From the essential meaning of urbanization, this paper establishes a comprehensive evaluation index system, including four aspects changing: population, economy, society and land. Based on the method of entropy, the measure and evolution of China's urbanization are analyzed since 1981. The results show that China's comprehensive urbanization level continues improving. Economic growth and geographical landscape are the main features of rapid evolution of urbanization, followed by the population urbanization, and the medical care level of social urbanization is the least advanced. The evolution of all the four subsystems has unique characteristics. The analysis of multiple regression model shows that the driving factors have been diversified. The market force is the most powerful driving force of China's urbanization, followed by intrinsic force, administration force, exterior force. From different stages of urbanization, the effects of market force, exterior force and the administration force on urbanization are increasing, while intrinsic force is decreasing. China's urbanization is the main endogenous process, hence more policies should be formulated to strengthen the market economy reform and coordinate urban and rural development.

中国经历了史无前例的快速城镇化进程,与之相伴随的是更加迅猛的土地城镇化过程。基于2000年和2015年中国土地利用现状遥感监测数据,综合运用空间分析、多元回归和地理加权回归的方法,深入分析了中国县域土地城镇化的区域特征及其影响因素。结果表明：① 中国县域土地城镇化率年均增长2.77%,其中近40%的区县城镇化率年均增长大于3%;在空间上呈现出不同于人口城镇化的扩散趋势。② 中国县域土地城镇化的南北分异规律较东西分异更为明显。土地城镇化的高值区域始终集中在胡焕庸线的东南半壁,而围绕主要的城市群地区则形成“组团式”增长的热点区,地区间差异趋于收敛。③ 人口集聚、经济发展、产业结构、城市特性与地理区位等要素对县域土地城镇化空间分异格局的影响较为显著、稳定,各要素对土地城镇化的影响均具有明显的时空依赖特征。分析揭示县域土地城镇化的时空特征及其动力机制,对于科学认识新型城镇化和实施城乡融合、乡村振兴战略,具有重要的理论价值与现实意义。

本文认为,此前一直被当作城市化地区的土地利用结构信息熵快速上升,应是指城市化地区郊区的土地利用结构信息熵上升。城市化时期郊区土地利用结构向均衡化方向的明显变动,引起了郊区土地利用结构信息熵的上升;城市建成区的土地利用结构信息熵却未有上升,其各种土地利用类型的面积占比在城市化时期基本稳定,或向居民点及工矿用地、交通用地类型有所集中,导致其土地利用结构信息熵基本不变或有所下降。郊区的局部城市化区域对郊区土地利用结构信息熵的上升有着主要贡献。数据分析显示,城市化时期郊区的农用地较多较快地转化成了城市建设用地,且后者的面积占比与土地利用结构信息熵之间具有高度正相关关系,说明城市建设用地的快速增加是引起郊区土地利用结构信息熵上升的主要原因。熵变化分析表明,城市化时期郊区系统的熵变化与郊区土地利用结构信息熵的变动方向一致,均大于零,表征了郊区的自然地理环境演化在此期间是向着有序性降低的方向发展的。

This paper pointed out that the alleged rapid increase of the information entropy of the land use structure in the urbanized areas should refer to the increase of the information entropy of the suburban land use structure in the urbanized areas. The obvious shift of the suburban land use structure towards the equilibrium direction during the period of urbanization leads to the increase of the information entropy of the suburban land use structure. Meanwhile the information entropy of the land use structure in urban built-up area has not increased. The proportion of various land use types in the urban built-up area during the period of urbanization is basically stable or enlarged on the residential areas, industrial and mining areas as well as the transportation land to some extent. This makes the information entropy of the land use structure in the urban built-up area basically remain unchanged or decrease somewhat. The local urbanized areas in the suburbs have made major contributions to the increase of the information entropy of the suburban land use structure. Data analysis shows that a great amount of suburban farmland is quickly transformed into urban construction land during the period of urbanization and the proportion of the urban construction land is highly and positively correlated with the information entropy of the suburban land use structure. It can be seen that the rapid increase of the urban construction land is the main reason for the increasing information entropy of the suburban land use structure. The analysis of entropy change indicates that the entropy of suburban system during the period of urbanization displays the same changing trend with the information entropy of the suburban land use structure, and both of them are greater than zero, which suggests that the suburban natural environments during the period of urbanization develop in a decline.

