新疆土地生态安全时空变化

Spatiotemporal change of land ecological security in Xinjiang

土地生态安全评价能高效引导土地合理利用,协调生态保护与区域经济发展之间的矛盾。以核密度估算法及克里金空间插值为技术支撑,构建基于突变级数法的土地生态安全评价指标体系,并采用空间变异系数法及灰色预测模型对新疆土地生态安全进行探索性测度分析。结果表明:(1)新疆土地生态安全总体水平不断提高。土地生态安全指数由2004年的0.76上升到2017年0.94,安全等级呈现"不安全→较不安全→临界安全→较安全"的发展趋势。(2)新疆各县市土地生态安全的不均衡性得到改善,空间差异缩小。新疆土地生态安全空间变异系数由2004年的0.51上升为2017年的0.84,呈持续上升趋势,其中2009年到2014年期间最快增加了0.29。(3)研究区人口增加了27.59%,同时未利用地和草地面积的减少量分别占到整个新疆面积的7.51‰和9.45‰。自然资源分布不均、社会经济发展对未利用地和草地的大量占用以及区域人口的急剧增加可能是新疆土地生态安全面临的主要问题。(4)通过灰色模型预测,2020年新疆土地生态安全将进一步得到改善,土地生态安全空间差异将进一步缩小。与2005年相比, 2020年空间变异系数将上升到0.85;安全区和临界安全区将分别增加2.06%和11.24%;较安全区、较不安全区、不安全区将分别下降2.98%、9.16%、1.15%。

Land ecological security assessment can guide rational land use efficiently and coordinate the contradiction between ecological protection and regional economic development. Supported by the kernel density estimation method and Kriging spatial interpolation, the index system of land ecological security evaluation based on catastrophe progression method has been constructed, and the spatial variation coefficient method and grey prediction model have been used to analyze the land ecological security in Xinjiang. The results indicated that:(1) the overall level of land ecological security in Xinjiang has continuously improved. The land ecological security index increased from 0.76 in 2004 to 0.94 in 2017;the development trend of "unsafe→less safe→critical safety→safer" is apparent at the ecological security level;(2) the disequilibrium of land ecological security has been improved and spatial differences have been reduced in all counties and cities of Xinjiang. The spatial variation coefficient of land ecological security in Xinjiang increased from 0.51 in 2004 to 0.84 in 2017. There has been a sustained upward trend, with the fastest increase of 0.29 between 2009 and 2014;(3) the population of the research area increased by 27.59%, whereas the area of unused land and grassland decreased by 7.51‰ and 9.45‰, respectively. The uneven distribution of natural resources, extensive occupation of unused land and grassland for socio-economic development, and sharp increase in regional population may be the main problems of land ecological security in Xinjiang;(4) through the gray model prediction, the land ecological security of Xinjiang will be further improved in 2020, and the spatial difference of land ecological security will be further reduced. Compared with the scenario in 2005, the spatial variation coefficient will increase to 0.85 in 2020;the safety and critical safety zones will be increased by 2.06% and 11.24%, respectively;and the safer, less safe and unsafe zones will be reduced by 2.98%, 9.16%, and 1.15%, respectively.