GS Question

The Himalayas and the Western Ghats are both mountain ranges, but there are several factors that contribute to the more frequent occurrence of landslides in the Himalayas compared to the Western Ghats. Additionally, the absence of delta formation by rivers in the Western Ghats can be attributed to specific geological and environmental conditions.

Causes for more frequent landslides in the Himalayas:

1. Tectonic activity: The Himalayas are located in a seismically active region. The collision between the Indian and Eurasian tectonic plates is ongoing, leading to constant geological forces that contribute to the instability of the mountain slopes and an increased likelihood of landslides.

2. Steep and rugged topography: The Himalayas are characterized by steep slopes, deep valleys, and rugged terrains. This rugged topography makes the slopes more prone to erosion and instability, enhancing the chances of landslides.

3. High precipitation and snowfall: The Himalayas receive high amounts of precipitation, including heavy monsoon rains and intense snowfall during the winter months. The excess water weakens the soil and rocks, making the slopes more susceptible to landslides.

4. Glacial melting: The Himalayan region contains numerous glaciers, which are melting due to global warming. The melting ice and increased water runoff from glaciers contribute to an increase in landslides by further destabilizing the slopes.

Causes for the absence of delta formation in Western Ghats rivers:

1. Relief and slope: Unlike the Himalayas, the Western Ghats have relatively gentle slopes and less rugged terrains. The rivers flowing through the Western Ghats do not encounter the steep gradient required for significant sediment deposition, which is necessary for the formation of deltas. The sediments carried by the rivers tend to get distributed and deposited along the lower slope areas instead.

2. Shorter river courses: The rivers in the Western Ghats tend to have shorter courses compared to those in the Himalayas. The shorter courses limit the distance over which the rivers can transport sediments and therefore restrict the opportunities for delta formation.

3. Type of rocks and geology: The Western Ghats are predominantly composed of hard and resistant rock formations, such as granite and gneiss. These rocks erode at a slower pace compared to the softer rocks found in the Himalayas. As a result, the erosion in the Western Ghats is not sufficient to create significant sediment loads required for the formation of deltas.

4. Coastal dynamics: The Western Ghats have a relatively narrow coastal plain. The low gradient coastal areas do not offer extensive opportunities for the rivers to build deltas, as the sediment transport is influenced by the balance between the river inputs and coastal currents.

Therefore, the combination of geological, topographical, and environmental factors contributes to the more frequent occurrence of landslides in the Himalayas compared to the Western Ghats. Similarly, the absence of delta formation in Western Ghats rivers can be attributed to the specific geological characteristics and limited sediment transport opportunities in the region.