统计与数据科学学院知识库

土地资源是一种有限资源，其特点之一是空间位置相对固定。随着我国经济建设的持续推进，人民生活的物质质量不断提升，由此产生的生态问题日益突出。由于工业化和城镇化的发展速度较快，我国城市建设用地规模不断扩大，道路硬化面积持续增加，农村生产用地和生态用地面积被动缩小，生产空间、生活空间和生态空间三者之间的矛盾愈演愈烈。为解决这一问题，必须加快转变生产方式，持续优化土地空间利用格局，以提高土地利用生态效率。基于此，本文通过构建“三生空间”下的土地利用生态效率的指标评价体系，明确三个子系统的土地利用生态效率在全国、区域及省域层面的具体状况，并在此基础上分析三个子系统的耦合协调度情况，探究“三生空间”下土地利用生态效率的影响因素，对推动区域协调发展具有重要意义。

本文首先梳理了近年来学者们关于“三生空间”及土地利用生态效率的基本内涵、指标体系的构建及测度方法的选择、时空特征和影响因素研究的相关文献，由于“三生空间”下子系统的耦合研究文献较少，本文对研究经济—社会—生态三者耦合协调的相关文献进行梳理，重点总结了土地利用生态效率的测度方法和实证研究方面存在的不足。其次，本文通过深入分析“三生空间”和土地利用生态效率的基本内涵，确认“三生空间”下土地利用生态效率指标体系构建的理论基础，从生产空间、生活空间和生态空间构建土地利用生态效率的指标评价体系，其中生产空间和生活空间包括城镇和农村两部分内容。基于此采用考虑非期望产出的超效率SBM模型测算除西藏、港澳台外我国30个省份2003-2020年“三生空间”下各子系统土地利用生态效率值，再通过运用熵权法求得“三生空间”下土地利用生态效率综合值；基于测算结果，对其时空特征进行分析；同时，由于“三生空间”是由三个子系统构成的，本文利用耦合协调度模型，度量了生产空间、生活空间和生态空间下的土地利用生态效率值的耦合协调水平，以进一步分析“三生空间”下土地利用生态效率的协调发展状况；最后，为进一步明晰导致“三生空间”下土地利用生态效率的差异化原因，本文通过构建个体时间双固定空间杜宾模型，分析不同影响因素对其影响程度的大小。研究结论如下：

（1）“三生空间”下土地利用生态效率的测算结果及变化趋势。从全国层面来看，2003-2020年“三生空间”下我国土地利用生态效率综合值的平均值为0.499，处于中低水平，变化趋势呈现“M”型；其中，三个子系统土地利用生态效率的排序为：生产空间>生态空间>生活空间，平均值分别为0.826、0.517和0.333；从区域层面来看，“三生空间”下七大地理区的土地利用生态效率整体波动范围在“0.4-0.6”之间；其中，生产空间下华北地区的土地利用生态效率值最高，华中地区的土地利用生态效率最低；生活空间下七大地理区整体保持下降状态；生态空间下七大地理区之间的土地利用生态效率具有明显差异，华南地区远高于其他地理区；从省域层面来看，“三生空间”下我国30个省份的土地利用生态效率在2003-2005保持增长，此后出现下滑；其中，生产空间下我国30个省份的土地利用生态效率优于生活空间和生态空间，生态空间下土地利用生态效率水平最低。

（2）“三生空间”下土地利用生态效率的空间特征。研究表明，“三生空间”下我国土地利用生态效率空间差异显著，华北地区和华东地区较高，东北地区较低；生产空间和生活空间下的土地利用生态效率具有明显的空间聚集现象，而生态空间因其内部构成基本保持不变，不存在显著的空间相关性。

（3）“三生空间”下土地利用生态效率的耦合协调度结果。生产空间、生活空间和生态空间的土地利用生态效率的耦合协调度处于轻度失调的水平，即三者之间的良性耦合程度较低。

（4）“三生空间”下土地利用生态效率的影响因素分析。我国“三生空间”下土地利用生态效率存在显著的空间溢出效应，空间滞后项系数显著为正，即某个省份“三生空间”下土地利用生态效率的提升会对相邻省份产生正面影响。在考虑空间溢出效应的前提下，经济发展对于“三生空间”下土地利用生态效率仍就呈现“U”型，产业结构、人口密度和对外开放水平的提高会促进“三生空间”下土地利用生态效率的改善；生产用地占比、土地开垦程度和土地财政压力的增加会对“三生空间”下土地利用生态效率产生负作用；提高科技水平、增加环境污染治理投资有利于推动“三生空间”下土地利用生态效率的改善。

Land resources are a limited resource, and one of their characteristics is that their spatial location is relatively fixed. As China's economic construction continues to advance, the material quality of people's lives continues to improve and the resulting environmental problems become increasingly prominent. Due to the rapid development of industrialization and urbanization, the scale of China's urban construction land is expanding, the area of hardened roads continues to increase, the area of productive and ecological land in rural areas is passively shrinking, and the conflict among production space, living space and ecological space intensify. To solve this problem, it is necessary to accelerate the transformation of production methods and continuously optimize the spatial land use pattern to improve the ecological efficiency of land use. Based on the above, this paper constructs an indicator evaluation system for the ecological efficiency of land use under the "three living spaces" and clarifies the specific status of the ecological efficiency of land use in the three subsystems at the national, regional and provincial levels, and explores the factors influencing the ecological efficiency of land use under the "three living spaces".  It is important to investigate the factors influencing the ecological efficiency of land use under the "three living spaces", which is important to promote the coordinated development of the region.

