基于大型水利工程建设阶段的三峡库区土地利用变化遥感分析

使用5 期TM/ETM数据,借助动态度、综合指数和程度变化指标,旨在对比理解不同建设阶段三峡库区土地利用变化的特征与轨迹。结果表明：① 耕地与林草地间的转换、耕地和林地被建设占用、林草地互换和耕地、林地与草地被水体淹没是三峡工程整个建设20 年来土地利用转换的主要方式;② 不同建设阶段因驱动者出现的时序不同和作用程度的差异,土地利用及其驱动者在总体格局框架下体现出显著的细部轨迹;③ 整个工程建设的20 年土地利用程度综合指数相对平稳,处于中等以上水平,而利用程度的变化总体呈降低趋势,带有正“W”型的动态格局;④ 主要土地利用转换方式在空间上的分布广度和集聚度具有较大差异,主体性工程对主要土地利用转换方式的影响呈现强异质性。研究结论有助于丰富对水利工程胁迫下土地利用的理解,为未来适应性土地利用调控政策的制定提供科学依据。

Remote sensing analysis of land use change in the Three Gorges Reservoir area,based on the construction phase of large-scale water conservancy project

There is a the strong correlation of major land use transformation patterns with the timing and strength of subjectivity projects and their hysteresis effects when large-scale water conservancy projects (especially extra-large reservoir) constructed. The construction phase of Three Gorges Project in this paper was divided into five time points, considering the impacts of strong cloudy and foggy on image quality and its availability. The objectives of this paper was to comparatively understand the characteristics and trajectories of land use change the different project construction stages in the Three Gorges Reservoir Area through single land use dynamic degree, land use composite index, land use degree change, using five-term TM/ ETM image data. The results showed: (1) The transformation of cultivation land and forest-grass land, building land occupied cultivation land and forest land, interchange between forest and grassland, and cultivation land, forest land and grassland water flooded by water body were the main ways of land use conversion throughout the construction phase of the Three Gorges Reservoir Area. (2) Land use change and its drivers presented significant detailed trajectory with the stage under the framework of the overall pattern, due to the drivers occurring at different times, and the differences of their role strengthen degree during various construction stages. (3) The composite index of land use degree was relatively stable, and it was more than in the middle level throughout the construction phase. However, the change in land use composite index took overall on decreasing tendency with a "W"-type dynamic pattern. (4) The distribution breadth and concentration degree of major land use conversion patterns possessed larger differences at spatial scale. Moreover, the effects of subjectivity projects on major land use conversion patterns showed strong heterogeneity with the deepening of project construction phase. The results of this paper will contribute to rich the people''s understanding to land use under the stress of water conservancy, and provide a scientific basis and reliable support to arrange adaptive land use regulation policy in the future.