In fact, it is estimated that Finland has one lake for every 26 persons. While this fact might be right to a certain extent, it must be remembered that the definition of a lake varies widely from place to place. There is no standard unambiguous definition of the size requirements for a water body to be classified as a lake. Finland's , lakes include all water bodies larger than sq. However, the list in the study was prepared by taking into account only lakes that are over 0. Hence, Finland failed to feature on this list.
Lakes in the Pantanal region of Brazil, the country with the 6th highest number of lakes in the world. Alaska has the most lakes in the United States, the country with the third highest number of lakes in the world.
Ellen Kershner July 31 in World Geography. Pantanal, Brazil. What Is A Plateau? Regions Of Europe. Transcontinental Countries Of The World. Western Asia. Is Greenland A Country? Arabian Peninsula Countries. Surface geology and climate govern the nature and distribution of lakes. Nearly all are of glacial origin. Thin soils and high resistance of the rocks to weathering tend to make the lakes clear, biologically unproductive and relatively long-lived because of slow sedimentation.
Within the peatlands are many small, shallow lakes and ponds having a teardrop shape aligned to the prevailing winds, the result of wave action on the fragile shorelines. Close to the coast, ancient beach ridges define long, narrow, shore-parallel lakes and ponds.
Old river channels, abandoned as the land rises, are frequently occupied by lakes in this region. Glaciers pouring off the Shield and carrying with them hard granitic debris, gouged deeply into the thin edge of the softer sedimentary rocks before spreading over the lowlands. Glacial deposition of till, rather than extensive scouring, marks the effect of glaciers on the plains.
Unlike Shield lakes, prairie lakes are formed in a thick overburden of clay, till and soil. Lakes in the Western Interior Lowlands tend to be more shallow, more rapidly filled by sediments and more biologically productive than Shield lakes. Annual rainfall decreases and evaporation increases from northeast to southwest; the corresponding trend in lake distribution is for fewer, sometimes seasonally transient lakes, carrying higher concentrations of dissolved materials.
In the dry southwest, numerous alkali lakes and ponds occur in which concentrations of dissolved materials reach saturation and evaporite crystals, usually sodium sulphate, precipitate out. Glacial deposition in the southwest has left the ground pocked with small depressions which fill to become ponds or sloughs in spring, often drying up by late summer.
Although the total water volume of these ponds is small in comparison with well-established lakes in other places, they are important to agriculture and as WATERFOWL habitat.
In the Far North, parkland and forest yield to the boreal forest proper, with extensive areas of muskeg and bog lakes. Lakes in western Canada are mainly of glacial origin: large lakes in BC and the YT are generally confined to deep, glaciated valleys; smaller scour lakes are found on upland plateaus.
Tectonic processes associated with mountain building provide other natural basins. Powell Lake, near Vancouver, was formed when isostatic rebound the tendency for land to rise once the heavy ice cover melts isolated a fjord from the sea. Although this took place thousands of years ago, the lake's bottom water is still salty, a fossil seawater. The Atlantic provinces lie in a region of ancient mountains, a northern extension of the Appalachians. This land was also heavily glaciated.
Many small coastal lakes occur in NS. The St Lawrence Lowlands and lower Great Lakes region contain some of Canada's richest farmland, but compared to the scoured region of the Shield, small- and medium-sized lakes are rare. However, this region is adjacent to the Great Lakes, which together constitute the largest body of fresh water on Earth.
The geology of the drainage basins has affected the primordial character of each lake and has determined the settlement patterns, which in turn have had a considerable impact on Lakes Erie and Ontario. Lakes are ecosystems: biological energy flows through a food chain and spent organic matter is recycled into materials that are again available to living organisms.
The first and most important stage, primary productivity, is photosynthesis, where nutrients are combined into organic matter through the energy of sunlight and the action of chlorophyll contained in plant cells. Most lake plants are single-celled microscopic ALGAE phytoplankton , which are suspended in the water and move with it.
In abundant quantities, they may colour the water, rendering it turbid. Bacteria decompose dead material into constituents available for new cycles of life.
Carbon, hydrogen and oxygen are usually freely available in sunlit surface waters. Usable forms of nitrogen and phosphorus may be scarce, limiting primary productivity. Nutrients may be supplied by inflows and by local runoff; their distribution within a lake is controlled by physical processes. Water movements in lakes are governed by 3 sources of energy: the flow of water from inlet to outflow and the stirring action of wind both mechanical sources , and heat energy, gained in spring and summer, lost in fall and winter.
The longest time scales of motion, having perhaps a yearly cycle, are those associated with the flow of water through a lake from inlet to outlet hydraulic component of flow. Outflow removes dissolved and suspended materials along with the water. Since lakes vary widely in size and rate of outflow, it is useful to define a flushing time as the volume of the lake divided by the average rate of outflow ie, the time required to drain the lake at the mean outflow rate.
Permanent lakes with flushing times much less than a year are quite rare, and their behaviour is strongly marked by vigorous flow, biological productivity usually being depressed. At the other extreme, lakes with flushing times greater than 10 years are considered sensitive to external changes; recovery from a polluted state requires at least one flushing time.
And the lakes can be highly influenced in a changing climate. In the north, which has most of the lakes in Canada, the future is uncertain: if the permafrost melts, we could lose lakes as they drain into the ground. But new lakes might also form. In Ontario's Lake Superior, for instance, the water lasts about years. Water in Great Bear Lake in the Northwest Territories has almost the same lifespan, between and years. This new information helps scientists determine how that water might interact with the environment and life around it.
For example, if a lake becomes highly polluted or heavy sediment flows into it, researchers will now be able to get a better idea about the repercussions. Lehner hopes that this new information will help advance more knowledge and study on the world's lakes. Nicole has an avid interest in all things science. As an amateur astronomer, Nicole can be found looking up at the night sky appreciating the marvels of our universe.
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