北京市不同功能区不透水地表时空变化差异

目前有关北京市不透水地表的相关研究多数是从整体层面开展,忽略了其内部功能区的作用及差异。运用分类回归树（CART）及系列变化检测模型得到北京市1991年、2001年、2011年和2015年四期不透水地表分布,并运用标准差椭圆、洛伦兹曲线、贡献指数及景观格局理论对各功能区不透水地表的时空变化进行分析。结果显示：1991-2015年北京市不透水地表的总面积增加了约144.18%,分布的主导方向由早期的东北—西南趋向于当前的正北—正南。各功能区间不透水地表的空间分布异质性逐渐减弱,但贡献指数值存在很大差异：功能拓展区的贡献指数最高,其四年中的最低值（1.79）高于其他功能区四年最高值,是北京市不透水地表增长最主要的贡献区;功能核心区的蔓延度指数值最高,约为其他功能区的2倍,为不透水地表的优势聚集区;发展新区的贡献值由负值变为正值并成倍增长,成为北京市不透水地表增长的主要源区;生态涵养发展区的贡献指数始终为负,并逐年减小。不同类型不透水地表的景观指数和质心偏移均存在差异,高盖度不透水地表的形状指数和斑块密度值最小,分布最为集中,对生态环境影响较大,北京市在未来发展过程中应合理规划控制其空间格局及增长模式,尽量减缓其增长速度及团聚程度。     

2003-2017年北京市地表热力景观时空分异特征及演变规律

利用2003-2017年MODIS地表温度数据,分别从数量、形状和结构角度揭示北京市不同季相和昼夜间地表热力景观时空分异特征,并进一步通过热力等级变化图谱及质心迁移轨迹揭示城市热力景观空间演变规律,探究热力景观等级转换生态过程。结论如下：① 城市地表热力景观季节和昼夜空间特征差异显著;② 中温区在城市热环境中占主导地位。白天中温区是最不稳定的热力景观等级;夜间次低温区和次高温区不稳定性增加;③ 地表热力景观等级变化以稳定型占主,反复变化型和前期变化型次之。地表热力景观等级通常呈现逐级递增或递减规律,山区呈现逐级降温趋势,北部城郊—山地交错地带表现出次低温和中温的反复转向,南部地区有一定的升温趋势;④ 2003-2017年高温区面积增大且质心向城市中心集中,低温区质心向城市外围扩散。生态涵养发展区对北京市地表热力景观质心迁移贡献率最高。热力景观时空分异特征及演变规律可为有效缓解城市热岛效应提供管理决策支持。     

近30年北京市ISP-LST空间特征及其变化

本文聚焦长时序地表的不透水与温度特征,利用Landsat影像数据,获取1991—2015年北京市的不透水地表盖度（Impervious Surface Percentage, ISP）与地表温度（Land Surface Temperature, LST）数据,构建不透水地表盖度-地表温度（ISP-LST）二维空间。结合标准差椭圆法,对ISP-LST空间密度分布的聚集特性进行分析,定量化表述各时期的特征与变化。研究发现：① ISP-LST二维空间特征表现为三种类型：弱相关、非完全正相关和显著正相关。② ISP-LST标准差椭圆的方向性和离散性均值为11.26和2.87,空间聚集性良好。随时间推移,高温现象受不透水地表的影响过程趋于复杂化。③ ISP-LST聚集区是城市热环境的重要表征,其在各功能区年际增长率为：功能扩展区（2.97%）>核心功能区（1.75%）>发展新区（1.63%）>生态涵养区（0.18%）。聚集区在东南方向增长明显,研究时段内累计增长14.77%。④ ISP-LST聚集区的斑块密度及形状复杂度的景观格局变化不大,但斑块连接性随时间推移有所降低。本文研究结果可为缓解城市热岛效应、制定生态环境调控政策提供相应参考。     

