♦ The study found that the region once experienced large floods that rose much higher than the current river level.
♦ It implies that in the event of global warming, when the higher Himalaya regions are expected to respond dramatically, the frequency of floods in Ladakh may increase, necessitating serious urban and rural planning.
♦ Large floods that occur naturally in major rivers in India fed by melting snow and glaciers, as well as a continental scale precipitation regime of Indian Summer Monsoon (ISM) and Westerlies, and East Asian Summer Monsoon (EASM), significantly alter the landscape and impact the lives and economies of all that encroach on its geomorphic domain.
♦ These floods are of various types and origins (glacial/landslide lake outbursts, cloud bursts, excessively strong monsoon) and have varying forcing factors and frequencies, adding significant uncertainty to flood prediction models.
♦ The researchers travelled through the difficult terrains of the Zanskar and Indus drained Himalayas, looking closely at geological signatures of past floods in the Ladakh region that date between 15 and 3 thousand years ago.
♦ Floods leave a stack of fine sand and silts along their channel where the flood energy is drastically reduced, such as wider segments of river valleys, confluences, and behind rock embayments, which are known as Slack Water Deposits (SWDs).
♦ The SWDs were placed at various points along the Zanskar and Indus rivers, counted vertically for the number of floods, and dated using Optically Stimulated Luminescence (OSL) and Accelerator Mass Spectrometry of 14C.