| Eastern Ghats | |
|---|---|
.JPG) | |
| Highest point | |
| Peak | Arma Konda, Andhra Pradesh |
| Elevation | 1,680 m (5,510 ft)[1][2] |
| Coordinates | 18°13′41″N82°43′23″E / 18.22806°N 82.72306°E /18.22806; 82.72306 |
| Dimensions | |
| Length | 1,750 km (1,090 mi) N–S |
| Width | 100–200 km (62–124 mi) E–W |
| Area | 75,000 km2 (29,000 sq mi) |
| Geography | |
 | |
| Country | India |
| Regions | Eastern andSouthern India |
| States | |
| Biome | Tropical forests andWetlands |
| Geology | |
| Rock types | |
TheEastern Ghats is a mountain range that stretches 1,750 km (1,090 mi) along theeastern coast of theIndian peninsula. Covering an area of 75,000 km2 (29,000 sq mi), it traverses thestates ofOdisha,Telangana,Andhra Pradesh,Karnataka, andTamil Nadu. The range forms a discontinuous chain of mountains along the eastern edge of theDeccan Plateau, stretching from north of theMahanadi River in Odisha toVaigai River in Tamil Nadu at the southern end of the peninsula. The Eastern Ghats meet theWestern Ghats at theNilgiris. The average elevation is around 600 m (2,000 ft) andArma Konda is the highest peak in the mountains at 1,680 m (5,510 ft).
Geological evidence indicates that the mountains were formed during thearcheozoic era and became part of theIndian subcontinent post the break-up of the supercontinent ofRodinia and the formation ofGondwana. The mountains were formed through furthermetamorphism during the mid-Proterozoic era. The northern section of the range has an elevation ranging from 900–1,400 m (3,000–4,600 ft) and lies mostly in Odisha. The middle section stretches up to thePenna River and consists of two parallel ranges with an average elevation of 520 m (1,710 ft). At the southern end, the range is made up of several smaller hills.
The Eastern Ghats form a part of one of the majorwatersheds of India, consisting of many perennial river systems such as theGodavari,Krishna, Mahanadi andKaveri. Because of the higher elevation of the Deccan Plateau on the west, most rivers originate from the Western Ghats and flow eastwards to cut across the range to theBay of Bengal. As the mountains are discontinuous and have a lower elevation, they have a considerably lesser influence than the Western Ghats on the weather patterns in India. However,orography studies indicate that the range does play a role in bringing rainfall to the eastern coastal areas.
The weather is normally dry and humid with seasonal rainfall. There are nine different forest types found in the region includingevergreen,deciduous andthorn forests. The Eastern Ghats region contains a large number of different species of flora and fauna, some of which are endemic to this region.
The name Eastern Ghats derives from the wordghat and the cardinal direction in which it is located with respect to the Indian mainland.Ghat, a term used in the Indian subcontinent, depending on the context, could either refer to arange of stepped hills such as the Western Ghats and Eastern Ghats, or a series of steps leading down to a body of water orwharf.[3][4] As per linguistThomas Burrow, the wordGhat was derived from similar words used in variousDravidian languages such askattu (mountain side, ridge, or dam) inTamil,katte (dam),gatta (mountain), andgatte (bank or shore) inKannada, andkatta (dam), andgattu (shore or embankment) inTelugu.[5]
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The Eastern Ghats are an ancientorogenic belt which started forming during the collision of crustal rocks during thearcheozoic era. Geologic evidence indicates that these became part of the Indian subcontinent following the break-up of the super-continent of Rodinia and the creation of Gondwana. The mountains were formed over millions of years throughmetamorphism, anderosion and are significantly older than the Western Ghats.[6][7] The rock layers were largely formed during the mid-proterozoic era by the accumulation ofsilt,carbonates andbasalt which later becamekhondalite andcalcium silicate rocks. The major rock types found arecharnockite,granite, khondalite,metamorphic, andquartzite.[7][8]