2000–2015年京津走廊耕地和建设用地变化监测研究（英文）

Rapid peri-urbanization has become a new challenge for sustainable urban-rural development worldwide. To clarify how unprecedented urban sprawl at the metropolitan fringe impacts urban-rural landscape, this study took the Beijing-Tianjin corridor of Beijing-Tianjin-Hebei metropolitan area, one of the largest urban clusters in China, as a typical example. By using Landsat-based landscape metrics and a practical methodology, we investigated the landscape changes and discussed the potential reasons in the context of rapid peri-urbanization of China. Specifically, multi-temporal land use maps derived from Landsat images were used to calculate landscape metrics and analyze their characteristics along the urban-rural gradients. The practical methodology was used to monitor spatio-temporal characteristics of landscape change in large metropolitan areas. The results showed that landscape patterns in the area had changed greatly from 2000 to 2015 with characteristics of construction land sprawl and arable land shrinkage. The intensity and scale of landscape changes varied along the urban-rural gradients. Sampled plots in urbanized areas and rural areas demonstrated distinguishable landscape patterns and significant differences. Urban areas had more heterogeneous and fragmented landscapes than rural areas. Peri-urban areas in general experienced higher levels of land diversification than rural areas. Rural residential land appeared to be more aggregated near Beijing and Tianjin cities. Besides, our findings also indicated that urban expansion was largely responsible for landscape patterns.The findings of this study potentially provide strategical insights into landscape planning around mega cities and sustainable coordinated urban-rural development.     

深圳市不透水表面的遥感监测与时空格局

定量监测城市不透水表面扩展过程,是分析城市景观格局动态,深入剖析城市地区空间镶嵌体内部异质性景观相互转化的重要基础。以深圳市为例,通过定量划分城市不透水表面等级体系,计算不透水表面的转移矩阵与景观格局指数,分析不透水表面的时空动态,结果表明:1990～2005年间,高盖度及极高盖度的不透水表面持续增加,中盖度及低盖度不透水表面先增加后减少,而自然地表及极低盖度的不透水表面则为先减少后恢复,反映了城市化进程对城市地表覆被的结构性影响。景观格局变化显示景观多样性程度较高,且经历了低-高-低-高的变化;斑块在1990年以自然地表为主,1995年以后以中盖度等级为主,高盖度等级显著增加。自然地表和中等盖度的不透水表面变化分别主导着前期和中后期的变化过程。城市建设的迅速扩张,将林地、农田、水体及滩涂等自然地表快速地转变为不同功能的建设用地,主导着不透水表面等级分布的梯度性变化。     

Spatio-temporal association analysis of county potential in the Pearl River Delta during 1990-2009

According to the highway data and some socioeconomic data of 1990, 1994, 2000, 2005 and 2009 of county units in the Pearl River Delta, this paper measured urban integrated power of different counties in different years by factor analysis, and estimated each county’s potential in each year by means of expanded potential model. Based on that, the spatio-temporal association patterns and evolution of county potential were analyzed using spatio-temporal autocorrelation methods, and the validity of spatio-temporal association patterns was verified by comparing with spatial association patterns and cross-correlation function. The main results are shown as follows: (1) The global spatio-temporal association of county potential showed a positive effect during the study period. But this positive effect was not strong, and it had been slowly strengthened during 1994-2005 and decayed during 2005-2009. The local spatio-temporal association characteristics of most counties’ potential kept relatively stable and focused on a positive autocorrelation, however, there were obvious transformations in some counties among four types of local spatio-temporal association (i.e., HH, LL, HL and LH). (2) The distribution difference and its change of local spatio-temporal association types of county potential were obvious. Spatio-temporal HH type units were located in the central zone and Shenzhen-Dongguan region of the eastern zone, but the central spatio-temporal HH area shrunk to the Guangzhou-Foshan core metropolitan region only after 2000; the spatio-temporal LL area in the western zone kept relatively stable with a surface-shaped continuous distribution pattern, new LL type units emerged in the south-central zone since 2005, the eastern LL area expanded during 1994-2000, but then gradually shrunk and scattered at the eastern edge in 2009; the spatio-temporal HL and LH areas varied significantly. (3) The local spatio-temporal association patterns of county potential among the three zones presented significant disparity, and obvious difference between the eastern and central zones tended to decrease, whereas that between the western zone and the central and eastern zones further expanded. (4) Spatio-temporal autocorrelation methods can efficiently mine the spatio-temporal association patterns of county potential, and can better reveal the complicated spatio-temporal interaction between counties than ESDA methods.     

