The RESYSMED project buildson previous achievements in the production of calibrated, georeferenced, normalized and corrected series of METEOSAT, NOAA-AVHRR, LANDSAT-TM, SMMR, SSM/I, and ERS 1-2 SAR and WSC data. From the measurements with these sensors specific "primary" land-surface parameters are derived. These "primary" data sets are used for diagnostic purposes to quantify changes at the landsurfaces in semi arid regions.
Combined with models they serve the production of more complex information, such as fluxes and soil moisture. The goal of the project is to merge these different information of the land-surface into a "land-surface change indicator" (LCI) that is applied to quantify the state of surface and - in combination with longe term data series - to analyse the process of desertification.
A three pronged strategy is followed in the project, on the basis of the results of the previous ENV4-CT95-0094: Firstly, the production and evaluation of normalized large scale and longer term "primary" data sets that more or less can be inferred directly from measurements made in space and used as indices for changes that occur at the land surface.
Secondly, the "upgrading" of these indices to process advanced quantities like fluxes (radiation, heat) or soil moisture changes, by combining the primary data with models. Thirdly, the application of these combinations of satellite data and models at limited areas where a validation of the information deduced from the spaceborne measurements can be performed by comparing them with collateral higher resolution remote sensing data or measurements made at specific sites at the surface.
The work proceeds in the following way: From satellite data obtained from various sources individual partners extract specific parameters and test them either at the basin or at the regional scales with respect to (i) their relationships with physical-biological quantities and (ii) their potential to provide (primarely relative) information about seasonal and interannual changes. Other groups build on the basis of these "primary" parameters algorithms that allow to compute the fluxes at the surface, specifically evapotranspiration. Still other groups correlate the changes inferred from the satellite data with climate variability (e.g. the interannual changes of the vegetation index with precipitation). Exemplary data series will soon be available to demonstrate the potential of the single elements and of the derived complex quantities (such as fluxes) to describe surface processes both with respect to areal integration and for (limited) time periods.
In particular, the proposed project will concentrate on two issues:
- to explore the synergetics between the individual components and put intercomparable scales on each line of Table 1, which means numbers that quantify the relationship between the degree of land-surface degradation and the individual indices to make the individual indices quantitatively comparable with each other, and to
- merge the results obtained for the individual parameters into the envisaged "land-surface change (or: desertification) indicator".
The merging will take place with all partners present at a mid-term "cloister" workshop at which the Land-surface Change Indicator (LCI) and the structure of the synthesis report will be finalized. The rest of the year is needed to demonstrate by a few examples the potential of the LCI and to cast the results into an integrated report.
Funding SchemeCSC - Cost-sharing contracts
67400 Illkirch Graffenstaden
1081 HV Amsterdam
6709 PA Wageningen
6700 AC Wageningen