Have you ever wondered about the changes that critical geographical features are undergoing? How have these affected the flora and fauna? Read further to know more about the changes in critical geographical features.
Geographical features are the distinct phenomena (Natural or Man-made) occurring at or near the earth’s surface at a regional to a global scale, for example, mountains, rivers, oceans, climate, human settlements, etc.
Critical geographical features among these are the ones that have a profound impact on both nature as well as human life. Therefore, understanding changes in such distinguished features becomes important for us, especially in the context of “sustainable development”.
Critical Geographical Features And Changes
The following are the various geographical features
Mountains are formed through various processes as explained by plate tectonics depending upon which these are classified as Fold, Volcanic, or Block mountains.
Although these appear as giant static units, when studied on the geological time scale, it is observed that these are continuously under dynamic changes. For eg: the Aravallis of India formed during Precambrian times, denuded and lowered in height over time, now stands as a relic of ancient fold mountains.
Changes in Mountains and Their Reasons
- Gradual denudation and lowering of reliefs due to geomorphic processes such as weathering and erosion by rivers, wind, groundwater, etc
- Endogenetic forces such as volcanism lead to the development of new volcanic mountains or changes in old formations.
- Anthropogenic causes such as urbanization, tourism, agriculture, and other developmental activities affect the morphology of mountains.
- Natural disasters such as earthquakes and landslides bring major structural and morphological changes in mountainous regions.
Effects of these changes
● Weathering and erosion help in soil formation downslope For eg: Great Indian Plains
● Loss of surface soil from slopes devoid of mountains of fertile soils
● Helps in understanding the formation and development of reliefs and their compositions
● Lack of knowledge of slope management practices renders developmental activities vulnerable to exceeded weathering and erosion as well as natural hazards
● Mining helps in the extraction of various mineral resources.
● Natural disasters such as earthquakes and landslides cause damage to human life and property. For eg: the Himalayan region is under Zone 4 and Zone 5 of Earthquake mapping zones in India
● Better planning and management practices. For eg: The watershed development program
● Threat to water security as mountains provide nearly 70% of freshwater to the planet
● Threat to livelihood as mountains provide nearly 20% of global tourism.
The following are the various water bodies and the changes associated.
Although rivers cover only 0.1% of the land, these are considered a critical part of landscapes due to their major role in human life.
This is corroborated by the fact that major settlements around the world have been around major rivers.
For example Prayagraj, Agra on banks of Ganga River System; Shanghai- Yangtze River; New york–Hudson River, etc. Therefore, studying changes in the river and its regime becomes important.
Changes in River and their Reasons
- The cycle of Erosion- of the river defines its ever-changing nature depicted through different stages i.e, the young stage(small, swift river with vertical corrasion), mature stage(large volume with lateral erosion), and old stage(senile, less volume with only deposition work).
- Headward erosion leads to the retreat of slopes causing river captures as well as a reduction in relief height.
- Climate change and resultant Changes in Rivers.
- Rise in water temperature For ex: According to a recent study by Scientific Report, river water temperatures could rise to 35 degrees Celsius from the present 30 degrees Celsius by 20270-2100, and dissolved oxygen concentrations could drop in Indian rivers.
- Depleting sources of rivers such as glaciers and lack of snow deposition on mountain tops.
- Frequent changes in river courses.
- Increasing pollution in rivers- Central Pollution Control Board in 2018 found 351 polluted stretches of rivers in India. This is largely due to sewage and industrial waste discharge into the rivers.
- Construction of Multipurpose projects on rivers for energy as well as drinking and agricultural purposes.
- Interlinking of Rivers to effectively manage water resources by providing excess water from water-rich states to water-deficient states.For ex-: The Ken-Betwa link project
- Other Anthropogenic factors affecting changes in river flows such as illegal sand mining for constructions, overexploitation of fish resources, discharge of untreated sewage and industrial waste, etc.
Effects of Changes On River Systems
The following are the major changes associated
- The cycle of erosion not only maintains the natural ecology of rivers but also:
- Deposit the fertile alluvium on flood plains necessary for agriculture.
