Assessment of spatial-temporal differences of industrial eco-efficiency in the huaihe river economic belt

To promote the coordinated and healthy development of ecology and economy of Huaihe River Economic Belt, the paper tries to make an exploration of the path of industrial eco-efficiency improvement. This study chooses 25 prefecture-level cities in Huaihe River Economic Belt of China as the case studies, then selects Slacks-Based Measure with Undesirable (SBM-Undesirable) model, Malmquist-Luenberger (ML) index and Kernel Density Estimation and analyses the characteristics of industrial eco-efficiency from 2010 to 2019. Then, the spatial distribution characteristics of industrial eco-efficiency were investigated based on Exploratory Spatial Data Analysis (ESDA). The results of the above situation indicate that: (1) The overall efficiency level of industrial eco-efficiency of the Huaihe River Economic Belt has been relatively low from 2009 to 2018. The efficiency growth of regional industrial eco-efficiency showed a distribution pattern that the Eastern Sea-River-Lake Linkage Zone was greater than that in the Northern Huaihai Economic Zone and that in the Midwestern Inland Rising Zone. (2) The kernel density curve of industrial eco-efficiency shifts to the right, the efficiency increases but the internal difference was great. The Technical Change (TC) index decomposed from ML index is the key factor affecting the industrial eco-efficiency. (3) The industrial eco-efficiency of the Huaihe River Economic Belt shows a decreasing trend from the northeast to the southwest, and the efficiency changes greatly in the north-south direction, with obvious spatial agglomeration, strong spatial stability and dependence. Therefore, this study estimated the ratio of the economic and ecological output to the input required for industrial production and focused on the identification of differences of efficiency. It was conducive to transforming the mode of industrial development and promoting the harmonious development of industrial ecology, and taking the road of sustainable development.