“源-汇”景观格局的热岛效应研究——以武汉市为例

论文基于2017年Landsat 8遥感影像,通过GIS技术选取城市地表温度、源汇景观密度、源汇景观贡献度和景观效应指数,结合地理空间分析和数理统计方法,分析了武汉市局部源汇景观格局对城市地表温度的贡献及其效应。结果表明：① 武汉市城区热岛(urban heat island, UHI)季节变化明显,夏季热岛强度大、范围广,呈“大”字型分布,工业集聚区和经济开发区产生的UHI更显著;② 武汉市城区平均地表温度(land surface temperature, LST)在距市中心约8 km处达到峰值后沿城乡梯度逐渐下降,呈现“倒钩型”特征,这一现象与景观密度变化密切相关;③ LST与源(正向)、汇(负向)景观密度存在极强相关性,不透水表面是城区热岛的主要贡献因子;④ 相同密度的水体和绿地,水体更具有削弱城市热岛效应的功能;⑤ 一般当汇-源景观面积比>0.89(汇区密度>0.47)时,局部景观格局对城市热岛有缓解作用,且局部汇区越集中缓解效果越显著。     

珠三角县域城市潜力的时空关联结构演变

基于1990、1994、2000、2005 和2009年公路网数据和经因子分析得到的县域城市综合实力指数,采用扩展的潜力模型测度县域潜力指数,运用时空自相关方法探讨珠三角县域潜力的时空关联格局及其演变,并与空间关联格局对比及与交叉相关函数比较检验其准确性。结果表明：① 珠三角县域潜力总体上具正时空关联性,但关联程度不高,1994-2005年缓慢加强而2005-2009年趋于减弱。大多县域潜力的局部时空关联特征相对稳定,且以正相关为主,但部分县市时空关联类型发生了明显转化。② 县域潜力的局部时空关联类型分布差异及其变化明显,时空HH区分布于中部地带和东部的深圳—东莞地带,2000年后中部的时空HH区范围收缩至广—佛核心都市区;西部时空LL区连片分布格局相对稳定,中南部2005年开始出现新的时空LL区,东部时空LL区范围1994-2000年扩大而后逐步收缩,2009年零星分布于东部边缘;时空异质区变化较剧烈。③ 三大地带县域潜力的局部时空关联特征反差鲜明,东部与中部差异趋于缩小,而西部与中、东部的差异进一步扩大。④ 时空自相关方法能有效挖掘县域潜力的时空关联模式,比仅考虑空间效应的ESDA方法更能准确客观揭示县域潜力间的时空交互关系。     

武汉市不透水地表时空格局分析

根据植被-不透水地表-土壤（V-I-S）模型,以武汉市2002、2009、2015年3期Landsat影像为数据源,利用线性光谱混合模型进行亚像元分解获取不透水地表比例的空间分布。在此基础上采用梯度分析、景观格局指数等方法对研究区内不透水地表空间格局及变化进行分析。得到以下结论：武汉市2002、2009、2015年的平均不透水地表比例分别是27.53%,34.65%,40.51%,呈不断增长的趋势。主城区的不透水地表比例明显高于新城区,但新城区不透水地表比例增加幅度大于主城区。武汉市不透水地表主要沿长江、汉江两条轴线分布,随着与城市中心距离的增大,不透水地表比例递减后趋于稳定,三环线内4 km和三环外10 km范围是平均不透水地表比例增量最大的圈层。2002~2015年,武汉市由自然地表与极低盖度等级占主导的景观格局逐渐演变为以中高盖度不透水盖度等级占主导。     

珠三角公路通达性演化及其对城市潜力的影响

将空间句法模型与GIS结合,基于1990年、2009年公路网数据,定量分析1990年以来珠三角公路网通达性时空演变,进而探讨其对城市潜力变化的影响。结果表明：① 近20 a来,珠三角公路网拓扑连接等级差异趋于缩小、整体通达性显著提高,但核心区内部和外部路网发育差距趋于扩大;② 公路通达性总体上呈“核心-外围”结构,核心区范围不断扩大,至2009年以广-佛核心都市区、深-莞-惠都市区为最高,向外围逐渐递减,并形成了“∧”型高集成度轴线分布带及由此向外放射状延伸的态势;各等级公路轴线分布格局变化空间分异明显,公路网拓扑连接的区域不均衡性更加明显;三大地带公路通达性空间差异明显,中部最高且提高较快,东部次之但与中部差异趋于缩小,西部相对最低且与中、东部的差异进一步扩大;③ 公路网总体布局上智能性、可理解性有较大提高,但核心区外部公路智能度仍普遍较差;④ 公路通达性与城市潜力呈正相关性并得到增强,公路交通对城市潜力变化影响更加显著,但2009年仍属中度相关。     

