Dynamic Prediction of Sandy Desertified Land in Northern China and Suggestion

Sandy desertification is a major problem of environment and social economy in the world as its fast speed and vast distribution.The total area of sandy desertified land was 13.7×10~4?km~2 during 1950s,(38.57×)10~4?km~2 in 2000 in northern China.The annual expanded amount was 1?560?km~2 during the late 1950s and 1975,2?100?km~2 between 1975 and 1987 and 3?436?km~2 from 1987 to 2000.The developed rate raise from(1.26%) to 4.76%.There are many factors which can affect the sandy desertification.We select five factors and create dynamic prediction model,we make the numerical prediction of sandy desertified land from 2004 to 2?033 year.From the result of prediction based on present rate,the total area of sandy desertified land is 185.54×10~4?km~2 in 2033,if the bad influence of human activity and climate factor on desertification is increased and decreased by 10%,the total area of desertified land will be increased 15.56×10~4?km~2 and decreased 14.44×10~4?km~2.If the bad influence is decreased,the total area is decreased with 1.1×10~4?km~2.