## 4 Discussion
### Limitations and Future Prospects  
Looking ahead, further research is needed to accurately identify high-value carbon budget areas in lake-intensive regions and guide carbon reduction and sequestration strategies:  
(1) Although the carbon balance model in this study is robust in the Dongting Lake region, future changes in urban planning or socioeconomic demands may alter the balance between carbon emissions and sequestration. For example, if industrial transformation policies in the Yangtze River Economic Belt encourage a shift from traditional manufacturing to clean energy industries, structural changes in GDP would significantly lower carbon emission intensity per unit of output. This transition may also increase water demand, particularly for hydropower, affecting the carbon sequestration capacity of aquatic ecosystems. To address these changes, future research should dynamically update carbon emission coefficients, adjust model parameters, and incorporate the latest socioeconomic and environmental data. By further exploring the interaction between socioeconomic policies and carbon emissions, the model's responsiveness to real-world changes can be ensured. For instance, we plan to integrate scenario analysis into the model and adjust carbon source-sink parameters dynamically using policy-driven factors (e.g., carbon taxes and ecological compensation) to enhance the flexibility of carbon balance projections. We will also explore integrating dynamic carbon sequestration models to track carbon emission fluctuations driven by regional policies, climate change, and industrial restructuring. Additionally, we recommend establishing a dynamic monitoring system to continuously track changes in socioeconomic activities and greenhouse gas emissions in the Yangtze River Basin. This will ensure forward-looking research findings.  
(2) This study does not comprehensively account for carbon-to-methane conversion across different land-use types. Methane, a potent greenhouse gas, is primarily emitted from rice cultivation in agricultural production spaces, coal mining in industrial-mining production spaces, wastewater treatment in urban living spaces, and lake sediments in water ecological spaces. Under anaerobic conditions, these land-use types may produce methane, influencing the overall carbon budget pattern. Due to data and model limitations, this study has not yet systematically analyzed methane emissions. Future research should investigate carbon-to-methane conversion mechanisms across land-use types, assess their dual effects on the carbon budget, and improve the scientific rigor of carbon balance evaluations.  
(3) Wetlands in lake-intensive regions are widely recognized as key carbon sequestration areas. Although wetlands have strong carbon sequestration capacity, their stability is highly sensitive to hydrological changes, land use alterations, and other factors, leading to fluctuations in their sequestration function. Future research should assess both the benefits and risks of wetland carbon sequestration, refine management strategies, and ensure the long-term sustainability of sequestration benefits.  
(4) Future studies on carbon budget driving mechanisms could incorporate additional factors related to economic development, urbanization, and carbon budgets to provide broader insights and more comprehensive findings. However, this does not affect the feasibility of the current research framework and findings. These limitations do not undermine this study's conclusions but instead highlight opportunities to improve the model's applicability in complex socioeconomic contexts.