This paper firstly compares the literature on the basic connotation of the "three living spaces" and land use eco-efficiency, the construction of the indicator system and the selection of the measurement method of land use eco-efficiency, and the spatial and temporal characteristics of land use eco-efficiency, and influcing factors in recent years. "This paper compares the literature on the coupling and coordination of economic-social-ecological systems and summarizes the shortcomings in the measurement methods and empirical studies of land use eco-efficiency. Secondly, through an in-depth analysis of the basic connotations of the "three living spaces" and land use eco-efficiency, this paper identifies the theoretical basis for the construction of a land use eco-efficiency index system under the "three living spaces", and constructs a land use eco-efficiency index evaluation system from production space, living space and ecological space. The evaluation system of land use eco-efficiency indicators is constructed from production space, living space and ecological space, in which production space and living space include both urban and rural areas. Based on this, the super-efficient SBM model, which takes into account non-expected output, is used to measure the eco-efficiency values of land use in each sub-system under the "three living spaces" in 30 provinces in China from 2003 to 2020, except for Tibet, Hong Kong, Macao and Taiwan, and then the entropy weight method is applied to obtain the comprehensive eco-efficiency of land use under the "three living spaces". "Finally, since the "three living spaces" are composed of three subsystems, this paper uses the coupling coordination model to measure the ecological efficiency values of land use in the production space, living space and ecological space. At the same time, as the "three living spaces" are composed of three subsystems, this paper uses the coupled coordination model to measure the coupled coordination level of land use eco-efficiency values in the production space, living space and ecological space,  to further analyze the coordinated development of land use eco-efficiency in the "three living spaces". Finally, in order to further clarify the reasons for the differentiation of land use eco-efficiency in the "three living spaces", this paper analyzes the magnitude of the influence of different influencing factors by constructing an individual-time bifixed SDM.The findings of the study are as follows:

1. The results and trends of land-use eco-efficiency under the "Three Life Spaces". At the national level, the average value of China's land use eco-efficiency under the "three living spaces" from 2003 to 2020 is 0.499, which is at a medium-low level, and the trend of change is "M"; among them, the three sub-systems of land use eco-efficiency are at the regional level, the overall land use eco-efficiency of the seven geographic regions under the "three living spaces" fluctuates between 0.4 and 0.6; the production space more than ecological space ,which greater than living space. The mean value of them are 0.826, 0.517 and 0.333 respectively. At the regional level, the overall land use eco-efficiency of the seven geographic regions under the "Three Life Spaces" fluctuates between 0.4-0.6; among them, the highest land use eco-efficiency value is found in North China under the production space, the lowest in Central China, and the overall decline in the seven geographic regions under the living space; there are obvious differences in the land use eco-efficiency among the seven geographic regions under the ecological space, with South China being much higher than the other geographic regions; at the provincial level, the At the provincial level, the land use eco-efficiency of 30 provinces in China under the "three living spaces" kept increasing from 2003 to 2005, and then declined thereafter; among them, the land use eco-efficiency of 30 provinces in China under the production space is better than that of the living space and the ecological space, and the land use eco-efficiency level under the ecological space is the lowest.
2. Spatial characteristics of land use eco-efficiency in the "three living spaces". The study shows that the spatial differences in land use eco-efficiency under the "three living spaces" are obvious, with higher levels in northern and eastern China and lower levels in northeastern China; the spatial aggregation of land use eco-efficiency under the production space and living space is obvious, while there is no significant spatial correlation in the ecological space as its internal composition remains basicall unchanged. The spatial correlation between the ecological space and the production space is not significant because the internal composition of the space remains the same.
3. The results of the coupling and coordination of land-use eco-efficiency under the "three living spaces". The degree of coupling and coordination of land-use eco-efficiency among production space, living space and ecological space is at a mildly dysfunctional level, i.e. the degree of benign coupling among the three is low.

(4)Analysis of the factors influencing the eco-efficiency of land use in the "three-living space". There is a significant spatial spillover effect on the ecological efficiency of land use under the "three living spaces" in China, and the coefficient of the spatial lag term is significantly positive, that is, the improvement of ecological efficiency of land use under the "three living spaces" in one province will have a positive impact on the neighboring provinces. Under the premise of the spatial spillover effect, the economic development still shows a "U" shape on the ecological efficiency of land use in the "three living spaces", and the improvement of industrial structure, population density and openness level will promote the ecological efficiency of land use in the "three living spaces". The increase of industrial structure, population density and openness will improve the ecological efficiency of land use in the "three living spaces"; the increase of the proportion of productive land, the degree of land reclamation and the pressure of land finance will have a negative effect on the ecological efficiency of land use in the "three living spaces"; the improvement of science and technology and the increase of investment in environmental pollution control will help promote the ecological efficiency of land use in the "three living spaces". Improving the level of science and technology and increasing investment in environmental pollution control are conducive to the improvement of ecological efficiency of land use in the "three living spaces".