Huai

Huai most commonly refers to the Huai River (淮河), a major river system in eastern China that is part of the Yangtze River basin. The river flows through Henan, Anhui, and Jiangsu provinces, with an overall length of about 1,000 kilometers (roughly 620 miles) and a drainage basin of around 180,000 square kilometers. Its course generally runs northeast, and its watershed supports extensive agricultural and urban areas. Historically, the Huai River valley has been considered a geographic boundary between northern and southern China, influencing climate, culture, and economic activity in the region.

Hydrology and flood management have long been defining features of the Huai. The river has a history of severe floods and droughts, prompting successive flood-control and irrigation projects. In the modern era, water management in the Huai basin has been integrated with broader eastern China hydraulic systems, including canals and diversion schemes, to regulate flow, protect populations, and support agriculture.

Places and names associated with Huai include the city of Huai'an in Jiangsu, which lies on the river and derives its name from the same character. The pinyin Huai can represent different Chinese characters depending on context, such as 淮 (the river) or 怀 (to cherish), among others. As a transliteration, Huai also appears in various place names and, less commonly, as a surname or part of personal names.

In summary, Huai principally designates a major eastern Chinese river and its surrounding basin, with additional usage in geographic names and linguistic contexts.