Simplified Method of Assessment of Weathering on Historical Stone Monuments: An Example of El-Merdani Mosque, Cairo, Egypt

Stone damage and deterioration of historical monuments due to weathering is a growing concern. Therefore, precise determination of weathering damages is vital for remedy and sustainable monument preservation. The aim of this study is to appraise the changes in the fragment of El-Merdani Mosque's facade years ago studied by B. Fitzner and by comparative research to develop a method of determining weathering forms and weathering intensity of this region's historical stone monuments with limited accessibility. Elaborated simplified weathering classification supported by Red Green Blue (RGB) colour model values for particular object and data statistical evaluation is performed. The results are verified in the limited area on the lower part of the southern facade of the Great Pyramid of Cheops at Giza. Such solution enables us to elaborate qualitative methods of evaluation that would be based on remote comparison and observation of the object.