KARACHI, July 30: Establishment of dams and barrages on the River Indus, besides an increase in the consumption of water in the northern plains of the country the in last few decades, is a major cause of the reverse flow of seawater causing disruption in the ecosystem, land degradation and conversion of cultivatable land into barren fields.

This was said by Naureen Aziz Qureshi of the Centre of Marien Biology, University of Karachi, while addressing a seminar on “Sea-water Intrusion: Prevention and Mitigation Measures” at the Institution of Engineers Pakistan (IEP) hall here on Tuesday.

The seminar was organized by the IEP Karachi centre in collaboration with the Society of Economic Geologists and Mineral Technologists (SEGMITE) and the Association of Geo-scientists for International Development (AGID).

Dr Naureen informed that owing to the decreased release of fresh water into the River Indus, the reverse flow of seawater in the southern parts of Sindh had resulted in the contamination of sweet water aquifer, besides adding to salinity of irrigated lands.

“ The inadequate release of fresh water in Indus downstream of Kotri is a major cause of seawater intrusion which, combined with the raised level of the Arabian Sea has made Thatta, Badin and Southern parts of the Hyderabad district waterlogged marshlands,” she said.

She said that owing to the imbalance in fresh-salt water, the coastal belt of Thatta and Badin, spread over thousands of acres, had been badly disrupted and vast areas of both the districts had become barren. She added that seawater intrusion had halted the growth of mangroves forests.

“If the proposed Kalabagh Dam is built on the River Indus, the sea water intrusion will completely destroy the fertile areas of Thatta, Badin, Sanghar, Nawabshah and the adjoining districts,” she said.

The seminar was followed by a panel discussion and the scientists evolved detailed recommendations to check seawater intrusion. They stressed the need for carrying out geological and oceanographic studies to better understand the issue, including determining the rate of sedimentation and erosion in the Indus delta, monitoring of the south-west monsoon, analyzing sediment distribution and its correlation with the growth of mangroves. They also underlined the need to conduct topographic surveys of coastal and mangrove forests, marine resources, hydrographic and hydro-geological studies and soico-economic communities.

The panelists also felt the need for creating mass awareness regarding conservation of fresh water and urged the government to have a check on over-extraction of underground water in coastal areas of Sindh.

A committee was also formed under the chairmanship of Rear Admiral E.M.I Arshad and Dr Viqar Hussain from KU as its conveyor, to prepare a comprehensive project proposal for submission to international donor agencies through the government of Sindh. A large number of participants from public and private organizations attended the seminar.—PPI