- This leads to the formation of picturesque features such as waterfalls, canyons, gorges,ox-bow lakes, deltas, etc which help the tourism industry to flourish and provide a livelihood to local people
- Natural changes help in maintaining the ecological flow and aquatic life of rivers
- Multipurpose projects have added to the clean, green, and renewable energy capacity of countries.
- Interlinking of rivers is a noble solution for water-stressed areas
- Climate change has impacted rivers in varying degrees right from depleting their sources, rising water temperatures, etc to threatening the natural habitats of native fish and other organisms
- Pollution in rivers has only added to the already scarce water resources which have threatened water security. For eg: More than 600 million people in India are suffering from severe water shortages, according to the NITI Aayog’s Composite Water Management Index.
- Frequent changes in river courses lead to floods causing damage to human life and property and it also affects river ecosystems. For example, A significant flood in India in 2008 prompted the Kosi River to switch to an older channel, displacing 3 million people and claiming more than 250 lives.
- Multipurpose projects are not without negative effects such as sedimentation on river beds, dislocation of people, and destruction of flora and fauna, especially aquatic life.
- Fluctuations in river flow also affect the Hydrological cycle as these are an essential component that further aggravates the scarcity of freshwater.
- Interlinking of rivers also affects the natural flows of rivers which will affect aquatic ecosystems, ecological flow, etc. of the rivers.
- Rising disputes between states over sharing of river water due to water shortages among different regions. For eg: the Cauvery water dispute between Tamil Nadu, Kerala, Karnataka, and Puducherry.
- Dams and reservoirs over transboundary rivers threaten water security in downstream countries. For eg: India’s concern since 2015 when China operationalized its project at Zangmu on the Brahmaputra river
A part of the rainwater percolates in the rocks and the soils and is available as groundwater.
Groundwater is vital to human welfare and development, and in many countries, it is the principal source of water for drinking, irrigation, and industry.
As a core component of the hydrological cycle, groundwater is also critical to sustaining many aquatic and terrestrial ecosystems.
However, various issues have emerged regarding its sustainable use and management especially in the present scenario when there are severe water shortages around the world.
Changes in Groundwater
- Depletion of groundwater resources– Dynamic Ground Water Resource Assessment Report 2022 states that the total annual groundwater recharge is 437.60 Billion Cubic Meters (BCM) and the annual groundwater extraction is 239.16 BCM.
- Agriculture -accounts for nearly 90% of groundwater withdrawals. Practices such as power subsidies for irrigation, MSP for water-intensive crops such as rice, green revolution, and lack of regulations have expedited its extraction.
- Use for drinking and cooking purposes in water-stressed areas
- Deforestation, urbanization, metalled road construction, etc has led to a decline in the percolation of water underground and hence the recharge of aquifers.
- Industries, the second-largest users of groundwater i.e approx.5%, likewise rely on groundwater to meet their water requirements.
- Virtual water trade plays a major role in depleting groundwater.
- Overexploitation of existing resources. Out of the country’s total of 7089 assessment units, 1006 units have been labeled as over-exploited.
- Pollution with the addition of contaminants such as arsenic, fluoride, iron, and other heavy metals is caused due to human activity, such as residential sewage, agricultural practices, industrial effluents, etc.
- The hydrological cycle is interrupted as groundwater acts as its major component
- Water stress and insecurity are already on the rise and depleting groundwater resources amplify this many folds. The rising population and increased urbanization also increase the demand for domestic water.
- Threat to food security as more than 60% of irrigation in agriculture is met by groundwater in India. This especially has risen after the green revolution.
- Increased incidents of droughts around the world.
- Health issues, such as groundwater contamination such as arsenic and fluoride cause cancer and skin problems.
- Health also impacts Human Capital formation because of high mortality and lifelong diseases among children and adults.
- The economy of the country is also impacted due to the dependence of many industries on groundwater
Oceans cover approximately 70.8% of the surface of Earth and contain 97.2%(including ice) of Earth’s water and are divided into five major oceans namely the Arctic, Atlantic, Indian, Pacific, and Southern Oceans.
In addition to this oceans represent the largest aquatic ecosystem on planet earth i.e, the Marine ecosystem. Also, oceans contain large reserves of various important resources such as petroleum, fish and other food resources, mineral resources, etc.
