1. Greater Himalayas (Himadri): This northernmost range includes some of the world's highest peaks, including Mount Everest (8,848 meters or 29,029 feet), the tallest mountain on Earth. It serves as the natural border between Tibet and Nepal.

2. Lesser Himalayas (Himachal or Himachalaya): Just south of the Greater Himalayas, this range consists of lower peaks and valleys. It is known for its lush forests, diverse flora and fauna, and terraced farming. Many popular hill stations in India, such as Shimla and Manali, are located in this range.

3. Shiwalik Range (Outer Himalayas): This range lies to the south of the Lesser Himalayas and acts as a transition zone between the mountains and the plains. It is characterized by rolling hills, foothills, and river valleys. The Shiwalik Range is rich in minerals and fossil deposits.

4. Purvanchal Range: Also known as the Eastern Hills, this range extends eastward from Nepal through northeastern India and into Myanmar. It is characterized by rugged terrain and dense forests.

5. Zanskar Range: Located in the western Himalayas, this range lies in the Ladakh region of India. It is known for its remote and challenging terrain, as well as its cultural significance to the local people.

6. Dhauladhar Range: This range is a part of the Lesser Himalayas and is located in the Indian state of Himachal Pradesh. It is known for its snow-capped peaks and picturesque landscapes.

7. Karakoram Range: While often associated with the greater Himalayas, the Karakoram Range is actually a separate mountain system. It lies to the northwest of the Himalayas and is known for some of the world's highest peaks, including K2 (8,611 meters or 28,251 feet).

8. Hindu Kush Range: This range is located to the west of the Himalayas, spanning across Afghanistan and northern Pakistan. It is less known than the Himalayas but still holds significant geological and cultural importance.

• According to scientific experts, the construction of dams on the Ganga river, encroachment on its riverbed, and mining operations in the area are causing significant detrimental effects on the region
• A public forum dedicated to the preservation of the sacred Ganga river, reports that a total of 244 dams are currently under construction along the river’s course
• It is worth noting that only three dams were halted following the declaration of a 100-kilometer segment, extending from the glacial source at Gaumukh to Uttarkashi town, as an eco-sensitive zone (ESZ) in December 2012
• The Centre for Science and Environment (CSE), located in New Delhi, has also established a connection between the disaster and the approach to development used in this unique location
• At present, there exist approximately 70 ongoing or planned projects along the Ganga river, with the objective of producing an estimated 10,000 megawatts (MW) of electricity. The model was characterised as “bumper to bumper development”, wherein projects are undertaken in rapid succession without any gaps in between
• Balancing development with environmental conservation is a crucial challenge that societies worldwide must address.
• While development is essential for improving living standards, economic growth, and social well-being, it should not come at the expense of the environment.
• Sustainable development seeks to harmonize these two goals, ensuring that the needs of the present are met without compromising the ability of future generations to meet their own needs. 

Pros:

• Renewable energy source: Hydropower does not produce greenhouse gas emissions, making it a clean and sustainable energy source.
• Reliable source of electricity: Hydropower plants can provide a reliable source of electricity, even during times of peak demand.
• Economic benefits: Hydropower projects can create jobs and boost the economy.
• Water supply: Hydropower projects can help to regulate water flow and provide water for irrigation and drinking.

Cons:

• Environmental impact: Hydropower projects can have a negative impact on the environment, such as by displacing people, disrupting ecosystems, and causing flooding.
• Cost: Hydropower projects can be expensive to build and maintain.
• Safety: Hydropower projects can be a safety hazard, especially during times of flooding.

Here are a few notable hydropower projects in the Himalayan region:

1. Sardar Sarovar Dam (Narmada River, India): While not located in the core Himalayas, the Sardar Sarovar Dam is one of the most controversial and large-scale dam projects in India. It involves the Narmada River and has led to displacement of communities, ecological disruption, and concerns over the dam's overall benefits.

2. Bhakra-Nangal Dam (Sutlej River, India): This is one of the oldest and largest multipurpose dams in India, located in the Sutlej River basin. It provides irrigation, drinking water, and hydropower to the region but also resulted in environmental and social impacts.

3. Run-of-the-River Projects (Various Rivers, Nepal): Nepal has been pursuing several small-scale run-of-the-river hydropower projects to meet its energy needs. These projects aim to minimize the environmental and social impacts associated with large dams.

4. Upper Tamakoshi Hydroelectric Project (Tamakoshi River, Nepal): This is one of Nepal's largest hydropower projects, designed to generate electricity and contribute to the country's energy self-sufficiency. It has faced delays and challenges related to construction and financing.

5. Kishanganga Hydroelectric Plant (Kishanganga River, India): Located in the state of Jammu and Kashmir, this project aims to harness the water resources of the Kishanganga River. It has led to diplomatic tensions between India and Pakistan due to water-sharing disputes.

6. Chukha Hydroelectric Plant (Wangchhu River, Bhutan): Bhutan has been developing hydropower as a significant source of revenue and clean energy. The Chukha Hydroelectric Plant was one of the country's earliest and most significant projects.

7. Gyama Hydropower Plant (Indus River, Tibet, China): China has been investing in hydropower development in its Tibetan regions. The Gyama Hydropower Plant is one example of such projects aimed at tapping into the region's water resources.

8. Diamer-Bhasha Dam (Indus River, Pakistan): This proposed dam project in Pakistan aims to provide water storage, irrigation, and hydropower generation. However, it has raised concerns about its environmental and social impacts, including displacement of communities.