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Monitoring rangeland dynamics in Senegal with advanced very high resolution radiometer data

January 1, 1992

Time‐series Normalized Difference Vegetation Index (NDVI) data, computed from Advanced Very High Resolution Radiometer data, are being used by regional and national programs in the African Sahel to monitor seasonal rangeland conditions. The data are often used as indicators of grazing conditions and drought. However, distinguishing rangelands from other vegetation cover types on NDVI images is difficult. A second complication is that rangeland types and their associated productivity vary geographically by soil type. To effectively assess rangeland conditions, seasonal fluctuations (due to climatic cycles) must be isolated from long‐term production characteristics associated with vegetation type and soil differences. Rangeland NDVI dynamics, including qualitative assessments of rangeland production, and the timing and length of the growing season in Senegal were examined by using 7.4‐km global area coverage satellite data. Analyses were based on 10‐day NDVI composite image data from 1982 through 1989. The NDVI image data were stratified by rangeland and soil polygons derived from locally available resource maps. Time‐series NDVI statistics were calculated from the resource polygons that had been interpreted into high, medium, and low production rangelands. Analysts monitoring rangeland conditions can better identify seasonal anomalies such as drought by comparing production potential within homogeneous; resource polygons with the current NDVI data.

Citation Information

Publication Year 1992
Title Monitoring rangeland dynamics in Senegal with advanced very high resolution radiometer data
DOI 10.1080/10106049209354356
Authors G. Gray Tappan, Dean J. Tyler, M. E. Wehde, Donald G. Moore
Publication Type Article
Publication Subtype Journal Article
Series Title Geocarto International
Series Number
Index ID 70187578
Record Source USGS Publications Warehouse
USGS Organization Earth Resources Observation and Science (EROS) Center