Question

why Shiwaliks
are more prone to earthquake and landslides

Answer 1

Shiwalik is made up of unconsolidated sediments and is the lowermost part of the Himalayas is found near river valleys which erodes the soil and hence prone to landslides. It is also located near the boundary of a tectonic plate and hence more prone to earthquake.

Answer 2

The shiwaliks ranges are still in the process of folding. This is the the youngest range of the Himalayas formed by unconsolidate rock material. Therefore these ranges are prone to earthquake and landslides.