Using MODIS Normalized Difference Vegetation Index to monitor seasonal and inter-annual dynamics of wetland vegetation in the Great Artesian Basin: a baseline for assessment of future changes in a unique ecosystem
The Great Artesian Basin mound springs (Australia) are unique wetland ecosystems of great significance. However, these unique ecosystems are endangered by anthropogenic water extraction. Relationships have been established between the vegetated wetland area and the discharge associated with individu...
Main Authors: | , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2012-07-01
|
Series: | The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences |
Online Access: | http://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XXXIX-B8/187/2012/isprsarchives-XXXIX-B8-187-2012.pdf |
Summary: | The Great Artesian Basin mound springs (Australia) are unique wetland ecosystems of great significance. However, these unique
ecosystems are endangered by anthropogenic water extraction. Relationships have been established between the vegetated wetland
area and the discharge associated with individual springs, providing a potential means of monitoring groundwater flow using
measurements of wetland area. Previous studies using this relationship to monitor Great Artesian Basin springs have used aerial
photography or high resolution satellite images, giving sporadic temporal information. These "snapshot " studies need to be placed
within a longer and more regular context to better assess changes in response to aquifer draw-downs. In this study, the potential of
medium resolution MODIS Normalized Difference Vegetation Index data for studying the long-term and high frequency temporal
dynamics of wetland vegetation at the Dalhousie Spring Complex of the GAB is tested. Photosynthetic activity within Dalhousie
wetlands could be differentiated from surrounding land responses. The study showed good correlation between wetland vegetated
area and groundwater flow, but also the important influence of natural species phenologies, rainfall, and human activity on the
observed seasonal and inter-annual vegetation dynamic. Declining trends in the extent of wetland areas were observed over the 2000–
2009 period followed by a return of wetland vegetation since 2010. This study underlined the need to continue long-term medium
resolution satellite studies of the Great Artesian Basin as these data provide a good understanding of variability within the wetlands,
give temporal context for less frequent studies and a strong baseline for assessment of future changes. |
---|---|
ISSN: | 1682-1750 2194-9034 |