HR: 1330h
AN: H22D-0968 [PDF]
TI: Statistical Relationship Between Drought Indices and NDVI Departure at Regional Scale
AU: * Ishak Boushaki, F
EM: fishakbo@uci.edu
AF: Department of Civil and Environmental Engineering, University of California, Irvine, 4130 Engineering
Gateway, Irvine, CA 92697-2175
AU: Imam, B
EM: bisher@hwr.arizona.edu
AF: Department of Civil and Environmental Engineering, University of California, Irvine, 4130 Engineering
Gateway, Irvine, CA 92697-2175
AB:
In recent years, satellite data have become widely available at global scales and resolutions that are adequate for
monitoring drought conditions. Therefore the development of drought monitoring tools that can benefit from such data holds
the potential for improving the timeliness and access to drought information without the cost of extensive ground monitoring
stations especially in developing countries where meteorological networks are sparse at best, if at all available. This work
is motivated by the need to develop a satellite-based drought monitoring tools. The objective is to contribute to the
development of such tools through detailed analysis of existing widely used drought indices and information that can be
generated from widely used satellite vegetation data.
To accomplish these objectives, time-series of several widely used drought indices such as the Palmer Drought Severity Index
(PDSI), derived from meteorological data, are analyzed in conjunction with concurrent time series of a coarse resolution
Normalized Difference Vegetation Index (NDVI), derived from the Advanced Very High Resolution Radiometer (AVHRR) imagery. In
this study, the relationships between several "palmer-based" drought indices and the departure of NDVI from its long-term
mean were investigated over semi-arid climate regions in the state of Arizona.
The crosscorrelation analysis shows an agreement between the NDVI data and three out of the four Palmer drought indices as
far as the spatial distribution is concerned for all climate regions. The subscaling of NDVI data from climate division to
vegetation cover type has improved the crosscorrelation between NDVI and drought indices. This test showed positive and
stronger correlation for particular vegetation covers such as open shrublands and needleleaf forest.
DE: 1800 HYDROLOGY
DE: 1812 Drought
SC: Hydrology [H]
MN: 2003 Fall Meeting