Based on MSS, ETM+ and 2006 satellite CBERS-2 satellite images obtained in 1975, 2000 and 2006, the authors

studied the changes in wetland areas of the total basin during the 31 years of 1975～2006. The survey reveals that the

total area of the wetlands steadily decreased from 1975 to 2000, with the total reduced area being 1 388.50 km2. The

results also show that, from 2000 to 2006, the area of the wetlands increased from 80 762.13 km2 to 81 825.15 km2. The

shrinkage of Yellow River Basin wetlands year by year has led the authors to believe that the geological background and

climate factors of the working area determine the overall distribution and changes of the wetlands, and that human factors

also play an equally important role in the variation of the wetlands.