Category: Geography Notes PPT

Map scales are useful to understand the sizes of objects and distances between objects (their relative sizes) in comparison to the actual sizes of objects and distances between them. This means that on a map it is not possible to denote the actual distances between objects or their sizes since then the map would need to be as big as the objects being measured. This would defeat the purpose of having a map in the first place. 

This is what it means when it is said that maps are drawn to scale. Scales are always mentioned on the maps so that whoever looks at them can get an idea of how to navigate through them. The scale represents how much the area on the map corresponds to the actual area on the ground that it shows. For example, if a map is drawn to a scale of one inch to one kilometre, it would mean that one inch on the map is equivalent to one kilometre on the ground. 

Classification of Maps

To understand what a map scale is, let us go through a few classifications of maps and map scales first. As per the common classification of maps, there are about five types of maps – thematic maps, general maps, navigation charts, topographic maps, series maps, cadastral, and plans. The types of map scale representations are discussed below. The basic type of representation of actual distance on maps is done by bar scales and lexical scales. In the bar scales used in maps, the distance ratio is expressed visually whereas, in lexical scales, the ratio is stated in words. 

There are 3 ways of representing the scale of a map, namely, representative fraction, verbal, and graphic. Out of these three, the representative fraction is the most commonly used scale. For example, the topographic maps help to understand the contour and general landforms of an area and most have the scale stated in representative fraction. In topographic maps, various colours are used to represent the contour of landforms, water bodies, settlements. 

Map Projections

Map projections are used to draw the parallels and meridians of the Earth systematically, on a flat surface. Various map projections are used to represent the landforms on maps. There are certain map projections that have equal-area properties. Also, projections that have the feature of conformal delineations are devised to represent the landforms on maps. 

In certain cases, the outlined shape of very small regions is nearly represented in the same way on the map as it is on the ground. It is not possible to completely avoid distortions of shapes of land areas on large-scale maps. The only way to reduce the distortions is to devise the most suitable for the purpose of the particular map. 

In general, the Mercator projection is devised on the navigational charts. The charts for the polar regions and the great circle charts do not devise the ordinary Mercator projections. The Great Circle charts that represent large map areas are generally depicted on quite small scales devising gnomonic projection. For example, the navigational chart for the Pacific Ocean. The navigators use these charts to lay a track between two ports and calculate the shortest distance between the ports.         

Symbolization

Symbols are the graphical representations of landforms, water bodies, winds, ocean currents, settlements, transport, and communication systems for maps. It may be said that symbols make a graphical language for maps and charts. The symbols were originally ordinary pictograms, which have now developed into conventional signs and symbols for the representation and interpretation of maps.

Standardization of symbols has been brought about by the joint efforts of the UN, NATO, International Map of the World agreements, and the international technical societies. It helped to reduce the confusion that used to arise in the interpretation of maps. The symbols can be classified as hypsographic and planimetric. These symbols can also be grouped based on conventional colours. 

For example, the blue colour is used to represent water bodies, black colour is used to represent occupation, cultures, and names of population, green colour is used to depict vegetation, brown colour is used to depict relief features, and red colour is used to depict types of roads and other special information. This is the standard use of colours, but there may be variations for geologic and soil maps. Planimetric features are used to represent the slopes, heights, and shapes of the land, on a map.

Nomenclature

To enhance the utility of maps, all the possible features and places are identified and labelled on a map. However, for the small-scale maps, only the important features and places are labelled, to enhance legibility. The nomenclature of maps has various parts. The geographic names are among the most troublesome parts of map nomenclature. The large-scale maps permit the naming of the minor features like streams, hilltops, ridges, etc. While making a topographic map, extensive research and documentation are carried out. 

Also, the local records are referred to for identifying and labelling all the parts of the area under concern. When a topographical map is published and distributed, it is used as an official document that eliminates confusion regarding the nomenclature of the local areas. The basic types of lettering that are used in the maps are Roman style, Italic, and Gothic style. 

What is the Significance of the Map Scale?

Map scales give people an accurate idea about how the distances mentioned are plotted on the map. This is useful in understanding how to go from one place to another, especially if one is a traveller or engaged in a similar profession. 

