黄土高原沟道耕作转型时空特征及启示——以延安黄土丘陵沟壑区为例

Spatiotemporal characteristics of gully farming transformation on the Loess Plateau and implications:A case study of the Yan’an Loess Hilly and Gully Region

深入开展黄土高原沟道农地转型过程特征与模式研究,可为黄土高原沟道人地关系演化规律探究和农业多功能转型提供科学参考。本文以延安市的黄土丘陵沟壑区为例,选取2012—2018年研究区12幅Landsat数据,利用CART决策树提取沟道农地分布信息,结合高清遥感影像数据和野外实地考察,分析研究区沟道耕作转型过程,进而揭示该区域沟道耕作转型的内在机制。结果发现:①研究区沟道耕作重心由1100~1300 m范围向800~1100 m的低海拔地区转移,且坡度范围主要集中在0~16°。②研究区沟道耕作向集聚转型,尤其在小空间尺度上沟道耕作集聚特征更加明显,沟道耕作转型可总结为6种地域模式,其转型过程主要受经济社会因素和政策因素的驱动。③黄土高原沟道耕作由耕作区域内广种薄收的纯农粗放生计方式向生态经济下的集约化转型,由传统农业向现代沟道农业转换,功能趋于多元化,人地系统发展趋于协调高效。研究结果不仅对探讨黄土高原沟道乡村土地利用转型、生态文明建设、人居环境改善及乡村产业发展具有参考价值,对深入理解黄土高原沟道人地系统绿色可持续转型也具有启示意义。

In-depth research on the characteristics and models of the transformation process of gully farming land on the Loess Plateau can provide scientific reference for the evolution law of human-land relationship and agricultural multi-functional transformation in the region.Taking Yan’an City of the loess hilly and gully region as an example,this study used 12 Landsat TM/OLI images in 2012-2018 and the CART(Classification And Regression Tree)decision tree to extract the distribution information of gully farming land,combined with high-definition remote sensing image data and field investigation,to analyze the process of gully farming transformation in the study area and reveal the internal mechanism of gully farming transformation on the Loess Plateau.The results show that:(1)The gully farming transformation center of gravity in the Yan’an loess hilly and gully region has shifted from 1100~1300 m altitude to the low-altitude area of 800~1100 m,and the slope of the area is 0~16°.(2)Gully farming in the study area is transforming to agglomeration,especially at small spatial scales.Gully farming conversion can be categorized into six regional change patterns on micro and macro scales,and the process of change is mainly driven by socioeconomic and policy factors.(3)Gully farming on the Loess Plateau is gradually transforming from sole agricultural livelihood with extensive utilization of land to intensive utilization under ecological economic development.The transformation from traditional agriculture to modern gully agriculture has diversified the functions of the land and promoted the coordinated and efficient development of the human-land system.The research results not only have important reference value for rural land use transformation,ecological civilization construction,improvement of human settlements,and rural industrial development and transformation of the Loess Plateau,but also have implications for understanding the green and sustainable transformation of the humanland system on the Loess Plateau.