甘肃省土地荒漠化状况及分析

采用"多因子数量化评价法"荒漠化评价指标体系,以TM卫星影象数据和1∶5万地形图为调查图,通过建立解译标志库,使用Arcview软件判读解译卫星影象数据和现地调查的方法,对甘肃省荒漠化区域内37个县区于2004年进行了第三次荒漠化监测研究;并在对1999年甘肃省第二次荒漠化监测和2004年第三次荒漠化监测的方法和结果对比分析基础上,对荒漠化土地发展趋势进行了分析结果表明,甘肃省荒漠化土地总面积为19347753.7 hm2,其中风蚀土地面积15619416.6 hm2、水蚀土地面积2881997.2 hm2、盐渍化土地面积691383.5 hm2、冻融土地面积154956.4 hm2;监测区域内荒漠化土地总面积较1999年减少232564.35 hm2,年逆转率0.21%;1999～2004年间土地荒漠化有所逆转,荒漠化程度减轻.

The condition and changing trend analysis of desertification land in Gansu Province

By adopting the multi-factor quantitative evaluation system, the third desertification monitoring and study on the condition of desertification land in 37 counties in Gansu Province was carried out in 2004. TM remote sensing data analysis with ARCView software, together with field surveying with the help of relief map on the scale of 1:50000 and globle positioning system was integrated. Furthermore, in according with comparatively analyzing method systems and evaluation parameters adopted in the second desertification monitoring project carried out in 1999, desertification trend from 1999 to 2004 was investigated in present study. The desertification area in 2004 in Gansu Province is 19347753.7 hm², with wind erosion land of 15619416.6 hm², water erosion land of 2881997.2 hm², salinization land of 691383.5 hm², and freeze thawing land of 154956.4 hm². The total desertification area in 2004 is about 232564 hm² less than in 1999, with the annual reversal rate of 0.21%. These results may simply reflect the fact that the process of desertification is slowed down and the severity of desertification is slightly alleviated in the monitoring period.