eLocust: an improved desert locust monitoring and early warning system

Keith Cressman

This year's locust invasion is threatening to devastate crops throughout the Sahel and spark a food crisis in West Africa's worst locust plague in 15 years. Keith Cressman explains how the FAO´s eLocust sytem tm a palmtop computer, GPS device and HF radio equipment that run on a car battery - is helping to minimize the consequences for the region's farmers.

Map locust plague situation on August 26, 2004 (FAO) On 20 July 2004 Reuters reported that swarms of desert locusts had infested large areas of Mauritania, and were sweeping into Senegal and Mali. According to a local official, the locusts threatened to destroy crops and spark a food crisis in West Africa’s worst locust plague in 15 years.*

The news report came five months after the UN Food and Agriculture Organization (FAO) first warned of a major locust plague in the making, potentially affecting agricultural production and food security throughout West and Northwest Africa. The FAO based this early warning in part on local meteorological and field survey data that are received daily through the Electronic Locust Information System (eLocust).

The desert locust, a creature similar to a grasshopper, breeds in the deserts of North Africa. Most years, the locusts stay within their breeding grounds. They are normally solitary, scattered insects but when climatic conditions are favourable, such as after a period of good rains and mild temperatures, they can rapidly increase in number. As the rainy season ends, the locusts tend to group together in the remaining areas of green vegetation. They then change their behaviour and appearance, and form enormous swarms that can devastate entire crop fields in minutes, and can travel more than 120 km per day. They can easily cross the Red Sea into the Arabian Peninsula and even to India, depending on the prevailing winds. They have even been known to reach the UK and the Caribbean.

Since the last desert locust plague of 1987–89, the FAO has been actively involved in strengthening the early warning and reaction capacities of the affected countries. Most of these countries have now established national locust units with teams of specialists who conduct regular field surveys using four-wheel drive vehicles equipped with eLocust monitoring and data transmission equipment.

The eLocust system consists of a palmtop computer (Psion 5mx), a hand-held Global Positioning System (GPS) device, and HF radio equipment (a mobile transceiver and data modem), all of which run on the vehicle’s battery. The palmtop is equipped with a customized database and shareware software (PsiDat, RealMaps).

Each day, between sunrise and sunset, a field survey team makes about a dozen stops to monitor environmental conditions, such as vegetation, temperature, rainfall and soil moisture. They are also on the lookout for locusts, and interview nomads, travellers, villagers and farmers along the way. At each survey and control location, the field officer opens a new record in the database and enters relevant data. He taps on the touch-sensitive screen with a stylus to select the appropriate items from a drop-down menu, and uses the full keyboard to enter the names of locations and general comments. The GPS device automatically adds the coordinates, date and time to the record, which is then stored in the computer database.

Different types of maps can be linked to the database, including satellite imagery such as Landsat or maps showing the extent of locust infestations in the past. The field team can view different combinations of the data as well as the survey route using the RealMaps software. Almost any type of map can be loaded onto the Psion. At scheduled times throughout the day, the officer connects the Psion to the HF radio and data modem inside the vehicle and within a minute or so transmits the data to the national locust centre.

With the eLocust system, data transmission is much faster and more reliable than in the past, when field officers recorded their observations on paper forms, which were then sent to the national centre. Most important, the data they send are now automatically included in a national geographic information system (GIS), together with data from the national meteorological service, such as temperature, humidity, wind direction and atmospheric pressure, and forwarded to the Desert Locust Information Service (DLIS) at FAO headquarters in Rome for analysis.

Nearly 20 locust-affected countries are currently using the eLocust system. A French version is available for use in at least seven of these countries. Data from the remotest parts of Africa now arrive at the FAO in a matter of minutes. This has led to significant improvements in analysis and forecasting, enabling the affected countries to take steps to reduce the frequency of desert locust outbreaks. During the current crisis the system is being used to track the movements of locust swarms, and to identify locations where targeted ground and aerial spraying could minimize their devastating consequences for farmers in some of the world’s poorest countries.

Keith Cressman is Locust Forecasting Officer at the FAO’s Desert Locust Information Service (DLIS). For more information, visit www.fao.org/.../

13 August 2004

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