贝叶经是最古老的文献典籍形式之一，具有重要的历史文献价值，因其特殊的叶片材质极易受到外 界因素影响而产生病害。水渍是贝叶经文物最常见的病害之一，这种渗透性的污染沉积直接影响贝叶经的外 观形貌，甚至危害到文物本体稳定性。本文针对两函馆藏贝叶经文物，采集其可见反射图像和紫外荧光图像， 使用便携式pH 计、色度仪对水渍和无水渍区域的物理性质参数进行测试，结果表明紫外光条件下水渍线更 加明显，水渍区域容易区分，且水渍区域的pH 值降低，出现了明显色差。大面积微区X 射线荧光成像和傅里 叶变换红外光谱ATR 测试结果表明，水渍区域K、Ca、P、S、Mn等元素出现聚集，纤维素和半纤维素的相对含 量降低。本研究首次采用基于无损技术的贝叶经水渍污染综合表征方法，对贝叶经水渍污染开展综合的认知 分析，为贝叶经的科学合理保存提供了基础，对贝叶经水渍污染的清洗和去除具有重要的指导意义。

Palm leaf manuscriptsarea kind of the oldestliterature with significant historical and literary values.The leaves are easilydamagedby external factors which can result in disea- ses.Water stainsareone of the most common diseaseson palm leaf manuscripts.They are per- meable contamination depositsthatcan affect the appearance of palm leafmanuscriptsand even damage the subjects'stability.In this paper,visible-reflected images andultravioletfluores- cence images oftwo sets of palm leaf manuscript collectionsare captured.Physical parameters- including pH values and chromatic aberration in water-stain and non-water-stain areasare measured by portable pH meter and colorimeter.The results show that"tideline"is more obvious and water-stain areasareeasier to distinguish under ultraviolet light.Meanwhile, pHvalues are all smaller in water-stain areasand the color differencebetween water-stain and non-water-stain areas is obvious.The results of micro-X-ray fluorescence and Fourier trans- form infrared spectroscopy coupled with ATR show that elements including K,Ca,P,S, and Mn are enriched in water-stain areas,with the decrease of the relative contents of cellu- lose and hemicellulose.Acomprehensive determination methodof water stain on palm leaf manuscripts based on nondestructive techniquesis first establishedin this study,whichpro- vides a deep understanding ofwater stain pollution.The method established in this study is meaningfulfor the scientific and rational preservation of palm leaf manuscriptsand can be a di- rection for furthercleaning and removal of water stain pollution.