山地丘陵区城市化进程中裸地的时空转化及改造利用的分类研究

针对近年来快速城镇化进程导致城市周边裸地显著增长但对其改造利用率低的问题，以山地丘陵型城市四川省绵阳市为例，采用1999~2017年4期Landsat TM/OLI遥感影像提取研究区包括裸地在内的土地利用/土地覆被变化信息，重点分析了城市化进程中裸地的时空分布及土地转移特征，并以2017年裸地为例探讨了裸地改造利用的分类分区方法。主要结论有： （1）1999~2017年，裸地在研究区最高约占6.34%（2011年），最低3.91%（1999年），年均增长率1.64%，低于同期城市不渗水面的年均增长率9.74%。空间上，裸地主要分布在460~500 m的高程范围和坡度8°以下，沿城乡过渡带、城市开发区以及新修道路两边是裸地主要分布区。（2）1999~2017年，约61.35%的裸地由耕地转化而来，23.58%来源于林地，同期又有51.88%裸地转换为耕地，24.79%转换为城市不渗水面。（3）综合裸地所处区位、地形、景观格局等因素后将2017年裸地划为社区利用型、城市绿化型、城市基础和公共服务设施建设型、都市农业型以及生态修复型5大类改造利用型，以期为研究区城市化进程中的裸地改造利用提供参考依据。

Study on Spatio-Temporal Conversion Characteristics and Classification of Transformation and Utilization of Bare Land in the Process of Urbanization in Mountainous and Hilly Areas

In recent years, the rapid urbanization process has led to a significant increase in bare land around cities, but the utilization rate of bare land is relatively low. Taking Mianyang City, Sichuan Province, as an example, this study used Landsat TM/OLI remote sensing images from 1999 to 2017 to extract the land use/cover change information, including bare land, mainly to analyze the spatial and temporal distribution and land transfer characteristics of bare land in the process of urbanization, and discussed the classification method of bare land transformation and utilization with bare land in 2017a as an example. The main conclusions as follows: （1) The highest rate and the lowest rate of bare land area accounts for in the study area is 6.34% (2011a) and 3.91% (1999a), respectively, the average annual growth rate is 1.64% during 1999-2017a, which is much lower than the average annual growth rate of urban impervious surface (9.74%) in the same period. The spatial distribution of bare land is scattered, and most of the bare land is located in the interval between 460-500 m and the slope below 8 degrees. The bare land mainly distributes along the boundaries of urban built-up areas and on both sides of newly built roads in different periods. The change of bare land landscape index reflects that before 2011, the growth mode of bare land area was mainly patch boundary expansion and patch merging. From 2011, bare land was segmented or reused on the basis of original patches. （2) From 1999 to 2017, 61.35% of bare land was converted from cultivated land and 23.58% from woodland. During the same period, 51.88% of bare land was transferred to cultivated land and 24.79% to urban impervious surface. （3) The evaluation index system of bare land transformation and utilization was constructed based on the factors of location, topography and landscape pattern. The bare land was classified into five types: community reuse, urban greening, urban infrastructure construction, urban agriculture and ecological restoration, the purpose of this study is to provide a reference for bare land transformation and utilization in the process of urbanization in the study area.