 |
| Titel |
Towards an integrated soil moisture drought monitor for East Africa |
| VerfasserIn |
W. B. Anderson, B. F. Zaitchik, C. R. Hain, M. C. Anderson, M. T. Yilmaz, J. Mecikalski, L. Schultz |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 16, no. 8 ; Nr. 16, no. 8 (2012-08-22), S.2893-2913 |
| Datensatznummer |
250013436
|
| Publikation (Nr.) |
 copernicus.org/hess-16-2893-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| Drought in East Africa is a recurring phenomenon with significant
humanitarian impacts. Given the steep climatic gradients, topographic
contrasts, general data scarcity, and, in places, political instability that
characterize the region, there is a need for spatially distributed, remotely
derived monitoring systems to inform national and international drought
response. At the same time, the very diversity and data scarcity that
necessitate remote monitoring also make it difficult to evaluate the
reliability of these systems. Here we apply a suite of remote monitoring
techniques to characterize the temporal and spatial evolution of the
2010–2011 Horn of Africa drought. Diverse satellite observations allow for
evaluation of meteorological, agricultural, and hydrological aspects of
drought, each of which is of interest to different stakeholders. Focusing on
soil moisture, we apply triple collocation analysis (TCA) to three
independent methods for estimating soil moisture anomalies to characterize
relative error between products and to provide a basis for objective data
merging. The three soil moisture methods evaluated include microwave remote
sensing using the Advanced Microwave Scanning Radiometer – Earth Observing
System (AMSR-E) sensor, thermal remote sensing using the Atmosphere-Land
Exchange Inverse (ALEXI) surface energy balance algorithm, and
physically based land surface modeling using the Noah land surface model. It
was found that the three soil moisture monitoring methods yield similar
drought anomaly estimates in areas characterized by extremely low or by
moderate vegetation cover, particularly during the below-average 2011 long
rainy season. Systematic discrepancies were found, however, in regions of
moderately low vegetation cover and high vegetation cover, especially during
the failed 2010 short rains. The merged, TCA-weighted soil moisture
composite product takes advantage of the relative strengths of each method,
as judged by the consistency of anomaly estimates across independent
methods. This approach holds potential as a remote soil moisture-based
drought monitoring system that is robust across the diverse climatic and
ecological zones of East Africa. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|