For academics, a map scale is useful to measure exact distances between objects and base their work on that. This is useful in calculating operations such as measuring the demographics of an area, measuring the geographical faults of an area, keeping a note of all physical features of the area and its vegetation, and so on. Measuring and making a note of all detailed features of an area on a map is only possible through map scales. If maps were not drawn to scale then no one would be able to navigate through an unknown place all on their own. 

In the Neogene Period, Miocene is the first geological period, this extends approximately from 23.03 to 5.333 million years ago. The name ‘Miocene’ was given by Charles Lyell, a Scottish author. This name comes from the Greek word ‘meiōn’ which means ‘less’ and from the word καινός which means ‘new’ this together means ‘less recent’. The Miocene period is preceded by the Oligocene period which is followed by the Pliocene period.

When the earth revolved from the Oligocene period to the Miocene and then into the Pliocene, the climate slowly became cooler and initiated the Ice Ages. If we trace back to the Miocene period, they are not demarcated by boundaries but consist rather of the regionally defined boundaries between the Oligocene which was a warmer age, and the Pliocene Epoch, a cooler age.

Miocene Period

With the commencement of the Miocene period, the earth faced an era of Miocene which had its own distinct changes. The Miocene earth has undergone changes in regard to the types of vegetation, climate, animals, and habitat. In the Miocene Era, specific animals and plants thrived to grow in the land. We will learn about the era, its vegetation, and animal life in detail in our prevailing section.

Miocene Age

Miocene time, which is also known as the Miocene Epoch marks the earliest major worldwide division of the Neogene period which is about 23 to 2.6 million years ago.

Miocene Age is Divided into:

• Early Miocene Epoch which is about 23 to 16 million years ago. 

• Middle Miocene Epoch that is 16 to 11.6 million years ago.

• Late Miocene Epoch that is 11.6 to 5.3 million years ago. 

The Miocene Period is then Divided into Six Stone Ages from the Oldest to the Youngest Stages. They are as follows:

1. The Aquitanian

2. The Burdigalian

3. The Langhian

4. The Serravallian 

5. The Tortonian

6. The Messinian 

The Miocene Age was followed by the Oligocene Epoch which is under Paleogene Period, after which the age was succeeded by Pliocene Epoch.  

We can see the Miocene period closer than other geological periods as their occurrence is recent than other periods. This helps us to interpret and understand the pattern of the events taking place. 

Miocene Animals 

In this section, we will learn about the Miocene Epoch Animals and Miocene Organisms that survived in this period. 

With the advent of diversification in the vegetation, another diversification of the temperate ecosystems consisting of the morphological changes in animals was witnessed. The mammals and birds which are particularly developed from their new forms, which are fast-running herbivores or the large predatory mammals and other birds, which are small quick birds and also the rodents thrived in this diversification. The Miocene Animals are projected below according to their types and diversification, we are putting it in points for a better approach:

1. In this Miocene period, the land-dwelling mammals were very much modern. Many of these animals got extinct by the end of the preceding Oligocene, and half of the mammalian families who are known today are present in the Miocene record. 

2. The Northern Hemisphere faced some interchange of the faunas that occurred between the Old and the New Worlds. This interchange was evident in Eurasia as well. While South America and Australia remained isolated here. 

3. The animal Horse evolved in the Miocene period. This occurred mainly in the Northern part of America.

4. Also, the dogs and bears first appeared at this time. 

5. The emergence of the bear-dog known as Hemicyon happened after few years after the origin of the bears. 

6. Next, from the primitive civets, the first hyenas evolved. 

7. The saber-toothed cats too originated in this time. They are the sub-family of Machairodontinae. 

8. Antelope, Deer, and giraffes also appeared in Eurasia in the Miocene period.

9. While the Ancestors of elephants were limited to Africa. The ancient elephants spread in the Eurasian continent during the Miocene and there they became more diverse in nature.  

10. The Santa Cruz Formation of Middle Miocene time also provides another excellent record of the unusual Miocene fauna of South America.

11. Marsupial Carnivores, aberrant edentates (they are mammals who resemble the anteaters, armadillos, and sloths), here litopterna are also present, they are the hoofed mammals which are quite similar to the horses and camels, these are among the odd groups which are represented here. 

Now, we will display some pictures of these animals from the Miocene Age:

Moropus is an extinct genus of the chalicotheres 

Toxodon – They were the common large-hoofed mammal found in South America. 

