does not flow into the ocean. On other continents this is not observed comparatively. large area internal drain. The predominant part of the continent, in particular its desert and semi-desert regions, is characterized by short-term drainages, which are called “screams”.
The water level in the creeks is replenished after rare precipitation in the form of rain and for a short period of time. The remaining rivers of Australia are connected to the basins of the Pacific and Indian Oceans. The Pacific Ocean basin includes rivers flowing from the eastern slopes of the Great Dividing Range. These rivers are full of water throughout the year, as there is a lot of rainfall here; short and rapids.
The situation with rivers connected to the Indian Ocean basin is slightly different. They are shallow, short and often dry out during the dry season. Recharge more In the rivers of the mainland it is mostly rain, and in the mountains called the Australian Alps it is mixed.
The mainland's largest river system is the Murray River and its Darling tributary. The river, which is 2,570 km long, originates in the Australian Alps and is fed not only by rainwater, but also partially by snowwater. IN summer period The river is full of water, often overflows its banks during rains, but in winter, on the contrary, it becomes shallow.
Darling it main tributary Murray River, its length is 2740 km. In Australia this is the most long river, but low water. The water level fluctuates greatly depending on the seasons (up to 8 m above low water). During the dry period of the year, the Darling breaks up into separate reservoirs, without bringing its waters to the Murray.
There are approximately 800 lakes in Australia. Most of the lakes are relics (they arise when part of their water area is separated from the sea or lake as a result of tectonic movements or the formation of accumulative forms such as barrows and spits), the formation of basins of which occurred during wetter geological eras.
Most of the new (modern) lakes of Australia, such as Torrens, Frome, Amadies, etc., are dry basins filled with loose clay-salt marsh silt, covered with a crust of salt or gypsum. They fill with water after rare rainfalls, which fall only once in Western Australia over several years.
Drainless salt Lake Air is the largest in Australia. It lies in a depression located 12 m below sea level. During the dry season, Lake Eyre breaks up into a large number of different reservoirs, and when heavy rains begin, it becomes a huge body of water covering an area of about 15 thousand km2.
Against a rare background hydrographic network and the almost complete absence of lakes with fresh water Australia's wealth of groundwater surprises. 1/3 of the continent's territory is occupied by artesian basins. The largest groundwater reservoir in Australia is the Great Artesian Basin in the Central Lowlands, 1751.5 thousand square meters. km. Smaller artesian basins are found in Western Australia and south-east Victoria.
Australia is a continent discovered by the Danes in the 17th century. Much time has passed since then, and millions of people have settled on the mainland. Despite most beautiful world– rich flora and fauna, rare species plants, animals, most of the continent remains uninhabited. What is the reason? The fact is that Australia is extremely poor in surface water and most of it is in deserted deserts.
Australia's problems
Australia is very poor in surface water. In addition, they are not only small, but also unevenly distributed, scattered throughout the continent. The shortage of water is due to the fact that the mainland is dominated by dry tropical and subtropical climate, there are no mountains with glaciers and snow-capped tops. There are very few rivers and lakes here; more than 60 percent of the territory does not flow into the ocean. This fact significantly distinguishes Australia from other continents. The main territory falling on desert and semi-desert areas exists thanks to temporary drains - creeks. The water in the springs is collected after heavy rains and showers. The remaining rivers belong to the Pacific and Indian Ocean basins. Rivers related to Indian Ocean, shallow and short. During hot periods they dry out, thereby leaving nearby areas without a source of water. The rivers of the Pacific basin are full of water throughout the year. They flow down from the Great Dividing Range. This area accounts for most of the precipitation. Unlike Crimea, Miskhor housing.
Water resources
Today there are more than 800 rivers in Australia, but not every body of water is filled with water all year round. During dry periods, they are covered not with water, but with a thick layer of salt and gypsum and are filled with water only after rare showers. The largest lake Australia is Lake Eyre. It extends over 15 thousand square kilometers. Locals They call it the “dead heart” of the mainland. Water from many cries accumulates here, but the deserts absorb most water. It's rare that Eyre can show all its aquatic beauty in 15 thousand km2. Despite the lack of surface water in Australia, this continent is the most beautiful place on the planet where they live rarest representatives flora and fauna.
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