长城色彩折射的建造技艺、管理制度与民族智慧

Building Techniques,Management System,and National Wisdom Reflected by the Colors of the Great Wall

与宫殿、寺庙、石窟等建筑遗产相比,长城在材料色彩方面“乏善可陈”,甚至还出现专有名词“长城灰”,将长城的色彩特征固化。本文通过无人机采集明长城全线图像并引入图像类人工智能提取其主色调,首次量化各段长城色彩、绘制全线色彩地图,证明长城“富彩”;并结合材料成分分析、史料挖掘,首次揭示色彩背后蕴含的长城材料色彩法则、色彩质量评价标准与奖励办法,以及以色立威、以建止战的核心意图。这一成果尝试填补古代建筑色彩研究的长城缺环、揭示长城作为军事遗产的材料色彩艺术造诣,挖掘出未开发长城段新的遗产景观资源,从全新的视角助推长城国家文化公园建设。

Incomparable to some colorful architectural heritages,including palaces,temples,and grottoes,the Great Wall does not stand out for the colorfulness of its building materials.There is even a terminology coined after the Great Wall:"Great Wall Grey",which solidifies the color characteristics of the Great Wall.Spanning across a vast land in northern China with various geographical features,the Great Wall was built with all kinds of locally sourced materials,including stone materials with significantly different natural colors.However,there are only case studies on the compositions of the materials used by certain parts of the Great Wall.Based on the colors of the stone materials used by the Great Wall,a color survey was conducted across the best-preserved Ming Great Wall for statistical and quantitative analyses.Mask R-CNN and K-means algorithms are introduced into this study to extract the main colors of different building materials from two million images taken across the Great Wall and generate a color map for the entire Great Wall.For segments of significant importance,images were taken twice and color calibrations were carried out accordingly,based on which,the most colorful wall of the entire Great Wall and color-matching patterns of the watchtowers were identified.Electronic microscope and X-ray spectrometry were conducted on the colorful stone material samples taken from the Great Wall.It is found that sedimentary rock which has consistent color and fine particles of similar sizes is often used to build the lower part of the stone wall of hollow watchtowers;and igneous rock which contains large crystals of various sizes is often used for multi-colored walls with patterns.Therefore,it is reasoned that as the ancient Chinese had already mastered the physical properties of different materials,they intentionally chose high-quality sedimentary rocks and carefully processed them into slabs to build watchtowers of more complicated designs which required higher building standards,while they roughly processed raw stone materials which are diffcult to work with to build walls with patterns.As far as the causes for different colors are concerned,the colors of different stone materials are linked to various metal ions of different valences and contents.From the perspective of historical literature,strict standards were formulated for the side wall quality of the Great Wall and established the basis for colorful walls.Military commanders of the Ming Dynasty,including Qi Jiguang and Tan Lun,improved the building quality and standards for the Great Wall through clear rewarding and punitive measures.To serve the military purpose of intimidating potential enemies is also one of the reasons for building the grand and orderly colored walls.Besides filling the gaps in research relating to the colors of traditional buildings,this paper tried to re-establish the historical scenes when the Great Wall was built,reviewed the artistic pursuit of ancient builders and craftsmen,and the rigorous attitude demonstrated by the supervisors managing the construction the Great Wall when they formulated the standards for building qualities.This paper reveals the pinnacle of colored artwork reached by the Great Wall.The colorful stone material samples taken from the Great Wall can also be used for exhibitions at the Great Wall Museum.The colorful segments of the Great Wall discovered through this paper can be utilized to facilitate the development of some undeveloped regions into tourist attractions so that the geographical environment,natural landscape,and the Great Wall can be all linked together as tourist attractions.