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Study on the Urban Heat Island Effects and Its Relationship with Surface Biophysical Characteristics Using MODIS Imageries

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Geo-Spatial Information Science 2010年第1期13卷 1-7页

作者： zeng yongnian HUANG Wei ZHAN E Benjamin ZHANG Honghui LIU Huimin School of Info-Physics and Geomatics Engineering Central South University 932 Lushannan Road Changsha 410083 China Texas Center for Geographic Information Science Texas State University San Marcos TX 78666 USA

This study assesses surface urban heat island (UHI) and its associated surface physical characteristics using remote sensing approaches. TERRA/MODIS images acquired in 2005 in three different seasons were selected to generate land surface tem-perature and surface characteristics for the Changsha-Zhuzhou-Xiangtan metropolitan area in China. The intensity of urban heat is-land effects and its seasonal variations were examined. The result showed that UHI effects were significant both in the summer and the spring. Land surface temperatures in the city were 8 ℃ to 10℃ warmer than those in surrounding rural areas in the spring and the summer seasons. Although UHI effects exist in winter, they are not significant. Land surface temperature in the city was 4℃ warmer than that in surrounding rural areas in winter. This study uses normalized difference vegetation index (NDVI) and normal-ized difference built-up index (NDBI) as indicators of surface physical characteristics and investigates the relationship among land surface temperature (LST), NDVI and NDBI. The results from this study indicate that, while the relationship between LST and NDVI changes in different seasons, there is a strong positive linear relationship between NDBI and LST for all seasons. The amount of slope and intercept of the linear relationship between NDBI and LST can indicate the magnitude of UHI for different seasons. This finding suggests that NDBI provides an alternative physical indicator for analyzing LST quantitatively over different seasons, and therefore providing a useful way to study UHI effects using remote sensing.

关键词： urban heat island biophysical indicators MODIS image Changsha-Zhuzhou-Xiangtan area China

Modelling urban expansion using a multi agentbased model in the city of Changsha

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Journal of Geographical Sciences 2010年第4期20卷 540-556页

作者： ZHANG Honghui zeng yongnian BIAN Ling YU Xijun School of Info-Physics and Geomatics Engineering Central South University Changsha 410083 China Department of Geography University at Buffalo State University of New York NY 14261 USA South China Institute of Environmental Science Ministry of Environmental Protection Guangzhou 510655 China

Although traditional urban expansion simulation models can simulate dynamic features, these models fail to address complex changes produced by different agents＇ behaviors. The paper has built up a set of spatial-temporal land resource allocation rules and developed a dynamic urban expansion model based on a multi-agent system, which can simulate the interaction among different agents, such as residents, peasants, and governments. This model is applied to simulate urban expansion process taking Changsha City, in China as a study area. The results show that this model can not only reflect basic characteristics of urban expansion, but also help explain the reasons for urban expansion process and understand the effect of agents＇ behavior on the expansion process, and provide insights into the causing factors behind the expansion. In addition, in contrast to simulation results with land use classification map from remote sensing images, the precision of the simulation reached over 68% with higher precision than cellular automata model according to the cell-by-cell comparison. The results suggest that the model can help to provide land use decision making support to government and urban planners.

关键词： multi-agent system cellular automata urban expansion land resource allocation Changsha

A self-monitoring microneedle patch for light-controlled synergistic treatment of melanoma

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Bioactive Materials 2023年第9期27卷 58-71页

作者： Chenyuan Wang yongnian zeng Kai-Feng Chen Jiawei Lin Qianqian Yuan Xue Jiang Gaosong Wu Fubing Wang Yong-Guang Jia Wei Li Department of Thyroid and Breast Surgery Zhongnan Hospital of Wuhan UniversitySchool of Pharmaceutical SciencesWuhan UniversityWuhan430071China School of Materials Science and Engineering South China University of TechnologyGuangzhouGuangdong510641China TaiKang Center for Life and Medical Sciences Wuhan UniversityWuhanChina Cancer Precision Diagnosis and Treatment and Translational Medicine Hubei Engineering Research Center Zhongnan Hospital of Wuhan UniversityWuhanChina Wuhan Research Center for Infectious Diseases and Cancer Chinese Academy of Medical SciencesWuhanChina

