Geospatial Analysis of Urban Heat Island Effects and Tree Equity

In recent decades, Urban Heat Island Effects have become more pronounced and more widely examined. Despite great technological advances, our current societies still experience great spatial disparity in urban forest access. Urban Heat Island Effects are measurable phenomenon that are being experienced by the world’s most urbanized areas, including increased summer high temperatures and lower evapotranspiration from having impervious surfaces instead of vegetation and trees. Tree canopy cover is our natural mitigation tool that absorbs sunlight for photosynthesis, protects humans from incoming radiation, and releases cooling moisture into the air. Unfortunately, urban areas typically have low levels of vegetation. Vulnerable urban communities are lower-income areas of inner cities with less access to heat protection like air conditioners. This study uses mean evapotranspiration levels to assess the variability of urban heat island effects across the state of Tennessee. Results show that increased developed land surface cover in Tennessee creates measurable changes in atmospheric evapotranspiration. As a result, the mean evapotranspiration levels in areas with less tree vegetation are significantly lower than the surrounding forested areas. Central areas of urban cities in Tennessee had lower mean evapotranspiration recordings than surrounding areas with less development. This work demonstrates the need for increased tree canopy coverage.

Assessing the Impact of Using Different Land Cover Classification in Regional Modeling Studies for the Manaus Area,Brazil

Land cover classification is one of the main components of the modern weather research and forecasting models, which can influence the meteorological variable, and in turn the concentration of air pollutants. In this study the impact of using two traditional land use classifications, the United States Geological Survey (USGS) and the Moderate-resolution Imaging Spectroradiometer (MODIS), were evaluated. The Weather Research and Forecasting model (WRF, version 3.2.1) was run for the period 18 - 22 August, 2014 (dry season) at a grid spacing of 3 km centered on the city of Manaus. The comparison between simulated and ground-based observed data revealed significant differences in the meteorological fields, for instance, the temperature. Compared to USGS, MODIS classification showed better skill in representing observed temperature for urban areas of Manaus, while the two files showed similar results for nearby areas. The analysis of the files suggests that the better quality of the simulations favorable to the MODIS file is straightly related to its better representation of urban class of land use, which is observed to be not adequately represented by USGS.

Remote Sensing Data and SLEUTH Urban Growth Model:As Decision Support Tools for Urban Planning

Sri Lanka is experiencing speedy urbanization by converting the agriculture land and other natural land cover into built-up land. The urban population of Sri Lanka is expected to reach to 60% by 2030 from 14% in 2010. The rapid growth in urban population and urban areas in Sri Lanka may cause serious socioeconomic disparities, if they are not handled properly. Thus, planners in Sri Lanka are in need of information about past and future urban growth patterns to plan a better and sustainable urban future for Sri Lanka. In this paper, we analyzed the characteristics of past land use and land cover trends in Matara City of Sri Lanka from 1980 to 2010 to assess the historic urban dynamics. The land use change detection analysis based on remote sensing datasets reveal that the conversion of homestead/garden and paddy into urban land is evident in Matara City. The historic urban trends are projected into the near future by using SLEUTH urban growth model to identify the hot spots of future urbanization and as well as the urban growth patterns in Matara City up to the basic administrative level, i.e., Grama Niladari Divisions(GND). The urban growth simulations for the year 2030 reveal that 29 GNDs out of 66 GNDs in Matara City will be totally converted into urban land. Whereas, 28 GNDs will have urban land cover from 75% to 99% by 2030. The urban growth simulations are further analyzed with respect to the proposed Matara city development plan by the Urban Development Authority(UDA) of Sri Lanka. The results show that the UDA's city development plan of Matara will soon be outpaced by rapid urbanization. Based on the calibration and validation results, the SLEUTH model proved to be a useful planning tool to understand the near future urbanization of Sri Lankan cities.

