Research on the Comprehensive Investment Benefits of the Three Gorges Project Based on DEA Model

The Three Gorges Project represents a colossal investment with an extended construction timeline and a far-reaching industrial impact, serving as a cornerstone in ensuring national water security, galvanizing substantial investment demand, and promoting economic expansion. This study employs the Data Envelopment Analysis (DEA) model to establish an input-output framework encompassing economic, social, and ecological dimensions, enabling a systematic scrutiny of the variations in indicators such as the scale of returns, input redundancy, output deficiency and comprehensive efficiency value of the Three Gorges Project spanning from 1995 to 2021. The findings reveal that barring 2004, 2009, and 2010, both the investment and output of the Three Gorges Project have consistently attained maximal benefits, attaining peak project efficiency. Moreover, the scale benefits derived from the Three Gorges Project exhibit an ascending trajectory from 1995 to 2016, stabilizing at a commendable level following the project's completion from 2017 to 2021. Notably, two indicators, namely the frequency of days with favorable air quality in the region and the regional Engel coefficient, have reached optimum output levels, emphasizing the significant positive impacts of the Three Gorges Project investment in ameliorating the ecological milieu and enhancing societal well-being. This investigation furnishes a scientific underpinning for analyzing and appraising the comprehensive benefits stemming from investments in the Three Gorges Project, offering a crucial point of reference for optimizing the comprehensive efficiency of major water conservancy project investments.