<p>To characterize the equilibrium extent of structure of urban land use, an index formula based on information entropy is advanced as follows: J=-&sum;NiP i log P i/ log N In the formula,P i=A i/A=A i/&sum;NiA i,where A is the area of urbanized area of a city, A i is the land area of a certain function type,and N is the number of land function types Correspondingly, the difference of an index is defined as I=1-J,which can be used to reflect the inequality of urban land use When information entropy is generalized to describe the spatial morphology of urban land use by means of making &lsquo;nets&rsquo; on maps,information dimension as one of the fractal dimensions can be computed to qualify the spatial patterns of urban land use.</p>

土地利用结构优化配置是实现土地利用效益增长的核心内容之一，研究两者之间的时空变化关系对于解决我国城市化快速发展中面临的一系列问题具有重要的现实意义。本文借助信息论原理，分析1997年～2007年湖北省嘉鱼县土地利用结构信息熵与均衡度动态演变特征；运用层次分析法原理构建简明化的指标体系，探讨其研究期间土地利用效益的变化特点；同时利用灰色关联分析法比较研究土地利用结构与效益变化的定量关系。研究表明：①1997年～2007年嘉鱼县土地利用结构信息熵与均衡度呈上升趋势，土地利用综合效益在此基础上出现较快增长，土地利用结构信息熵与土地利用综合效益变化之间呈现出较明显的相关性，关联度为0.7679；②不同土地类型的结构变化与土地利用综合效益变化之间分为强、较强、中等3种关联性，强关联的是居民点及工矿用地、园地，关联度均在0.8以上，较强关联的是林地、未利用地与耕地，关联度都高于0.7，中等关联的是交通用地与水域，关联度分别为0.6714与0.6672；③合理的土地利用结构是土地利用效益有效发挥的前提，土地利用效益变化是土地利用结构时空变化的即时效应与累积效应的共同结果。

Land use efficiency is one of the primary fields in land use study as it is an essential indicator for land use assessment. Land use efficiency refers to the direct outputs or effects brought by the land use process. Land use efficiency is an integrated concept comprising three sub-systems, which are economy, society and ecology. One important component of improving land use efficiency is the optimization of land use. Spatial-temporal analyses of land use structure and land use efficiency are useful for addressing the problems related to the rapid urbanization in China. Based on information theory, the changes in information entropies of land use structure in Jiayu from 1997 to 2007 are generated by using the land use data. The indicator system for evaluating land use efficiency is set up by means of AHP, in which 3 indicators representing economy, society and ecology are included. Finally, with the method of grey correlation analysis, the correlations between land use structure and land use efficiency are studied. The results show that the information entropies and equilibrium degrees of land use structure have increased gradually in Jiayu from 1997 to 2007, and the corresponding index values of land use efficiency have manifested a rapid increase from 0.0428 to 0.7608 in the study area. There are certain logical relations between land use structure and land use efficiency, and the correlation degree is 0.7679. The land use potential of Jiayu County is comparatively large and there is still space for further optimization of its land use structure. According to the actual situation of study area, the standards of correlation degree of land use types are classified into three levels: high (>0.8); secondary (>0.7) and medium (>0.6). The descending order of correlation degree for each land use type is: residential and unattached industrial land (0.8104), garden (0.8087), forestland (0.7405), unused land (0.7264), cultivated land (0.7011), traffic land (0.6714) and water area (0.6672). Land use structure plays an important role in improving land use efficiency with instant and accumulative effects. The information entropy of land use structure maintains a rising-adjusting-rising trend, and the land use efficiency maintains a growing trend according to the changes. In further study, more attention should be paid to the functions of the different spatial combination and land use types distribution in order to improve land use efficiency.

