APPENDIX B. FAO AGROCLIMATIC DATABASES AND MAPPING TOOLS

B.1 BACKGROUND

The Agro-ecological Zone (AEZ) Project was started by FAO in the 1980s to assess the global agricultural production potential in developing countries. Essential data requirements, next to level of technology, included available environmental resources such as soils and climate.

At the time of the first AEZ publications, the FAO climate database included about 3200 stations. The number has been growing constantly and currently includes approximately 29 000 stations. The scope of the database has also changed, with the number of Member countries increasing (for instance, Uzbekistan and Kyrgyzstan) and the emphasis moving more towards the support of the Multilateral Environmental Agreements (conventions on biodiversity, climate change and desertification). As a result, efforts had to be made to expand the database from developing country coverage to global coverage, updating the averages to more recent reference periods, ideally 1971-2000 (but more often 1961-1990). The averages are either obtained from national meteorological services, from other published databases, or recalculated by FAO based on time series. Particular efforts have been made recently to develop a more complete set of data for potential evapotranspiration according to Penman-Monteith (Penman-Monteith PET).

B.2 DATA AVAILABILITY

The database is most commonly referred to as FAOCLIM. It contains only monthly data for up to 14 observed and computed agroclimatic parameters: minimum, maximum and average temperatures, computed daytime and nighttime temperatures, rainfall, PET (computed), moisture expressed as dewpoint, vapour pressure or relative humidity, wind speed, and solar energy as sunshine hours, sunshine fraction or radiation. Needless to say, average temperature and rainfall are the most commonly available parameters.

As to time-series, the database includes 30 941 individual series of monthly data for eight variables. For these series data, 30 percent refer to rainfall and 30 percent to temperatures. The average length of a series is just under 50 years. Some series exceed 200 years, while the longest rainfall series covers 299 years. On the other hand, 185 rainfall series include only one year.

Further, some 80 percent of the series exceed 20 years and about 45 percent are longer than 50 years. This corresponds to a maximum distance between stations of 62 km for rainfall series of 20 years. With 90 percent of rainfall time series and 86 percent of temperature series have no gaps, i.e. on average a missing data item occurs over ten years for rainfall time series. Table B2b below, lists the availability of time series data by continents.

Table B2b
Inventory of time series of various variables according to continents

B.3 DATA VISUALIZATION AND MAPPING

B.3.1 FAOCLIM and LocClim

The climatic database operated by SDRN includes a number of additional data (daily and ten-daily) that are used for near real-time crop monitoring. As their coverage is not global, they are not included in the “standard” FAOCLIM dataset, but could be made available upon request. The data are managed using access and oracle in FAO headquarters.

Monthly data for up to 14 parameters and time-series for rainfall and temperatures are available as the “FAOCLIM CD-ROM” (currently in version 2), published in 2001 as Number 9 in the Environment and Natural Resources Service (SDRN) Working Papers series of FAO. The CD-ROM includes two pieces of software to access the data: (1) FAOCLIM proper, to select data by geographic area, time period and parameter, and export them for processing by other software packages; (2) GeoContext, a user-friendly programme to visualise the information in graph form.

Since FAOCLIM Version 1 was published in 1994, considerable progress has been made in the development of more user-friendly software tools which can be used spatially to interpolate climatic data^[34]. FAO has published the LocClim CD-ROM published in 2001 as Number 9 in the Environment and Natural Resources Service (SDRN) Working Papers series^[35].

LocClim was developed to provide an estimate of climatic conditions at locations for which no observations are available. To achieve this, the programme uses the stations of FAOCLIM 2.0.

Next to a "no questions asked" automatic mode, the "benchmark" mode gives the user full control over the interpolation procedure, e.g. Inverse Distance Weighting, with location inputs: being entered from the keyboard as coordinates, via a mouse click on a map, or from user-provided ASCII files. Output can be in the form of ASCII files or user-defined georeferenced grids^[36].

The programme also provides estimates of growing season characteristics based on a comparison of rainfall and potential evapotranspiration (Franquin's method). Estimates of monthly, ten-daily and daily values of common climate variables are given together with error estimates, using a number of options to correct for regional variability, altitude dependency and horizontal gradients of the variables. For any given location LocClim searches for the nearest stations that fulfil given criteria (absolute number, maximum distance, altitude constraints). If desired LocClim fits a linear altitude function through the observations to reduce all of them to the elevation of the desired location. This minimizes the systematic error resulting from the different elevations of the neighbouring stations.

The altitude of the desired location can either be given by the user or taken from a built-in digital elevation model (DEM) with a spatial resolution of 10 km and an altitudinal resolution of 20 m (DEM downgraded from the NOAA/NCDC Global Land One-kilometre Base Elevation). LocClim can perform climate gradient correction by fitting a plane surface to the observations over the latitude-longitude plane. Thus the smooth geographical climate variation is taken into consideration. If desired a shadowing routine can be applied that gives neighbours hidden by closer neighbours a low weight.

