Someone tell that stupid and ill logical women ...
Sea water is threat to Indus Delta along the coastal area in Sindh.
Seawater Intrusion in the Indus Delta and Associated Hazards
- Pervaiz Asghar
- July, 2016
- 106
- Environment
Seawater intrusion into the once-fertile Indus Delta has unfortunately become a way of life, simply because almost everyone not directly impacted by this phenomenon has started taking it for granted and very few are willing to do anything about it. This has resulted in substantial damage to the ecology and biodiversity of the environment, as well as the regional economy and more specifically, the livelihood of the local inhabitants.
The Indus Delta, which is 150 kms wide at its mouth and covers almost 85% of Sindh's coastal belt, is the most prominent ecological feature of the coast east of Karachi. It comprises 17 major creeks and numerous minor creeks, all intermingling with mangrove forests in the creek pockets, as well as expansive mudflats. .
Cash crops like rice and wheat used to be grown here in abundance and though the percentage of people deriving income from farming has dwindled to barely 20%, this source is coming under increasing strain from the twin scourges of water-logging and salinity, exacerbated by the influx of seawater. .
This degradation has been precipitated, amongst other associated factors, by the gradual ingress of seawater, some 70 kms inland by some estimates, during the past 30 years. The reasons for this are threefold: drastically reduced waterflows downstream of Kotri, dwindling mangrove cover and overall seawater rise due to global warming. .
Although the Water Apportionment Accord of 1991 guarantees the release of 10 MAF of Indus water into the delta, the same could not be implemented in practice, simply because this requirement has been relegated to the lowest possible priority. For nine months of the year, hardly any water-flow can be seen in the delta. During the 6 month long Rabi season in particular, there is virtually zero flow below Kotri for five-sixths of the time. The problem is aggravated by the fact that hardly 10% of the 12000-plus watercourses that constitute the irrigation infrastructure downstream of Kotri are lined, which enables water seepage to further deplete the availability of water at the tail end. .
The coast of Sindh, notably the Indus Delta, hosts the largest arid climate mangroves in the world. It is a sad commentary on our part that these mangrove forests, which are beneficial on many counts, are being deforested at an alarming rate, despite the best efforts of certain concerned organizations to arrest this trend by planting more saplings. The reasons are not hard to find: negligible supply of fresh water to the delta, ever-increasing volumes of untreated sewage and industrial effluents drained into the sea and extensive land reclamation and clearance projects as well as its attendant construction work. Unless these root causes are addressed, simply planting more saplings may not work to any appreciable extent. .
A mangrove forest is nature's gift to the coastal environment. Apart from acting as a bulwark against natural disasters, it serves as a life-sustaining eco-system for nourishing all types of flora and fauna. It is also a valuable source of nutrients as well, for both freshwater and marine fisheries. Their roots provide a natural protection against coastal erosion, retarding the process through their ability to hold the soil together by trapping suspended particles. The lack of a natural seawater flushing mechanism, so vital for preserving their health, has resulted in wiping out all the less salt-tolerant species. 98% of whatever mangroves remain in the Indus Delta constitutes of the most salt-tolerant variety, referred to as Avicenna Marina. Even this variety cannot flourish for long without being regaled by freshwater inputs. Freshwater flushing serves the added purpose of removing pollutants from the industrial effluents being discharged untreated into the sea, they without which toxify the coastal environment. .
The ever-increasing global carbon emissions have given rise to global warming and an alarming rise in sea levels. In the last hundred years or so, sea levels have risen more than during the past 2000 years and, if carbon emissions are not capped, could rise to double as much within just the next two decades. The harmful impact of this rise is most felt along the flat topography of the Indus Delta, which is hardly in a position to keep it at bay.