| Abstract: | The researchers calculated seasonal integrated normalized difference vegetation index (NDVI) for each of 7 years using a time-series of 1-km data from the Advanced Very High Resolution Radiometer (AVHRR) (1992-93, 1995) and SPOT Vegetation (1998-2001) sensors. We used a local variance technique to identify each pixel as normal or either positively or negatively anomalous when compared to its surroundings. We then summarized the number of years that a given pixel was identified as an anomaly. The resulting anomaly maps were analysed using Landsat TM imagery and extensive ground knowledge to assess the results. This technique identified anomalies that can be linked to numerous anthropogenic impacts including agricultural and urban expansion, maintenance of protected areas and increased fallow. Local variance analysis is a reliable method for assessing vegetation degradation resulting from human pressures or increased land productivity from natural resource management practices. ?? 2004 Published by Elsevier Ltd. |
| Genre: | Article |
| ProdID: | 70026375 |
| Citation Author: | Budde, M. E.; Tappan, G.; Rowland, J.; Lewis, J.; Tieszen, L. L. |
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| Citation End Page: | 498 |
| Citation Issue: | 3 |
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| Citation Language: | English |
| Citation Larger Work Title: | Journal of Arid Environments |
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| Citation Number Of Pages: | 18 |
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| Citation Search Results Text: | Assessing land cover performance in Senegal, West Africa using 1-km integrated NDVI and local variance analysis; 2004; Article; Journal; Journal of Arid Environments; Budde, M. E.; Tappan, G.; Rowland, J.; Lewis, J.; Tieszen, L. L. |
| Citation Start Page: | 481 |
| Citation Volume: | 59 |
| Citation Year: | 2004 |
| Type: | citation/reference |
| Text: | Assessing land cover performance in Senegal, West Africa using 1-km integrated NDVI and local variance analysis; 2004; Article; Journal; Journal of Arid Environments; Budde, M. E.; Tappan, G.; Rowland, J.; Lewis, J.; Tieszen, L. L. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1016/j.jaridenv.2004.03.020 |
| Date Other: | Thu, 1 Jan 2004 00:00 -0600 |
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