Spatial heterogeneity of urban land-cover landscape in Guangzhou from 1990 to 2005

Urbanization has been the most important process that changed land cover landscape in Guangzhou since reformation, especially since 1990. It is essential for monitoring and assessing ecological consequences of urbanization to understand landscape quantitative characteristics and its changes. Based on four land-cover type maps interpreted from remote sensing TM images of 1990, 1995, 2000 and 2005, combining gradient analysis with landscape metrics, the quantified spatial pattern and its dynamics of urbanization in Guangzhou was got. Three landscape metrics were computed within different regional areas including the whole study area, two transects along two highways (one N–S and the other W–E) and radiation zones with equal distance outwards the city center were set. Buffer zones for transects N–S and W–E were outlined along highways. The following questions should be answered in this paper: What responses were implied with changing spatial grain size or extent for landscape pattern analysis? Could gradient progress of urbanization be characterized by landscape pattern analysis? Did landscape metrics reveal urban expanding gradually? Were there directional differences in land cover landscape pattern during urbanizing development? The results gave some affirmative answers. Landscape pattern exhibited obviously scale-dependent to grain size and extent. The landscape metrics with gradient analysis could quantitatively approach spatial pattern of urbanization. A precise location for urbanized area, like city center and sub-center, could be identified by multiple landscape metrics. Multiple adjunctive centers occurred as indicated by analysis of radiation zones around the city center. Directional differences of landscape pattern along the two transects (N–S and W–E) came into being. For example, fragmentation of landscape in the transect W–E was obviously higher than that in the transect N–S. All in all, some interesting and important ecological implications were revealed under landscape patterns of two transects or radiation zones, and that was the important step to link pattern with processes in urban ecological studies and the basis to improve urban environment.     

1990-2005年广州城市土地覆被景观变化

Urbanization has been the most important process that changed land cover landscape in Guangzhou since reformation, especially since 1990. It is essential for monitoring and assessing ecological consequences of urbanization to understand landscape quantitative characteristics and its changes. Based on four land-cover type maps interpreted from remote sensing TM images of 1990, 1995, 2000 and 2005, combining gradient analysis with landscape metrics, the quantified spatial pattern and its dynamics of urbanization in Guangzhou was got. Three landscape metrics were computed within different regional areas including the whole study area, two transects along two highways (one N-S and the other W-E) and radiation zones with equal distance outwards the city center were set. Buffer zones for transects N-S and W-E were outlined along highways. The following questions should be answered in this paper: What responses were implied with changing spatial grain size or extent for landscape pattern analysis? Could gradient progress of urbanization be characterized by landscape pattern analysis? Did landscape metrics reveal urban expanding gradually? Were there directional differences in land cover landscape pattern during urbanizing development? The results gave some affirmative answers. Landscape pattern exhibited obviously scale-dependent to grain size and extent. The landscape metrics with gradient analysis could quantitatively approach spatial pattern of urbanization. A precise location for urbanized area, like city center and sub-center, could be identified by multiple landscape metrics. Multiple adjunctive centers occurred as indicated by analysis of radiation zones around the city center. Directional differences of landscape pattern along the two transects (N-S and W-E) came into being. For example, fragmentation of landscape in the transect W-E was obviously higher than that in the transect N-S. All in all, some interesting and important ecological implications were revealed under landscape patterns of two transects or radiation zones, and that was the important step to link pattern with processes in urban ecological studies and the basis to improve urban environment.     

不透水地表盖度视角下中美城市群空间结构对比——以“京津冀”与“波士华”为例

将城市不透水地表盖度产品应用于城市群空间结构研究具有重要价值。本文基于多源遥感数据提取了“京津冀”与“波士华”城市群近40年（1972-2011年）亚像元级不透水地表专题信息,构建了城市群空间结构对比分析数据集;并引入引力模型和景观格局理论,利用引力指数、景观格局指数以及空间结构参数等,采用地理信息系统空间分析方法,从城市群与城市两个尺度对城市群空间结构进行了对比研究。结果表明：① “京津冀”城市群不透水地表快速增长,而“波士华”城市群较为稳定;② “京津冀”城市群空间结构经历了城市孤立发展阶段、双核心城市群阶段、城市群组阶段以及城市群网络化阶段,“波士华”城市群空间结构较为稳定,空间结构呈现出“点—轴”带状分布;③ 中国城市不透水地表盖度“高—高”聚集区呈现出典型团块状“摊大饼”形态,而美国城市呈现出一种“多中心集聚、分散成组”的态势;④ “京津冀”城市群生态、生产与生活用地不透水地表面积占比均高于“波士华”城市群。最后,基于两国城市群空间结构的对比结果,从空间布局优化角度对“京津冀”城市群的发展提出了初步建议。     