Oceans and oceanic currents play a major role in maintaining the earth’s climate and wind patterns. Hence these become an important part of the study of changing critical geographical features.
Changes in Oceans
- Natural changes such as:
- Sea Floor Spreading along Mid Oceanic Ridge(Plate Tectonics).
- Creation of new oceans such as the Great African Rift Valley which is in the nascent stage in the process of ocean formation.
These, however, are prolonged processes that take millions of years to complete.
- Climate change results in changes such as:
- Ocean acidification lowering of ocean pH is a shift in ocean chemistry brought on by the ocean’s uptake of carbon compounds from the atmosphere.
- Ocean warming– According to IPCC since 1970, the world’s oceans have continued to warm, absorbing more than 90% of the extra heat in the climate system.
- Sea level rise due to temperature rise( Thermal expansion of oceans), melting of glaciers, etc. IPCC Sixth Assessment Report- Global mean sea level increased by 0.20m between 1901 and 2018.
- Pollution: creates the following changes
- Eutrophication occurs when the environment becomes
- enriched with nutrients, increasing the amount of plant and algae growth in estuaries and coastal waters.
- Plastic pollution – Land-based activities such as urban and stormwater runoff, sewer overflows, littering, improper waste management, industrial operations, tire abrasion, building, and illegal dumping are the main sources of plastic debris detected in the ocean.
- Coral Bleaching due to climate change, increased ocean temperature, and eutrophication.
- Human-induced changes such as increased exploration for oil and mineral resources, ocean thermal energy extraction, fishing, transportation of goods, etc impact oceans and their ecosystem. For eg: oil spills create dead zones in oceans.
Impacts of such changes
- Natural changes help us understand the evolution of the earth and its crust such as the presence of a relatively new oceanic crust near Mid Oceanic Ridge which becomes older away from it as well as the oceanic crust being relatively new concerning continental crust.
- Oceans absorb extra heat from the atmosphere therefore these changes help regulate the Earth’s climate
- Energy security by harnessing ocean wave energy.
- Food and nutritional security through fishing, whaling, ocean ranching, etc., and alternate livelihood opportunities for the poor.
Nevertheless, the above benefits are availed at a much larger cost:
- Climate change – has led to the following harmful impacts on oceans:-
- Changes in oceanic current patterns and the reduction difference between cold and warm currents have impacted the earth’s heat budget, fish production, the livelihood of fishers, etc
- Change in wind and weather patterns for ex: the frequency of El NINO – Southern Oscillations has increased.
- Sea level rise has become a major problem for Small Island Nations as they face submergence danger. This also impacts coastal erosion, coastal livelihood, etc.
- The increased temperature of oceans has also impacted their biodiversity due to the increased demand for oxygen.
- Pollution in oceans has threatened marine species as well as humans on a larger scale.
- For example, Eutrophication contaminates water, negatively affects seashore recreational opportunities, creates a dead water zone or hypoxia, and depleted oxygen levels impair or could kill fish in large numbers and change species composition.
- Plastic, mainly in the form of microplastic, enters the food web through bioaccumulation and biomagnification.
- Other pollutants such as disposal of harmful chemicals, industrial waste, Agri nutrients, etc also deteriorate ocean ecosystems.
- Coral bleaching also is dangerous for many reasons. Corals are an indicator of a healthy marine ecosystem and play a major role in its food chain, their destruction can impact coastal protection and biodiversity. Their destruction also impacts tourism and therefore the livelihood of people.
- Overexploitation of fish resources through unscientific practices such as trawling has impacted ocean diversity.
- Extraction of petroleum, polymetallic nodules, other metallic and non-metallic minerals, and oil spills also disrupt marine life.
Glaciers and Ice-Caps
Currently, glaciers and ice caps cover around 10% of the earth’s land surface, especially in regions like Greenland and Antarctica. Glaciers can be found in mountain ranges also, although, on Earth, 99% of the glacial ice is stored within enormous ice sheets in the polar regions.
The amount, variability, and water quality of runoff in their immediate vicinity are all impacted by glaciers, which are significant components of Earth’s water cycle.
These also provide some of the most spectacular landforms such as Moraines, fiords, cirques, icebergs, etc. on the surface of Earth.
