关键词: 中国北方, 沙漠化土地, 演变

Abstract: It was disclosed by former researches that the desertification land in northern China developed at rate of 1 560 km² per year from late of 1950s to middle of 1970s,and till late of 1970s the already desertified land had reached 17.6×10⁴ km²,the light degree and potential desertification lands had reached 15.8 10⁴ km²;During the following ten years the developing rate was up to 2 100 km² per year,and till late of 1980s the already desertified land had reached 33.3×10⁴ km².In order to further disclose the status and developing trend of desertification land in China from then on and provide dependable bases for the strategy making of desertification control,another field investigation and monitoring with remote sensing to the desertification status in 256×10⁴ km² area of Northern China was conducted in 2000.The results showed that the total desertified land area had increased to 38.576×10⁴ km² from 33.895×10⁴ km² in 1987,among which the light degree and potential desertification land was 13.93×10⁴ km²,occupied 36.1% of the total;the middle degree was 9.977×10⁴ km²,occupied 25.9%;the serious was 7.907×10⁴ km²,occupied 20.51%;the very serious was 6.756×10⁴ km²,occupied 17.5%.The developing rate of desertification land was further raised to 3 500 km² per year during 1990s.In details,although the desertification in part of agricultural and agro-pastoral areas inversed distinctly,the area of desertification land in desert steppe and steppe desert continuously extended and the degree intensified.

Key words: the North of China, desertification land, evolution