城市土地利用/覆盖变化与热环境生态调控研究进展与展望

城市土地利用/覆盖变化(LUCC)与热环境生态调控是城市生态学和城市气候适应性关注的热点问题。在提出城市LUCC/空间结构与生态服务热调节功能连接的重要性的基础上,综述了城市土地利用变化、城市绿色基础设施在热岛减缓和气候适应性发挥的作用,评述了观测实验、定量遥感和过程模型方面以及热调控的进展情况。基于此认为,局地或区域尺度城市高精度结构组分高精度遥感探测方法、城市高精度下垫面多尺度(功能区/覆盖组分/构造或材质等)对局地气温和辐射能量平衡影响机理和定量贡献识别、城市生态系统热调节功能的城市地表结构组分调控阈值确定、以及区域或全球尺度城市土地利用/覆盖变化影响的生物地球物理机制定量化认知等,是未来重要的发展方向。     

近20年珠三角城市群城市空间相互作用时空演变

利用改进的引力模型和潜力模型,结合GIS空间分析方法,从地级市和县域两个空间尺度分析了近20 a珠三角地区城市间相互作用的时空演变。结果表明:珠三角地级城市空间联系总体逐步加强,并充分体现出广州的中心城市地位;县域尺度上,空间联系强度较大的主要是各地市市区之间及广-佛都市区的县市间和各地市市区与其所辖县市之间,其它县市间联系强度则较小;珠三角核心区内大部分县市之间联系总体呈逐渐增强趋势,核心区外的县市之间及其与核心区内的县市间联系强度有升有降,规律性不明显。广-佛都市区和深圳-东莞-惠州都市区的城市潜力较大且变动较大,对外辐射带动作用强,其它城市潜力相对较小且变化不明显;珠三角城市潜力的区域不平衡态势明显,城市潜力的空间分异和空间辐射的特征与演变规律明显。     

北京市制造业空间格局演化及影响因子分析

制造业的空间扩散是推动城市空间结构呈现多极化、多中心地域系统的主要驱动力, 对制造业区位变迁及影响因素的研究是认识城市空间重构机制的微观基础。本研究基于北京市1996、2001、2010 年制造业企业数据, 以邮政编码区为空间单元, 刻画了北京市制造业空间集聚格局及演化特征。采用计量模型, 检验了导致北京制造业空间重构的主要区位因子, 对比了这些影响因子作用强度随时间的变化以及在制造业行业间的差异。结果表明, 北京市的制造业在中心城区的集聚度明显减弱, 呈显著的郊区化集聚;主要集聚区位于距市中心半径为15~35 km的空间范围内, 总体空间格局呈现出大都市区尺度上的扩散以及产业园区尺度的再集聚特征。计量模型计算结果显示, 区位通达度、集聚经济、科技园区规划与政策引导是北京制造业总体空间格局演化的主要驱动因素, 但不同区位因子的作用强度存在行业间差异。本研究揭示了北京市的制造业空间重组机制是政府规划引导下的市场经济作用机制。认识到城市经济活动空间重组中市场与政府的交互作用机理, 有助于决策者对转型期大都市区制造业空间集聚和扩散格局进行更加有效地引导, 以优化大都市区的空间结构与功能体系。     

近20年京津唐主体城区地表热场空间特征变化分析

基于Landsat遥感影像获取京津唐主体城区1995~2015年地表温度(Land Surface Temperature, LST)和不透水地表盖度(Impervious Surface Percentage, ISP)数据。采用热点聚集和阈值分割法,依据地表的温度和不透水盖度属性将京津唐主体城区划分成9种地表热场类型,分析并探讨地表热场的发展规律、年际变化状况和区域贡献作用。研究发现,京津唐主体城区地表温度与不透水地表盖度间存在显著的正向相关关系,两者分别呈现“阶梯降”和“两端高、中间低”的变化特征。京津唐主体城区地表热场的发展主轴保持在西北-东南方向,且随时间推移沿主轴呈聚集态势。 京津唐主体城区地表热场的影响范围在空间上持续扩张,对于不同的主体城区,其在整体区域的热场贡献中有差异化表现。     

