Geomorphology is the study of landforms, their processes, form and sediments at the surface of the Earth (and sometimes on other planets). Study includes looking at landscapes to work out how the earth surface processes, such as air, water and ice, can mould the landscape. Landforms are produced by erosion and deposition, as rock and sediment is worn away by these earth-surface processes and transported and deposited to different localities. The different climatic environments produce different suites of landforms. The landforms of deserts, such as sand dunes and ergs, are a world apart from the glacial and periglacial features found in polar and sub-polar regions. Geomorphologists map the distribution of these landforms so as to understand better their occurrence.

Earth-surface processes are forming landforms today, changing the landscape, albeit often very slowly. Most geomorphic processes operate at a slow rate, but sometimes a large event, such as a landslide or flood, occurs causing rapid change to the environment, and sometimes threatening humans. So, geological hazards, such as volcanic eruptions, earthquakes, tsunamis, landslides, fluvial deformation etc. fall within the interests of geomorphologists. Advancements in remote sensing from satellites and GIS mapping as well as modelling techniques have benefited geomorphologists greatly over the past few decades.

Geomorphology is a diverse discipline and the basic geomorphological principles can be applied to all environments. Various areas of geomorphology include: (i)glacial and periglacial geomorphology,(ii) fluvial geomorphology, (iii)aeolian (desert) geomorphology, (iv) volcanic and tectonic geomorphology, and even (iv) planetary geomorphology. Most research is multi-disciplinary, combining the knowledge and perspectives from contrasting disciplines, combining with subjects as diverse as civil engineering,ecology, geology,sedimentology, seismology, hydrology andhydraulics, morphodynamics, soil scienceetc.

(Remark: Adapted from website of British Society for Geomorphology)

Geomorphology of Nepal

Nepal is a mountainous country with tremendous geographical diversity despite the relatively small size of the country. Within a distance of 200 km from South to North, the topography in Nepal ranges from 60 masl (meters above sea level) in the plains to 8,848 masl at Mount Everest, the highest peak in the world.  The southernmost portion of the plains is called the Terai (an extension of Indo-Gangetic plain). Nepal comprises five mountain ranges – Chure (Siwaliks), MahabharatLekh,  Pahad (Midhills), High Mountain (temperate Lekh) and High Himal, formed in different geological time.

Nepal’s High Himal is occupied by snow and ice where glacial and periglacial processes have dominated. Fluvial processes have shaped the middle mountains and Terai whereas the northern trans-Himalayan region, such as Mustang, tends toward arid or semi-arid climate. In some areas, like Pokhara, karst topography is common.

Nepal represents diverse physiographic and morphogenetic regions due to active tectonics, complex geological formations, high altitudinal differences, and the multi-directional orientation of mountain ranges. As a result, several features predominate by region:

Region Features Cause(s)
Terai/Bhabar

Avulsion

Bank erosion

Braiding of rivers

High sediment loads

Flooding

 Heavy precipitation, deforestation, infrastructure development including river bed sediment abstraction without due consideration of geomorphic processes
Chure Landslides, intense soil erosion, gullies, fans, aggradation, river bank erosion, braiding of rivers, avulsion Weak geology, high relief, heavy precipitation, deforestation, infrastructure development including river bed sediment abstraction without due consideration of geomorphic processes
Mahabharat Lekh Landslides, erosion, debris flow Cloud burst, land use and land cover change
High Mountain Landslides, erosion, debris flow, landslide dam and landslide dam outburst floods High relief, cloud burst, land use and land cover change
High Himal Avalanche, glacial and periglacial landforms and processes, glacial lake outburst flood, bare ground Climate change – melting of snow and ice, degradation of ground ice

These various features by region place constraints on irrigation and hydropower development in Nepal. These natural geomorphic processes are further intensified due to unplanned human activities such as changes in land use and infrastructure development (e.g., roads, bridges, culverts). It is also expected that climate change will exacerbate these conditions through warming temperatures and a significant rise in severe weather events.

In this context, appropriate geomorphological knowledge is crucial for sustainable development. Realizing the need for a platform to improve our understanding of geomorphology through research and dissemination of geomorphic knowledge, the Geomorphological Society of Nepal (GSN)has been formed, registered with the Government of Nepal on 18 June 2017 AD (2074/03/05 BS). Our registration number is 1162

Ongoing and proposed activities for 2017/18

  1. Preparing an inventory of geomorphologists and their contributions in Nepal;
  2. Collecting, compiling, and documenting relevant literature, publications, and photographs on geomorphological work in Nepal;
  3. Conducting field work to investigate and study geomorphic events;
  4. Organizing workshops for sharing experiences and preparing workshop proceedings;
  5. Publishing the Journal of Geomorphological Society of Nepal: Landform and Processes
  6. Networking with relevant experts and institutions both inside and outside Nepal