The Himalayan Ranges

The Himalayas, formed by the collision of tectonic plates, are a young and formidable mountain range spanning 2,400 kilometers across 13 Indian states and territories. Divided into three groups based on relief, they consist of the Greater, Middle, and Outer Himalayas. Evidence of their youth includes deep gorges, U-turn river courses, parallel ranges, steep gradients, and frequent earthquakes. Notable for their biodiversity, they serve as a barrier to the monsoon, regulate climate, and are the source of major rivers. However, climate change threatens their glaciers, leading to increased floods, droughts, and habitat loss. Preserving this fragile ecosystem requires collective action and sustainable practices to ensure the Himalayas' enduring majesty for future generations.

The Himalayas, formed as a result of the collision between the Indian and Eurasian tectonic plates, are relatively young fold mountains. This collision began around 50 million years ago and continues to shape the landscape today. The immense pressure exerted during this collision uplifted the Earth's crust, giving rise to the towering peaks and deep valleys that characterize the Himalayan range. Their width ranges from 400 kilometers in Kashmir to 150 kilometers in Arunachal Pradesh. Altitude fluctuations are more pronounced in the eastern section compared to the western portion. In the northwestern region of India, these ranges predominantly trend from northwest to southeast. The southern slopes exhibit steep inclines, while the northern slopes are relatively gentler.

The Himalayas are renowned as the highest and most rugged mountain range globally. Extending over approximately 2,400 kilometers, they form a sweeping arc. Most of the Himalayan ranges are situated within the territories of India, Nepal, and Bhutan. The Indian Himalayan Region is spread across 13 Indian States/Union Territories (namely Jammu and Kashmir, Ladakh, Uttarakhand, Himachal Pradesh, Arunachal Pradesh, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim, Tripura, Assam and West Bengal).

On the basis of relief, alignment of ranges, and other geomorphological features, the Himalayas can be divided into three groups. They are: a) The Himalayas b) The Trans-Himalayas c )Purvanchal or the hills of the north-east

1. The HimalayasThree parallel ranges can be identified in the Himalayas. These are:
   1. Greater/Inner Himalaya - Himadri
      • The northernmost segment of the Himalayas is referred to as the Great Himalayas, Inner Himalayas, or the 'Himadri'.
      • This range is exceptionally continuous and boasts the loftiest peaks, averaging around 6,000 meters in height.
      • It encompasses all the prominent Himalayan summits, including the world's highest peak, Mount Everest (8,848 meters). Other notable peaks surpassing 8,000 meters include Kanchenjunga, Makalu, Dhaulagiri, and Annapurna. Kanchenjunga holds the distinction of being India's highest Himalayan peak.
      • The core of this part of Himalayas is composed of granite.
      • The Himadri range remains snow-covered year-round, hosting numerous large and small glaciers. Upon snow and ice melt, these glaciers feed the rivers of northern India, ensuring their perennial flow. Noteworthy examples include Gangotri and Yamunotri glaciers.
      • This region boasts several crucial passes facilitating trade and transportation.
      
      

      State and Passes of Greater Himalayas

      • Jammu and Kashmir: Banihal Pass, Chang La, Khardung La, Pir Panjal Pass, Burzil Pass, Zoji La, Aghil pass
      • Himachal Pradesh: Baralacha La, Shipki La, Rohtang Pass, Debsa Pass
      • Uttarakhand: Niti Pass, Lipu Lekh, Mana Pass, Muling Pass, Mangsha Dhura
      • Sikkim: Nathu La, Jelep La
      • Arunachal Pradesh: Dihang Pass, Diphu Pass, Chankan Pass, Bomdila Pass, Lekhapani Pass, Pangsang La
   
   
   2. Middle/Lesser Himalaya - Himachal
      • Situated south of the Himadri, this range constitutes the most rugged mountain system
      • The ranges predominantly comprise highly compressed and altered rock formations.
      • Altitudes within this range typically range between 3,700 and 4,500 meters, with an average width of approximately 50 kilometers.
      • Notable ranges within this system include the Pir Panjal, which stands as the longest and most significant, alongside the Dhaula Dhar and the Mahabharat ranges.
      • Kashmir Valley, renowned for its beauty, lies nestled between the Pir Panjal and Himadri ranges, while the famous valleys of Kullu and Kangra are also part of the Himachal ranges.
      • The majority of hill towns and resort areas are situated within the Himachal range, including popular destinations like Shimla, Nainital, Mussoorie, Almora, and Darjeeling.
      • Nainital is particularly famous for its stunning lakes, adding to the region's allure and providing serene settings for relaxation and recreation.
      
