基于Landsat数据的沂蒙山区耕地种植速生林时空格局识别
Identification of Temporal and Spatial Patterns of Fast-Growing Forests Planting in Yimeng Mountains Based on Landsat Data

耕地是人类赖以生存的重要资源，但随着经济快速发展和人口数量急剧增加，耕地占用问题越发突出。速生林因其较高的经济效益成为侵占耕地资源的潜在威胁之一。耕地资源紧张的现实下对耕地利用的空间格局和时空变化特征的监测迫在眉睫。文章以沂蒙山区为研究区，基于所有可获得的连续Landsat影像数据，利用像元合成法和随机森林法获取2000年、2010年和2018年研究区土地覆被类型图，进而分析不同阶段之间的土地覆被转移情况以及耕地流失和向速生林的转化情况。分析结果显示，2000~2018年，耕地面积大幅度减少了100.8平方千米，绝大部分都转移为林地。该研究通过揭示耕地种植速生林区域土地覆被类型的时空变化特征，为进行耕地保护提供重要数据支撑，为政策制定提供重要依据，指导区域发展的实践。
Cultivated land is an important resource for human survival, but with the rapid economic devel-opment and the rapid increase in population, the problem of cultivated land occupation has be-come more and more prominent. Fast-growing forests have become one of the potential threats to encroaching on cultivated land resources because of their high economic benefits. Under the reality of the shortage of cultivated land resources, it is urgent to monitor the spatial pattern and temporal and spatial change characteristics of cultivated land use. In this paper, based on all available continuous Landsat image data in the Yimeng Mountain area, pixel synthesis method and random forest method were used to obtain land cover type maps in 2000, 2010 and 2018, so as to analyze the land cover transfer between different stages as well as the loss of cultivated land and the conversion to fast-growing forest. The analysis showed that from 2000 to 2018, the area of cultivated land decreased by 100.8 square kilometers, most of which was transferred to forest land. This study revealed the spatial-temporal variation characteristics of land cover types in fast-growing forests of cultivated land, provided important data support for cultivated land protection, and provided important basis for policy making, which guided the practice of regional development.