In research of spatial structure evolution of land use of Shenyang in recent century, this paper used the multi-temporal and multi-source historical data, with the special historical period divided into 5 stages of research from 1910 to 2010. With the support of the single land use type dynamic degree, land use type transfer matrix and the method of spatial, we analyzed various city land use type, structure, mutual transfer and distribution characteristics of Shenyang in the past century. The results showed that: living land increased by 118.81 km², industrial and commercial land increased by 148.21 km², transportation land increased by 130.97 km², presenting an increasing trend, while utilities land, green spaces and other land use generally went up slowly. In different periods land use structure was obviously different, and residential land had been dominant, accounting for an average of 32.36%, which declined in proportion after the founding of New China, but the industrial and commercial land use increased by 25.17% on average. In addition, conversion of each land use type was divided into three parts: transfer, transferred and constant, among which, non-construction land shifted to various land types accounted for the largest proportion, and constant part of the same land use has the greatest proportion, while the quantity transferred to the residential land and transportation land was the greatest. With the time went, the ratio of residential land was gradually reduced in the central area of the city, and in the sub-center the ratio increased first and then decreased. The proportion of industrial and commercial land increased gradually from central to marginal area, and the proportion was the highest in the marginal area. Public utilities land was outwardly gradually decayed, and in the center of the city public utilities accounted for a larger proportion. It is concluded that land use spatial structure in Shenyang presented a circular pattern from the inside to the outside.

构建城市用地结构时空格局演变分析框架,引入信息熵和偏移份额模型定量剖析2000—2017年中国东北地区城市用地结构时空格局演变特征,通过计量经济模型分阶段对比分析收缩情境下东北地区城市用地结构演变的动力机制。结果表明：东北地区城市用地总面积持续增长,用地结构信息熵整体呈现先上升、后下降的趋势。2011年以后,城市用地结构有序性、多样性不断提升,单一优势地类主导作用显著下降。公共设施用地、道路交通用地及绿地与广场用地为增长型地类,是东北地区城市用地规模扩张和结构演变的主要动因。用地结构竞争性偏移量具有显著的空间非均衡性,总体与辽中南和哈长两大城市群空间格局基本吻合,新增城市用地的集聚效应不断凸显。城市人口规模变迁、城市经济发展水平提升、产业结构升级与城市居住条件改善对城市用地结构演变具有显著的正向驱动作用。收缩情境下,各因素的拉动作用逐渐减弱,国家宏观政策的约束力不断增强,城市公共服务水平改善的强需求成为驱动用地结构演变的外在动力。

Based on the analysis framework of spatio-temporal evolution of urban land use structure with the context of shrinkage, this study introduced the Information Entropy Model and the Shift-Share Model to examine the spatio-temporal evolution characteristics of urban land use structure in Northeast China, using panel data from 2000 to 2017. The dynamic mechanism of structural evolution of urban land use in Northeast China was analyzed by econometric model. The results demonstrated that: (1) the total area of urban land in Northeast China increased continuously since 2000, while the information entropy of urban land use structure increased firstly and then decreased. After 2011, with the improvement of diversity and equilibrium degree of urban land use structure, the order of urban land use structure has been enhanced and the leading role of single dominant land type has been significantly reduced. (2) The three types of urban land, i.e., land for public facilities, land for road, street and transportation and land for green space and square were growing, which is the main reason for the rapid increase of the total urban land area in the study region. (3) There exists significant spatial imbalance of competitiveness of different urban land types, which evolve constantly in different regions, and the overall spatial pattern is basically consistent with the distribution pattern of the two major urban agglomerations of central and southern Liaoning city groups and Harbin-Changchun megalopolis. Meanwhile the agglomeration effect of new-added urban land area is increasingly prominent. (4) The dynamic change of urban population, urban economic development, the upgrading and adjustment of industrial structure, and the improvement of urban living conditions all have significant positive impact on the dynamic evolution of urban land use structure in Northeast China. In the context of urban shrinkage, the effect of various factors is gradually weakened, and the binding force of national macro policies is increasing. Meanwhile, the demand for the improvement of urban public services has become the external driving force for the evolution of urban land use structure. To realize the overall revitalization of Northeast China, differentiated measures should be taken to reverse the trend of population loss, and boost the vitality of regional economic development.