      

      Prominent ranges in the Lesser Himalayas area include:

      • The Pir Panjal Range in Jammu and Kashmir
      • The Dhauladhar Range in Himachal Pradesh
      • The Mussoorie Range and Nag Tibba Range in Uttarakhand
      • The Mahabharat Range in Nepal
   
   
   3. Outer Himalayas - Shiwalik
      • Positioned between the Great Plains and the Lesser Himalayas, the Shiwaliks form the outermost range of the Himalayas.
      • They constitute an almost continuous chain of low hills, spanning a width of 10 to 50 kilometers, with altitudes ranging between 900 and 1100 meters.
      • Composed primarily of unconsolidated sediments carried by rivers from the higher Himalayan ranges to the north, these ranges are characterized by thick layers of gravel and alluvial deposits.
      • Over time, rivers have carved their paths through the conglomerate deposits, draining away lakes and leaving behind flat plains known as 'duns' in the west and 'duars' in the east.
      • The longitudinal valleys situated between the Lesser Himalayas and the Shiwaliks are referred to as Duns. Examples include Dehradun, Kotli Dun, and Patli Dun, which are notable for their geographical features and significance.
      
      

      Different Names of Siwaliks in Different Areas

      • Jammu Region: Jammu Hills
      • Arunachal Pradesh: Dafla, Miri, Abor and Mishmi Hills
      • Uttarakhand: The Dhang Range, Dundwa Range
      • Nepal: Churia Ghat Hills
   
   
   4. The Trans-Himalayas/ Tibetan Himalayas
      • Positioned north of the Greater Himalayas and running parallel to them, the Trans-Himalayas include the Zaskar Range. Beyond the Zaskar Range lies the Ladakh Range. Further northward is the Karakoram Range, situated at the extreme northern boundary of the region. Notably, K2, the world's second-highest peak, is located within the Karakoram Range.
      • These ranges have been shaped by sedimentary rock formations.
      • Originating from this region are several significant rivers, including the Sutlej, Indus, Brahmaputra (also known as the Yarlung Tsangpo in Tibet), which are considered antecedent rivers.
      • The Trans-Himalayas span approximately 1,000 kilometers in an east-west direction, forming a rugged and remote landscape with unique geological features and rich biodiversity.
   
   
   5. Purvanchal/ North-Eastern Hill & Mountains
      • These form a significant part of the Himalayan mountain system, characterized by their alignment from north to south.
      • They are recognized by various local names:
        • In the northern region, they are referred to as the Patkai Bum, Naga Hills, and Manipur Hills.
        • In the southern region, they are known as the Mizo or Lushai Hills.
      • These hills are relatively low in elevation and are inhabited by diverse tribal groups that engage in various traditional agricultural practices, including Jhum cultivation.
      • The landscape is often dissected by small rivers, creating valleys and adding to the distinctiveness of each hill range.


2. Division From West To East (Regional)
   The Himalayas have also been divided on the basis of regions from west to east demarcated by river valley.

   PUNJAB HIMALAYAS

   • Spanning approximately 560 kilometers, the Punjab Himalayas constitute the Himalayan region situated between the Indus and Satluj rivers.
   • This region serves as the drainage basin for all major rivers within the Indus river system
   • Predominantly located in Jammu and Kashmir and Himachal Pradesh, the Punjab Himalayas are also referred to as the Kashmir and Himachal Himalaya.
   • The landscape features a series of mountain ranges, including the Karakoram, Ladakh, Zanskar, and Pir Panjal ranges.
   • Notably, the Kashmir Himalayas are renowned for their Karewa formations, which are conducive to the cultivation of Zafran, a local variety of saffron.
   • Karewas are thick deposits of glacial clay and other materials embedded with moraines.
   • Important passes within the region include Zoji La on the Great Himalayas, Banihal on the Pir Panjal, Photu La on the Zaskar, and Khardung La on the Ladakh range, facilitating transportation and trade.
   • The region is dotted with significant freshwater lakes such as Dal and Wular, as well as saltwater lakes like Pangong Tso and Tso Moriri.
   • Towards the southernmost part of the Punjab Himalayas lie longitudinal valleys known as 'duns,' with examples including Jammu Dun and Pathankot Dun, which contribute to the region's diverse topography and ecosystems.
   
   

   KUMAON HIMALAYAS

   • The Kumaon Himalayas, situated in Uttarakhand, stretch from the Satluj to the Kali river.
   • The Lesser Himalayas in the Kumaon Himalayas are characterized by the presence of the Mussoorie and Nag Tibba ranges
   • Notably, two distinct physiographic features define this region: the 'Shiwalik' and 'Dun' formations
   • The Shiwalik formation in this area extends south of the Mussoorie range, lying between the Ganga and Yamuna rivers.
   • Additionally, the region boasts five famous Prayags, which are confluences of rivers, adding to its geographical significance and cultural importance.
   
