Kochi: Floods gone, now time for drought

Kochi: Climate change scientist Dr C.G. Madhusoodanan, who was with IIT Mumbai, conducted a study on the implications of disastrous floods in August last and warned severe drought in state this year.

As per the study, there were disturbing indicators that forewarn the possibility of a severe drought. The report was submitted to the Chief Minister and other ministers concerned and government department heads seeking immediate measures to address the crisis.

In the study report titled ‘Can floods lead to drought?  After the flood, severe drought looming over Kerala’ prepared by Dr Madhusoodanan and K.G. Sreeja, the probable reasons for advancement of drought immediately after the floods based on the unique hydrology of the Western Ghats were analysed. The report has also outlined the possible methods to alleviate the severity of an imminent drought.

“After the monsoon, water availability in a region is dictated by a process which holds water in soil and makes it available through discharge into streams/ rivers/ groundwater flow. From December to May (the rainless...period) the active soil water storage releases water to streams until the storage is exhausted. This year, the active soil water storage is fast depleting due to the enlarged soil pipes and massive loss of stored soil water due to landslides and extensive destruction of riverbank and riverine vegetation. This will lead to severe drought,” said Dr Madhusoodanan. Soil pipes are the sub surface tunnels through which water drain faster than through the soil matrix.

It is the active soil water storage which normally helps to tide over the rainless period.

The discharge from the soil pipes into the stream/ river channels along the banks is regulated by riparian vegetation which plays a crucial role in controlling the discharge velocity of stream flow. The vegetation has been completely wiped out by torrential floods, landslides and by the sudden massive release of water from dams. Absence of the vegetation results in uncontrolled release of sub-surface water into rivers, accelerating depletion of active soil water storage.

“The severity of the drought will vary from place to place depending upon the region’s hydro-geology,” he added.