2.1. Study Area

The Huaihe River is one of the seven major rivers in China, located between the Yangtze River and the Yellow River. The watershed covers an area of 270,000 km² and spans five provinces in China, including Henan, Jiangsu, Hubei, Anhui and Shandong Provinces. The Huaihe River originates in Xinyang City in Henan Province and enters the Yangtze River and Yellow Sea from Jiangsu Province. There is a large drop in the elevation of the watershed, with hilly areas accounting for one-third of the watershed area; plains account for the remaining two-thirds. The Huaihe River flows through the territory, with developed water systems and numerous tributaries. Precipitation varies greatly from year to year, and rainfall occurs in a relatively concentrated time frame. The flood season occurs from June to September, with flood disasters occurring once every two to three years on average, The Huaihe River watershed is one of the watersheds with the most frequent and serious flood problems, due to the mountainous terrain in the upper reaches, relatively concentrated rainfall in the watershed and other influencing factors, including human activities. Disputes over drainage in the Huaihe River watershed continue. According to incomplete statistics, from 1949 to 1985, there were more than 400 disputes over drainage, water use and aquatic products between Shandong and Jiangsu Provinces. However, Jiangsu Province is one of the most economically developed provinces in China; the losses caused by floods to Jiangsu Province are also huge. The Huaihe River flows through eight cities in Jiangsu Province, including Xuzhou, Nantong, Lianyungang, Huai’an, Yancheng, Yangzhou, Taizhou and Suqian (see Figure 2).

Jiangsu section of the Huaihe River watershed.