Global assessments of land degradation available today (Oldeman et al. 1991; Stoorvogel and Smaling 1990; Wood et al. 2000; UNEP 1997) are an important first step, but they do not provide the level of detail and accuracy that is needed to support many types of land management decisions. They are of low resolution, contain ambiguous and subjective information, and are too costly to frequently repeat as needed to monitor changes in degradation over time (Scoones and Toolmin 1998; Mazzucato and Niemeijer 2000).

This has been a fundamental constraint to combating desertification. It has caused experts to differ widely in their estimates of the extent and causes of land degradation, and to have difficulty measuring progress against it.

In this Theme we will use new tools from the emerging sciences of geographic information systems, satellite remote sensing and mathematical modelling to develop more accurate and affordable analytical methods. Whereas past remote-sensing methods emphasized vegetative cover, for example which has many ambiguous interpretations, we will test new methods that make direct measurements of ecological processes such as evapotranspiration from inexpensive, frequently-sampled satellite data (Rosema 1993).

These remote sensing analyses will be combined with on-the-ground participatory assessments of community perceptions and valuations of degradation and drought in target research areas. Combined with an understanding of ocean-atmosphere interactions, these tools will significantly strengthen the capacities of communities, nations and regions to develop drought and desertification coping strategies through better and more timely information, including improved early predictions of impending drought risk (Palmer and Anderson 1994; Hastenrath 1995; Goddard et al 2001).

Expected outputs for impact include: rapid-assessment hotspot detection methodology and tools to identify areas of likely degradation; pressure, state and impact indicators for the soil, water, biotic, and productivity components of land degradation and climatic variability; protocols and tools to measure and monitor actual land degradation in drylands integrating field and satellite data; participatory evaluation framework for the impact of land degradation and drought on dryland ecosystem functions; livelihood coping strategies using improved information on climatic variability; and training of local research partners and other stakeholders in generating, interpreting and using predictive and monitoring information on land degradation and climatic variability.

Initial core partners

EARS for remote sensing technology; Wageningen University for land degradation assessment, participatory and monetary valuation, and environmental indicator development; and IRI for drought prediction, all in partnership with GIS capacity at ICRISAT and ICARDA as well as national and regional partners.

References

Hastenrath, S. 1995. Recent Advances in Tropical Climate Prediction. J. Climatol. 8:1519-1532.

Mazzucato, V. and Niemeijer, D. 2000a. The cultural economy of soil and water conservation: Market principles and social networks in eastern Burkina Faso. Development and Change 31:831-855.

Oldeman, L. R., Hakkeling, R. T. A. and Sombroek, W. G. 1991. World map of the status of human-induced soil degradation: an explanatory note. Second Edition. Wageningen, The Netherlands and Nairobi, Kenya: International Soil Reference and Information Centre/United Nations Environment Programme.

Palmer, T. N. and Anderson, D. L. T. 1994. The prospects for seasonal forecasting - a review paper. Meteorological Society 120:755-793.

Rosema, A. 1993. Using METEOSAT for operational evapotranspiration and biomass monitoring in the Sahel region. Int. J. Remote Sens. Envir. 45:1-25.

Scoones, I. and Toulmin, C. 1998. Soil nutrient budgets and balances: what use for policy? Agriculture, Ecosystems & Environment 71:255-267.

Stoorvogel, J. J. and Smaling, E. M. A. 1990. Assessment of soil nutrient depletion in Sub-Saharan Africa 1983-2000. 28, Wageningen: The Winand Staring Centre for Integrated Land, Soil and Water Research (SC-DLO).

UNEP 1997. World Atlas of Desertification. London: Arnold.

Wood, S., Sebastian, K. and Scherr, S. J. 2000. Pilot analysis of global ecosystems: agroecosystems. Washington, D.C.: World Resources Institute and International Food Policy Research Institute.