This is a picture of Chalicotherium, which is a Miocene mammal. This mammal is from Kazakhstan. Chalicotherium mammal was an “odd-toed” hoofed mammal. Here the perissodactyls and the artiodactyls went through a period of rapid evolution during the Miocene period.

Miocene Plants 

While we study the pattern of the biological change for the Miocene, this informs about the open vegetation systems like the deserts, tundra, and grasslands. Here the closed vegetation types or the forest was not much noticeable. 

When we study the plant in the Miocene age studies, the Miocene is primarily focused on the spores and pollen. Miocene plant studies are represented by the end of the Miocene, in which 95% of modern seed plant families existed, here no such families have gone extinct till the middle of the Miocene. The mid-Miocene warming is here followed by the cooling that is considered here responsible for the fall in the tropical ecosystems, in the expansion of northern coniferous forests, they have increased seasonality. 

Among the various extraordinary incidences that the earth hosts, ocean current is one. It is the seawater movement directionally and continuously influenced by gravity, the Coriolis Effect of the wind, and the density of water. Now the ocean current can show two directional movements- horizontal and vertical. The former is termed as “current” while the latter is termed as “upwelling” or “downwelling.” Ocean currents, a part of the abiotic system of the environment, contribute to the transfer of heat, bringing in biodiversity variations and also develop the global climate system.

What are the Types of Ocean Currents?

Broadly, as ocean currents UPSC syllabus determines, the ocean currents are of two types- warm and cold. Equator regions carry the warm ocean currents while cold currents originate from the Polar Regions. Based on the strength of the flow, the currents can be of two more types. Western boundary currents are the ones with strong and fast currents, whereas Eastern boundary currents are the ones with comparatively shallow and moderate strength of the currents. 

What is Thermohaline Circulation?

Thermohaline circulation, or THC, is a part of the ocean circulation where the density gradient of the ocean water plays a pivotal role. The difference in density is caused by the flow of freshwater and the surface heat. It is the temperature and the salt content of the water that gives rise to the different density of the seawater leading to the name “thermohaline,” where thermo refers to temperature and haline refers to the salt content. 

What is Agulhas Current?

Agulhas current, a warm current, is formed by the merging of Mozambique and Madagascar current. This current continues southwards till it meets the Northwesterly wind. It increases temperature along the east coast of South Africa. 

What is Kuroshio Current?

Yet another warm ocean current, the Kuroshio Current, flows from Taiwan to the Bering Strait. It is also known as the Japan current or the Black current, or the Black stream. It is generally found on the west side of the North Pacific Ocean. Being a western boundary current, this type of wind is quite powerful. 

What is Gulf Stream Current?

One of the strong ocean currents, the Gulf Stream, is responsible for bringing warm water into the Atlantic Ocean from the Gulf of Mexico. The eastern coasts of Canada and the United States is the region where this current extends. Oceanic gyre is the main reason behind its formation. Gyres are a system consisting of powerful winds and a series of circular currents. One such gyre is the North Atlantic Subtropical Gyre, of which the Gulf Stream Current is a part. As the Gulf Stream brings in the warm water, the cold water already existing in the Atlantic Ocean is forced to move south as it is denser. Ultimately the cold water flows to Antarctica.

What is Oyashio Current?

It is one of the cold ocean currents. The Kamchatka current flows along the Kamchatka peninsula from Bering Strait in SW direction. This later form Oyashio Current and some of its parts join the North Pacific Current. The water that Oyashio Current carries comes from the Arctic Ocean and continues to flow along south through the Bering Sea. Along the way, it comes across the Kuroshio Current around the Eastern Japan shore and together forms one of the Pacific Ocean currents, namely North Pacific Current. The current brings cold water from the Arctic sea into the Pacific Ocean. 

What are Equatorial Currents?

There are two types of Equatorial currents- north and south. The brief details of these currents are as follows:

1. North Equatorial Currents: 

This current originates from the western coast of Mexico and flows in a westerly direction. California current and NE monsoon is responsible for the formation of this current. It carries warm water towards Alaska.

2. South Equatorial Currents: 

This originates due to the influence of SE trade winds and flows from East to West. Then it gets bifurcated near New Guinea into the Northern and Southern Branch. The first one turns eastward and flows as a counter equatorial current, and the latter moves into the north direction along the NE coast of Australia.

