Remote sensing of global wetland dynamics with multiple satellite data sets

Thiss tudy isthe firs t global effort to quantify seasonality and extent of inundation with a suite of satellite observations, including passive and active microwave along with visible and infrared measurements. A clustering tech- nique which merges the satellite observations is used to de- tect inundation. Monthly flooded areasare then calculated by estimating pixel fractional coverage of flooding using the passive microwave signal and a linear mixture model with end-memberscalibrated with radar obs ervationsto account for vegetation cover. The global results, comprising natural wetlands, irrigated rice, and lakes/rivers, indicate a min- imum inundated area for the July 1992-June 1993 period of 2.16x10 6 km 2 , about 38% of the maximum 5.75x10 6 km 2 , to be compared to maximum areasof 5.83x10 6 km 2 and 5.70x10 6 km 2 from independent data sets. Comprehensive evaluation requires substantial additions to the sparse ob- servational record now available.