In themesoproterozoic era, the range was compacted and re-aligned north-east. The structure includes multiplethrusts andstrike-slip faults along its range.[9] TheEparchaean Unconformity of theTirumala Hills is a majordiscontinuity ofstratigraphic significance that represents an extensive period of erosion andnon-deposition, which is evident from the steep natural slopes, and ravines.[10][11] Along the western edge,sedimentary rocks were deposited due tovolcanic activity, which and later formedschist belts. The region consists ofbauxite,iron ore andlimestone reserves. The major soil types found arered,black,laterite, andalluvial.[7]
The Eastern Ghats extend from north of theMahanadi River and run approximately 1,750 km (1,090 mi) to theVaigai basin in the south of Indian peninsula.[12] It covers an area of 160,000 km2 (62,000 sq mi), traversing across theIndian states ofOdisha (25%),Telangana (5%),Andhra Pradesh (40%),Karnataka (5%), andTamil Nadu (25%).[13][14]: 24
The Eastern Ghats form a discontinuous chain of mountains with an average elevation of 600 m (2,000 ft) and run parallel to theeastern coast of India along the Bay of Bengal.[7][15] TheEastern coastal plains are the 100–130 km (62–81 mi) wide region between the Eastern Ghats and the Bay of Bengal.[16][17] The average width of the mountains range from 100–200 km (62–124 mi) with the mountains wider in the north and narrower in the south.[12][14]: 24 Arma Konda is the highest peak in the mountains at 1,680 m (5,510 ft).[15][18]
The range can be roughly divided into three separate sections. The northern section of the range lies majorly in Odisha and stretches from the Similipal hills in the north to the Andhra Pradesh border. It has an elevation ranging from 900–1,400 m (3,000–4,600 ft) with the highest peak atDeomali (1672 m).[18][14]: 24 The central section lies in Telangana and Andhra Pradesh and stretches up to thePenna River. It consists of two parallel ranges with an average elevation of 520 m (1,710 ft) and is separated by a 160 km (99 mi) wide gorge through which the riversGodavari andKrishna flow. The hills continue asJavadi andShevaroy Hills, south ofChennai and meet with the Western Ghats atNilgiris. TheBiligiriranga andMalai Mahadeshwara Hills in Karnataka extend to Talamalai in Tamil Nadu, and is separated from the Western Ghats meet by theMoyar River valley.[19] At the southern end, the Eastern Ghats is made up of several smaller hills such as theSirumalai.[15][18][14]: 24
The Eastern Ghats form one of the majorwatersheds of India with major river systems such asGodavari,Kaveri,Krishna andMahanadi cutting across the range.[7][18][20] Most rivers flow eastwards towards the Bay of Bengal owing to the steeper gradient moving from east to west.[21] The Eastern Ghats are the source for many small and medium rivers of the east coastal plains.[22]
| Riparian state | Rivers |
|---|---|
| Odisha | Baitarani,Brahmani,Budhabalanga,Nagavali,Rushikulya,Sabari,Subarnarekha,Vamsadhara |
| Andhra Pradesh | Champavathi,Chitravathi,Gosthani,Gundlakamma,Kundu,Penna,Sarada,Sileru,Swarnamukhi,Tammileru |
| Tamil Nadu | Amaravathi,Palar,Ponnaiyar,Swetha,Thamirabharani,Varaha,Vaigai,Vellar |
The streams and rivers give rise to numerous waterfalls in the region. The region also consists of manywetlands and large coastallagoons such as theChilika,Kolleru andPulicat lakes.[14]: 36 The rivers have been dammed forhydroelectric andirrigation purposes, with major reservoirs spread across the region.[23][24]
