Objective  This research aims to explore the key role of modular control in the formation of the "landscape-city integration" phenomenon in traditional landscape cities, and to understand the relationship between traditional landscape construction and urban order.

Methods  Taking the Jinan Prefectural City in Ming and Qing dynasties (before 1860) as the research object, this research, based on the field survey of Jinan and the analysis of historical materials such as chorographic maps and historical images, sorts out the evolution of the water system in Jinan Ancient City during the period from Wei and Jin dynasties to the end of late Qing Dynasty and, with the help of relevant drawings, clarifies the development of the "landscape-city integration" urban structure of Jinan City in such aspects as urban site selection, urban morphology and urban landscape construction under the guidance of the modular system. The research conducts a matching study on module and important urban spaces and landscape elements of Jinan City such as streets, De Prince Palace and scenic spots, to reveal their key connections with the urban modular system. In addition, based on the modular system, the research reveals the morphological changes generated in three dimensions of urban contour, street and scenic spot, and elaborates on the humanistic design considerations of landscape beyond the modular system.

Results  The morphological pattern of Jinan Ancient City changes mainly in three historical periods: Licheng City in Wei and Jin dynasties, Qizhou City in Tang and Song dynasties, and Jinan Prefectural City in Ming and Qing dynasties. During Wei and Jin dynasties, the location and form of Licheng City were determined according to many factors such as ritual system and landscape topography, and the landscape pattern then promoted the formation of the city with a modular scale of 450 meters (about 280 Ming steps) from the city wall to the middle street. This modulus, as the basic modulus of Licheng City, accompanied the evolution of the city's form several times. During Tang and Song dynasties, with the expansion of city scale by nearly four times, Licheng City was renamed Qizhou City. According to relevant literature, the scale and pattern of Jinan Ancient City were mostly formed in Tang and Song dynasties, and the modular system thereof may also be formed in this period. During Ming and Qing dynasties, with the gradual perfection of the modulus of urban construction, Qizhou City was renamed Jinan Prefectural City. Jinan Prefectural City in Ming and Qing dynasties takes the scale of 450 meters (about 280 Ming steps) of Licheng City in Wei and Jin dynasties as the basic unit of expansion, showing that the old urban order became the standard for the expansion of the new city. The construction of De Prince Palace and the Temple of Heaven and Earth reinforced the control of the modulus of 224 meters (about 140 Ming steps) in the east-west direction and formed the control scale of the urban form of 322 meters (about 200 Ming steps) in the north-south direction, reshaping the modular system of Jinan Prefectural City, highlighting the control position of the central axis, and accordingly transforming the modular system of Jinan Ancient City from an evenly and horizontally distributed system to a center-dominated one, which influences not only the layout of city streets, but also the construction of scenic spots. The outlines of walls, the layout of streets and the construction of scenic spots are all controlled by the modular system, reflecting the unity from urban form to the construction of scenic spots under modular control, which also becomes the evidence of the modular order of traditional urban construction in Jinan. Although the structure and form of Jinan Ancient City are under modular control overall, there still exists a certain variation in part of the urban form and the construction of several crucial scenic spots, which is mostly related to natural conditions and human control. For example, some of the scenic spots along the central axis are off-axis due to the influence of water system. Some of the scenic spots are created by the springs nearby, with public buildings built around the springs, forming a new pattern of urban landscape element layout that deviates from the modular system.

Conclusion  This research clarifies the role of the modular system in controlling the skeleton of Jinan's "landscape-city integration" pattern, and the modular control of the traditional integrated landscape and city construction forms an urban pattern featuring "unity of man and nature" that incorporates "changes" into "rules", which shows the plurality and richness of traditional urban rules. This research aims to, through the study of Jinan Ancient City, extend the exploration of landscape issues in the study of traditional urban order, discover the neglected landscape and node elements, and incorporate such elements into the study of the overall urban pattern, while arousing people's interest in the non-intuitive and non-figurative implicit relationship between key elements (streets and nodes) in the conservation of ancient cities. As an important component of urban structure, ancient cities should be adequately protected in urban conservation.