Comparación espacial y temporal de índices de la vegetación para verdor y humedad y aplicación para estimar LAI en el Desierto Sonorense* Comparison of vegetation indexes in the Sonoran desert incorporating soil and moisture indicators and application to estimates of LAI

A multi-temporal comparison was made of four spectral vegetation indexes among 50 sites in a subtropical, coastal arid region. Greenness indexes (NDVI, SAVI and TSAVI) and one of moisture (NDII) were evaluated. NDVI and SAVI were very closely correlated, while TSAVI fluctuated less and NDII showed strong seasonal variations. Topographic correction (illuminated surface) of raw data usually increased the slope of TSAVI's soil line by >20%. The indexes, except NDII, were used to estimate Leaf Area Index; signal-to-noise analysis of LAI suggested that SAVI is usually close to NDVI but TSAVI has much more signal in the drier months.