Abstract: As one kind of the important carriers and of the spatial distribution types of the man-land interaction in pastoral area,the spatiotemporal characteristics of settlements can be used to characterize the evolution law of pastoral areas and human settlements.In this study,the statistical analysis methods of GIS and Excel were used to study the spatiotemporal distribution of pastoral settlements in the typical grassland in Zhenglan Banner during the period from 2000 to 2017,and the main factors affecting the settlement formation and development were analyzed.The conclusions are as follows: ① Spatiotemporal distribution of the settlements in Zhenglan Banner was in a rapid growth trend,the overall distribution of settlements was centralized,and the settlement density was high in the south but low in the north; the scale of settlement patches was quite different,and the small settlements were dominant; ② In the region,there was an obvious regional difference in distribution pattern of settlements.Settlements were mainly distributed in the regions with slope of 5°-15°and elevation of 1 196-1 428 m a.s.l.With the change of elevation and slope,the number and scale of settlement patches tended to be a normal distribution,and the number and the scale of settlement patches tended to a gradual decrease with the change of roads and rivers; ③ Hydrology,traffic,topography and other geographical factors limited the location choice of settlements in Zhenglan Banner,and these factors were dominant in spatial distribution of the settlements.In general,the analyzed results of development and formation mechanism of the settlements in pastoral area could provide the important references for regulating and optimizing the spatial layout of the whole pastoral area.

Key words: pastoral area, settlement, spatiotemporal evolution, formation mechanism, Zhenglan Banner, Xilingol League