What is Humboldt Current?

This current is the continuation of west Wind drift from the Antarctic that flows northwards along the western coast of South America. It is associated with the El-Nino effect in South America. It also affects the timely arrival of the Indian monsoon.

What are Labrador and Benguela Currents?

Labrador current originates in the Baffin Bay and the Davis Strait and moves eastward, merging with Gulf Stream near Newfoundland. Its confluence with Gulf Stream produces heavy fog along the coast of Newfoundland, a vital fishing ground globally, such as as- Grand Bank, Dogger Bank, George Bank.

Benguela Current flows from south to north along the western coast of South Africa and merges with the South Equatorial current. It leads to foggy conditions along the coast of Namibia. This particular current helped in the development of the Namibian and Kalahari Desert.

Did you know?

• Rotation of the earth creates oceanic water to bulge out. 

• Currents move clockwise in the northern hemisphere, whereas in the southern hemisphere, left deflection currents lead the counterclockwise movements.

• Western Boundary Currents lack nutrients and thus contain sterile water.

• Eastern boundary currents do not have well-defined boundaries.

A pediplain is an extensive flat land formed by the coalescence of pediments. In Geology and Geomorphology, the term pediment is derived from the Latin word ‘pes’ which means the genitive case, and ‘ped’ which means foot. On the other hand, the term pediment is a gently sloping bedrock surface formed by lateral erosion and mechanical weathering. The process through which pediplain is formed is known as pediplantation, and the concepts that help in explaining this phenomenon were first introduced by geologist Lester Charles in 1942.

What are Pediplains?

A pediplain is a relatively flat rock surface formed by joining several pediments. Pediments are generally found in arid and semi-arid areas and may have a thin veneer of sediments. It may be said that pediplain may be the last stage of landform evolution, and the final stage of the erosion process.

What are Pediments?

A pediment, also known as concave slope or waning slope, is a gently sloping erosion surface or plane of low relief formed by running water in arid and semi-arid areas at the base of the receding mountain front.

 

Pediments are generally erosional surfaces. A pediment develops when sheets of running water wash over it in intense water. A pediplain is covered by the thinly discontinuous veneer of soil and alluvium derived from the upward areas. Much of this alluvial material is transitted across this surface, mining during episodic storm events or blowing winds.

The term pediment should not be confused with the bajada which is a merged group of alluvial fans.

How Do Pediments and Pediplains Form?

The formation of pediplain depends on erosion, which is the force behind the formation of pediments. Pediment forming processes are much talked about, but it is seen that rocks such as granite and coarse sandstone form all the pediments virtually in the Mojave desert. The pediment formation has not been well documented and accordingly became a subject matter of study, but there are pre-existing theories that attempt to explain this process.

Erosion begins along the steep margin of the landmasses or the steep side of the tectonically controlled steep incision feature over the landmass. The pediments generally have slopes between 0.5 and 7 degrees and are concave in shape. The rock continues to degenerate grain by grain rather than fracturing and further being minimized in grain size by alluvial transport processes. As the pediments are formed by a  steep slope followed by the clive or free face above it, the steep wash slope and free face move backward.

Where Do Pediments Form?

Pediments are formed in the arid and semi-arid areas where rainfall is immense for brief periods of time. This phenomenon of erosion is termed as the retreat of slopes through backwashing. So, through parallel retreat of slopes, the pediments extend backward at the expanse of the mountain front, and gradually the mountain gets minimized leaving an inselberg which is termed as the remnant of the mountain.

Pediments that formed in humid areas are generally obscured by vegetation and may be difficult to observe. This is how the high relief in desert areas is minimized to low featureless plains known as pediplains.

Did You Know?

• In 1877, Grove Karl Gilbert first observed the pediments in the Henry Mountains in Utah.

• As per Gilbert, the origin of sediments was in the Henry Mountain area, due to stream plantation and active erosion of the desert.

• A pediment, also known as concave slope or waning slope, is a very gently sloping ( 0.5 – 0.7) inclined bedrock surface.

In soil science, podzols are common soils of coniferous or boreal forests. And they are also the typical eucalyptus forest soil and the heathlands of southern Australia. In Western Europe, podzols grow on the heartland, which is often built to be disturbed by a human for grazing(food) and burning. In some parts of the British like moorlands with podzolic soil, cambisols are stored under Bronze Age beetles (Dimbleby, 1962).

