黄土高原丘陵沟壑区是我国西部新型城镇化实践的克难攻坚地,在未厘清地域性特征的情况下,现代城乡规划设计的介入对当地环境和文化产生了较大冲击。以陕北米脂县东沟为例,基于卫星遥感影像、数字高程模型（DEM）等数据,利用格网法揭示东沟地形变化与聚落规模的空间分布特征,借助四象限散点图法和立体网格分维模型测度并评价东沟地形复杂性与聚落集聚性的耦合协调关系及聚落空间分布效率,总结适宜于沟壑区的聚落空间营建模式。结果表明：（1） 东沟聚落从沟口至沟内存在明显的空间分异特征：如聚落逐步偏离河岸,其建筑密度和容积率呈现从高到低、再升高降低的变化等。（2） 根据东沟地形复杂度与聚落集聚度的叠加分析,平缓地形中的集聚聚落与复杂地形中的分散聚落属于人地关系协调的聚落类型,这两类聚落约占所有聚落总规模的70.5%。（3） 东沟聚落的立体网格分维数分段特征明显,其中台地行列式和自由行列式聚落的立体分维数最高,为2.35~2.55。（4） 在5种东沟典型人居空间模式中,台地行列式、自由行列式及密集斑块式聚落具有人地协调、空间利用高效的双重特征,可作为丘陵沟壑区聚落空间营建的参考。

The hilly-gully region of the Loess Plateau is a great challenge in the practice of new urbanization in western China. Without clarifying its regional characteristics, the intervention of modern urban planning and design has impacted the local environment and the native culture considerably. With the destruction caused by human settlements to the natural environment and the impact of modern towns on traditional settlements in the Loess Plateau of northern Shaanxi, an urgent task is to make rational use of the land in hilly-gully regions and explore the construction mode of settlements on the basis of the wisdom and experience of local people from the perspective of urban-rural integration and harmony between human beings and nature. Three-dimensional spatial characteristics in the long-term evolution of human settlements in hilly-gully regions are becoming increasingly obvious. To improve the utilization efficiency of hilly-gully land in urban construction, three-dimensional fractal analysis for organic growth of settlements has become one of the important contents of urban morphological study. With Donggou, Mizhi County, in northern Shaanxi taken as an example, this article revealed the topographical changes in Donggou and the spatial features of its settlement distribution by using the mesh method on the basis of satellite remote sensing images and digital elevation model altitude data. This work also analyzed and evaluated the coordination relationship between Donggou’s topographical complexity and settlement density through four-quadrant classification, and then measured and compared the spatial efficiency of various settlement patterns by using 3D grid fractal dimension models. This work proposes that settlement samples with high grid fractal dimensions and fit into the landscape are important references in dealing with the urban spatial development problems in the hilly-gully region of the Loess Plateau. The results are as follows: (1) The settlements in Donggou exhibit obvious spatial variation from the outside to the inside; the building density and the floor area ratio first decrease then increase and decrease again as the settlements move farther away from riverbanks. (2) Overlay analysis of Donggou’s topographical complexity and settlement agglomeration degree shows that the concentrated settlements on smooth terrain and the scattered settlements on complex terrain reflect a harmonious man-land relationship, and these two settlement types account for about 70.5% of the total land area of all settlements. (3) The 3D grid fractal dimension value of the settlements in Donggou is obviously segmented, while terrace parallel and free parallel settlements have the highest 3D fractal dimension value of 2.35-2.55. (4) Among the five typical spatial patterns of settlements, three efficient and appropriate patterns, terrace parallel, free parallel, and block mass types, are characterized by a harmonious man-land relationship and efficient space utilization, and can thus be used as a reference in creating settlement spaces in hilly-gully regions.