基于3S技术的乌珠穆沁沙地近20 a动态变化特征

Dynamic Change Characteristics of Ujimqin Sandy Land during Recent 20 Years based on 3S Technology

乌珠穆沁沙地是环北京风沙带的组成部分之一,是距离北京较近的沙地,也是京津冀沙尘暴的来源地。本研究以乌珠穆沁沙地1995年、2000年、2005年、2010年、2015年遥感影像数据为依据,使用ENVI软件和ArcGIS软件对研究区近20 a的动态变化以及植被覆盖度变化进行研究,结果表明:(1)乌珠穆沁沙地总面积从1995年的38.34万hm^(2)减少到了2015年的20.13万hm^(2)。(2)沙地类型中,1995—2000年重度沙化土地占比最高,2000年之后中度沙化土地占比最高,2010年甚至达到了76%。(3)近20 a研究区的荒漠化指数呈现先上升后下降再上升的过程,总体来说有下降趋势,可以看出近20 a乌珠穆沁沙地的治理取得初步成效,但形势依然严峻。针对乌珠穆沁沙地治理现状,继续开展沙地治理工程,同时制定相应的保护政策。

Ujimqin Sandy Land is one of the components of the sandstorm belt around Beijing,which is close to Beijing and also a source of sandstorm for Beijing-Tianjin-Hebei region.Based on the remote sensing images data of 1995,2000,2005,2010 and 2015,the dynamic change and vegetation coverage change of Ujinmqin Sandy Land during recent 20 years were studied by use of ENVI and ArcGIS software.The results showed:(1)The total area of Ujimqin Sandy Land decreased from 383400 hm^(2) in 1995 to 201300 hm^(2) in 2015.(2)The proportion of sever desertified land was the highest from 1995 to 2000,the proportion of moderate desertified land was the highest after 2000,even reached 76% in 2010.(3)During recent 20 years,the desertification index in the study area showed a process of first increasing,then decreasing and then increasing,with a general downward trend.It can be seen that the control of Ujimqin Sandy Land in recent 20 years has achieved preliminary effects,but the situation is still serious.In view of the current controlling situation of Ujimqin Sandy Land,the controlling project should be continuously carried out,and the corresponding protection policies should be formulated.