Surveys by the Institute of Fundraising have shown that non-DEC charities are concerned that any negative publicity around the anniversary could have an effect on future donations to charities in general.
"We certainly see it as important for DEC charities to get the message over about the impact they've made, because there is likely to be considerable media interest at the anniversary," said Lindsay Boswell, chief executive at the institute.
Concern about a giving backlash is strongest among some smaller charities, which are already coping with lower incomes this year after the tsunami appeal.
Although there is conflicting evidence as to whether other giving is down because of the appeal, some are in no doubt that the unprecedented £350m raised for tsunami aid has affected their own fundraising.
A recent survey of 1,000 people conducted by the Samaritans found that, although 81 per cent of Britons donated to the appeal, one in six said they would give less to charity as a result.
The survey also found that 40 per cent of respondents did not give regularly to charity and one in five did not give at all. "We all have good intentions, but it often takes a celebrity or significant media event to remind people to donate," said David King, chief executive of the Samaritans.
However, a website set up to protest against the Disasters Emergency Committee is closing after finding that there was very little opposition to the coalition.
Victor Bull, director of operations at Christian Hope International, launched www.decprotest.org.uk at the beginning of August, out of concern at the effect that the DEC west Africa appeal would have on non-DEC member charities. He claimed the site was "a fact-finding exercise" rather than a protest, but that the domain name was the best he could get at short notice.
Some 43 charities responded to the survey on the site. Although 61 per cent felt the DEC should not have launched a new appeal so soon after the tsunami, only 6 per cent had seen their income drop this year and most respondents were generally in favour of the DEC.
Separate research from the British Market Research Bureau has shown that the west Africa appeal achieved high visibility in the UK. Almost two-thirds of the 1,000-plus adults surveyed said they were aware of the crisis in Niger and, of those, 30 per cent have donated.