In this paper,we analyzed the land use change in Chuxiong city,a plateau area and Shuangbai county,a mountainous area in Yunnan Province,based on their TM images in 1980 and 2000.Four kinds of indexes for land use/land cover,two kinds of indexes for the spatial patterns of regional landscape,the land use type transition matrix and information entropy of land use structure were calculated to examine spatial patterns and dynamics of land use change in Chuxiong and Shuangbai.The results show that,due to human activity,the land use change in Chuxiong was greater than that in Shuangbai during the past 20 years.The built-up area and timberland have increased,but cropland,grassland and water area have decreased in both Chuxiong and Shuangbai.The change of water area and grassland in Shuangbai was faster than that in Chuxiong,the change of built-up area and cropland in Chuxiong was faster than that in Shuangbai.Index for landscape diversity in Shuangbai was lower than in Chuxiong,showing a decreasing tendency in Chuxiong,but an increasing tendency in Shuangbai.Landscape fragmentation indexes were high,the landscape fragmentation indexes in Chuxiong were greater than in Shuangbai,both showing a decreasing tendency.The land use system tended to be unstable in Chuxiong,but oppositely in Shuangbai.The main driving forces of regional land use change in Chuxiong and Shuangbai were natural conditions,economic development,structure of production,level of urbanization and governmental decision makings.Effect of population increase on land use in Shuangbai was notable,but it was not marked in Chuxiong.

本文提出一种基于随机森林的元胞自动机城市扩展(RF-CA)模型。通过在多个决策树的生成过程中分别对训练样本集和分裂节点的候选空间变量引入随机因素,提取城市扩展元胞自动机的转换规则。该模型便于并行构建,能在运算量没有显著增加的前提下提高预测的精度,对城市扩展中存在的随机因素有较强的容忍度。RF-CA模型可进行袋外误差估计,以快速获取模型参数;也可度量空间变量重要性,解释各空间变量在城市扩展中的作用。将该模型应用于佛山市1988-2012年的城市扩展模拟中,结果表明,与常用的逻辑回归模型相比,RF-CA模型进行模拟和预测分别能够提高1.7%和2.6%的精度,非常适用于复杂非线性特征的城市系统演变模型与扩展研究;通过对影响佛山市城市扩展的空间变量进行重要性度量,发现对佛山城市扩张模拟研究而言,距国道的距离与距城市中心的距离具有最重要的作用。

Cellular automata (CA) has been frequently used to investigate the logical nature of self-reproducible systems and simulate the evolution of complex geographical phenomena such as urban expansion. The core of cellular automata is to define transition rules. Traditionally, approaches for defining the transition rules of cellular automata had difficulty to balance the interpretability, accuracy, and convenience. This article presents a new cellular automata model for simulating urban expansion based on random forest algorithm. The proposed model extracts CA transition rules of urban expansion by introducing random factors in training samples and candidate spatial variables that split nodes during the multiple decision trees building process. One significant advantage of our approach is that it can be easily adopted for parallel implementation and has high prediction accuracy and tolerance to random factors in urban expansion. Another strength of the proposed approach is that it can estimate out-of-bag errors to obtain model parameters quickly and measure the importance of spatial variables and explain the contribution of each variable in urban expansion. The model was applied to simulate urban expansion in Foshan City, Guangdong Province. We used the urban land change of 1988 and 2000 as the dependent variable and the spatial variables as the independent variables to construct the CA model based on random forests, then simulate and predict urban expansion of 2000 and 2012. The results show that random forest model can improve the simulation and prediction accuracies by 1.7% and 2.6%, respectively, when compared to the logistic regression model commonly used in CA simulation. This suggests that random forest model is superior for modeling complex nonlinear urban evolution. Urban expansion of Foshan City in 2024 was also predicted according to its urban development trend. Through measuring the importance of some spatial variables that affect urban expansion, we found that distance to national roads and to the city center are the two most important spatial variables for urban expansion simulation in Foshan City.