Morphological Characteristics 

The typical Podzol in the zonal has a greyish-grey, highly leached eluvial horizon beneath the dark-skinned living atmosphere, and above a very dark brown surface. Most Podzols have a layer of the top layer (H-horizon) 1 to 5 cm thick, open and sponge, and grading into Ah-horizon with humified organic matter. According to the layer of debris, in particular, fragments of individual plants are still recognisable and the living roots can be exposed to mycorrhizae. Ah-horizon contains a dark mixture of grey organic matter and minerals (especially quartz). Basic bleached E-horizon has a single grain structure and the formation of brown to black illuviation soil varies from loose (unusual) through the firm, subangular blocky to very hard and large. 

 

At the end of the dry season of the zonal, Podzols usually have a high chroma indicating the accumulation of iron oxides (as well as aluminium oxides). In humid regions, Bhs-horizon is black and has a high content of organic transfer. The profile of the intrazonal tropical podzol has a top layer decomposed (‘raw’), and the acid humus with a high carbon to nitrogen ratio. A-horizon below the hummus is poorly developed and it rests on the top of a light grey to white eluvial E-horizon of sand texture that can be from 20 cm to several metres thick (‘Giant Podzols’).

 

If you go still deeper in the illuvial horizon soil, it is commonly dark brown and irregular in-depth and you can rarely find the mottels or soft concentration and aluminium oxides. And slightly more clay in the illuvial horizon compared to the higher in the profile. Brightly coloured B(h)s-horizons with sesquioxides accumulates which occur in the temperate zone, which is uncommon in the tropics where podzolization is greatly restricted to iron-poor parent materials under the influence of ground-water.

 

Mineralogical Characteristics

The mineralogy characteristics of Podzols are somewhat different but it is nearly always marked by a predominance of quartz. In a cool, humid climate environment where the leaching is intense, and the parent material may be originally intermediate or even basic composition. Iron and aluminium can be found at maximum at different depths in the B-horizon, depending on the genetic history of a particular podzol soil. In the USA, the level of podzol tends to have the maximum iron content above the Aluminium maximum content. 

 

Well-developed intrazonal Podzols in Western Europe normally have the maximum amount of Aluminium content at the top of the B-horizon, with the iron maximum at a larger depth. Weathering processes in the A and E-horizons of well-developed Podzols on clay-poor materials will make the material transform clay to smectite (beidellite), and sometimes kaolinite. Whereas clays in the B-horizon may be Alumunium – interstratified. Allophane is the amorphous Aluminum- silicate which appears to accumulate in B-horizons having rich parent material.

 

Hydrological Characteristics

This podzol is generally wet because of its climate or terrain condition. The movement of the water through the soil will be impaired even in the dryland areas if the soil is having a dense illuviation horizon or an indurated layer at some depth of the soil. The formation of a thin iron pan takes place upon periodic water stagnation in the soil, either in the B horizon or below that some of the examples are Densic and Placic podzols. Podzols are even associated with the regions having annual precipitation surplus, the low water holding capacity of these soils may still cause drought stress in the dry periods. 

 

Physical Characteristics

Most of the Podzols have a sandy texture and weak aggregation of the structural elements. their bleached eluviation horizon contains normally less than 10 percent clay but the clay content could be slightly higher in the underlying illuvial horizon.

 

Chemical Characteristics

According to the chemical characteristics, the organic matter profile of Podzols shows two areas of concentration, one at the surface and another one is the spodic horizon. The carbon to nitrogen ratio is typically between 20 and 50 on the surface horizon of the soil, which decreases to 10 – 15 in the bleached horizon and then again it increases to 15 – 25 in the spodic horizon. The level of nutrients in the podzols have low consequences of a high degree of leaching. 

 

The plant nutrients are mainly concentrated in the surface horizons where the cycling elements are released on the decomposition of the organic debris but the phosphates may accumulate in the B-horizons (as the iron and aluminium phosphates). The surface region of the soil is generally acidic in nature with pHy150, which ranges between 3.5 and 4.5. As the depth of the zonal podzol increases, the pH value also increases to a maximum of about 5.5 in the deep subsoil, whereas the soil pH in the intrazonal podzols tends to be lowest in the top of the B-horizon.  

