改革开放40a来新疆土地覆被变化的空间格局与特征

Spatial pattern and characteristics of land cover change in Xinjiang since past 40 years of the economic reform and opening up

改革开放40 a以来,新疆土地利用和地表覆被发生了巨大变化,在产生巨大社会经济效益的同时,也产生了许多生态与环境问题。为了给未来新疆土地利用、水资源开发及社会经济可持续发展国土空间规划提供依据,通过采用分区分层的决策树方法和向量相似度的变化检测方法,完成了新疆2015年、2010年、2000年、1990年、1975年的土地覆被1∶100000矢量数据集,准确反演了过去40 a(改革开放40 a)来新疆地表覆被变化过程,分析了新疆土地覆被变化与国家改革开放政策相互关系,从垦荒(1975—1990年)、农业资源开发(1990—2000年)、西部大开发(2000—2010年)、对口援疆(2010—2015年)4个阶段,阐述了国家政策力度和导向对土地覆被变化的影响。分析表明:新疆土地覆被变化由耕地开垦、人工表面增长的高速发展模式开始向兼顾生态文明建设的可持续发展方向转型,各主要地类的变化也由急剧发展转向基本可控。近40 a新疆耕地面积增加了128%(50414.02 km2),新增耕地依照水土资源配置特征,遵循空间规律分布;人工表面(建设、交通、工矿用地)面积增加了197%(7497.11 km2),在2000年后增速明显,2010年后南疆增加幅度很大;1990年前林地面积呈现减少趋势,1990年后呈增加的态势,新增林地广泛分布在全疆天然林封育保护范围和天保工程实施区内;湿地1990年前面积减少明显,1990—2000年保持稳定,2000年后呈增加趋势;草地和其他类型的面积呈现持续减少态势。

Since the economic reform and opening up 40 years ago,land use and land cover of Xinjiang,China have undergone tremendous changes.While generating great socio-economic benefits,many ecological and environmental issues have also arisen.In order to provide a basis for future Xinjiang’s land use,water resources development,and socio economic sustainable development of land and space planning,a partitioned and layered decision tree method and a vector similarity change detection method were used to complete the Xinjiang Land Cover 1∶100000 vector dataset in 2015,2010,2000,1990,and 1975 in this paper.The evolution of Xinjiang’s land cover change over the past 40 years(reform and opening up of China)was analyzed.From the four stages of reclamation(1975—1990),agricultural resource development(1990—2000),western development(2000—2010),and counterpart assistance to Xinjiang(2010—2015),the paper described the impact mechanism of national policy on land cover changes.The analysis showed that the land cover change in Xinjiang has begun to transform from a high speed development model to a sustainable development combined the construction of ecological civilization.The changes of major land types have also shifted from rapid development to basic controllability.In the past 40 years,the area of cultivated land in Xinjiang increased by 128%(50414.02 km2).The new cultivated land was distributed to the characteristics of water and land resources distribution.The area of artificial surfaces(construction,transportation,industrial,mining land)increased by 197%(7497.11 km2).The growth rate was obvious accelerated after 2000,and the increase rate in southern Xinjiang after 2010 was very large;the area of forest land before 1990 showed a decreasing trend,and it showed an increasing trend after 1990.The newly added forest land was widely distributed in the natural forest enclosure and within the implementation area of Xinjiang Natural Forest Protection Project.The area of wetlands decreased significantly before 1990,remained stable from 1990 to 2000,and showed an increasing trend after 2000.The area of grassland and other types continued to decrease.