开展城市空气质量时空格局演变特征及其影响因素的研究,对于深入认识城市环境与社会经济系统的互馈机理、制定高效的环境治理措施、提升城市发展质量具有重要的理论与实践意义。本文以中国全面实施《大气污染防治行动计划》的2014年为起点,刻画了2014&#x02014;2019年286个地级以上城市6种空气污染物浓度（CO、NO₂、O₃、PM₁₀、PM_2.5、SO₂）的时空演变特征,并基于面板回归模型分析各污染物浓度之间的相互作用关系;进而利用随机森林模型对城市6种空气污染物浓度与13个自然和社会经济影响因子的关联强度进行探究,从中梳理出关键影响因子。结果显示：① 研究期内,O₃污染加剧,其余污染物年均浓度逐年下降,其中SO₂浓度降幅最大。虽然典型的重污染区范围有所减小,但京津冀、山东半岛、山西、河南等地区的城市空气污染物浓度仍相对较高。② 城市6种空气污染物浓度之间存在显著的相互影响关系,城市空气复合污染特征明显。③ 自然因素和社会经济因素对不同种类空气污染物浓度的影响差异较大,且与污染物浓度之间呈非线性响应关系。自然因素中,城市年均气温与空气污染物浓度的关联强度最大,其次是植被指数。社会经济影响因素中,土地城市化水平和二产比重是主导影响因子,其次是电力消耗总量和交通因子。偏依赖分析进一步刻画了不同污染物浓度对主导影响因子的响应突变阈值。鉴于人类对于自然环境和气象条件的控制能力有限,建议继续通过优化城市密度、控制人为排放源及严格的空气污染防控措施以进一步有效提高城市空气质量。

：Research on the spatiotemporal evolution of urban air pollution and its driving forces has great theoretical and practical significance because it helps to deeply understand the mutual feedback mechanism between urban environment and socio-economic system and improve the efficiency of environmental governance. This paper illustrated the regional evolution characteristics of six urban ambient air pollutants, namely, CO, NO2, O3_8h, PM10, PM2.5, and SO2, in 286 sample cities at the prefecture level in China from 2014 to 2019, starting from the year when the "Air Pollution Prevention and Control Action Plan" was fully implemented in China. The interactions between the concentrations of each pollutant were then analyzed on the basis of panel regression models. Furthermore, random forest model was employed to explore the correlations between concentrations of these six pollutants and thirteen natural and socio-economic impact factors so as to sort out crucial ones. The results are shown in three aspects. First, the average annual concentration of O3_8h increased while that of the other urban ambient air pollutants decreased year by year, among which SO2 concentration decreased the most. Although the typical heavy pollution areas had shrunk, cities in the Beijing-Tianjin-Hebei region, Shandong Peninsula region, Shanxi Province, and Henan Province still have witnessed relatively high concentrations of air pollutants. Second, there was a significant interaction between concentrations of these six pollutants, indicating that comprehensive measures for urban air pollution prevention are necessary. Third, the impact of natural factors and socio-economic factors on urban air quality varied greatly towards different air pollutants, together with a nonlinear response relationship with the pollutant concentrations. Within the selected five natural factors of temperature, precipitation, wind speed, humidity and NDVI, the urban annual average temperature had the strongest correlation with air pollutant concentrations, followed by NDVI. Among the eight selected socio-economic factors, the level of land urbanization and the proportion of secondary production were the two leading drivers of the urban air pollution, followed by the total power consumption and traffic factors. Besides, partial dependence model was used to further analyze the response threshold of different pollutant concentrations to the dominant influencing factors. In consideration of the limited ability of human to control the physical environment and meteorological conditions, it is recommended that urban air quality should be further effectively improved by means of the optimization of urban density, the control of man-made emission sources, and the implementation of strict air pollution prevention and control measures.