 

Biological Characteristics

In boreal and temperate climates, ‘large’ soil animals such as earthworms are scarce in most Podzols; decomposition of organic matter and surface soil homogenization are slow and are mainly done by fungi, small arthropods and insects. Many Australian Podzols show signs of earthworm activity. The activity of moles and earthworms increases rapidly when the podzols are fertilized.

 

Podzolization 

Podzolization is also known as podsolization is a process of complex soil formation by which the dissolved organic matter and ions of iron and aluminium are released through weathering of various minerals. These form organo-mineral complexes (chelates) and they are moved from the upper level of the soil profile and get deposited in the deeper parts of the soil. Through the process of podzolization, the eluvial horizon of the soil becomes bleached and of ash grey colour. The complexes of the soil move with the percolating water further below to the illuviated horizons of the soil, which is generally brown, red or black in colour as they accumulate and they consist of the cemented sesquioxides and organic compounds. It is a typical process of soil formation in the podzols. 

 

Preconditions

Podzolization usually occurs under forest or heath vegetation and is common in cool, humid areas as these climates prevent the activity of soil microbes in the topsoil. Overall, the formation of podzolization occurs when biological decay is inhibited and as a result, layers of acidic organisms (more) form. Under these acidic conditions, nutrient deficiencies continue to interfere with the microbial degradation of organic complexing agents. Medium to dark soils with poor parent material (usually rich in quartz) also promotes podzolization, as it promotes the flow of saturated water.

 

Key Steps

Mainly there are two steps in the process of soil formation of podzolization:

1. In the first step, mobilization and translocation of organic matter like Fe (Iron) and Al(aluminium) from the surface, the horizon takes place.

2. Further, Immobilization and stabilization of organic matter, Fe (Iron) and Al (aluminium) into the subsoil occurs.

In the topsoil of the acidic soils, organic matter (especially from plant waste, a layer of humus and roots exudates) along with the Aluminum and Iron ions, forming organo-mineral structures. These soluble chelates then move with percolating water from A (or E horizon) to B-horizon. As a result, horizon E (or Ae horizon in the Canadian soil classification system) has been left bleached and ash-grey in colour, while B-horizon is enriched with the relocation of organo-mineral structures. The colour of the B horizon is therefore red, brown, or black, depending on the iron ions of the metal or living organism. In general, the boundary between the B-line and eluvial Ae (or E) is very different, and sometimes hardpan (or Ortstein) can form, as Fe and Al transported with organisms increase mineral particles, cementing them into this compacted layer.

There are a number of reasons why these organo-mineral structures immobilize in the B-horizon. If Aluminium or too many iron ions bind to the organic compounds, the complexes might get fluctuated as the solubility decreases with the increasing metal to carbon ratio. Apart from that, a higher pH (or higher Calcium content) in the lower soil horizons can result in the breakdown of metal-humus complexes. In the lower layers of the soil, the organic complexing agents are degraded by the function of the microorganism. Some of the already established complexes in the B horizon will act as a filter, to absorb and travel the complexes from the upper soil horizons. A decreased water conductivity due to higher clay content can also result in the initial slope of organo-mineral complexes.

 

The substances relocated can separate the illuvial horizon soils sometimes. The uppermost part of the illuvial horizon is highly enriched in the organic substance, whereas Iron and Aluminium oxides are largely found in the lower parts of the illuvial horizon. Podzolization will also promote the relocation of some nutrients like (Cu, Fe, Mn, Mo and P) that brings them closer to the plant roots.

 

Did you know?

What is podzol in real life? In soil science, podzols are the typical soils of coniferous or boreal forests. They are also the typical soils of eucalypt forests and heathlands in southern Australia and In Western Europe, podzols developed on heathland are often used to construct human interference through grazing and burning.

In trust and simplest meaning, “relief” is the opposite of the feature “flatness”. Relief is the difference in the height between two points, which is the high point and the low point on a landscape, this is measured in feet or in metres. Relief structures can also be defined as qualitative characteristics like the “low relief plains” or the “high relief rolling hills”. We can also differentiate the relief region by comparing its elevation with the surrounding area.

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On this page, we will discuss this feature in detail, we will elaborate on the landform structure and its features. Let us now proceed.