Melanoma is the most aggressive and malignant form of skin *** melanoma treatment methods generally suffer from frequent drug administration as well as difficulty in direct monitoring of drug ***,a self-monitoring microneedle(MN)-based drug delivery system,which integrates a dissolving MN patch with aggregation-induced emission(AIE)-active PATC microparticles,is designed to achieve light-controlled pulsatile chemo-photothermal synergistic therapy of *** PATC polymeric particles,termed D/I@PATC,encapsulate both of chemotherapeutic drug doxorubicin(DOX)and the photothermal agent indocyanine green(ICG).Upon light illumination,PATC gradually dissociates into smaller particles,causing the release of encapsulated DOX and subsequent fluorescence intensity change of PATC particles,thereby not only enabling direct observation of the drug release process under light stimuli,but also facilitating verification of drug release by fluorescence recovery after light ***,encapsulation of ICG in PATC particles displays significant improvement of its photothermal stability both in vitro and in *** a tumor-bearing mouse,the application of one D/I@PATC MN patch combining with two cycles of light irradiation showed excellent controllable chemo-photothermal efficacy and exhibited~97%melanoma inhibition rate without inducing any evident systemic toxicity,suggesting a great potential for skin cancer treatment in clinics.

关键词： Microneedle Controlled release Melanoma AIE Photothermal therapy Chemotherapy

Using autologistic spatial models to simulate the distribution of land-use patterns in Zhangjiajie, Hunan Province

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Journal of Geographical Sciences 2010年第2期20卷 310-320页

作者： WU Guiping zeng yongnian XIAO Pengfeng FENG Xuezhi HU Xiaotian Department of Geographical Information Sciences Nanjing University Nanjing 210093 China School of Info-Physics and Geomatics Engineering Central South University Changsha 410083 China

Nowadays, spatial simulation on land use patterns is one of the key contents of LUCC. Modeling is an important tool for simulating land use patterns due to its ability to integrate measurements of changes in land cover and the associated drivers. The conventional regression model can only analyze the correlation between land use types and driving factors but cannot depict the spatial autocorrelation characteristics. Land uses in Yongding County, which is located in the typical karst mountain areas in northwestern Hunan province, were investigated by means of modeling the spatial autocorrelation of land use types with the purpose of deriving better spatial land use patterns on the basis of terrain characteristics and infrastructural conditions. Through incorporating components describing the spatial autocorrelation into a conventional logistic model, we constructed a regression model （Autologistic model）, and used this model to simulate and analyze the spatial land use patterns in Yongding County. According to the comparison with the conventional logistic model without considering the spatial autocorrelation, this model showed better goodness and higher accuracy of fitting. The distribution of arable land, wood land, built-up land and unused land yielded areas under the ROC curves （AUC） was improved to 0.893, 0.940, 0.907 and 0.863 respectively with the autologistic model. It is argued that the improved model based on autologistic method was reasonable to a certain extent. Meanwhile, these analysis results could provide valuable information for modeling future land use change scenarios with actual conditions of local and regional land use, and the probability maps of land use types obtained from this study could also support government decision-making on land use management for Yongding County and other similar areas.

关键词： land-use patterns spatial simulation autologistic model spatial autocorrelation Yongding County of Zhangjiajie City

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融合高时空分辨率数据估算植被净初级生产力

遥感学报 2018年第1期22卷 143-152页

作者：张猛曾永年中南大学地球科学与信息物理学院长沙410083 中南大学空间信息技术与可持续发展研究中心长沙410083

植被净初级生产力NPP(Net Primary Production)遥感估算与分析,有赖于高时空分辨率的遥感数据,但目前中高分辨率的遥感数据受卫星回访周期及天气的影响,在中国南方地区难以获取连续时间序列的数据,从而影响了高精度的区域植被净初级生... 详细信息