自然保护区是生物多样性最丰富的区域,针对近年来庐山自然保护区森林生物多样性进行调查,了解保护区内植被的分布及其变化,对于保护庐山境内的林业资源具有重要的意义。论文利用2015—2018年Proba-V卫星100 m分辨率5 d植被指数产品,使用最大值合成法、Hants时间序列谐波分析方法对数据进行平滑降噪处理,并采用随机森林算法进行分类,同时对庐山林地变化进行分析。结果表明：① 2015—2018年庐山林地随机森林分类的总体精度分别为85.00%、84.25%、84.75%、85.25%,Kappa系数分别为0.80、0.79、0.81、0.80。分类结果与LC-CCI、Globcover、Globeland30、MODIS等植被覆盖分类产品的对比分析表明,基于时序NDVI产品的随机森林分类器在空间分辨率和制图精度上都取得了较好的分类效果和较高的分类精度。② 庐山自然保护区内针叶林、阔叶林分布较为集中,混交林与竹林零散分布,其中,针叶林的分布面积最大,占比39.36%;竹林的分布面积最小,占比为14.63%。③ 2015—2018年间,庐山林地类型分布变化不大,阔叶林、针叶林、混交林变化率均低于10%,阔叶林变化最小,竹林由于受到人类活动影响,4 a间变化幅度波动较大。

Nature reserves are the areas with the most abundant biodiversity. Conducting a survey of current forest biodiversity in Lushan Nature Reserve and understanding the distribution and changes of vegetation in the protected area is of great significance for the protection of forest resources in Lushan. In this study, we used the Proba-V satellite 100-meter resolution 5-day vegetation index product from 2015 to 2018 using the maximum synthesis and Hants time series harmonic analysis methods to smooth the data and reduce noise, and used a random forest algorithm to classify the forest vegetation. The changes of Lushan vegetation communities were also analyzed. The research results show that: 1) The overall accuracies of the random forest classification of Lushan forestland from 2015 to 2018 were 85%, 84.25%, 84.75%, and 85.25% while Kappa coefficients were 0.80, 0.79, 0.81, and 0.80, respectively. Compared with the Cover-CCI-2010, Globcover-2009, Globeland30, and MODIS-2010 land cover products, the classification results by random forest classifier based on time series NDVI products have achieved good classification effect and high classification accuracy in spatial resolution and mapping accuracy. 2) In Lushan Nature Reserve, coniferous forest and broad-leaved forest are concentrated while mixed forest and bamboo forest are scattered among them. Coniferous forest has the largest distribution area, accounting for 39.36% of the total forest area, and the bamboo forest has the smallest distribution area, accounting for 14.63%. 3) From 2015 to 2018, the spatial distribution of forest vegetation communities in Lushan did not change much. The change rates of broad-leaved forest, coniferous forest, and mixed forest were all less than 10%. Bamboo forest fluctuated during 2015-2018 because of the interference of human activities while the change of broad-leaved forest was the smallest.

基于长沙市中心城区1979年、1989年、2003年、2011年、2014年5个年份的土地利用现状图,借助ArcGIS、SPSS分析工具,提取居住、工业、服务三大功能用地,从方向、圈层、强度、用地间转变及轴带趋向对长沙城市功能用地扩展的时空特征及驱动力进行研究。结果表明：① 用地扩展模式以“圈层式、轴带式”为主,并逐渐向“多组团式”过渡,由单一的向外扩展向内部功能间演替和外部扩展相结合转变。整体扩展方向经历了由“东、南、东南-西北、东、东南、北”的变化,但各类用地的扩展方向有所差异;② 从扩展强度看,居住用地远远高于城市总体扩展强度,造成了城市功能空间失衡的现象,服务配套明显滞后,部分分区在扩展过程中,出现了与规划定位严重不符的矛盾;③ 功能用地间的转变主要集中在城市核心区,表现出以核心-外围明显分异的差距。外围片区的功能较为单一,融合度不够,未来应增强配套服务功能。④ 从经济驱动力、政策调控力、生态制约力与吸引力、社会助推力四个方面分析了功能用地扩展时空差异的驱动因素。⑤ 从“问题导向-现象归纳-本质剖析-策略应对”提出了城市功能用地扩展研究的基本研究框架。