As the mountains are discontinuous and have a lower elevation, they have a considerably lesser influence than the Western Ghats on theweather patterns in India. However,orography studies indicate that the range does play a role in rainfall patterns along the coast. The range blocks winds at the low level which brings rainfall to the eastern coastal plains.[25] The Eastern Ghats region has atropical climate and receives rainfall from themonsoon. It is hot in the summers with temperatures reaching 44 °C (111 °F) during summer withhumidity levels of 65–75%. The northern region receives 120–150 cm (47–59 in) of rainfall and the lower regions receive 60–110 cm (24–43 in) of rain. The temperature is lowest in the winter month of January with an average of 20–25 °C (68–77 °F). The higher hill ranges are generally wetter and cooler with the lower parts remaining semi-arid and dry. The coastal regions experiencetropical cyclones during the monsoon season.[18][14]: 28
There are nine forest types in the Eastern Ghats region, namelytropical evergreen,semi-evergreen,moist deciduous,riverine,southern dry deciduous,northern dry deciduous,dry savannah,thorn scrub, anddry evergreen forests.[12] The vegetation varies considerably with altitude with scrubs and dry forests at lower altitudes and deciduous, semi-evergreen forests, and evergreen forests at higher altitudes.[18] Tropical evergreen forests occur in small patches inShevroy in Tamil Nadu and in north Andhra Pradesh. Semi-evergreen forests are found in the northern section and southern fringes. Moist deciduous forests occur in Odisha andNallamala in Andhra Pradesh–Telangana. Dry deciduous, dry savannah and scrub forests occur across the range. Dry evergreen forests are limited to south Andhra Pradesh, and north Tamil Nadu.[14]: 44
The region is home to more than 4500 species ofangiosperms, which account for 13% of the flowering plant species in India.[18][7] About 166 species of flowering plants areendemic to the Eastern Ghats and more than ten new species have been discovered in the region since the early 2010s.[12] About 184 species offerns, and 190 species oforchids have been recorded in the region.[14]: 43 Commercially viable tree species includeIndian rosewood,teak,mahogany, andred sandalwood.[14]: 44 [7]
| Group | Species in Eastern Ghats | Species in India |
|---|---|---|
| Mammals | 100 | 250 |
| Birds | 425 | 1224 |
| Reptiles | 99 | 197 |
| Amphibians | 100 | 408 |
| Fishes | 155 | 2546 |
Mammals found in the region include theBengal tiger,leopard,sloth bear,Indian wild dog,golden jackal,Indian fox, and other cat species such asjungle cat,fishing cat, andleopard cat. Large herbivores includeIndian elephant,blackbuck,sambar deer,spotted deer,barking deer,Indian gazelle,four-horned antelope,Indian bison,wild boar,Indian crested porcupine,mouse deer, andnilgai. Other smaller mammals includegrey slender loris,Indian hare,Indian hedgehog,Indian mongoose,mole rat,smooth coated otter,Indian pangolin,palm civet,Indian giant flying squirrel, andMadras treeshrew.[14]: 43 Bonnet macaque,rhesus macaque, andHanuman langur are the majorprimates. The region is also home to more than 15 species ofbats.[14]: 44
Bird surveys have found about 425 species belonging to 57 families in the region. Four species ofhornbills are found in the region and are consideredkeystone species.[14]: 50 [26] TheJerdon's courser was thought to beextinct in the wild before it was re-discovered in the range in 1986. More than 50% of the wild population of thecritically endangeredIndian bustard is found in the region.[14]: 53 Common and widespread species include thered-vented bulbul,white-browed bulbul,red-whiskered bulbul,common iora, andpurple-rumped sunbird. Five species of birds that are endemic to the Western Ghats region have been sighted in the fringes of the Eastern Ghats. These includegrey-headed bulbul,Nilgiri wood pigeon,Malabar parakeet,crimson-backed sunbird, andrufous babbler. Other species of avifauna includelaughing dove,Indian nightjar,jungle owlet,red avadavat,Malayan night heron,striated heron,white-naped woodpecker,savanna nightjar,brown hawk-owl,Nilgiri flowerpecker,spot-bellied eagle-owl,blue-eared kingfisher,green imperial pigeon,oriental dwarf kingfisher,Indian swiftlet, andwhite-browed fantail.Raptors includedwhite-eyed buzzard,grey-headed fish eagle,lesser fish eagle.[27][28] Two species ofcritically endangeredvultures –Indian vulture andred-headed vulture have been reported in the region.[29][30]