B.3.2 Web_LocClim and New_LocCLim

Since LocClim Ver.1 was published in 2002, a simplified Web version was developed^[37]. The version is “simplified” in that it offers fewer options to fine-tune the interpolation than the full CD-ROM version. The Web_LocClim site allows other servers to perform interoperability transactions: other servers can directly query the LocClim service to get climate data that they can process for their own purposes. Technical information about the interoperability service can be obtained from [email protected].

A new version of LocClim (New_LocClim) was developed in collaboration with the Deutscher Wetterdienst (German Weather Service), more specifically the Global Precipitation Climatology Centre GPCC^[38]. The New_LocClim has all the standard interpolation methods (IDW, kriging, Shepard, thin-plate splines...) and a number of added functionalities in comparison to LocClim Ver.1. One of the most useful additions is the possibility for users to interpolate their own data and to prepare maps (grids) at any spatial resolution.

The underlying FAOCLIM database was also significantly improved, in particular as regards data coverage in developed countries and countries in transition, PET availability, and the inclusion of daytime and night-time temperatures. The New_LocCLim in fact constitutes the convergence of FAOCLIM Ver.2 with LocClim Ver.1 and the publication of FAOCLIM will be discontinued. The joint publication of the New_LocClim can be obtained from [email protected].

FAO Environment and Natural Resources series

1. Africover: Specifications for geometry and cartography, 2000 (E)

2. Terrestrial Carbon Observation: The Ottawa assessment of requirements, status and next steps, 2002 (E)

3. Terrestrial Carbon Observation: The Rio de Janeiro recommendations for terrestrial and atmospheric measurements, 2002 (E)

4. Organic agriculture: Environment and food security, 2003 (E and S)

5. Terrestrial Carbon Observation: The Frascati report on in situ carbon data and information, 2002 (E)

6. The Clean Development Mechanism: Implications for energy and sustainable agriculture and rural development projects, 2003 (E)*

7. The application of a spatial regression model to the analysis and mapping of poverty, 2003 (E)

8. Land Cover Classification System (LCCS), version 2, 2005 (Multil)

9. Coastal Gtos. Strategic design and phase 1 implementation plan, 2005 (E)

10. Frost Protection: fundamentals, practice and economics- Volume I and II + CD, 2005 (E)

Availability: October 2005

The FAO Technical Papers
are available through the authorized
FAO Sales Agents or directly from:

Sales and Marketing Group - FAO
Viale delle Terme di Caracalla
00100 Rome - Italy

ENVIRONMENT AND NATURAL RESOURCES WORKING PAPERS

1. Inventory and monitoring of shrimp farms in Sri Lanka by ERS SAR data, 1999 (E)

2. Solar photovoltaics for sustainable agriculture and rural development, 2000 (E)

3. Energia solar fotovoltaica para la agricultura y el desarrollo rural sostenibles, 2000 (S)

4. The energy and agriculture nexus, 2000 (E)

5. World wide agroclimatic database, FAOCLIM CD-ROM v. 2.01, 2001 (E)

6. Preparation of a land cover database of Bulgaria through remote sensing and GIS, 2001 (E)

7. GIS and spatial analysis for poverty and food insecurity, 2002 (E)

8. Enviromental monitoring and natural resources management for food security and sustainable development, CD-ROM, 2002 (E)

9. Local climate estimator, LocClim 1.0 CD-ROM, 2002 (E)

10. Toward a GIS-based analysis of mountain environments and populations, 2003 (E)

11. TERRASTAT: Global land resources GIS models and databases for poverty and food insecurity mapping, CD-ROM, 2003 (E)

12. FAO & climate change, CD-ROM, 2003 (E)

13. Groundwater search by remote sensing, a methodological approach, 2003 (E)

14. Geo-information for agriculture development. A selection of applications. (E) **

15. Guidelines for establishing audits of agricultural-environmental hotspots, 2003 (E)

16. Integrated natural resources management to enhance food security. The case for community-based approaches in Ethiopia, 2003 (E)

17. Towards sustainable agriculture and rural development in the Ethiopian highlands. Proceedings of the technical workshop on improving the natural resources base of rural well-being, 2004 (E)

18. The scope of organic agriculture, sustainable forest management and ecoforestry in protected area management, 2004 (E)

19. An inventory and comparison of globally consistent geospatial databases and libraries, 2005 (E)

20. New LocClim, Local Climate Estimator CD-ROM, 2005 (E)

21 AgroMetShell: a toolbox for agrometeorological crop monitoring and forecasting CD-ROM, 2005 (E) **

22. Agriculture atlas of the Union of Myanmar (agriculture year 2001-2002) (E)

Availability: October 2005

The FAO Technical Papers
are available through the authorized
FAO Sales Agents or directly from:

Sales and Marketing Group - FAO
Viale delle Terme di Caracalla
00100 Rome - Italy