The expansion of urban functional space has always been a core issue in the study of urban geography and urban planning. In this paper, we mainly focus on the following three types of urban functional spaces: residential space, industrial spaces and service space, and we take the central city of Changsha as our study area. Based on the land use map covering the years of 1979, 1989, 2003, 2011 and 2014 as well as corresponding statistical yearbooks, in combination of taking GIS and SPSS statistical tools, this article analyzed the dynamic features and driving forces of the functional space evolution of Changsha by citing a variety of models such as sector fractal, “center-periphery” spheres density, expansion intensity, coupling degree and axial sprawl index. The results were obtained as follows: (1) The urban functional space of Changsha's central city expanded rapidly between 1979 and 2014. And the pattern of extension was still displaying the “circle mode” and “axis belt mode”, but gradually transited to “polycentric structure”. In the process of quick external expansion, the urban land also filled internally in the study period. The direction of functional transformation presented a phase difference clearly, which had experienced the process of “east, south and southeast” from 1979 to 1989 to the “northwest, east, southeast and north” during 2011 to 2014. Meanwhile, it showed some differentiation of different types of functional land. (2) Residential space showed excessive expansion and guided other spaces extension, which was incompatible with other functional urban spaces, causing an imbalance in urban functional space. Some zones even showed serious contradiction with city planning during the process of expansion. (3) Functional spaces coupling showed significant “core-peripheral” geographic differentiation, and mainly focused on the core area. Functional space types in peripheral area were relatively single, which means that the level of alignment was insufficient. To strengthen urban comprehensive competitiveness, local government should improve service function and promote functional integration. (4) This study also probes the dynamic driving forces of the evolution of the functional space in Changsha City, mainly including economic, administrative, ecological and social factors. And the administrative factor played a significant role in the evolution. (5) We propose the basic research framework for the study of urban functional land expansion from "problem orientation -phenomenon induction - essential analysis - strategy response", which can provide theoretical guidance for optimizing the internal space structure and improve the functional efficiency of the central city.

分税制改革后,地方政府采取“以地生财、以财养地”的城市土地经营模式,凭借土地出让获取土地收益,并用于城市基础设施等城市建设投资,以推动城市经济发展,但土地经营对城市规模的空间扩张机制仍有待理清。基于地方政府土地收益和城市建设投资两个维度,本文构建了中国地方政府土地经营驱动的城市空间扩张理论逻辑,选择2003—2017年中国273个地级及以上城市面板数据,利用固定效应模型进行实证分析。研究结果表明：①2003—2017年中国城市空间规模、地方政府土地收益和城市建设投资均处于快速扩张阶段,然而以地谋发展的城市土地经营模式逐渐呈现出不可持续的端倪;②从全国尺度来看,土地经营模式下地方政府土地收益和城市建设投资均显著推动城市空间规模扩张。城市非农人口、城市人均GDP、城市三产产值占比以及城市人均道路面积对城市空间扩张均存在显著的促进作用;③从区域尺度来看,在东部、中部和西部地区,地方政府土地收益均显著推动城市空间扩张,但地方政府城市建设投资影响存在空间异质性,仅对西部地区城市空间扩张存在显著推动作用。此外,产业结构升级仅对东部地区存在显著的正向作用。新型城镇化背景下,地方政府应基于城乡互动关系,积极推进城市发展格局优化下的城市空间均衡扩张。

After the tax-sharing reform in China, local governments adopted the urban land conduct model of “making money from land and developing land with the money”, and relied on land transfer to obtain fund for urban infrastructure investment and to promote urban economic development. However, the mechanism of influence of land conduct on urban spatial expansion remains to be clarified. Based on the two dimensions of land revenue and urban construction investment of local governments, this study explored the mechanism of urban spatial expansion driven by local government land conduct. The panel data of 273 prefecture-level and above cities in China from 2003 to 2017 and the fixed effects models were used for an empirical analysis. The results show that: (1) China’s urban spatial scale, local government land revenue, and urban construction investment were all in a stage of rapid expansion from 2003 to 2017, but the urban land conduct model, based on the pursuit of land development, is gradually showing unsustainable signs. (2) From the national perspective, local government land revenue and urban construction investment have significantly promoted urban spatial expansion in China under the land conduct model. Urban spatial expansion was also remarkably stimulated by urban per capita GDP, urban non-agricultural population, the proportion of tertiary output value, and urban per capita road area. (3) From the regional perspective, local government land revenue has significantly promoted the urban spatial expansion in the eastern, central, and western regions. However, there is a spatial heterogeneity in local government urban construction investment, which only plays a tremendous role in promoting urban spatial expansion in the western region. In addition, compared with the whole country, the proportion of the tertiary output value has a notable positive effect only in the eastern region. Under the background of new urbanization, local governments should push forward more vigorously the balanced expansion of urban space under the partial equilibrium of urban development based on the interaction between urban and rural areas.

