经济集聚对中国三大城市群土地利用生态效率的影响

基于非期望产出的超效率EBM模型,测算2005—2016年京津冀、长三角和珠三角等中国三大城市群土地利用生态效率,采用核密度函数对其演变特征进行分析,并运用面板门槛回归模型和面板向量自回归模型,从产业和人口两个角度分析经济集聚对城市群土地利用生态效率的非线性影响和直接冲击。结果表明：（1）2005—2016年间中国三大城市群土地利用生态效率总体呈现先收敛后分化的演化特征,不同城市群之间的土地利用生态效率时空演变具有显著差异;（2）第三产业集聚水平和人口集聚水平对城市群土地利用生态效率表现出单门槛效应,表明适度产业集聚和人口集聚对城市群土地利用生态效率具有正向促进作用,反之则会导致促进作用下降甚至出现负向影响;（3）第三产业集聚水平和土地利用生态效率自身对土地利用生态效率的直接冲击都是从开始就达到顶峰而后收敛为0,而第二产业集聚水平和人口集聚水平则是先负向冲击后持续正向冲击。城市群在制定经济发展政策和土地利用政策时,既要充分发挥经济集聚的正面环境效应,也要重视不同经济集聚的适度性和动态性。

Impact of economic agglomeration on land use eco-efficiency of three major urban agglomerations in China

Analyzing the impact of economic agglomeration on land use eco-efficiency in urban agglomerations is helpful in improving cities' competitiveness and the quality of environment. Using the Super-EBM of undesirable output, in this article we measured the land use eco-efficiency of the three major urban agglomerations of China, namely, the Beijing-Tianjin-Hebei Region, the Yangtze River Delta and the Pearl River Delta, from 2005 to 2016. Then it analyzed the spatio-temporal evolutionary characteristics of land use eco-efficiency by using Kernel density function. Finally, panel threshold regression model and panel vector auto regression model (PVAR) were established. We discussed the non-linear impact and linear direct impacts of economic agglomeration on the land use eco-efficiency in the urban agglomerations from the perspective of industry and population. The main results are as follows. (1) During 2005-2016, the land use eco-efficiency of the three major urban agglomerations showed an evolutionary characteristic of convergence and differentiation and each urban agglomeration had its own spatio-temporal evolutionary rules. (2) The tertiary industrial agglomeration level and population agglomeration level showed a single threshold effect on the land use eco-efficiency of the urban agglomerations. Therefore, moderate industrial agglomeration and population agglomeration have a positive promotion effect on the land use eco-efficiency of the urban agglomerations, otherwise, the promotion effect will decline or even have a negative impact. (3) The direct impact of the tertiary industry agglomeration level and land use eco-efficiency on the land use eco-efficiency reached the peak from the beginning and then converged to 0, while the secondary industry agglomeration level and population agglomeration level had negative impacts and then changed to be positive. When formulating policies concerning economic development and land use, the local governments must give full play to the positive impact of economic agglomeration on the environment. In addition, they should pay attention to the appropriateness and dynamics of different economic agglomerations.