深圳市近20年城市景观格局演变及其驱动因素

基于深圳市1996—2015年土地利用数据,利用景观指数、景观转移矩阵和景观扩张指数等方法探究了深圳市近20年景观格局时空变化、主要景观类型转移和建筑用地扩张模式,最后使用Binary Logit模型考察了市级和区级建筑用地景观扩张的主要驱动因素。结果表明：① 1996—2015年,深圳市建筑用地景观优势性逐步增强,面积增加15.81%,以蔓延式（61.9%）和填充式（36.27%）扩张为主;② 1996—2006年为城市化快速扩张期,建筑用地扩张呈集中开发形态,景观多样性和均匀性增加,城市扩张中心略微向北部和东部移动,2006—2015为城市化低速过渡期,景观破碎化加剧,城市扩张重心向北部和西部偏移;③ 在市级尺度上,GDP密度和人口密度对建筑用地景观扩张有显著正影响,生态控制线、高程、坡度和至道路的距离有着显著负影响。每单位生态控制线范围、坡度的增加分别将使建筑用地景观扩张的机会比率将平均减少到原来0.8168倍、0.8841倍。各驱动因素表现出区域和尺度差异性,GDP对宝安区、南山区和坪山区,人口增长对宝安区、龙华区,以及交通可达性对大鹏新区、龙岗区驱动分别最为突出。研究结果可以为中国城市快速扩张过程中的景观格局变化提供科学实践。     

Monitoring land changes in an urban area using satellite imagery,GIS and landscape metrics

Monitoring land changes is an important activity in landscape planning and resource management. In this study, we analyze urban land changes in Atlanta metropolitan area through the combined use of satellite imagery, geographic information systems (GIS), and landscape metrics. The study site is a fast-growing large metropolis in the United States, which contains a mosaic of complex landscape types. Our method consisted of two major components: remote sensing-based land classification and GIS-based land change analysis. Specifically, we adopted a stratified image classification strategy combined with a GIS-based spatial reclassification procedure to map land classes from Landsat Thematic Mapper (TM) scenes acquired in two different years. Then, we analyzed the spatial variation and expansion of urban land changes across the entire metropolitan area through post classification change detection and a variety of GIS-based operations. We further examined the size, pattern, and nature of land changes using landscape metrics to examine the size, pattern, and nature of land changes. This study has demonstrated the usefulness of integrating remote sensing with GIS and landscape metrics in land change analysis that allows the characterization of spatial patterns and helps reveal the underlying processes of urban land changes. Our results indicate a transition of urbanization patterns in the study site with a limited outward expansion despite the dominant suburbanization process.     

不透水地表盖度视角下中美城市群空间结构对比——以“京津冀”与“波士华”为例（英文）

Under the background of China's rapid urbanization, study on comparative analysis of the spatial structure of urban agglomerations between China and the US can provide the policy proposals of space optimization for the Chinese government. Taking the Beijing-Tianjin-Hebei(BTH) and Boswash as study area, we mapped the subpixel-level impervious surface coverage of the BTH and Boswash, respectively, from 1972 to 2011. Further, landscape metrics, gravitational model and spatial analysis were used to analyze the differences of the spatial structures between the BTH and Boswash. The results showed that(1) the area of the impervious surface increased rapidly in the BTH, while those remained stable in the Boswash.(2) The spatial structure of the BTH experienced different periods including isolated cities stage, dual-core cities stage, group cities stage and network-style cities stage, while those of the Boswash was more stable, and its spatial pattern showed a "point-axis" structure.(3) The spatial pattern of high-high assembling regions of the impervious surface exhibited a "standing pancake" feature in the BTH, while those showed a "multi-center, local aggregation and global discrete" feature in the Boswash.(4) All the percentages of the impervious surface of ecological, living, and production land of the BTH were higher than those of the Boswash. At last, from the perspective of space optimization of urban agglomeration, the development proposals for the BTH were proposed.