However, with the advent of human-induced climate change, these experience various changes some of which are irreversible.
Changes experienced by Glaciers and Ice caps
The following changes are associated with icecaps
Climate change is the leading cause of changes in the mass of ice cover over the earth’s surface. This process of climate change affecting ice cover is natural as is evident from the geological time scale.
There have been numerous warm periods—as when the dinosaurs were alive—and many cold ones, like the most recent ice age, which lasted for around 20,000 years. A large portion of the northern hemisphere was covered in ice and glaciers during the last ice age.
However, at present, this change is more prominent due to anthropogenic activities such as agriculture, industrialization, carbon emissions, deforestation, vehicular emissions, etc causing global warming.
- Greenland ice sheet- lost ice mass at an average rate of 278 billion tonnes every year between 2006 and 2015(IPCC report). Also, another phenomenon is called zombie ice, which does not accumulate fresh snow even while continuing to be part of the parent ice sheet.
- Antarctica’s Melting Ice – for ex: Doomsday Glacier also known as The Thwaites Glacier is 120 km wide at its widest point, moving quickly, and melting rapidly over time.
- Thawing of Permafrost regions – Permafrost is a permanently frozen layer on or under Earth’s surface. It consists of soil, gravel, and sand, usually bound together by ice. Permafrost usually remains at or below 0°C (32ºF) for at least two years. Permafrost can be found on land and below the ocean floor. According to a recent study, an additional 1.5 million square miles of permafrost may eventually disappear for every 1.8°F (1°C) of warming.
- Changes in glacial landforms such as an increased number of glacial lakes, moraines, glacial till, etc.
Impact of Melting Glacier and Ice Caps
- Sea Level Rise– for ex: Thwaites glaciers’ melting already contributes 4% annually to the rise in sea level causing storm surges and coastal erosion, coastal storms like hurricanes and typhoons brought on by warming air and ocean temperatures.
- Change in Weather patterns – Because of modifications to the jet stream brought on by a combination of warming air and ocean temperatures in the Arctic and the tropics, the polar vortex is surfacing outside of the Arctic more regularly. This is due to the change in circulations in oceans brought about by melting Antarctic and Greenland Ice.
- Loss of wildlife habitats as glacier mountains are home to critical species such as snow leopards, polar bears, etc.
- Depleting sources of freshwater as many major glaciers feed the headstreams of major rivers. In the Himalayan, for example, the Ganga River, Yamuna River, and Indus River are all fed by glaciers such as Gangotri and Yamunotri.
- Increased incidents of floods and Glacial Outbursts due to increasing water influx lead to loss of life and property.
- Loss of livelihood especially in coastal areas due to coastal erosion, submergence, increased storm surges due to sea level rise
- Impacts of Permafrost Thawing –
- Increasing incidents of Viruses and Bacteria- The potential danger was highlighted by a 2016 anthrax epidemic in Siberia that was connected to a decades-old reindeer carcass revealed by melted permafrost.
- Thawing of frozen soil – recommences the decomposition process of dead organic matter that was earlier paused due to the freezing of dead plants and animals which results in the emission of greenhouse gases.
Flora and Fauna
The term “flora” refers to all plant life that is present in a certain area or time, usually only the native, naturally occurring plants. Whereas, all of the animal life that is present in a certain area or time is known as fauna.
Because they make up the delicate web of life, where each organism has something to offer, even if only in a very small way, the flora and fauna are essential.
The earth’s plants create the oxygen that the fauna breathes, and the fauna then exhales the carbon dioxide that the flora needs to survive. Humans are unable to survive without either of these substances.
Therefore it is important to understand any changes in flora and fauna for us to implement better planning and management practices concerning sustainable development.
Changes in Flora
The following are the various changes associated
- Grasslands make up 40% of the land area. These typically exist between mountainous and desert climates. Only 10% of the world’s grasslands are protected, though.
- Only 1% of the original tallgrass prairie remains today, while over 50% of all temperate grasslands and 16% of tropical grasslands have been converted to agriculture or industrial purposes.
- Conversion of grasslands for economic activities such as ranching, Dairy Farms, Sheep rearing for wool, etc in North and South America, New Zealand, Australia, etc.
