摘要:
地表覆盖类型变化对研究区域生态环境变化具有重要意义。为准确掌握黄河流域巴彦淖尔段1989—2020年间地表覆盖类型变化,该文利用Landsat卫星数据影像,以目视解译和随机森林监督分类相结合的方法,对黄河流域巴彦淖尔段内各旗县1989—2020年平均每隔10 a的地表覆盖类型进行解译分类。经过精度验证总体分类精度均大于85%,Kappa系数均大于0.80。通过地表覆盖类型转移变化矩阵,发现黄河流域巴彦淖尔段1989—2020年间沙地减少22.17%,草地减少26.18%,耕地增加20.83%,水面变化不明显; 不同区域地表覆盖类型变化情况各不相同,荒漠草原区表现为沙地与草地之间的相互转化,耕地区和沙地区主要表现为沙地向耕地的转化,其中磴口县最为显著,2020年较1989年沙地减少了32.17%,耕地增加了57.48%。荒漠草原区以社会因素和自然因素共同驱动地表覆盖类型变化,耕地及沙地分布区主要以社会因素驱动地表覆盖类型变化。研究结果可为更加合理地规划利用土地空间提供有力的数据参考和支撑。
Abstract:
Changes in land cover types play a significant role in investigating the changes in regional ecological environments. This study aims to accurately determine the changes in land cover types in the Bayannur section of the Yellow River basin from 1989 to 2020. Based on Landsat data images, and combining visual interpretation with supervised random forest classification, this study interpreted and classified the land cover types of banners/counties within the Bayannur section at an average interval of 10 years from 1989 to 2020. The accuracy verification reveals an overall classification accuracy of above 85% and a Kappa coefficient of above 0.80. As demonstrated by the transfer change matrix of land cover types, the Bayannur section during the study period saw a decrease of 22.17% in sandy land, a reduction of 26.18% in grassland, an increase of 20.83% in cultivated land, and subtle variations in water surfaces. Different areas exhibited distinct changes in land cover types. Desert steppe areas were characterized by mutual transformation between sandy land and grassland. Cultivated and sandy land areas primarily exhibited a shift from sandy land to cultivated land, significantly represented by Dengkou County, where the sandy land decreased by 32.17% and the cultivated land increased by 57.48% in 2020 compared to 1989. Changes in land cover types of desert steppe areas were driven by both social and natural factors, whereas those of cultivated and sandy land areas were predominantly subjected to social factors. The results of this study will provide effective data reference and support for more rational planning and utilization of land space.
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