植被净初级生产力NPP(Net Primary Production)遥感估算与分析,有赖于高时空分辨率的遥感数据,但目前中高分辨率的遥感数据受卫星回访周期及天气的影响,在中国南方地区难以获取连续时间序列的数据,从而影响了高精度的区域植被净初级生产力的遥感估算。为此,提出一种基于多源遥感数据时空融合技术与CASA模型估算高时空分辨率NPP的方法。首先,利用多源遥感数据,即Landsat8 OLI数据与MODIS13Q1数据,采用遥感数据时空融合方法,获得了时间序列的Landsat8 OLI融合数据;然后,基于Landsat8 OLI时空融合数据,并采用CASA模型,以长株潭城市群核心区为例,进行区域植被NPP的遥感估算。研究结果表明,基于时间序列Landsat融合数据估算的30m分辨率的NPP具有良好的空间细节信息,且估算值与实测值的相关系数达0.825,与实测NPP数据保持了较好的一致性。

关键词： Landsat 8 OLI MODIS 时空融合高时空分辨率净初级生产力遥感估算

长株潭城市群湿地景观时空动态变化及驱动力分析

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农业工程学报 2018年第1期34卷 241-249页

作者：张猛曾永年中南大学地球科学与信息物理学院长沙410083 中南大学空间信息技术与可持续发展研究中心长沙410083

针对长株潭城市群的湿地景观面积迅速减少、破碎化程度增加等情况,该文基于时间序列Landsat数据及物候特征参数,采用面向对象方法的随机森林算法获得了长株潭城市群2000-2015年湿地时空格局及变化数据,利用景观格局指数、质心迁移等方... 详细信息

针对长株潭城市群的湿地景观面积迅速减少、破碎化程度增加等情况,该文基于时间序列Landsat数据及物候特征参数,采用面向对象方法的随机森林算法获得了长株潭城市群2000-2015年湿地时空格局及变化数据,利用景观格局指数、质心迁移等方法分析了近16 a来长株潭城市群湿地时空格局及变化特征,并通过Logistics回归模型分析了城市群湿地演化的驱动力因素。研究结果表明:1)湿地类型主要为人工湿地水田,其次为河流湿地与库塘湿地,湖泊湿地与苔草沼泽分布面积相对较小;2)2000-2015年研究区湿地总面积呈减少趋势,减少231.12 km^2,减少6.64%,同时湿地的空间转移也十分剧烈。3)研究期间,长株潭城市群湿地景观破碎度在呈增强趋势,且景观形状也趋于复杂。同时,研究区景观连通性在不断降低,而景观丰富度在不断增加。4)研究期间,长株潭城市群5种湿地类型的质心在均发生了不同程度的的迁移,其中河流、库塘和水田的质心迁移相对较大,湖泊的质心位置相对稳定。5)长株潭城市群地区降水量的减少及气温的升高,加之高强度人类干扰是近年来湿地变化的主要原因,其中人类活动加剧了湿地变化的复杂性和差异性。该研究可为长株潭城市群湿地资源的可持续发展提供科学、可靠的数据支持。

关键词：遥感湿地提取长株潭城市群景观气候人类活动

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城市扩展极限学习机模型

测绘学报 2018年第12期47卷 1680-1690页

作者：王鹤曾永年中南大学地球科学与信息物理学院湖南长沙410083 中南大学空间信息技术与可持续发展研究中心湖南长沙410083

城市空间结构及其扩展的模拟是城市科学管理与规划的重要前提,本文基于极限学习机提出了顾及不同非城市用地转化为城市用地差异与强度的城市扩展元胞自动机模型(ELM-CA)。模型验证表明:(1)ELM-CA模型的模拟精度达到70.30%,相比于逻辑回... 详细信息

城市空间结构及其扩展的模拟是城市科学管理与规划的重要前提,本文基于极限学习机提出了顾及不同非城市用地转化为城市用地差异与强度的城市扩展元胞自动机模型(ELM-CA)。模型验证表明:(1)ELM-CA模型的模拟精度达到70.30%,相比于逻辑回归和神经网络分别提高了2.21%和1.54%,FoM系数分别提高了0.025 9和0.017 9,Kappa系数分别提高了0.024 7和0.016 9,且Moran I指数接近于实际值,说明极限学习机模型较逻辑回归和神经网络能更有效模拟城市扩展的空间形态及其变化;(2)ELM模型的训练时间仅为神经网络的1/3左右,体现了ELM学习速度的优势;(3)在小样本情况下,逻辑回归和神经网络都受到明显的影响,而极限学习机还能保持良好的性能,这个特点使其在样本难以获取的情况下具有明显的优势。两个时相的城市扩展模拟与真实数据的比较表明:基于极限学习机的城市扩展元胞自动机模型(ELM-CA),简化了CA模型的复杂度,并在小样本情况下能有效提高模拟精度,适合于复杂土地利用条件下城市扩展模拟与预测。

