近30a黄河源地区荒漠遥感动态监测

Remote Sensing Monitoring on Dynamics of Desertified Lands in Yellow River Source Region in Last 30 Years

利用遥感和GIS的空间分析技术,以黄河源地区多期遥感数据为主要信息源,将荒漠分为沙地、戈壁、盐碱地和高寒荒漠四种类型,通过目视解译的方法提取黄河龙羊峡以上区域内的四期土地覆盖的荒漠数据,在此基础上进行了荒漠动态变化分析。研究结果表明:荒漠集中分布于研究区中西部,以高寒荒漠和沙地为主,其次是戈壁和盐碱地。近30 a来研究区内整体上荒漠先增加后减少,其中沙地的变化最为明显,尤其是1989年度以来的10 a扩张速度明显加快。

Desertified lands are the main land cover types in Yellow river source region. By method of remote sensing and GIS and based on the information source of remote sensing data in typical periods of the study region, the desertified lands in this area are classified into four types： sandy desert, Gobi desert, alkaline desert and preglacial desert. Using the database of desertified lands derived from Landsat MSS in the middle 1970＇s, Landsat TM in 1989＇s, Landsat ETM in 2000＇s and Landsat TM in 2005＇s, we discussed the dynamics of desertification. The results show that the desertified lands mainly distribute in the middle and western areas of the study region, mainly include preglacial desert and sandy desert. In the last 30 years, the desertified land area generally increased before 2000 and decreased since 2000, especially the change of sandy desert was obviously and it increased more rapidly in period from 1989＇s to 2000＇s than in other periods.