23 November 2007

The USAID Famine Early Warning System Network (FEWS NET)

Primary Sources:
5 August 2005: New York Times
Malnutrition Is Ravaging Niger's Children
2 February 2006: BBC
Ethiopia's food aid addiction
7 February 2006: IRIN Africa
ETHIOPIA: Struggling to end food aid dependency
7 February 2006: NASA Earth Observatory
Aiding Afghanistan
16 October 2007: Reuters
Cost of food aid soars as global need rises
Additional sources include Wikipedia and specific links provided below. All information used here is available from public sources.

Are you ready for a peek behind the curtain? This is operational hydrology, in one aspect at least...

A number of agencies in the US government participate in an operational endeavor called the Famine Early Warning System Network (FEWS NET), which is oriented almost entirely on the evaluation of food security in areas of the world where drought and crop failures are chronic issues. The main partners are:
The FEWS was started in 1986 in the US in response to the devastating 1984-5 famine in Ethiopia, in which an estimated 1M people died of starvation due to drought and political instability. The system was expanded to a network across several countries in Africa in 2000 and currently covers 22 countries on that continent, as well as one in Central Asia (Afghanistan) and four in Central America and the Caribbean. At NOAA, this latter extension of FEWS NET activities is known separately as the Mesoamerica FEWS (MFEWS).

NOAA also operates, by another extension, the Asia Flood Network (AFN). The AFN includes monitoring of cyclones and tsunami, especially in the Indian Ocean, and could be linked with the NOAA/USAF Joint Typhoon Warning Center, based in Guam, to provide an overwatch for almost all of coastal Asia and the Maritime Continent.

But the focus here with FEWS is not flooding and the problems those natural disasters provide. Drought is different: it's something more of a creeping disaster, with various definitions and thresholds that depend on your location, your business, the population and resource stress, etc. Areas in the Sahara are not considered in drought, perpetually - we call that desert. At the southern edge of the desert, however, many Africans make their livelihoods in a region known as the Sahel, a grassy savanna that provides marginal support. With climate change, droughts, unsustainable farming practices, and a lack of water supply for irrigation, these areas can turn to desert, and the Sahara advances. With the monsoon season, however, rapid greening is often observed in the Sahel and the farmers advance to reclaim the land. In some places the advance-and-retreat goes on an annual cycle, but longer-term trends such as drought and a warming climate tend to favor the desertification of the Sahel.

In other areas of Africa, the monsoons are not so much at issue, and it is beyond the margins of the rainforests in Sub-Saharan Africa that most of the problems with drought and famine occur. Before we go much farther, let's look briefly at the different types of drought:
  1. Meteorological drought, in which precipitation totals fall below a statistical threshold or there is a complete lack of precipitation for a measurable time period.
  2. Agricultural drought, in which precipitation and/or irrigation is insufficient for crop growth and production.
  3. Hydrological drought, in which water resources in rivers or reservoirs fall below a statistical threshold.
  4. Economic drought, in which commodity (food) stores and prices are affected, and foreign aid is often requested.
This is far different from the observation of tropical and mid-latitude storm events, which are described with wind speeds and wave heights, precipitation totals and various measures of severity such as the Saffir-Simpson scale. The storm events are finite and the damage can be evaluated not long after the event has passed. Not so, with a drought. In civil engineering, storm events are often ranked in order of precipitation depth and assigned a recurrence interval (e.g. ''the 100-year storm'') according to the length of record-keeping. With droughts, however, the severity is measured in various ways: precipitation can be rendered as an absolute or as a deficit from normal, and the time period of the drought is often at issue, primarily because recognition of the drought does not occur until it has already started. With a rainstorm, we can see it coming, we can watch The Weather Channel, we know when it arrives, and we know when it leaves. With a drought, a few days of rain are missed here and there, we figure it will be made up for later, and the next thing we know the plants are wilting and there's still not a storm in the forecast for weeks to come. By the time the reservoirs are down to half-capacity and our water rations have run out, it's already too late to save the crops, but maybe the people can survive on what remains, with help.

And that's where FEWS NET comes in. With early warning of a drought, an impending crop failure, or a full famine crisis, the primary goal is the acquisition and positioning of food aid, mostly cereal grains, for those affected. In 2006 USAID administered more than $1.5B in two categories related to food assistance, the International Disaster and Famine Assistance program and the P.L. 480 Food for Peace initiative.

In the areas of Africa covered by FEWS NET, Ethiopia has been the main beneficiary of international food aid for the past 30 years, and USAID has provided the majority of that assistance. Given rising populations and a steady decline in agricultural production, some have suggested that Ethiopia and other parts of Africa are addicted to such foreign aid. Some nations, however, remain under foreign and domestic political pressure. Sudan and Ethiopia have been threatened by Egypt upon any hint or suggestion in the direction of water resource development in the upper Nile River basin. Numerous countries in the FEWS NET area remain politically unstable, mired in civil conflicts and under the control of warlord factions who dictate the distribution of such aid. The word for these regimes, a term marked as potentially biased on Wikipedia, is kleptocracy.