基于改进型不透水表面指数的城市V-I-S特征研究——以兰州市为例

为了更好的利用光谱指数特征对城市V-I-S地表覆被格局特征进行研究,在深入分析研究区基本组分地表覆被类型特征后,通过创建改进型归一化差值不透水表面指数(MNDISI),并结合改进型归一化差异水体指数(MNDWI)、土壤调节植被指数(SAVI),以及不同地表覆被类型在近红外和短波红外波段的平均反射率值等六组参数作为主要特征,基于Landsat TM影像,在面向对象的最邻近分类器中进行城市V-I-S基本组分地表覆被类型信息的提取与分类,精度评价得出生产者精度、用户精度、总体精度和Kappa系数分别达到92.5%、88.4%、87.5%和0.85以上.结果证明该方法实现了大范围区域城市V-I-S基本组分地表覆被类型信息和格局特征的自动准确提取.

黔中城市群碳储量对土地利用/覆被变化的响应及脆弱性

[目的]探究土地利用/覆被变化对区域生态系统碳储量及生态系统脆弱性的影响,以期为区域绿色低碳和生态系统的可持续发展提供参考依据。[方法]以2000,2010,2020年黔中城市群核心经济区3期土地利用/覆被数据为基础,运用InVEST模型和土地利用转移矩阵定量分析生态系统碳储量及其空间分布格局,并采用潜在影响指数(PI)对区域生态系统服务脆弱性进行评估。[结果]①2000—2020年,黔中城市群核心经济区土地利用/覆被变化总体表现为耕地和林地持续下降,建设用地持续上升。研究区土地利用/覆被转移主要表现为耕地、林地、草地向其他地类的转移,其中,2000—2010,2010—2020年分别有3339.35,3669.15km^(2)土地发生了转移,前者林地转为草地是主要转移类型,后者耕地转为建设用地为主要转移类型。②2000—2020年区域的碳储量表现为减少趋势,由4.42×10^(7)t减小到4.33×10^(7)t,累计减小9.40×10^(5)t,林地转为草地是引起碳储量减少的主要原因。各年度碳储量密度均呈现西部、东部高,中部低的分布态势;20a间,高密度区未发生明显变化,低密度区表现为由中心区域向外围扩散。③2000—2020年黔中城市群核心经济区主要扮演碳源的角色,土地利用程度指数增加了2.83,PI指数分别为-0.04,-0.31,均表现为负面潜在影响,且脆弱性不断增强。[结论]增加林地、控制林地转为其他用地及建设用地扩张是促进区域绿色低碳和生态系统的稳定可持续发展的重要手段。

快速城镇化背景下生态系统服务价值时空变化及空间特征研究——以潮州市潮安区为例

生态系统服务价值(ESV)动态评估可为区域可持续发展提供决策。基于生态系统服务价值当量法、双变量空间自相关分析法,分析了潮安区2008—2018年生态系统服务价值变化特征,及与主要经济指标的空间分析。结果表明:(1)2008—2018年期间,潮安区的主要的生态用地阔叶林、水田和水域大面积减少;(2)南部平原区ESV相对变化率较大,相反北部山地丘陵区各镇ESV相对变化率较小;(3)人均GDP、工业生产总值比例与生态系统服务价值存在明显的负相关关系,其中工业总产值比例与生态系统服务价值的负相关性最强;其双变量LISA图也具有相似的空间分异特征,高—低聚集区总体分布于潮安区南部平原区,低—高聚集区主要分布在北部山地丘陵地区。建议应注重产业经济的发展与生态环境保护的协调与平衡,以提高生态用地服务功能的发挥。

城市扩张对区域生态安全格局影响研究——以合肥市为例

城市用地空间扩张对生态环境的影响映射出人类社会活动和生态环境保护之间的交互作用,系统地研究城市空间无序蔓延所诱发的城市土地利用方式变化对城市生态环境的影响程度,对助推中国生态文明建设目标具有重要现实意义。为探究合肥市城市扩张对生态安全格局的影响程度,综合运用生态遥感指数、最小累积阻力模型、电路理论和斑块生成土地利用模拟模型,构建合肥市生态安全格局,识别生态夹点和生态障碍点,再从模拟验证的基础上(总体精度为94.71%,Kappa系数为90.04%,Fom值为0.102),预测了2030—2040年的城市扩张,并根据预测结果探讨城市扩张对区域生态安全格局影响程度。研究发现:合肥市生态环境质量整体呈现南高中低的分布格局,识别出合肥市生态源地共计35处,源地间活跃生态廊道70条,非活跃廊道共17条,生态夹点290个,生态障碍点112个。2020—2040年合肥市城乡、工矿居民用地、林地、水域和未利用土地面积将不断增加,而耕地以及草地面积将持续减少。2020—2040年期间城镇建成区分别侵占了生态廊道、源地、夹点、障碍点面积为55.95、10.51、1.04、1.35 km 2。研究结果可为今后快速发展城市的生态环境治理和国土空间生态保护修复工作提供理论依据和技术参考。

