丝绸之路经济带沿线典型地区荒漠化动态变化遥感监测

Remote sensing monitoring of dynamic change of desertification in typical areas along the Silk Road Economic Zone

在高强度人类活动影响下,"丝绸之路经济带"的资源环境面临严峻问题与挑战,而对研究区的荒漠化动态变化进行遥感监测可为荒漠化的防治和治理提供理论基础和数据支持。以2000—2014年的250 m分辨率MOD13Q1为数据源,利用归一化植被指数和决策树分类进行荒漠化程度划分,得到丝绸之路经济带荒漠化土地动态变化和转移面积矩阵。结果表明:2000—2014年研究区荒漠化土地面积增加,其荒漠化土地增长量为98 912.26km^2和增长率为0.11%。其中,非荒漠化向荒漠化共转移308 289.73 km^2,大于荒漠化向非荒漠化的转移面积266 497.67 km^2。在空间分布上,中亚荒漠化土地由西南的严重荒漠化向东北的轻度荒漠化逐渐减轻,且向哈萨克斯坦北部地区不断推移;中国的荒漠化土地多集中分布在塔里木、吐鲁番和柴达木三大盆地中,且以宁夏陕西甘肃北部地区的减少为主。总体上,丝绸之路经济带沿线地区总荒漠化面积增加,程度趋于严重,荒漠化问题日益突出。

[ Background ] Under the influence of high intensive human activities, resources and environment of ＂ Silk Road Economic Zone＂ is facing severe problems and challenges. The ecological environment is very fragile along this region, especially in the middle part of the Second Eurasian Continental Bridge. Desert and Gobi area accounts for the greater proportion in this region, and desertification problems are very serious. The development and maturity of remote sensing technology may provide strong support for the analysis of the dynamic change of desertification. [ Methods] MOD13Q1 with 250 m resolution from 2000 to 2014 were used as data sources, and normalized difference vegetation index method was applied to estimate vegetation coverage, and decision tree classification method of vegetation coverage was to classify desertification degree, then the dynamic change and transfer matrix of land desertification in Silk Road Economic Zone were obtained. [ Results] The desertification land in thestudy area increased from 2000 to 2014, in which the growth amount of desertification land was 98 912.26 km2 and the annual growth rate was 0. 11%. Among them, the total area of none desertification transferred to desertification was 308 289.73 km2 , which was larger than that of desertification transferred to none desertification and the area was 266 497.67 km2. In spatial distribution, the desertification degree in Central Asia gradually reduced from extremely severe desertification in southwest to light desertification in northeast, and this desertification trend was moving towards the north part of Kazakhstan constantly. Land desertification in China was mostly concentrated in Turpan, Tarim and Qaidam Basin, but the area of desertification in the northern part of Ningxia, Shaanxi, Gansu was reducing. [Conclusion] On the whole, the total desertification area along the Silk Road Economic Zone is increasing, and the desertifieation degree trends to more severe. The desertification problem is becoming more and more serious. By monitoring and analyzing the dynamic changes of desertification along the Silk Road Economic Zone using remote sensing during 2000--2014, this study provides a theoretical basis and data support for regulation and construction of sustainable development of the oasis in Silk Road Economic Zone.