Characterization of vegetation fraction estimated using spot-vegetation NDVI data for regional climate modeling in India

Abstract

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Vegetation fraction (VF) is an important input in mesoscale climate models, such as MM5. The most commonly used VF inputs in modeling is the climatic monthly VF generated by Gutman and Ignatov (1998)  (GI) using NOAA-AVHRR NDVI global data sets. This paper reports the generation of 1 km VF data set using SPOT-VEGETATION 10-day composite NDVI products from April 1998 to November 2003 for the Indian region. Sensor-specific thresholds of NDVI associated with 0% and 100% VF for SPOT-VEGETATION were found to be 0.04 and 0.804, respectively, in contrast to 0.04 and 0.52 of GI. Comparison of derived VF with climatic VF of GI was carried out.  Analysis of VF for three latitudinal zones (<16, 16-24, >24) indicated the differences up to 15 percent from GI.  Significant difference was observed for the area having rain-fed agriculture. Results of the seasonal and year-to-year variations of derived VF are discussed.