Comparison of AHP and BWM methods based on ArcGIS for ecological suitability assessment of Panax notoginseng in Yunnan Province, China

Panax notoginseng (P. notoginseng) is a traditional Chinese medicinal material with high economic and medicinal value. There is an urgent need to find new cultivation areas due to continuous cropping barriers and the effects of climate change. This study integrated the geographical environment of Yunnan with the necessary requirements for a suitable habitat for P. notoginseng and comprehensively analyzed climatic, topographical and soil factors. Furthermore, the criteria were weighted and prioritized by the analytic hierarchy process (AHP) and the best worst method (BWM) respectively, and the overlay analysis method was used to present the suitability map in the GIS environment. Two ecological suitability assessment models were established and compared to explore the ecological suitability regionalization of P. notoginseng in Yunnan Province, China. The results showed that:(1) Among the 12 driving factors, precipitation in the hottest season is the most important, followed by average temperature in the coldest season, average temperature in the hottest season, altitude, and annual precipitation. (2) The most suitable, suitable, and unsuitable regions obtained by the AHP-GIS model accounted for respective 17.98%, 33.41%, and 48.61% of the total area of Yunnan. The values for BWM-GIS model were 13.93%, 40.25%, and 45.81%, respectively. (3) The suitable regions obtained by the two models were overlayed and concentrated in Wenshan, Qujing, Kunming, Chuxiong, Baoshan, Dali, Lijiang, Honghe and Yuxi in central Yunnan, while the unsuitable regions were distributed in Xishuangbanna, Puer, Dehong, Diqing, and southwestern Zhaotong. The sensitivity of the assessment model was analyzed, and its reliability was verified by receiver operating characteristic (ROC) and area under curve (AUC). The BWM-GIS model (AUC=0.85) had higher accuracy than AHP-GIS model (AUC=0.822), and was more suitable for ecological suitability analysis of P. notoginseng. Our research results provide a theoretical basis for the rational expansion of cultivation regions of P. notoginseng and agricultural layout planning in Yunnan Province of China.