অক্টোবর 04, 2012
Half a year on, scientists are starting to understand the ecological impact of Pakistan’s devastating floods – and it’s a mixed bag. Zofeen T Ebrahim reports.
Five months ago, floods triggered by torrential rains submerged one-fifth of Pakistan, killing 2,000 people and destroying the property, livelihoods and infrastructure of millions. Now, the waters have receded – and with them the media’s attention. But for many environmentalists, like Ghulam Akbar, senior director at WWF, work has only just begun.
WWF-Pakistan, in collaboration with its partners (including provincial forest, fisheries, irrigation and wildlife departments) has initiated a comprehensive assessment of the damage caused by the deluge in four sites in the Indus basin. Teams comprising zoologists, plant ecologists, taxonomists, fisheries specialists, water-quality scientists, reptiles and amphibians experts, along with experts in geographical information systems (GIS), have gone into the field to survey the impacts.
In the mountainous region of the north, in places like Swat valley in Khyber Pakhtunkhwa province – where the floods originated – landslides not only washed away coniferous forests but also denuded the fertile top soil. “This loss of soil cannot be replenished even over decades,” laments Akbar. The loss of forest cover and soil in turn allowed the nesting places of large and small mammals to be washed away, while displaced bird species were forced to re-locate.
Swat was a storehouse for huge quantities of timber belonging to the government. “All of it was washed away by the deluge and the government incurred huge losses,” says Tahir Qureshi, a forester and expert on coastal ecosystems working with the International Union for Conservation of Nature (IUCN). He fears more forests will be cut to compensate for the loss.
As for the impact on wildlife, Akbar says that birds and animals kept in captivity suffered the worst hit. “All the animals and birds as well as 24 black bears in the Kund Park, along River Kabul in the Khyber Pakhtunkhwa province, which had a bear rehabilitation centre, were taken away by the flood,” he says.
According to Hussain Bux Bhagat, a conservationist associated with the provincial wildlife department of Sindh province, wildlife in the riverine forests – including birds, reptiles and mammals – also suffered severely: “The floods were a death blow for the hog deer and grey and black partridges and we fear their populations may have been reduced by between 30% and 40%.” In particular, high numbers of grey partridge, which nests on trees and doesn’t leave its habitat, “starved to death”, he says.
In addition, natural springs in the hilly areas have been destroyed, while water quality has deteriorated and may take some time to normalise.
Further south, on the Indus plain, the nature of the damage was somewhat different, though nonetheless serious, as the river banks were eroded, causing damage to protected areas situated either inside or along the River Indus.
The drifting of between 60 and 100 endangered Indus River dolphins into shallow water was a serious loss. “In all, there are an estimated 1,200 to 1,300 blind dolphins left in the River Indus and 950 in the dolphin reserve between Guddu and Sukkur barrages,” says Bhagat. “In January, when the de-silting of canals take place, we usually carry out rescue of dolphins that have strayed into canals during that period. So far, no dolphins have been reported dead.”
Among the many lessons offered by June’s disaster, the most glaringly obvious is the need for better flood-plain management. Around the world, says Akbar, flood plains are properly managed to preserve local ecology and to save precious human life and property from natural calamities like floods.
Since the time of the British occupation, protective embankments have been constructed at distance of about 15 to 20 kilometres along either side of the River Indus. But with changes in weather patterns caused by global warming, the severity and frequency of storms and floods will increase, rendering “these protective embankments counterproductive”, says Nasir Panhwar, executive director of Hyderabad-based Centre for Environment and Development. He says “more sophisticated techniques” based on proper and holistic understanding of the workings of global weather conditions, the rivers and coast are needed.
Pakistan’s flood plains are state-owned and, historically, were covered by dense riverine forests. But over the years, due to decrease in downstream river water, poor law enforcement and weakening of government institutions, the forests were illegally occupied and denuded, replaced by rich agriculture land for growing cash crops like bananas, vegetables and sugarcane.
The absence of a credible land-use plan has been underlined by the summer’s floods. According to Akbar, anyone can construct a building, cultivate land or establish housing project anywhere. “In hilly areas and even in the plains, multi-storied buildings were constructed right at the edge of river banks. Similarly, steep slopes had been brought under cultivation, which is [an] extremely vulnerable [state].” Panhwar adds: “Lack of an explicit land use policy resulted in inhabitants along the rivers taking advantage of these areas.”
Flooding is both bane and boon for local ecosystems, however, and the recent deluge has brought benefits as well as tragedy: the brackish Lake Manchar (in Sindh province) has turned into a freshwater lake again, says Akbar, while all saline and saline-sodic soils submerged by the flood are now salinity-free and have become productive soils. “[The flood] has given the mangrove and the riverine forests a new lease of life, as the fresh water and silt deposition will help both the natural artificial regeneration,” adds Qureshi of the IUCN.
In addition, aquatic biodiversity all over the Indus plain has increased: “The floods have been a boon for dolphins and freshwater turtles,” Bhagat says. Akbar adds: “One can find fish species in the Sindh region which were never found earlier in those areas. The same is the case with plants. New plant species are appearing due to dissemination of seeds from upstream to downstream areas.”
The land lost to sea intrusion has been recovered in the deltaic region; due to the deposit of millions of tonnes of silt brought by the flood, new mud-flats have appeared that will benefit the mangrove forests. Moreover, the riverine belt is almost free from encroachers: “The challenge for the provincial governments would now be to prevent future encroachments on riverbeds,” says Panhwar.