Past Is the Key to the Present
Rahul Verma
Published: October 01, 2021.
Abstract
The title of my write up may surprise you a bit. But the fact is that the present day geo-environmental scenario is totally a repercussion of the events that took place in the past. I will site two examples only, considering the limit of the write up.
The first example is the flooding in the river Brahmaputra during monsoon and post monsoon times. The mighty Brahmaputra creates havoc in Arunachal and Assam. The present-day floods are due to the plate collision phenomena that took place since Miocene times. The Indian plate is still subducting under the Eurasian plate and we all know that Himalaya is still rising. This event gave rise to the Geosynclinal set up in the region. The prominent lithology on either side of Brahmaputra is consisting of sedimentary rocks of Tertiary Era. The mighty Brahmaputra passes through these sedimentary terrains. These sedimentary rocks viz. Sandstone, Shale and Siltstones are very prone to erosion. A huge amount of eroded sediments is carried through the tributaries of Brahmaputra and ultimately, they are deposited in the riverbeds. The situation is analogues to the story of the thirsty crow’’ who was putting pebbles in the pot to raise the level of water. The same situation is practically found in the Brahmaputra riverbed, that gets over flooded due to the excess sediment load in the basin. Needless to say, that if we have to control the floods in Assam valley, we must take measures to check erosion in the upper reaches of the Brahmaputra and its tributaries by vigorous plantation, check dams etc.