There are about 99reptile species found in the region. These includeIndian monitor lizard, and endemic species such asYercaud slender gecko,burrowing limbless skink,spotted Eastern Ghats skink, andMadras spotted skink. TheIndian golden gecko, andJeypore ground gecko were rediscovered in 1986 and 2010 respectively.[14]: 49 [31] Other reptiles includegeckos,skinks,lacertas,iguanas,chameleons, andmonitors.Snakes includeblind snakes,shield-tailed snakes,sand boas,cobras,vipers,kraits,coral snakes, andpython. There are about 100 species ofamphibians found in the region includingtoads,pond frogs,cricket frogs,bull frogs,burrowing frogs,balloon frogs,small-mouthed frogs,tree frogs, andgolden-backed frogs.[32] There are also about 155 species offreshwater fish from 28 families found across the waters in the region.Insects include nearly 150 species ofbutterflies and nine species oftarantulas amongst others.[14]: 51
A 2017 study indicated that the Eastern Ghats region has lost about 32,200 km2 (12,400 sq mi) forest cover between 1920 and 2015. Forests which occupied 43.5% of the land area reduced by nearly 16 percent.[14]: 119 An estimated 7.92 percent of the forest area converted for agriculture and 3.80 percent to grasslands from 1920 to 2015. As of 2018, only 3.53 percent of the total area was declared asprotected areas.[13] The major threats includedillegal logging,mining,grazing,agriculture,forest fires andtourism,poaching, and illegal tapping of forest resources which have resulted indeforestation and fragmentation of forests.[12][13] Variousnatural disasters such as heavy rainfalls, extreme temperature, environmental changes, competition due toinvasive species have been threats to the biodiversity in the region. The absence ofpollinators have also had an effect on the natural regeneration of vegetation.[12]
Till 1980, logging was a major contributor for the loss of forest cover with decrease in tree species such asteak,sal,red sanders, and sandalwood. Though laws in 1988 curtailed illegal logging, wood is still quarried by people for makingcharcoal,firewood, and construction.[14]: 91 Forest produce is a source of income for people living in the fringes of the ranges. Over harvesting of forest produce forfodder,traditional medicine, and domestic uses along with unscientific extraction methods and burning of forests have been threats.[14]: 92 The introduction of alien species either by deliberate or non deliberate means have resulted in competition to native species.[14]: 93 The construction of largedams across rivers in the region have submerged more than 2,300 km2 (890 sq mi) of forest cover.[14]: 94
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The Eastern Ghats region is rich inminerals andsemi-precious stones. Illegal mining, poor mining processes, over exploitation, and unsafe disposal of debris have resulted in issues bio-degeneration of the areas.[14]: 98–99 Eight of the 29 forest fire prone districts are located in the region and, Odisha and Andhra Pradesh recorded the most forest fires in 2014. With more than 90% of these fires caused by humans, this has resulted in loss of forest cover.[14]: 101 Practices such asshifting cultivation,plantations, and illegal encroachments are the major agricultural contributors to deforestation.[14]: 103, 107 Increasedurbanisation, and expansion of cities, construction of roads and railways, and tourism have led to encroachments into forest lands, and threats to bio-diversity in the region.[14]: 112, 114
TheGovernment of India had enacted various policies over the years to address the environmental concerns, access to forest resources, and protection of wildlife.[14]: 140 Threenational parks, twobiosphere reserves, and 22wildlife sanctuaries are present in the Eastern Ghats region. The protected areas include fivetiger reserves under theProject Tiger, and an elephant reserve under theProject Elephant protection plans. About 13 eco-sensitive zones have been declared, which are jointly managed with the local communities.[14]: 144–146
