Solution:The flat plains along the sub-Himalayan region in North India, are called Bhabar. It is a narrow belt only 8 to 16 kms in width and lying parallel to the Shiwalik foothills at the break-up of the slope.This zone is studded with pebbles and it consists of porous beds which have been laid down by the numerous streams as they descend down the hills. The porosity is so high that all streams lose themselves in the Bhabar.
South of the Bhabar is the Tarai belt, with an approximate width of 15-30 km where most of the streams and rivers re-emerge without having any properly demarcated channel, thereby, creating marshy and swampy conditions known as the Tarai. This has a luxurious growth of natural vegetation and houses a varied wildlife.