Determination of production regions for pollution-free Chinese medicinal materials by geographic information system: Achyranthes bidentata (Niu Qi) in Tianjin as an example

BACKGROUND: The land and ecology suitability for producing pollution-free Chinese medicinal materials should be evaluated based on Geographic Information System (GIS). This study aims to determine production regions for pollution-free Achyranthes bidentata in Tianjin as a case to illustrate the workflow based on GIS. METHODS: The slopes, land usage, residential areas and roads were selected to evaluate the land suitability, to avoid the potential pollution sources. The ecology suitability evaluation was performed based on the soil type and nine climate factors, such as active accumulated temperature, mean January temperature, mean July temperature, the lowest temperature in January, the highest temperature in July, mean annual temperature, sunshine duration, relative humidity, annual precipitation, affecting the natural growth of A. bidentata. RESULTS: The best production regions for pollution-free A. bidentata in Tianjin, with a total area of approximately 575 km(2), were found in Jinghai County, Ninghe County, Wuqing District, and Dagang District. CONCLUSION: This study illustrated a workflow based on GIS for determining the production regions in Tianjin for pollution-free A. bidentata.