Construction of a Visible Rainbow Assessment Conceptual Model and Analysis of Rainbow Resource Spatio-temporal Distribution in China

Rainbows are a weather landscape resource with great ornamental value but no effective observation data. To know the distribution of rainbow resources in China and provide meteorological services for local tourism and other industries, on the basis of relevant theories, four factors necessary for rainbows are determined, which are the number of thunderstorms, the solar altitude, the terrain, and the visibility affecting rainbow viewing quality. A conceptual model of visible rainbow evaluation is constructed based on these factors. Using this model, the distribution of rainbow resources is evaluated based on the national meteorological observation data and latitude data from 1980 to 2010, and the following conclusions are drawn: (1) The rainbow resources in South China, southern Yunnan and the Qinghai–Tibet Plateau are relatively rich. Among them, the possibility of a rainbow appearing in different seasons in South China is at the forefront of the whole country, but few rainbows appear in winter. (2) the abundance of rainbow resources is smaller in the northern region than in the south, but in some places, it is very high in the national ranking because of the comprehensive influence of solar altitude, topography, visibility, and thunderstorm weather. For example, the western part of Xinjiang and some parts of northern North China have the advantage of developing rainbow ecotourism. Particularly in Zhaosu, Xinjiang, from May to September, the number and ornamental value of rainbows ranked first in China. (3) inspection shows that the conceptual model can be used to evaluate or rank the richness of rainbow resources throughout the country and can be further applied to the rainbow forecasting model, which will improve the accuracy of rainbow predictions.