Data indicates 190% rise in land clearance in August and September compared with same period last year

The deforestation of the Brazilian Amazon has accelerated rapidly in the past two months, underscoring the shortcomings of the government’s environmental policies.

Satellite data indicates a 190% surge in land clearance in August and September compared with the same period last year as loggers and farmers exploit loopholes in regulations that are designed to protect the world’s largest forest.

Figures released by Imazon, a Brazilian nonprofit research organisation, show that 402 square kilometres – more than six times the area of the island of Manhattan – was cleared in September.

The government has postponed the release of official figures until after next Sunday’s presidential election, in which incumbent Dilma Rousseff of the Workers’ party faces a strong challenge from Aécio Neves, a pro-business candidate who has the endorsement of Marina Silva, the popular former environment minister .

But the official numbers are expected to confirm a reversal that started last year, when deforestation rose by 29% after eight years of progress in slowing the rate of tree clearance.

Among the reasons for the setback are a shift in government priorities. Under Rousseff, the government has put a lower priority on the environment and built alliances with powerful agribusiness groups. It has weakened the Forest Code and pushed ahead with dam construction in the Amazon.

The environment ministry has tried to step up monitoring operations and campaigns to catch major violators, but farmers and loggers have also become more sophisticated by clearing areas of less than 25 hectares – below the range that can be detected by the Deter satellite, which the government had been using until recently.

More precise images should be available with a new satellite that has come into operation, but it is thought that better pictures will be likely to show even sharper deterioration.

Covert GPS surveillance of timber trucks by Amazon campaigners has shown how loggers evade the authorities. Much of the timber is laundered and sold to unwitting buyers in the UK, US, Europe and China, Greenpeace revealed this year.

Despite the worsening situation in the Amazon – and São Paulo’s most severe drought since records began – the environment has played little part in the debates between the two presidential candidates.

Alarmed by these trends of environmental degradation and political complacency, Imazon, the Environmental Research Institute of Amazonia and Friends of the Earth have come together to urge the next administration to make diversity and sustainability official priorities for the Amazon.

“It’s time to realize that current investments in the Amazon do not promote development, and deforestation is impeding development. Based on this, you need to design and implement a regional development policy based on diversity of the territory,” said Roberto Smeraldi, director of Friends of the Earth.