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Managing droughtManaging drought The Bureau's Drought Watch Service has been a key component of national drought management since 1965. It is based on a nationwide daily rainfall measuring network and established relationships between rainfall deficiency and the severity of recorded drought. Its rainfall information assists government, business and the rural community. It also helps to assess the current situation, providing early indication of the need for contingency action or drought relief. Since the implementation of Commonwealth Government 'National Drought Policy' initiatives in 1992, the Bureau has expanded its rainfall analysis services. Many of the new products are available through 'Weather by Fax', the World Wide Web or Bureau offices. Using monthly rainfall analysis, areas suffering from rainfall deficiencies appear in the Drought Statement as well as the publication Monthly Drought Review. If the accumulated rainfall over three successive months was within the lowest 10 per cent on record, a Drought Watch is commenced and the region is highlighted. This initial dry period stretches to six months for arid regions. Consideration is also given to whether an area is usually dry at that time of the year. There are two rainfall deficiency categories:  A
severe rainfall deficiency exists in a district when rainfall for
three months or more is in the lowest 5 per cent of records (see graph
- orange section). A serious deficiency lies in the next lowest 5 per cent i.e. lowest 5 per cent to 10 per cent of historical records for a three month or longer period (see graph - yellow section). Allowing for seasonal conditions, the Drought Watch may continue for many months and ceases when plentiful rainfall returns. 'Plentiful' is defined as well above average rainfall for one month, or above-average rainfall over a three-month period. The Drought Watch Service provides a consistent starting point for national drought alerts. Drought declarations take account of other factors in addition to rainfall and are the responsibility of the State Governments. |