基于不同土地利用产品的华东地区夏季陆气相互作用模拟研究

土地利用和土地覆盖变化(Land Use and Land Cover Chang,LUCC)通过影响局地陆面过程及陆气相互作用进而影响局地天气和气候。为探究LUCC产品对陆气相互作用的影响,本文采用了三套LUCC产品,包括USGS、Landsat和MODIS,模拟研究不同LUCC产品对华东地区土壤和近地面温度、湿度的影响。结果表明,不同LUCC产品的土地利用类型差异主要在城市、农田和以草地、森林为主的自然植被。与USGS产品相比,Landsat和MODIS产品的城市和森林面积分别增加了2%和15%以上,农田面积则减少了17%左右。模拟结果表明,Landsat和MODIS产品的城市面积增加导致该区域的土壤温度和湿度增加,感热通量分别增加了28.1 W·m^(-2)、68.3 W·m^(-2),潜热通量分别减少了28.3 W·m^(-2)、81 W·m^(-2),这使得2 m气温增加了1.5℃左右,相对湿度减小了约9%。USGS产品中的农田和草地在Landsat和MODIS中改变为森林也使得土壤温度、湿度和近地面能量通量、温度和湿度的空间分布随之产生变化,但相比于城市面积改变导致的变化较为复杂。此外,不同LUCC产品之间的城市面积变化对土壤温度、湿度和近地面能量通量、温度和湿度的影响要大于农田和自然植被变化产生的影响。最后,对比三个试验模拟的土壤温度、土壤湿度、2 m气温和相对湿度结果与GLDAS(the Global Land Data Assimilation System)或站点观测资料的相关性、均方根误差、平均偏差和认同指数可以发现,使用更准确、细致的Landsat产品的模式对近地面气象条件的模拟性能要优于USGS和MODIS产品模拟结果。

基于区域城市化LUCC的人类生态过程定量研究——以上海市区典型城市化样带为例

借鉴流域研究的范例,根据上海市1987年、1995年和2003年3期Landsat5TM遥感影像记录的土地利用/覆被数据和有关的社会经济统计数据,运用RS和GIS技术在上海市中心西南城市边缘建立典型城市化样带。采用生态足迹法分析该样带内人类的生态供给与需求;提出一城市化区域人类生态过程的新研究方法,得出城市化过程中区域的人类生态质量指数与波动指数,并根据模型计算出的指数值,对样带区域总体及其中城乡区域在城市化中的人类生态状况进行了动态分析,以尝试对区域城市化中人类生态过程进行定量化研究。

基于CLUE-S模型的干旱区典型绿洲城市土地利用变化时空动态模拟研究——以新疆奎屯河流域为例

在水资源条件约束下,干旱区绿洲城市有其独特的城市空间形态,水资源分布直接影响着城市的选址、规模及空间扩展等。该文利用新疆奎屯河流域主要城镇1999-2011年的土地利用/覆被变化(LUCC)、自然资源及社会经济数据,建立了现势延续、协调发展、节水发展和经济优先4种情景驱动的CLUE-S模型,模拟奎屯河流域2011-2030年的土地空间格局变化,分析水资源约束下干旱区土地利用空间发展过程。结果表明,所有情景中各土地利用类型都存在转换,其中:草地变化最大,平均占比38.16%;耕地次之,为23.63%;林地、未利用地和盐碱地的平均占比依次为11.63%、11.40%和9.47%。从土地利用变化需求趋势和情景模拟结果可知,节水型发展是研究区未来空间发展的最优模式。

A Multi-agent Model to Simulate Regional Land Use Change with an Application to the Poyang Lake Area of China

