摘要：Building Sustainable Cities and Human Communities is one of the 17 Sustainable Development Goals of the United Nations. And the sustainability of culture plays an important role in the sustainable development of cities and human communities. Language is an important carrier of culture, and the sustainability of language is the key factor in the sustainability of culture. How to measure the sustainability of language and its niche is key to achieving sustainable cities and communities. This paper systematically summarized the concept of niche and the theory of ecolinguistics as a theoretical basis for the quantitative study of the linguistic niche, and at the same time, the methods of niche measurement were summarized to provide mathematical support for the quantitative study of the linguistic niche. The Shannon-Wiener index and Pianka index were used to quantitatively study a particular linguistic niche for the first time, based on the use of Hmong and Mandarin in Jianhe County, Guizhou Province, China. The results showed that in the temporal dimension, the niche overlap indexes of Hmong and Mandarin were all above 0.9 in the sample villages, but in the spatial dimension, the niche overlap indexes of both languages were between 0.5 and 0.6. The spatial niche separation moderated the high temporal niche overlap, which made the two languages’ spatio-temporal niche overlap at a medium-high level. The quantitative study of a linguistic niche proved helpful in quantifying the level of sustainable development of language and culture, thus providing timely, accurate, and dynamic reference data to inform macro-control policies on the sustainable development of cities and human communities.
