Met drought declared

The Ministry of Natural Resources and Environment (M.N.R.E) has declared what it calls a “metrological drought,” calling on members of the public to conserve water.

The declaration was made in a statement issued by the Samoa Meteorology Division during the weekend.

The warning follows an equally important warning from the Fire and Emergency Services Authority (F.E.S.A) asking members of the public to be extremely careful given the continuing dry conditions that could lead to forest fires.

Some rainfall fell on Saturday and Sunday but it was nowhere near enough.

“In light of this, the public is advised to conserve, store and manage water in a sustainable manner. It is also highly recommended for the public to refrain from open burning of rubbish in grass or forest areas during this time”

In a statement, M.N.R.E said there has been a lack of decent rainfall over certain areas in the country. These areas include the central and south east of Upolu and east Savai’i.

“Over the course of the last few months, the Samoa Climate Early Warning System (C.L.E.W.S) has observed rainfall over the country to be generally lower than average,” the statement said.

“A meteorological drought is the first of the four levels of severity or drought definitions. Meteorological drought is defined usually on the basis of the degree of dryness (in comparison to some “normal” or average amount) and the duration of the dry period. The reduced rainfall levels over the country are associated with the current dry season, and compounded by the current phase of the El Nino Southern Oscillation.

“In our view and assessment of the most recent rainfall observational data, we are satisfied that the north and central region of Upolu (from Saoluafata, Apia to Faleolo) and eastern region of Savai’i (from Maota, Tuasivi to Vaipouli) are now declared to be under a Meteorological Drought (refer Figure 1).

“Other areas that includes the south (Safata and Siumu) and south east of Upolu (Falealili and Aleipata) still enjoy isolated rainfall and therefore bordering to drought thresholds but not yet in drought.

“These windward areas are more prone to extended dry conditions, and if current dry run continues for few more months, it is likely these areas and/or all of Samoa, will also enter into drought territory.

"The advanced climate early warning and forecasts issued to the public to support improved resilience to climate impacts; back in May 2014 anticipating this drought event has allowed for better preparedness across many sectors here in Samoa. Drought impacts in neighbouring Pacific Island countries without any climate early warning system are more profound and severe."

The Met Office says the likely impacts of a meteorological drought will include;

• likely failure of certain weed and grass species due to precipitation deficiency,

• reduced ground water recharge

• reduced surface water flow and water availability

• increase risk of forest and bush fires, increase surface dryness (dusty) due to increased evaporation and transpiration

• greater sunshine exposure due to less cloud cover

“In light of this, the public is advised to conserve, store and manage water in a sustainable manner. It is also highly recommended for the public to refrain from open burning of rubbish in grass or forest areas during this time. Concerned agencies and ministries are hereby advised to take measures to mitigate the potential impacts of this phenomenon.”

Additional Information

Meteorological drought is defined usually on the basis of the degree of dryness (in comparison to some “normal” or average amount) and the duration of the dry period. Meteorological drought is the first of four levels of severity or definitions.

The more severe drought definitions are Agricultural Drought, Hydrological Drought and Socio-economic Drought.

Agricultural Drought

Agricultural drought links various characteristics of meteorological (or hydrological) drought to agricultural impacts, focusing on precipitation shortages, differences between actual and potential evapotranspiration, soil water deficits, reduced groundwater or reservoir levels, and so forth.

Hydrological Drought

Hydrological drought is associated with the effects of periods of precipitation (including snowfall) shortfalls on surface or subsurface water supply (i.e., streamflow, reservoir and lake levels, groundwater). The frequency and severity of hydrological drought is often defined on a watershed or river basin scale. Although all droughts originate with a deficiency of precipitation, hydrologists are more concerned with how this deficiency plays out through the hydrologic system.

Hydrological droughts are usually out of phase with or lag the occurrence of meteorological and agricultural droughts. It takes longer for precipitation deficiencies to show up in components of the hydrological system such as soil moisture, streamflow, and groundwater and reservoir levels. As a result, these impacts are out of phase with impacts in other economic sectors.

Socioeconomic Drought

Socioeconomic definitions of drought associate the supply and demand of some economic good with elements of meteorological, hydrological, and agricultural drought. It differs from the aforementioned types of drought because its occurrence depends on the time and space processes of supply and demand to identify or classify droughts. The supply of many economic goods, such as water, forage, food grains, fish, and hydroelectric power, depends on weather.

Because of the natural variability of climate, water supply is ample in some years but unable to meet human and environmental needs in other years. Socioeconomic drought occurs when the demand for an economic good exceeds supply as a result of a weather-related shortfall in water supply.