关键词：城市空间扩展复杂土地利用地类转化差异元胞自动机极限学习机

基于多时相Landsat数据融合的洞庭湖区水稻面积提取

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农业工程学报 2015年第13期31卷 178-185页

作者：张猛曾永年中南大学地球科学与信息物理学院长沙410083 中南大学空间信息技术与可持续发展研究中心长沙410083

洞庭湖区作为中国重要的商品粮基地,水稻种植面积的变化对国家粮食安全有重要的影响,准确获取水稻面积及其变化显得十分重要。为解决数据缺失问题,该文利用STARFM(spatial and temporal adaptive reflectance fusion model)模型融合高... 详细信息

洞庭湖区作为中国重要的商品粮基地,水稻种植面积的变化对国家粮食安全有重要的影响,准确获取水稻面积及其变化显得十分重要。为解决数据缺失问题,该文利用STARFM(spatial and temporal adaptive reflectance fusion model)模型融合高时间分辨率的MODIS数据与中等空间分辨率的Landsat数据,得到时序Landsat NDVI数据,并利用时序Landsat NDVI数据对水稻种植面积进行提取。结果显示,该方法能够有效地提取水稻种植面积,总体分类精度94.52%,Kappa系数为0.9128。水稻分布几乎覆盖整个研究区,水稻种植总面积达7.88×105hm2。双季稻种植面积为7.75×105hm2,主要集中于湖区北部及西北部,且分布较连续。一季稻种植面积为1.3×104hm2,分布相对零散,有小范围集中于湖区中部及西北部。

关键词：遥感作物数据融合洞庭湖区水稻 MODIS Landsat

亚热带山地丘陵区植被NPP时空变化及其与气候因子的关系——以湖南省为例

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地理学报 2016年第1期71卷 35-48页

作者：陈晓玲曾永年中南大学地球科学与信息物理学院长沙410083 中南大学空间信息技术与可持续发展研究中心长沙410083

以湖南省为研究区,采用250 m×250 m空间分辨率的MODIS-NDVI数据,结合相应时间段的气象数据,使用改进的CASA模型,模拟并分析该区域2000-2013年间的植被NPP的时空变化特征,并借助统计分析方法对不同土地覆盖类型中植被NPP的变化趋势及其... 详细信息

以湖南省为研究区,采用250 m×250 m空间分辨率的MODIS-NDVI数据,结合相应时间段的气象数据,使用改进的CASA模型,模拟并分析该区域2000-2013年间的植被NPP的时空变化特征,并借助统计分析方法对不同土地覆盖类型中植被NPP的变化趋势及其显著性、NPP与气候因子的相关性进行量化分析。结果表明：1该区域的净初级生产量年际变化特征明显,年净初级生产量分布在41.62~125.40 Tg C/yr之间,平均值为86.34 Tg C/yr,总体来看,14年间湖南省植被净初级生产量呈波动减少趋势,年际减少趋势为2.70 Tg C/yr;2 NPP空间分布差异较大,基本特点是西高东低、南高北低,从西南向东北呈逐渐递减趋势,其中,各植被分区的NPP有明显差异;3 2000-2013年,湖南省植被NPP呈极显著增加（slope〉0,p〈0.01）、显著增加（slope〉0,0.01≤p〈0.05）、无明显变化（p≥0.05）、极显著减少（slope〈0,p〈0.01）和显著减少（slope〈0,0.01≤p〈0.05）的区域分别占总面积的比例为5.40%、2.02%、61.64%、16.79%和14.15%。植被NPP变化趋势总体上显示为减少的趋势,而不同土地覆盖类型的植被NPP变化趋势及显著性存在较大差异,其中草地的NPP变化趋势最为显著,接着依次是森林、其他土地、建设用地和农田;4分析不同土地覆盖类型的植被NPP对气候因子的响应,发现NPP与降水量之间的相关关系强于其与温度的相关关系。

关键词： NPP 气候亚热带山地丘陵湖南省