The evolution of geographical environmental system obeys the second law of thermodynamics: the order degree changes of the system are anti-related to its total entropy changes. The order degree increases when the total entropy changes are negative, and it is useful for human beings' survival and development, and vice versa. The analysis shows that the spontaneous evolution of natural geographical environment is developing towards ordering. The impacts of large-scale human activities on city system and human geographical environment are totally positive, and push its ordering development; their impacts on natural geographical development are both positive and negative. The positive impact is mainly the incremental production of low-entropy material and energy, which has been reflected in the increase of agricultural products and the application of new energy technology, such as solar energy, and ecological environment construction. The negative impacts are consumption of low-entropy material and energy, discharge of "three wastes" and elimination heat to the environment during the process of consumption and industrial production. These impacts lead to decrease of stock of low-entropy material and expansion of entropy increase during the geographical development, and have already caused common anxiety. Ordering of background evolution of natural geographical environment and technological possibility indicate that the evolution of geographical environment can continue ordering by introducing more low-entropy material and energy and decreasing the discharge of entropy.

新型城镇化背景下,传统粗放的城镇土地利用模式难以为继,控制城市规模、优化空间格局已成为当前国土资源管理的重点工作之一。城市增长边界(UGB)作为一种西方国家控制城市蔓延的技术手段和政策工具已逐渐被引入国内。采用文献资料法和归纳演绎法,梳理并分析了国内外城市增长边界的理论模型、划定方法与实效评价,挖掘未来城市增长驱动力和增长边界制定方法可能的研究方向,为后续研究和未来其在中国的实践提供参考。结果表明：① 城市增长边界实证研究的理论基础主要源于古典单中心城市模型,由于国情不同,国内主要关注经济水平、产业结构和可达性对城市增长的影响,而国外在此基础上还关注公共政策和服务、外部性以及主体间的博弈对城市蔓延的促进或抑制作用;② 城市增长刚性边界划定主要以土地适宜性和承载力评价为基础,弹性边界可采用元胞自动机进行空间辅助模拟;③ 国外城市增长边界的实施效果具有地区差异性,国内目前还缺乏城市增长边界实施效果评价相关方面的研究。因此,城市增长驱动力后续研究应吸纳多源理论,识别不同尺度下其机理特征,探索宏观环境的情景变量对微观环境下&#x0201C;驱动力—城市增长&#x0201D;这一关系的影响。城市增长弹性边界制定需要考虑城乡土地利用转换背后不同情景下主体间的复杂博弈对用地转换在空间上分布的决定作用。为了保证政策的持续性和统筹区域发展,未来需要明确城市增长边界的管理机构,制定对应的法律条款和管理体系。

The traditional extensive urban land use will not meet the requirements of new urbanization. As a result, controlling urban sprawl and land use optimization have become one of the key tasks of land resources management. The purpose of this study is to provide new perspectives and identify research areas for urban growth boundary study through the review and analysis of existing theoretical models, methods, and effectiveness evaluation cases. The research methods we employed are literature review and induction and deduction. The results indicate that the theoretical basis of urban growth analysis came from monocentric city model. Most studies in China mainly focused on the impact of economic factors, industrial structure, and accessibility on urban growth while public policies and services, externality, and stakeholder power struggles are also thought to have effects on urban growth. Urban growth rigid boundary design is mainly based on suitability and carrying capacity assessments, and elastic boundary is usually modeled by using cellular automata. The effectiveness of urban growth boundary on controlling urban sprawl is different in different cities in developed countries. There are few case studies to evaluate the effectiveness of urban growth boundary in China. We should adopt diversified theories to study the mechanism of urban growth. The effects of multilevel drivers on urban growth should be considered in future research. Most importantly, stakeholder power struggles should be taken into consideration in future elastic boundary modeling. In order to make urban growth boundary policies sustainable and balance regional development, legal and management systems of urban growth boundary should be designed in the future.