In many regions both urban expansion and rural development take place simultaneously, and for the purpose of understanding the dynamic process of land use/cover change （LUCC） in such large areas, this study develops a multi-agent based land use model. Taking the Poyang Lake area of China as a typical case, this study applies the mechanism of diffusion-limited aggregation to simulate the behavior of urban agents, while rural land use is illustrated with a bottom-up based model consisting of agent and environment layers. In the agent layer, each household agent makes its own decisions on land use, and at each time interval a government agent takes control of land use by implementing policies. According to incomes and the rate of migrant workers, household agents are divided into six categories, among which different decision rules are followed. For complex LUCC in the Poyang Lake area of China from 1985 to 2005, the artificial society model developed in this study yields results highly consistent with observations. Importantly, it is shown that governmental policies can impose significant effects on the decisions of individual household agents on land use and the multi-agent-based land use model developed in this study provides a robust means for assessing the effectiveness of governmental policies.

土地利用与土地覆盖变化对中小城市净初级生产力的影响

为了探索研究当前城市化进程中,土地利用与土地覆盖变化对中小城市净初级生产力的影响,以张家港为研究区域,利用MODIS遥感影像数据和NPP相关模型,分别估算2008年的实际和潜在的净初级生产力(NPPact和NPPo),研究土地利用覆盖变化造成NPP损失(NPPlucc)的空间分布。结果表明,在张家港的城市化进程中,由于土地利用和土地覆盖方式的改变损失了大量的NPP,城市区域年净初级生产量以较大幅度减少;林草生态系统的NPPlucc较低,农业用地由于灌溉、施肥、田间管理等,导致其具有比潜在NPP更高的生产力,在所有用地类型中NPPlucc最低。张家港市的NPPlucc在城乡梯度上的变化呈现出从城市中心到农村纵深地区逐渐下降的趋势,其中在城乡结合部位、在农村工业区有2个上升的峰状突起。研究认为,可通过政策管理措施和工程技术手段,改善对自然生态系统的干扰,进而减少由于土地利用/覆盖变化和人类活动对周边植被干扰造成的NPP损失,是降低人类社会对净初级生产力的占用(HANPP)的可行途径,也是解决人们广泛关注的生物资源耗竭性问题与可持续发展问题的有效手段。

基于CAS的城市空间演化多主体模型方法研究

在回顾城市空间演化研究发展轨迹的基础上,提出复杂适应性系统理论适合于研究城市化进程中出现的各类复杂问题,对比了复杂性研究方法中的元胞自动机、分形以及多主体方法在城市土地利用空间演化中的应用,得出多主体建模的方法更适宜研究具有高度复杂性的城市空间演化问题的结论。在此基础上,采用自下而上的仿真思路,着重从建模思路、主体行为描述和通信模型三方面阐述和分析了构建城市空间演化仿真模型的多主体方法,而从发现并分析城市中家庭、政府、企业、开发商等微观主体的交互行为以及这些行为是如何导致城市土地利用空间上的宏观演化。

Simulation of urban expansion based on cellular automata and maximum entropy model

Urban expansion is a hot topic in land use/land cover change(LUCC)researches.In this paper,maximum entropy model and cellular automata(CA)model are coupled into a new CA model(Maxent-CA)for urban expansion.This model can help to obtain transition rules from single-period dataset.Moreover,it can be constructed and calibrated easily with several steps.Firstly,Maxent-CA model was built by using remote sensing data of China in 2000(basic data)and spatial variables(such as population density and Euclidean distance to cities).Secondly,the proposed model was calibrated by analyzing training samples,neighborhood structure and spatial scale.Finally,this model was verified by comparing logistic regression CA model and their simulation results.Experiments showed that suitable sampling ratio(sampling ratio equals the proportion of urban land in the whole region)and von Neumann neighborhood structure will help to yield better results.Spatial structure of simulation results becomes simple as spatial resolution decreases.Besides,simulation accuracy is significantly affected by spatial resolution.Compared to simulation results of logistic regression CA model,Maxent-CA model can avoid clusters phenomenon and obtain better results matching actual situation.It is found that the proposed model performs well in simulating urban expansion of China.It will be helpful for simulating even larger study area in the background of global environment changes.

