DOI: 10.1016/j.jag.2015.04.021
Scopus记录号: 2-s2.0-84943635321
论文题名: Spatiotemporal variation in the terrestrial vegetation phenology of Iraq and its relation with elevation
作者: Qader S ; H ; , Atkinson P ; M ; , Dash J
刊名: International Journal of Applied Earth Observation and Geoinformation
ISSN: 15698432
出版年: 2015
卷: 41 起始页码: 107
结束页码: 117
语种: 英语
英文关键词: Elevation
; Iraq
; NDVI
; Phenology
; Time-series
Scopus关键词: elevation
; land surface
; MODIS
; NDVI
; phenology
; spatial variation
; temporal variation
; time series analysis
; vegetation
; Iraq
英文摘要: Iraq contains the Great Mesopotamian alluvial plain of the Euphrates and Tigris rivers. Its regional vegetation phenological patterns are worthy of investigation because relatively little is known about the phenology of semi-arid environments, and because their inter-annual variation is expected to be driven by uncertain rainfall and varied topography. The aim of this research was to assess and map the spatial variation in key land surface phenology (LSP) parameters over the last decade and their relation with elevation. It is the first study mapping land surface phenology during last decade over the whole of Iraq, and one of only a few studies on vegetation phenology in a semi-arid environment. Time-series of Moderate Resolution Imaging Spectroradiometer (MODIS) normalised difference vegetation index (NDVI) data at 250m spatial resolution and 8 day temporal resolution, were employed to map the spatial variation in three LSP parameters for the major vegetation types in Iraq during 2001-2012. LSP parameters were defined by inflection points after smoothing the vegetation phenological signals using the Fourier technique. The estimated key LSP parameters indicated that the relatively shorter length of season (LOS) in the north of Iraq resulted from a delayed start of season (SOS). Greater spatial variation occurred in the SOS than end of season (EOS), which may be due to the spatial distribution of rainfall and temperature as a function of elevation. A positive correlation was observed for SOS and EOS with elevation for all major land cover types with EOS producing the largest positive correlation (R2 = 0.685, R2 = 0.638 and R2 = 0.588, p < 0.05 in shrubland, cropland and grassland, respectively). The magnitude of delay in SOS and EOS increased in all land cover types along a rising elevation gradient where for each 500mincrease, SOS was delayed by around 25 or more days and EOS delayed by around 22 or more days, except for grassland. The SOS and EOS also varied temporally during the last decade, particularly the SOS in the lowland, north of the country where the standard deviation was around 80 to 120 days, due mainly to the practice of crop rotation and the traditional biennial cropping system. Thus, the results of this research emphasize the effect of elevation on key LSP parameters over Iraq, for all major vegetation types. © 2015 Elsevier B.V.
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/79528
Appears in Collections: 气候变化事实与影响
There are no files associated with this item.
作者单位: Geography and Environment, University of Southampton, Southampton, United Kingdom
Recommended Citation:
Qader S,H,, Atkinson P,et al. Spatiotemporal variation in the terrestrial vegetation phenology of Iraq and its relation with elevation[J]. International Journal of Applied Earth Observation and Geoinformation,2015-01-01,41