Figure 1 Location of the 8 study sites in Anhui Province and the reasons for choosing themAs the provincial capital of Anhui Province, Hefei’s gross domestic product (GDP) broke the trillion-dollar mark in 2020. Hefei’s annual per capita disposable income of urban residents is $7469, an increase of 6.3% yearly, which is 2.8 and 1.2 percentage points higher than the national and provincial levels, respectively. For rural residents, the per capita disposable income was $3756, an increase of 8.1%, which was 1.2 and 0.3 percentage points higher than the national and provincial levels, respectively. Hefei lies in the central part of Anhui Province, so it was selected as a typical representative. Tongling, Anqing, and Ma’anshan are located in the southern part of Anhui Province and are located along the Yangtze River. Their economic levels are better than that of northern Anhui. They were chosen as representatives of southern Anhui. Huainan, Bengbu, Fuyang, and Huaibei are all located along the Huaihe River. Economic development is low in the province, but the population size is huge. The per capita GDP is not high, and they were selected as the representatives of northern Anhui. Image by Adobe Photoshop CC2019.