- Degradation of grasslands due to unscientific agricultural practices such as monocropping, chemical fertilizers, and overgrazing.
- The advent of invasive species has impacted local vegetation.
- Therefore, the fauna inhabiting these grasslands is also in decline such as African Cheetah being vulnerable under IUCN.
- Climate Change has also impacted grasslands as their relatively flat geography makes them more vulnerable to the effects of climate change and animals must travel great distances to adapt to temperature changes.
- Biodiversity loss due to the extinction of plant and animal species.
- Land degradation and desertification.
- Food insecurity will further as these sustain major agricultural activities.
- Impact on cultural and recreational activities such as Savanna Safari where people interact with nature and wild animals.
- Threat to the livelihood of tribal people who are dependent on grassland and its fauna for survival.
According to the Global Forest Resources Assessment 2020 (FRA 2020), representing almost 31% of the world’s surface area, forests were reported to encompass 4.06 billion hectares in 2020.
Forests offer more than just habitat for animals and means of subsistence for people. They also protect watersheds, stop soil erosion, and lessen the effects of climate change.
Given these advantages, the forest area around the world is still in decline.
Changes in forests
- Loss of Forests due to deforestation which in turn is caused by various activities such as agriculture, urbanization, mineral exploration, etc. According to the State of the World’s Forests 2022 420 million hectares of forests have been lost between 1990 and 2020 from deforestation.
- Forest Degradation due to illegal logging.
- Declining floral and faunal biodiversity of forests due to human encroachments, climate change, etc.
- Conversion of forests into conservation reserves and protected areas to protect local flora and fauna.
- Invasive species of trees are on the rise.
- Increased incidence of Forest fires. For eg: Wildfires in the Amazon forests in Brazil and in Australia in the last two years, were caused by both climate change and human activities.
- Western Maharashtra, Southern Chhattisgarh, regions of Telangana and Andhra Pradesh, together with central Odisha, are “extremely prone” forest fire hotspots, according to the MoEFCC 2020–2021 annual report.
Effects of Changes in Forests
- Increased Greenhouse Gas Emissions as 15% of greenhouse gas emissions are due to deforestation and forest degradation.
- Rise in temperatures, changes in patterns of weather and water, and an increased frequency of extreme weather events due to climate change caused by such emissions.
- Soil Erosion increases due to shifting cultivation, removal of forests for agriculture, etc.
- Disruption of the Hydrological cycle because by assisting in maintaining equilibrium between water on the ground and water in the atmosphere, trees play a significant part in the local water cycle. However, this equilibrium can be upset by deforestation or environmental degradation, changing precipitation, and river flow.
- Destruction and Loss of biodiversity due to wildfires.
- Disruption of Livelihoods- Around the world, 1.25 billion people depend on forests for their homes, means of subsistence, and access to water, fuel, and food. And 750 million people live in the woods, which is almost one-fifth of all rural residents.
- Loss of culturally significant sacred groves.
- Increase in Infectious Diseases: Forests are related to 15% of 250 Emerging Infectious Diseases.
Mangrove forests are fertile wetlands that grow in coastal intertidal zones. They are also known as mangrove swamps, mangrove thickets, or mangals. Due to mangroves’ inability to survive subfreezing temperatures, mangrove forests are primarily found in tropical and subtropical latitudes.
Around 80 different species of mangroves have been identified as existing on maritime beaches throughout the world. Based on remote sensing and worldwide data for 2010, the Global Mangrove Watch Initiative published a global baseline in 2018.
According to this, there are mangrove forests in 118 different countries and territories with a total area of 137,600 km2 (53,100 sq mi) as of 2010.
Changes in Mangrove forests
- In the face of infrastructural development, urbanization, and agricultural land conversion, mangroves are disappearing at a rate that is three to five times faster than the overall loss of world forest cover, according to UNESCO.
- A fifth of the degradation of mangrove ecosystems is due to shrimp cultivation.
- Climate Change – Greater sea level increases have been linked to the breakdown of the mangrove ecosystem, according to recent studies.
- Illegal logging, invasive species, and a decline in biodiversity have also altered mangrove distribution.
Impacts of Changes in Mangroves
- Ecological Destabilization as mangroves serves as a reservoir in the tertiary absorption of waste, helping to construct and preserve the soil.