Relief Landform 

The mountain reliefs affect the climatic condition because they stand in the path of wind systems and force the air to rise over them. When the air rises it expands and then cools down, which leads to a higher amount of precipitation on the windward mountain slopes, this forms the orographic precipitation which descends leeward slopes and becomes warmer.

The natural features include these reliefs, these are at times mistakenly understood to be the only feature which marks a topographic map, and the hydrographic features, these are lakes and rivers; the man-made features, which include other characteristics of the area, like; the cities, towns, villages, roads, railways, canals, dams, bridges, and tunnels.

Features of Relief

The Characteristic of the Features of Relief are as follows: 

• Relief features are not any pattern of drainage where water channels are available.

• But water patterns are not included in the relief features.

• In the study of geography, the structure of relief means the highest and lowest elevation points that are based in a particular region.

• In the low-lying areas, there are elevated points such as Mountains, Ridges, and Valleys. They are of mountain heights and altitude.

Land Relief

Land Relief is also known as the quantitative measurement of the elevation which is vertically aligned and responsible for changing the landscape. This measurement is the difference between the maximum and minimum elevations within a given area, this is to a limited extent.

The relief feature of a landscape can change the size of the area when the same is measured, thus this makes the measurement very important. This measurement is well related to the slope of surfaces in which the area of interest and the gradient of the streams are present, the relief of a landscape feature is a useful way to study the surface of the earth. The relief energy is defined along “the maximum height range in a regular grid”, this is quite important for the indication of the ruggedness or for the relative height of the terrain.

In Order to Understand the Terrain, There are Critical Reasons Which Include:

The terrain of this feature determines the suitability for the human settlement, the flatter alluvial plains tend to farm with adequate soils with steeper and rockier uplands. In the case of environmental quality, agriculture, hydrology, and other related sciences the understanding of the terrain feature will assist the understanding of the watershed boundaries, the drainage characteristics, the groundwater system, and the water movement.

  

Understanding this terrain feature also conserves the soil essentially for agriculture. Contour ploughing is the practice that enables sustainability on the sloping land. This is the practice of ploughing along the lines in order to ensure equal elevation rather than up and down slopes.

This terrain is very much critical as this determines the ability of the army to take control of these areas and move their troops into and through the areas.

Also, the terrain is quite important while determining the weathering patterns. The two areas which are geographically very close to each other may also differ radically in case of precipitation level or by the timing because of the difference in their elevation.

  

Good knowledge of the terrain is also very much vital in aviation activities. The terrain will also affect the range and the performance of the radars and the terrestrial radio navigation systems.  While a hilly or mountainous terrain can also strongly impact the implementation of the new type of aerodrome and orientation of the runaways.

How do various natural agents and man-made activities affect relief landforms?

• Landforms are always in a dynamic state of existence. Internal forces such as the constantly moving seismic plates are the cause of many of the relief features. Landforms are continuously created, destroyed and reformed partly by the environmental forces and partly by man-made activities. It is crucial to understand these agents to protect landforms (and their natural vegetation) against unjustifiable human destruction.

• The natural forces affecting the landforms are Weathering, Volcanic eruptions, Soil erosion, deposition, natural catastrophes such as landslides, earthquakes, floods, etc.

• The human agents affecting landforms are crop and irrigation activities, industrial activities, mining, construction of roads and highways, buildings, airports and other commercial projects. It is said that over time, man-made activities even on a small scale such as dam construction can have a lasting impact by increasing the rate at which landforms are destroyed.

• There have been several studies by environmentalist organisations and conservation biologists that support this viewpoint. For example, the study published in the Conservation Biology journal in December 2012, extensively studied the impact of the construction of a huge number of dams in the Himalayan region in the last few decades (this region shows the densest global dam construction in the world, with over 290 dams in a 3000 square kilometres region). Researchers concluded that since 88% of the project sites fall in the regions of rich biodiversity areas, deforestation and habitat extinction is very high. More than 90% of the valleys and 25% of dense forests in the Himalayas have been affected. These lead to an increasing number of landslides (forests hold the soil in place) and geological problems for the northern plains.

Conclusion

The climate and environment are of utmost importance and their conservation should be our priority. Learning about landforms through this article can be a stepping stone in your life and help you make sustainable choices.