成渝城市群黑碳气溶胶的时空分异特征及其对土地利用/土地覆被变化(LUCC)的响应

基于2000—2015年MERRA-2的黑碳气溶胶(BC)空间分布数据和土地利用/土地覆被数据,利用GIS空间分析手段和地理加权回归模型,识别成渝城市群BC浓度的时空分异和土地利用/土地覆被变化(LUCC)特征,探讨BC浓度对LUCC的响应关系。结果表明:(1)成渝城市群BC浓度在整体上呈现出中部高、四周低的同心圆格局,且这一态势在15 a中没有发生明显改变;2000、2005、2010和2015年的年均浓度分别为3.86、4.97、4.91和4.51μg·m^(-3),以2005年为拐点呈先上升后下降的趋势,且2005年高值区的空间范围最大,经历了扩张-收缩的变化过程;在季度水平上表现出冬季>秋季>春季>夏季的趋势,秋冬季BC污染形势严峻;(2)2000—2015年成渝城市群土地利用/土地覆被的主要类型为耕地、林地和草地,该时期3种地类面积总和的占比均在94.61%以上,土地利用结构未发生明显改变;以耕地与草地连续减少和建设用地持续增加为LUCC的主要特征,水域、林地和未利用地略有增加;(3)不同土地利用/土地覆被类型下的BC浓度总体上呈现出建设用地>耕地>水域>林地>未利用地>草地的特征;在不同的土地利用/土地覆被转换方式下,当人工用地转为自然用地时BC浓度降低,当自然用地转为人工用地时BC浓度增加;(4)地理加权回归模型计算结果表明,局域拟合系数较高区域的LUCC对BC浓度的影响较为显著,且呈现出明显的空间分异现象。

城市发展模式变化对地下水补给的影响——以北京市大兴区为例

近年来,城市发展模式由资源消耗型转变为智慧生态型。人类活动对地下水环境不再仅带来“负效应”,更通过管网渗漏、人工补给、节水压采等途径逐渐突显出对地下水资源的“正效应”,因此,需要从“正负效应”综合分析城市化对地下水资源的影响。北京市大兴区具有城市发展模式转变的典型特征,以1996年、2006年、2016年为时间节点,分析该地区浅层水在城市发展过程中的时空变化特征。分析表明大兴区城市化扩张明显,建设用地的面积占比由1996年的19.80%增长至2016年的53.61%,而水位变幅小于0.3 m的区域面积从1996年的5.17 km^(2)增长至2016年507.99 km^(2),与建设用地的范围高度重合。不透水面空间的连续性和集中性,更易阻碍雨季降水对地下水的补给,致使水位变幅减弱。随降水量的增加和再生水的推广利用,浅层水位得到控制并回升,局部范围甚至改变了原有的地下水流场状态。2006—2016年浅层地下水储量增加约0.72亿m3,灌溉区和永定河沿岸的增加量占其中的83.33%。人工补给已经是除自然降水外不可忽视的地下水补给方式,并使人为活动产生的“正效应”在对地下水资源的影响中发挥主导作用。

The Evolution Pattern and Simulation of Land Use in the Beijing Municipal Administrative Center(Tongzhou District)

