Multisource detection of drought events at the European scale
Simone Rossi(1), Giovanni Laguardia(1), Blaz Kurnik(1), Monica Robustelli(1), Stefan Niemeyer(1) and Nadine Gobron(1)
(1) European Commission Joint Research Centre, Via E. Fermi, 2749, 21027 Ispra (VA), Italy
In this work we evaluate and compare information from independent sources of data suitable for drought monitoring from different perspectives.
We compared a well known meteorological drought indicator (Standardized Precipitation Index - SPI), the anomalies of an indicator of the state and productivity of vegetation retrieved from remote sensing (Fraction of Absorbed Photosynthetic Active Radiation - fAPAR), and the normalized results of two independent soil moisture estimate methods.
The SPI was calculated for different averaging periods based on monthly rainfall observations obtained from the MARS-STAT activity at the European Commission Joint Research Centre (JRC).
fAPAR is widely recognized as an important indicator of the state of the vegetation and therefore it is an effective drought detection tool. In this work fAPAR estimates are retrieved from data provided by two different sensors: the ESA Medium Resolution Imaging Spectoradiometer (MERIS) and the NASA Sea-viewing Wide Field-of-view Sensor (SeaWIFS). The MGVI algorithm developed at the JRC is used by ESA to operationally provide fAPAR estimates as the MERIS primary L2 land surface product. A comparable retrieval algorithm has been developed at the JRC for SeaWIFS and applied over multiple years.
The first set of soil moisture estimates used in this work was obtained by means of the LISFLOOD hydrological model, which is run in a pre-operational setup within the Institute for Environment and Sustainability of the JRC.
The second set of soil moisture estimates was produced by the Microwave Remote Sensing Group of the Technical University of Vienna from backscatter measurements acquired with scatterometers onboard the satellites ERS-1 and ERS-2, processed through a change detection and modelling approach.
We have assessed the relations between the variables by means of correlation analysis and evaluated the detection of historical drought events.
The evaluation and comparison of information from different sources is carried out in view of the integration of different methodologies for multisource drought detection in order to improve an effective and operational monitoring and forecasting of drought events at the European scale.
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,