Assessment on eco-environmental quality of the Yellow River Basin by considering desertification index

Desertification has had a significant impact on the ecological environment of the Yellow River Basin(YRB) in China. However, previous studies on the evaluation of the ecological environment quality(EEQ) in the YRB have paid limited attention to the indicator of desertification. It is of great significance to incorporate the desertification index into the spatiotemporal assessment of the EEQ in the YRB in order to protect the ecological environment in the region. In this study, based on multi-source remote sensing data from 91 cities in the YRB, this article proposes a desertification remote sensing ecological index(DRSEI) model, which builds upon the traditional Remote Sensing Ecological Index(RSEI)model, to analyze the spatiotemporal changes in the EEQ in the YRB from 2001 to 2021. Furthermore,using the geographic detector(GD), and geographically and temporally weighted regression(GTWR) model, the study assesses the impact of human and natural factors on the EEQ in the YRB. The research findings indicate that:(1) Compared to the traditional RSEI, the improved DRSEI shows a decreasing trend in the evaluation results of the EEQ.Among the 24 cities, the change in DRSEI exceeds 0.05compared to RSEI, accounting for 26.37% of the YRB.The remaining 67 cities have changes within a range of less than 0.05, accounting for 73.63% of the YRB.(2)The results of the GD for individual and interactive effects reveal that rainfall and elevation have significant individual and interactive effects on the EEQ. Furthermore, after the interaction with natural factors, the explanatory power of human factors gradually increases over time. The spatial heterogeneity results of GTWR demonstrate that rainfall has a strong direct positive impact on the EEQ,accounting for 98.90% of the influence, while temperature exhibits a more pronounced direct inhibitory effect, accounting for 76.92% of the influence. Human activities have a strong negative impact on the EEQ and a weak positive impact.