With the rapid development of China’s ice and snow industry, the use of snow-melting agents as a nonpoint source pollution source is increasing, and the impact on the environment cannot be ignored. This paper expounds the agent, purpose, mechanism, and current situation of snow-melting agents at home and abroad and analyzes the national standards, industry standards, and technical indicators of various provinces and cities. This paper puts forward the standard of snow-melting agents, standardizes the production management and detection method of snow-melting agents, improves the quality of snow-melting agent products, and solves the adverse effects of environmental pollution of snow-melting agents. In order to select an economical, effective, and environmentally friendly snow-melting agent application plan that is suitable for cold mountainous areas, the article proposes a TOPSIS method evaluation model with the purpose of source control combined with grey correlation. Calcium, magnesium chloride, chloride salt mixed snow-melting agent (1 : 1 : 1 ratio), and calcium and magnesium acetate are used to melt snow in four specific environments (high cold and high sensitivity, high cold and low sensitivity, low cold and high sensitivity, and low cold and low sensitivity). The pros and cons of the dosage regimen are evaluated. The combined weighting method is used to overcome the shortcomings of the individual subjective and objective weighting methods, and it is concluded that calcium and magnesium acetate is the optimal solution in high-cold and high-sensitivity areas, calcium chloride is the optimal solution in high-cold and low-sensitivity areas, and magnesium chloride is the optimal solution in low-cold and high-sensitivity areas. As the optimal solution, calcium chloride with low cold and low sensitivity is the optimal solution.

Abstract. Written information on the surface of cultural relics can record important historical events. Due to the influence of natural and human factors, the surface of cultural relics fades and the words are difficult to identify. Take advantage of the hyperspectral data image and spectral unity and wide spectral range, a cultural relics surface handwriting enhancement method based on manifold learning and mixed pixel decomposition was proposed. First, the minimum noise fraction (MNF) transformation was carried out on the hyperspectral image, and then the top 10 bands were selected for inverse MNF transformation to reduce noise of the hyperspectral image. Then, the reconstructed image was dimensionally reduced by locally linear embedding (LLE) to obtain a gray image with the maximum amount of information. At the same time, the spectral features of the handwriting and background area in the reconstructed image were analysed. The automatic target generation process (ATGP) was adopted for endmember extraction on the reconstructed image to identify the endmember of handwriting. The abundance map of handwriting area was obtained by the fully constrained least squares (FCLS). Finally, the gray image and the abundance map of the handwriting region were weighted together to obtain the handwriting enhanced image. The true color image was synthesized from the reconstructed image, Then the true color image and the handwriting enhancement image were fused to obtain the handwritting fusion image. The hyperspectral image of a faded text in Shuozhou City, Shanxi Province, China, was used as an example for verification, and the results showed that the method can effectively enhance the text on the surface of the artifacts.