新疆玛纳斯河流域绿洲耕地扩张差异与驱动力研究

新疆现代绿洲是两种不同经营模式(兵团农场耕作和地方家庭承包)下团镇绿洲耕地长期扩张的真实写照。本文以玛纳斯河流域石河子垦区144团与玛纳斯县兰州湾镇为例,首先基于1958—2018年的6期影像数据,采用土地利用动态变化度,分析了团镇耕地的扩张过程;进而采用多元逐步回归等方法,分析了兵团与地方绿洲扩张的驱动力;最后从全流域绿洲扩张的角度出发,结合绿洲扩张模型,测算了绿洲耕地的适宜规模。结果表明:144团与兰州湾镇的耕地面积均大幅增加,扩张的耕地主是由草地、林地转化而来;兵团耕地扩张的核心驱动因子为节水灌溉面积、水资源径流量、农牧业平均收入;地方则为人均GDP、农牧业平均收入、农业生产总值。流域的耕地面积远超适宜规模,生态安全隐患已经凸显。建议流域的各级政府遵循"山水林田湖草生命共同体"的理念和建设要求,统筹推进流域的综合开发;加快构建现代土地资源管理制度体系,科学划定生态红线,严格限定绿洲的扩张规模,促进兵团与地方的土地利用结构优化;坚持最严格水资源管理制度,"以水定地",实现水资源高效利用,防控沙漠化对绿洲的威胁;推行土壤退化治理与土地整治相结合,提高土地利用效率和潜力,从而实现绿洲耕地的数量、质量、生态三位一体保护。

Differences in and driving forces of cultivated land expansion in the Manas River Basin oasis, Xinjiang

The Xinjiang modern oasis is an example of a long-term expansion of the oasis arable land in regiments of the Xinjiang Production and Construction Corps and local townships under different operating modes (corps farm and local household contracting). This paper used image data from six periods (1958 to 2018) to assess the change degrees of land use of the 144 Regiment of Shihezi Reclamation Area and Lanzhouwan Town of Manas County in the Manas River Basin. This study examined the process of oases expansion in regiments and local town, and analyzed the driving forces of expansion using multiple stepwise regression. Finally, to assess oasis expansion in the whole basin, the oasis expansion model was used to calculate the appropriate scale of oasis cultivated land. The oasis change process in the 144 Regiment and Lanzhouwan Town had obviously increased the arable land area, and the increased arable land was mainly transformed from grassland and forest land. The driving factors of the regiment arable land expansion were water-saving irrigation area, water resources runoff, and average income of farming and herding industries. The local driving factors were income per capita, average income of farming and herding industries, and gross agricultural product. Moreover, the arable land in the basin had greatly exceeded the appropriate size, and the potential ecological security had been highlighted. All levels of government in the basin should follow the concept and construction requirements of "mountains-rivers-forests-farmlands-lakes-grasslands life community" to promote the comprehensive development of the basin, accelerate the construction of a modern land resource management system, scientifically delineate the ecological red line, strictly limit the scale of oasis expansion, and promote optimal land use by the corps and localities. Adherence to the strictest water resources management system, "water to determine the land" could aid efficient water resource use, prevent and control oasis desertification, promote soil degradation management and land remediation, and improve the efficiency of land use to protect the quantity, quality, and ecology of the oasis arable land.