RESYSMED: Synthesis of change detection parameters into a land-surface change indicator for long-term desertification studies

• Unité de recherche: PCRD EU
• Numéro de projet: 97.0237
• Titre du projet anglais: RESYSMED: Synthesis of change detection parameters into a land-surface change indicator for long-term desertification studies

Mots-clé (Anglais)

Net radiation; flux measurement; remote sensing; desertification; radiation modelling

Programme de recherche (Anglais)

EU-programme: 4. Frame Research Programme - 3.1 Environment

Description succincte (Anglais)

See abstract

Autres indications (Anglais)

Full name of research-institution/enterprise:
Universität Basel
Institut für Meterologie, Klimatologie und Fernerkundung
Departement Geographie

Partenaires et organisations internationales (Anglais)

Coordinator: CeSIA (I)

Résumé des résultats (Abstract) (Anglais)

The main goal of RESYSMED was to compile the results of the 10 research groups from RESMEDES in the final integrated report 'Mediterranean Land-surface Changes Observed From Space'. Within a series of workshops and editorial sessions the integrated report was worked out and will be published as a text book (Springer Publishers).
All reports from MCR Lab within RESMEDES and RESYSMED are made available on the internet (http://www.gib.unibas.ch/mcr/PROJECTS/resmedes/index.htm).
The micrometeorological field data from the two measurement campaigns of RESMEDES were further analysed and compiled to be used for model verification within the RESYSMED community. Small scale spatial variation of storage fluxes was investigated and different measurement approaches (soil heat flux plate, temperature profile) were intercompared for a sugar beet field. Integrated spectral reflectance measured with a spectroradiometer was compared to broadband albedo and showed excellent agreement. Repeated tests of radia-tion instrumentation helped to identify a problem in the calibration of pyrgeometers which is linked to different transmissivities of the domes. The problem was solved by referencing the instruments to one instrument at the World Radiation Center in Davos, Switzerland. Now the pyrgeometers agree under outdoor conditions within ±1 W m-2. The turbulent heat fluxes for 4 different landuse classes were calculated from eddy covariance measurements and com-pared to estimates from scintillometer measurements on a landscape scale. The agreement is fair and leaves open questions how to verify different aggregation approaches.
In addition to the field campaign in the Piano di Rosia test site the spatial distribution of radiation fluxes derived from satellite data was a very important aspect of the project. During field campaign there was a satellite overpass of Landsat-TM. Data were ordered by the Swiss NPOC and analysed according to the model conception. After correction of terrain induced illumination effects Landsat-TM data of the visible and near infrared wavelength are used to compute albedo. From a digital elevation model which was digitised from topographic maps slope and aspect was calculated for each pixel in a resolution of 30 m. From Landsat-TM channel 6 data the longwave emission was computed after atmospheric correction. Finally atmospheric counter radiation can be estimated by using temperature and vapour pressure field data and net radiation is easy to calculate. The influences of land use and terrain on radiation fluxes are considered in all these data layers resulting in significant variations in the spatial domain of up to several hundred Wm-2.

Références bases de données (Anglais)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 97.0237