   

   NEPAL HIMALAYAS

   • It lies between the Kali River in the west and the Teesta River in the east.
   • This region is home to the Great Himalaya range, where peaks reach their maximum heights.
   • Renowned peaks such as Mt. Everest, Kanchenjunga, Makalu, Annapurna, Gosainthan, and Dhaulagiri are situated here, adding to the region's allure and mountaineering appeal.
   • The Lesser Himalaya in this area is referred to as Mahabharat Lekh.
   • Rivers like the Ghaghara, Gandak, and Kosi cross through this range, contributing to the region's hydrology and ecosystem.
   • Between the Great and Lesser Himalayas, one finds the Kathmandu and Pokhara lacustrine valleys, characterized by their scenic beauty and cultural significance.
   
   

   ASSAM HIMALAYAS

   • This section of the Himalayas stretches between the Tista River in the west and the Brahmaputra River in the east, covering a distance of approximately 720 kilometers.
   • It is characterized by high mountain peaks like Kanchenjunga and deep valleys, offering stunning landscapes and challenging terrain.
   • While the southern slopes exhibit steep gradients, the northern slopes are comparatively gentler.
   • The Himalayas are narrower in this region, with the Lesser Himalayas positioned closer to the Great Himalayas.
   • Fluvial erosion, primarily driven by heavy rainfall, plays a significant role in shaping the landscape of the Assam Himalayas.
   • Instead of the Shiwaliks found elsewhere, the Assam Himalayas feature 'duar formations,' which have also been utilized for tea gardens, highlighting the region's agricultural significance and economic contributions.
   • The British introduced tea plantations in this region due to favorable physical conditions such as moderate slopes, thick soil cover with high organic content, well-distributed rainfall throughout the year, and mild winters.

• In India
  • Kanchenjunga: 8598 metres (Sikkim)
  • Nanga Parbat: 8126 metres (Gilgit–Baltistan, Pakistan occupied Kashmir)
  • Nanda Devi: 7817 metres ( Uttarakhand)
  • Kamet: 7756 metres ( Uttarakhand)
  • Namcha Barwa: 7756 metres (Arunachal Pradesh)
• In Nepal
  • Mt. Everest: 8848 metres
  • Makalu: 8481 metres
  • Dhaulagiri: 8172 metres
  • Annapurna: 8078 metres
  • Gurla Mandhata: 7728 metres

• Extending from the Indus gorge in the west to the Brahmaputra gorge in the east, the Syntaxial Bends of the Himalayas run in a west-east direction.
• At these gorges, the mountain ranges sharply bend southward, creating what are known as syntaxial bends of the Himalayas.
• The western syntaxial bend occurs near Nanga Parbat, while the eastern syntaxial bend arises near Namcha Barwa.
• Beyond the Dihang gorge, the Himalayas take a sharp southward turn and spread along the eastern boundary of India, forming the Purvachal or Eastern Hills and Mountains.
• These ranges stretch along the India-Myanmar Border, extending from Arunachal Pradesh in the north to Mizoram in the south. Examples include the Patkai Bum Hills, Naga Hills, Manipur Hills, Jaintia, Khasi, and Garo Hills, as well as the Mizo Hills.

• Regulation of Monsoon: The Himalayas act as a barrier to the southwest monsoon winds, causing heavy rainfall in northern India. This rainfall is crucial for agriculture and sustenance in the region.
• Natural Barrier: Serving as a natural barrier, the Himalayas provide protection to the Indian subcontinent from external threats and climatic influences.
• Source of Rivers: The Himalayas are the source of numerous perennial rivers, including the Indus, Ganges, and Brahmaputra. These rivers provide water for irrigation, drinking, and hydropower generation, supporting millions of people.
• Tourist Attraction: The Northern Mountains of the Himalayas are a paradise for tourists, offering breathtaking natural landscapes, diverse wildlife, and opportunities for trekking, mountaineering, and adventure sports.
• Cultural and Spiritual Centers: Many renowned hill stations and pilgrimage centers, such as Amarnath, Kedarnath, Badrinath, and Vaishno Devi temples, are situated in the Himalayas, attracting pilgrims and tourists alike.
• Natural Resources: The Himalayas provide raw materials for various forest-based industries, including timber, medicinal plants, and herbs, supporting local economies and livelihoods.
• Climate Regulation: The Himalayas act as a buffer against cold winds from central Asia, helping to moderate temperatures and protect India from severe cold weather conditions.
• Biodiversity: The region is home to important populations of numerous large bird and mammal species, including vultures, tigers, rhinos and wild water buffalo.
  • The Eastern Himalaya is a centre of diversity for several widely distributed plant taxa, such as Rhododendron, Primula, and Pedicularis.
  • Mammals found here are the golden langur, the Himalayan tahr, the pygmy hog, langurs, Asiatic wild dogs, sloth bears, gaurs, snow leopard, black bear, blue sheep, takin, the Gangetic dolphin, wild water buffalo, swamp deer

