Just normal rainfall indicates looming water woes

Nellore: Andhra Pradesh witnessed a normal rainfall activity during the monsoon season last year indicating measures-needed to be taken for conservation of water resources to meet the demand for the ensuing summer season.

Only two districts out of 26 recorded 40 to 50 pc of excess rainfall and the remaining districts recorded only normal rainfall. Overall average excess rainfall thus recorded in the State is only 2.6%.

Experts in the hydrology department indicate that there could be depletion in water table if severe hot days are experienced during summer and this could trigger water woes. The government must consider measures for resolving them.

Further, nine districts still fall under deficit-rainfall category, according to weather data.

Nellore is having a deficit rainfall of 1.9% while only Anantapur and Sri Satya Sai districts have recorded excess rainfall between 40% and 49%. Further, districts such as Srikakulam, Visakhapatnam, Anakapalli, Krishna, NTR, Prakasam, Nellore, Nandyal and Tirupati recorded deficit rainfall even after showers during both Southwest and Northeast monsoons.

Nellore has received a deficit rainfall of 43% in 2016, 60% in 2018 and over 40% in 2019.

But in 2020, it recorded 51% excess rain due to active monsoon. In 2021, weather systems played havoc and the excess rainfall situation forced the release of huge volume of water from the reservoirs resulting in floods in many areas close to River Penna.

Studies have been conducting on the changing trend of weather in AP. Analysis based on the recent 30 years of data from 1989 to 2018 on rainfall pattern indicates that AP receives maximum rainfall only during the South West Monsoon in the month of August (28 %).

Next comes September with a rainfall of 27.7%, followed by July 25.3% June 18.9%. Prakasam, Guntur and Nellore districts showed a significant decreasing trend when annual rainfall data is considered.

Analysis on annual frequency of rainy days indicates that northern districts and some parts of Chittoor and Nellore record 45 to 61 rainy days, followed by Prakasam and some parts of the Nellore, Kadapa and Kurnool districts with 40-45 rainy days. Anantapur district recorded the lowest number of annual rainy days of 35 to 40 during the last three decades.

Data also indicated that last year only four districts such as Kakinada, Bapatla, Anantapur, and Sri Satya Sai received seasonal excess rainfall between 20% and 45%.

"The happiest thing is there are no large excess or large deficit districts in the State during the last monsoon season. Government must monitor water table constantly and should take measures for resolving possible water problem during summer," said Dr Venkateswara Rao, a retired hydrologist from Nellore.