Beijing Municipal Administrative Center(Beijing MC)in Tongzhou District has inherited the non-capital core functions of Beijing’s central urban area,and its rapid construction and development urgently require a scientific understanding of the pattern of land use evolution in the region.This paper analyzes the pattern of land use evolution in Tongzhou District over the past 40 years,from 1980 to 2020.According to the historical evolutionary characteristics of land use and urban development planning goals,combined with the driving factors of cultural tourism development,the Future Land-use Simulation(FLUS)model is used to simulate the spatial distribution of land use in Beijing MC(Tongzhou District)in 2035 under three scenarios of urbanization acceleration,deceleration and sustainable development.The results show three major trends.(1)Beijing MC(Tongzhou District)is dominated by urban development and construction.During the high-speed urbanization stage from 1980 to 2010,the urban expansion pattern of“along the Sixth Ring Road and along the Grand Canal”was formed.During the low-speed urbanization stage from 2010 to 2020,the land distribution was stable,and Tongzhou District formed a pattern of urban-rural differentiation and land intensification from northwest to southeast.As a typical area of Tongzhou District’s urbanization,Beijing MC has the same characteristics of the temporal and spatial evolution as Tongzhou as a whole.(2)By 2035,there are significant differences in land use among the three scenarios with respect to the magnitude of change and spatial distribution.The area and distribution of ecological land under the urban sustainable development scenario are optimal,which is conducive to the realization of sustainable urban development.In analyzing the degree of conformity with the three Beijing MC zoning plans,the prediction simulation under the sustainable development scenario is highly consistent with the land use of the“Beijing Municipal Administrative Center Regulatory Detailed Planning(Block Level)(2016–2035)”(hereinafter referred to as“Planning”)issued by the municipal government.However,there are certain deviations between the simulation predictions in the cultural tourism function area and the livable living scenery area and the corresponding“Planning”expectations.During the urban construction process,the internal ecological land area still needs to be increased.(3)Tongzhou District may lack a close connection between the urban and rural areas in the southeast.Potential risks such as the imbalance in the development of northern and southern townships require further attention in the development process.The prediction and simulation results of the model can provide certain data and methodological support for the construction of a harmonious and livable city in Beijing MC(Tongzhou District).

A spatio-temporal assessment and prediction of Ahmedabad's urban growth between 1990–2030

Analyzing long term urban growth trends can provide valuable insights into a city’s future growth.This study employs LANDSAT satellite images from 1990,2000,2010 and 2019 to perform a spatiotemporal assessment and predict Ahmedabad’s urban growth.Land Use Land Change(LULC)maps developed using the Maximum Likelihood classifier produce four principal classes:Built-up,Vegetation,Water body,and“Others”.In between 1990-2019,the total built-up area expanded by 130%,132 km^(2) in 1990 to 305 km^(2) in 2019.Rapid population growth is the chief contributor towards urban growth as the city added 3.9 km^(2) of additional built-up area to accommodate every 100,000 new residents.Further,a Multi-Layer Perceptron-Markov Chain model(MLP-MC)predicts Ahmedabad’s urban expansion by 2030.Compared to 2019,the MLP-MC model predicts a 25%and 19%increase in Ahmedabad’s total urban area and population by 2030.Unaltered,these trends shall generate many socio-economic and environmental problems.Thus,future urban development policies must balance further development and environmental damage.

WRF土地利用/覆被数据优选及其在城市热岛模拟中的应用

针对WRF模式自带土地利用数据更新不及时及精度不高的现象,本文将国内外主要土地利用数据（MODIS2012、GLC2009、GLC2000）与WRF模式耦合进行土地利用数据的优选,并将优选数据初步应用于枣庄城市热岛模拟中.结果表明：①MODIS2012数据能够较好地反映研究区域土地利用类型的空间分布特征,有较好的模拟结果;②研究区10月份热岛强度最大为0.671℃,其次是1月份和7月份分别为0.570℃和0.550%,而4月份热岛强度较小为0.467℃;城市热岛强度日最大值出现在22～23点,最小值出现在13～14点;③由于盛行风向的影响,滕州市与枣庄市中区城市热岛中心均存在春夏季北进、秋冬季南移的现象;④枣庄地区城市热岛主要受枣庄市中区的影响,各土地利用类型对城市热岛的贡献率大小排序为：城镇建设用地＞农田＞林地＞未利用地＞草地＞水体.

城市地表特征数值模拟研究进展

城市化改变了城市地区和周边区域热力、动力以及水文气象过程,从而对地表与大气相互作用产生一系列复杂的影响。目前,我国正处于城镇化的快速发展阶段,城市地表特征及其气候效应研究对于建设生态宜居城市非常重要。从城市地表特征观测与分析研究、城市下垫面特征变化对天气气候的影响途径及机理以及城市陆面模式发展3个方面总结了近年来国内外城市地表特征数值模拟研究进展。指出了当前城市地表特征数值模拟研究存在的一些问题,并且提出了今后进一步研究发展的主要方向。