• Deep Gorges: The presence of deep gorges, such as the Indus Gorge and the Brahmaputra Gorge, indicates ongoing tectonic activity and rapid erosion. These gorges are formed by the relentless force of rivers cutting through the uplifted mountain ranges, showcasing the youthful nature of the Himalayas.
• U-Turn River Courses: Many rivers in the Himalayan region exhibit U-turn or meandering courses, a result of the active tectonic processes uplifting and deforming the landscape. These meanders are indicative of ongoing geological changes and the youthful nature of the mountain range.
• Parallel Mountain Ranges: The Himalayas consist of parallel mountain ranges running in a northwest-southeast direction. This parallel alignment suggests recent uplift and folding processes, characteristic of a young fold mountain range.
• Steep Gradients and Landslides: The steep gradients of the Himalayan slopes, combined with the ongoing tectonic activity, result in frequent landslides and rockfalls. These events are common in young fold mountains where the slopes are still adjusting to the uplift processes.
• Frequent Earthquake Occurrence: The Himalayas experience frequent earthquakes due to the ongoing collision between the Indian and Eurasian tectonic plates. These seismic events are evidence of the active tectonic processes shaping the landscape and indicate the youthfulness of the mountain range.
• Youthful Rivers: The rivers originating from the Himalayas, such as the Ganges, Brahmaputra, and Indus, exhibit youthful characteristics, including swift currents, steep gradients, and narrow valleys.

• Himalayas: The Himalayas are susceptible to landslides due to both natural and anthropogenic factors.
  • Naturally, their tectonic activity, caused by the drifting Indian plate, leads to frequent earthquakes and instability. Moreover, their composition of sedimentary rocks and unconsolidated deposits exacerbates this vulnerability.
  • Additionally, the steep slopes of the Himalayas, combined with heavy snowfall in winter and subsequent melting in summer, induce debris flow, which is further intensified by numerous streams and rivers.
  • Anthropogenic activities such as shifting cultivation, dam construction, and tunnel excavation also contribute to the increased risk of landslides in the region.
• Western Ghats:
  • In the Western Ghats, landslides are more prevalent on the steep slopes of the western side, where high rainfall creates ideal conditions for instability. However, the gentler eastern slopes, characterized by lower rainfall and mature river systems, are less prone to landslides.
  • Unlike the Himalayas, the Western Ghats experience fewer earthquakes as they are situated on a more stable part of the Indian plate.

The relationship between the shrinking Himalayan glaciers and climate change in the Indian subcontinent is evident through various symptoms:

• Increased seasonal melting and higher water discharge from Himalayan rivers, combined with intensified rainfall, result in more frequent and severe floods in Northern India, such as the floods in Uttarakhand.
• There is a likelihood of an increase in Glacial Lake Outburst Floods (GLOFs) due to the shrinking glaciers.
• Erratic water flow during the summer months leads to drought-like conditions, impacting agricultural productivity and food security.
• Current trends indicate that rivers like the Ganges and other Himalayan rivers may become seasonal, posing significant challenges for agriculture, food security, and employment opportunities for millions of people.
• The melting of glaciers has also contributed to an increase in avalanches and landslides in the region.
• The melting ice from glaciers contributes to the rise in sea levels, which in turn increases the frequency of tropical cyclones in the region.
• Biodiversity in the Himalayan region is disturbed and vulnerable to extinction due to the changing climate and habitat loss.

• The National Action Plan on Climate Change (NAPCC) is India’s domestic plan for ecologically sustainable development to be implemented with her own resources. Eight national missions have been recommended for implementation, in the NAPCC in which one of the missions is National Mission for Sustaining Himalayan Eco-system (NMSHE).

The mission would attempt to evolve management measures for sustaining and safeguarding the Himalayan glaciers and mountain ecosystem by:

• Enhancing monitoring of Himalayan ecosystem with a focus on recession of Himalayan glaciers and its impact on river system and other downstream socio-ecological processes.
• Establishing observational and monitoring network to assess ecosystem health including freshwater systems.
• Promoting community-based management through developing mechanisms for incentives for protection and enhancement of forested lands.
• Strengthening regional cooperation through established mechanisms for exchanging information with countries sharing the Himalayan ecology

The Himalayas stand as a testament to the awe-inspiring power of nature and the enduring resilience of human spirit. From their towering peaks to their lush valleys, the Himalayas captivate the imagination and inspire a sense of wonder in all who encounter them. However, as we marvel at their beauty, we must also recognize our responsibility to protect and preserve this fragile ecosystem for future generations to cherish and enjoy. Only through collective action and sustainable practices can we ensure that the Himalayas continue to enchant and inspire for centuries to come.