- Loss of Biodiversity with loss of mangroves as diverse varieties of fauna, including birds, fish, insects, mammals, and plants, find habitat and safety here.
- Mangrove forests protect the shoreline from erosion caused by storm surges, currents, waves, and tides. Hence, these also protect human life and property in coastal areas. For example, during the 2004 Tsunami coastal communities in Tamil Nadu suffered minimal damage.
- Positive Feedback to Climate Change – because these represent 10–15% of carbon burial.
- Loss of LIvelihood to many coastal communities dependent upon mangroves for their fuel and fodder.
Changes in Fauna
- According to scientific research, Earth’s wildlife populations have decreased by an average of 69% in just under 50 years.
- The average size of the wildlife population has seen the steepest decline which is 94% in 48 years in Latin America and the Caribbean, including the Amazon.
- The sixth mass extinction, which is the biggest loss of life on Earth since the extinction of the dinosaurs, is widely believed to be occurring right now, and many scientists feel that humans are to blame.
- Freshwater populations have decreased the most, according to the WWF, with an average reduction of 83% between 1970 and 2018. According to the IUCN Red List, amphibians are the species that are most in danger, followed by corals and an ancient group of seed plants called cycads.
- Extinction of species – most recently such Pinta Giant Tortoise, Yangtze River Dolphin, Western Black Rhinoceros, and Ivory Billed Woodpecker with more than 42,100 species facing extinction.
- Habitats of many species such as Asiatic lions, African Cheetahs, tigers, etc. have come to only a few restricted places. For example, Asiatic Lions are only found in Gir National Park.
- Increasing the number of conservation areas around the world to protect the loss of biodiversity.
Reasons for changes in Fauna
- Natural causes: Floods, landslides, earthquakes, volcanic eruptions other natural disasters also cause loss of biodiversity.
- Habitat loss and fragmentation – are the main factors causing the extinction of animals and plants. Natural forests are cut down to provide room for businesses, farms, dams, homes, recreational activities, etc. Tropical rainforests are the most shocking examples of habitat loss.
- Land use change is still the biggest current threat to nature, destroying or fragmenting the natural habitats of many plant and animal species on land, in freshwater, and the sea.
- Overexploitation by humans over the past 500 years has led to the extinction of numerous species (Steller’s sea cow, passenger pigeon), etc.
- Climate Change – Animals have reacted differently to climate change than humans. Climate change causes species to migrate, adapt, or, if neither of those things happens, to go extinct.
- Introduction of alien invasive species – The native catfish in Indian rivers are in danger due to the recent illegal introduction of the African catfish for aquaculture reasons.
- Illegal Poaching and Hunting are the main cause of extinction of many animal and fish species, for ex: Asian cheetah while others are on the brink of extinction such as the one-horned rhino, Tiger, Elephants
- Illegal trade in wildlife for their use in medicines and decorative purposes eg Mongoose hair, rhino horn, snake skins, tiger and leopard claws, etc
Effects of Changes in Fauna
- Disruption in Ecosystems – If a species has a unique function in its ecosystem, it’s the extinction of other species and the ecosystem itself.
- Multiple Effects of Losing Apex Predators – Scientists claim that the loss of these species has contributed to pandemics, fires, the invasive spread of species, the deterioration of ecosystem services, and a drop in carbon sequestration.
- Pollination is negatively impacted as approximately all blooming plants in the tropical rainforest are pollinated by animals, as are 75% of the world’s food crops, which are either entirely or partially pollinated by insects and other animals.
- Losing the healing benefits of nature – More than 25% of prescription drugs include compounds that were found in plants or animals. The source of penicillin was a fungus.
- Increased Human-Wildlife conflict due to habitat loss and deforestation. For ex: In reserves, 125 people were killed by tigers between 2019 and 2021. With 6 deaths, Maharashtra accounted for almost half of these.
- This also leads to other Impacts such as damage to crops, increased cruelty towards animals, the economic burden on farmers, etc.
- Destruction of livelihood – According to a study for the U.N., the continued loss of species could cost the world 18 percent of global economic output by 2050.
Article Written By: Ankit Sharma