Nevertheless, countries like Ethiopia and Somalia watch the weather and keep tabs on climate indicators, such as the western Pacific ENSO index and the Indian Ocean dipole. The Ethiopian highlands, where African easterly waves that sometimes turn into Atlantic hurricanes are born, also foster coffee plantations in the rich volcanic soil. But they can't eat coffee, and Egypt has warned them off of building big dams on the upper Blue Nile because Ethiopia provides as much as 90% of the total flow in the Nile River north of Khartoum, so every drought becomes a disaster because there remains no security in the country's water resources. The government reaches for agricultural development, some measure of sustainability with a reduction of foreign aid, but USAID's website indicates that the country has remained in Warning or Emergency status since July 2002.

So let's talk guts. The FEWS NET evaluation process is supported by several input datasets, including:
  • Normalized Difference Vegetation Index (NDVI), an indicator of plant growth and health, from NOAA satellite imagery and NASA processing procedures.
  • Meteosat Rainfall Estimation (RFE), based on processing of visible and infrared imagery from the EU's Meteosat geostationary sensors. The most recent RFE algorithm for use in FEWS was implemented by NOAA researchers in 2001.
  • A Water Requirements Satisfaction Index (WRSI) map based on imagery of crop areas at the beginning of the growing season, known crop-specific watering requirements from UN FAO datasets, and measured precipitation over the area within the growing season up to the time of evaluation.
  • The 10-day average latitudinal position of the African Inter-Tropical Convergence Zone (ITCZ), provided by NOAA, which suggests areas of recent and current rainfall.
  • Country- and region-specific Livelihood Maps, a product that employs evaluations of predominant livelihood activities (agriculture, livestock, pastoralism, fishing, and labor) in combination with known and forecast food availability in order to provide a relative context to the concepts of security and scarcity.
The first four of these are geophysical datasets, observable from space or estimated from a combination of space-based and ground observations. Two of these, the NDVI and WRSI, require both outside datasets and consistent updates on a monthly or dekadal (10-day) basis throughout the growing season. The other two, Meteosat RFE and the ITCZ position, are monitored constantly and rendered to dekadal time scales for analysis and dissemination. Much of the processing and combination of these geophysical datasets is performed by the USGS at their Earth Resources Observation and Science (EROS) data center. Sources of individual datasets include several NASA sites, such as the NASA Land Processes (LP) Distributed Active Archive Center (DAAC) and the Goddard Earth Sciences (GES) Data and Information Services Center (DISC).

The last dataset listed seems, by far, the most complicated to produce and keep up-to-date on a regular basis. As described on the main FEWS NET site,
"The livelihoods lens has shaped project work from early warning reporting to emergency needs assessments to special studies of affected populations. The livelihoods framework was adopted in order to provide essential baseline material for interpreting early warning indicators. The main advantage to a livelihood-based early warning system is that the focus is now on understanding the context of survival. Once this context is understood, the analyst can better judge the impact of a shock on household food access."
Basically, the orientation of FEWS analysis shifts from absolute indicators of food security, provided by the geophysical information collected and processed above, to a relative assessment based on the "normal" food security in a particular region or country. A "food gap" can be identified and addressed with warnings, preventative measures, and if necessary, foreign aid. As described further on the site, "the livelihood vision keeps FEWS NET staff focused on the essential questions during a food crisis, and that is: how, and to what extent, have households’ normal patterns of food access been affected?"

Naturally, NASA is also involved in this area through a partnership with Columbia University in the NASA Socioeconomic Data and Applications Center (SEDAC). The SEDAC is a veritable treasure trove of maps and geospatial information on both natural (vegetation, land cover, natural resources, environmental sustainability) and human aspects (locations, population density, urbanization, economic indicators, census details) of the problems at issue.

The end results of all this processing and evaluation are the analyses and food security status warnings issued on the main USAID FEWS NET site. Each country in the program's coverage is observed constantly, and the analyses are updated on a monthly basis or more frequently depending on recent events, especially rains and at harvest times. In the countries and regions of interest, USAID's monitoring and reporting activities are translated to on-the-ground responses through the well-defined FEWS NET Contingency and Response Planning Framework. The elements of this framework are enabled in direct cooperation with the authorities and major stakeholders in the target countries and regions, providing contingencies and responses that are tailored to the specific resources and needs there.

1 comment:

Isi said...

Really an interesting article. Thanks. C.