KARACHI: Seawater intrusion has reached alarming levels and is playing havoc with human life in the coastal areas of Sindh, where a vast majority of the population is deprived of potable water, losing sources of livelihood and is forced to migrate to other places due to increasing salinity.

These were some of the important points highlighted at an international workshop on seawater intrusion, affecting coasts, ecosystems and livelihoods, organised by the National Institute of Oceanography (NIO) at a local hotel on Tuesday.

Underlining the need for immediate intervention to address sea intrusion, Saeed Ahmed Bablani of Sindh University’s centre of geology said that seawater had intruded fresh groundwater and had polluted the whole aquifer system in Thatta district.

“Out of the over 1.2 million population of Thatta district, 70pc people are deprived of potable water. Surface water is not available even near the coast and people are bound to purchase water for their basic needs,” he said, adding that seawater had intruded as far as 30km inland and up to 50km in water channels, making thousands of acres of farmland saline.

As the groundwater had turned saline, he pointed out, salts had also come to the surface and surface salinity had increased, making the land unfit for cultivation or even growing natural grasses and vegetation.

Giving an example of Kharo Chhan taluka, Thatta district, he said that seawater had devastated the area by inundating 8,300 hectares of land, rendering it unfit for cultivation or any other use.

“Eighty-six per cent of land in the district has been taken over by the sea over the past four to five decades. In another Thatta area, Ghora Bari, 14 of the 61 dehs have been damaged. This has resulted in a loss of 15,800 hectares, or 34pc of the total area of the taluka,” he told the audience.

About the situation in Keti Bundar, another coastal area worst hit by sea intrusion, he said, the seawater had completely engulfed 28 of the 43 dehs over the last 40 years, and 15 of the dehs had been partially damaged. The total area affected by seawater intrusion is 46,137 hectares.

The entire situation, he said, was leading to an increased unemployment, low productivity, illiteracy and violence and crime. No lucrative trade in the region was left and people continued to migrate to other places for their livelihood.

He called for increasing the flows downstream Kotri barrage and said that the water acted as a natural barrier against the intruding seawater.

Pro-Vice Chancellor of Sindh University Sarfraz Hussain Solangi in his presentation presented some measures to tackle sea intrusion that included relocation of pumping wells, use of subsurface barriers, natural or artificial recharge and abstraction-desalinisation recharge.

Giving a presentation on the Indus delta — options for a marine protected area (MPA), Dr Samina Kidwai of the NIO said eight sites had been identified to be declared as an MPA.

“The Indus delta, as a whole or some selected parts, can be considered for an MPA because of unique estuarine and hyper-saline habitats having mangroves, mudflats and sandy shore with distinct fauna and flora,” she said.

The decrease in freshwater flows, she said, had led to a loss of sediment, increased subsidence, rapid local relative sea-level rise, inland intrusion of seawater and decreased biological productivity and biodiversity.

Additional secretary of the ministry of science and technology Abid Hussain, Dr Huan Daji and Prof Xu Dongfeng of the Second Institute of Oceanography in China, Dr Shahid Amjad of the Institute of Business Management, Dr Haider Hasan of the NED University of Engineering and Technology and Dr Nuzhat Khan of the NIO also spoke.

Published in Dawn, October 21st, 2015

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