基于土地利用的中国城镇化SD模型与模拟

中国正处在快速推进的城镇化进程中,耕地与林地、牧草地和水域等生态用地将如何变化,以及建设用地是否仍将快速增长?这不仅是国家宏观政策制定者关心的问题,也是广大学者和普通民众面临的具体问题。通过构建基于土地利用的中国城镇化系统动力学（System dynamics,SD）模型,尝试对上述问题作出分析。研究结果表明：（1）本文构建的模型是有效的,具备可靠性和稳定性。（2）若要保持国家耕地保有量不少于18.25亿亩,到2050年需补充83.17万~412.67万hm²耕地资源。（3）到2050年,如果中国城镇化水平达到78%左右,建设用地总量将达到4007.29万~4214.25万hm²,较2020年净增加了155.87万~342.88万hm²。（4）2020—2050年生态用地数量表现为先增加后减少,其中,林地显著增加,牧草地减少,水域略有增加。研究成果可为全国国土空间规划多方案模拟、评估和决策提供科学服务。

China's urbanization SD modelling and simulation based on land use

China is still experiencing the process of rapid urbanization. How will cultivated land and ecological land, such as woodland, grassland, and water body change? Will construction land continue to grow rapidly? These are not only the concerns of national macro-policy makers, but also the specific problems faced by scholars and ordinary people. This paper attempts to make a multi-scenario analysis of the above issues by constructing a system dynamics (SD) model of China's urbanization based on land use. This SD model integrates the relationship between land use and multi-factors in the urbanization process, including economy and population, and highlights the dominant role of land resources in the urbanization process. The conclusions can be drawn as follows: First, according to the results of stock-flow validation and sensitivity analysis, the China's urbanization SD model based on land use is effective with great reliability and stability. Therefore, the model can be used to predict and simulate the future trend of urbanization process and land resource use in China. Second, in order to meet the requirement of the "National Land Planning Outline (2016-2030)" that the amount of cultivated land should be maintained at 12166.67×10⁴ hm², there will be a need to supplement 83.17×10⁴-412.67×10⁴ hm² of cultivated land from other types of land by 2050. This is because the cultivated land will show a decreasing trend in the China's urbanization in the future. In the low scenario, medium and high-speed economic growth, the amount of cultivated land by 2050 will be reduced to 12366.60×10⁴, 12083.50×10⁴, and 11754.00×10⁴ hm², respectively. Third, with the improvement of urbanization levels, the total amount of construction land will increase accordingly. Specifically, if China's urbanization level reaches 78% by 2050, the total construction land will increase to 4283.89×10⁴-4464.90×10⁴ hm², with a net increase of 155.87×10⁴-342.88×10⁴ hm² compared with 2020. Fourth, the overall trend of ecological land in 2020-2050 is to increase first and then decrease. By 2050, the woodland will significantly increase to 29406.60×10⁴-30733.80×10⁴ hm², the grassland will decrease to 25784.50×10⁴-27809.90×10⁴ hm², and the water body will not decrease and even increase slightly, the area of which would be 4283.89×10⁴-4464.90×10⁴ hm². The research results can provide scientific supports for the multi-scenario simulation, evaluation, and decision-making of territorial spatial planning.