Instrução: Leia o texto para responder à questão.
Drought brings Amazon tributary to lowest level ∈a century
26 October 2010.
One of the most important tributaries of the Amazon river has fallen to its lowest level ∈ over a century, following a fierce drought that has isolated tens of thousands of rainforest inhabitants and raised concerns about the possible impact of climate change on the region.
The drought currently affecting areas of Amazonia has been described as the one of the worst ∈ the last 40 years, with the rio Negro or Black river, which flows into the world-famous rio Amazonas, reportedly hitting its lowest levels since records began ∈l902 on Sunday. In 24 hours the level of the rio Negro near Manaus ∈Brazil dropped 6cm to 13.63 metres, a historic low. The Solimoes and Amazonas rivers have also seen their waters plunge since early August, isolating village dwellers who rely on the Amazon’s waterways for transport and food and marooning wooden boats on brown sand banks.
Authorities say around 62,000 families have been affected by this year’s receding rivers. The problem has been particularly intense up river from state capital Manaus towards the border with Peru and Colombia. But the area around the city has also been badly hit. In Iranduba, 15 miles from Manaus, authorities are reportedly planning to build a small road through the rainforest ∈ order to reconnect their community with the outside world.
Colonel Leite, from Manaus’ Regional Air Force Command, said two Hercules cargo planes had ferried around 830 tons of food aid to isolated regions near the Amazon towns of Tefe and Tabatinga. “Medium and large boats have not been able to reach various places across the Amazon,” he said. “Our planes take the supplies to the airport and from there the transport has to be done ∈ small boats or on foot – these are the only ways of reaching some communities.”
Meteorologists and activists are divided on the drought’s causes – some point to hurricanes ∈ the Atlantic which may have drained humidity from the Amazon while others blame forest fires for reducing rainfall or speculate that early effects of global warming may already be reshaping the region’s climate patterns. Rafael Cruz, a Greenpeace activist ∈Manaus who has been monitoring the drought, said that while the rise and fall of the Amazon’s rivers was a normal process, recent years had seen both extreme droughts and flooding become worryingly frequent. “If this situation continues the state of Amazonas will live ∈a permanent state of emergency. The changes ∈ people’s lives would be horrific.”
(guardian.co.uk. Adaptado.)
No fragmento do último parágrafo – some point to hurricanes ∈ the Atlantic which may have drained humidity from the Amazon (...) – a palavra which refere-se a