Economic and Environmental Effects Assessment of Water Transport Infrastructure Based on MRIO Modeling and System Dynamics Simulation: A Case Study of the Jinghan Canal of China

The Jinghan Canal, aimed at resolving the “middle blockage” problem of the Yangtze River's golden waterway and addressing the comprehensive challenges of navigation safety and ecological protection, as well as enhancing the water security capabilities of the four water systems in the Jianghan Plain's four lakes area and Dongting Lake, is located in Hubei Province. With a total length of 246 km (including 93.5 km of new canal) and seven 10,000-ton-class port areas along its route, this paper systematically evaluates its strategic value and economic-environmental effects using a combined short- and long-term analytical framework. A Multi-Regional Input-Output (MRIO) model estimates the short-term stimulus of the 77.93-billion-yuan investment during construction. Results show an investment multiplier of approximately 2.76, driving over 215 billion yuan in total output and generating more than 84.9 billion yuan in value added across the Yangtze River Economic Belt. Hubei Province benefits most significantly, with cross-regional synergies in metal smelting, transportation, and finance. A System Dynamics (SD) model simulates the medium- to long-term evolution of Hubei, Hunan, and other provinces. The findings indicate that canal operation, by reducing logistics costs and optimizing transport structure, continuously promotes regional economic growth and industrial upgrading. Carbon emissions exhibit a green transition pattern characterized by an “overall decline with gradually slowing reduction rate,” though significant spatial heterogeneity exists across provinces. The study concludes that the Jinghan Canal is not only a key project for optimizing the national waterway network but also a systemic strategic project fostering regional coordination and green growth, offering policy references for major infrastructure planning in other regions.