The urban heat island(UHI) effect has significant effects on the quality of life and public health. Numerous studies have addressed the relationship between UHI and the increase in urban impervious surface area(ISA), ...The urban heat island(UHI) effect has significant effects on the quality of life and public health. Numerous studies have addressed the relationship between UHI and the increase in urban impervious surface area(ISA), but few of them have considered the impact of the spatial configuration of ISA on UHI. Land surface temperature(LST) may be affected not only by urban land cover, but also by neighboring land cover. The aim of this research was to investigate the effects of the abundance and spatial association of ISAs on LST. Taking Harbin City, China as an example, the impact of ISA spatial association on LST measurements was examined. The abundance of ISAs and the LST measurements were derived from Landsat Thematic Mapper(TM) imagery of 2000 and 2010, and the spatial association patterns of ISAs were calculated using the local Moran’s I index. The impacts of ISA abundance and spatial association on LST were examined using correlation analysis. The results suggested that LST has significant positive associations with both ISA abundance and the Moran’s I index of ISAs, indicating that both the abundance and spatial clustering of ISAs contribute to elevated values of LST. It was also found that LST is positively associated with clustering of high-ISA-percentage areas(i.e.,>50%) and negatively associated with clustering of low-ISA-percentage areas(i.e.,<25%). The results suggest that, in addition to the abundance of ISAs,their spatial association has a significant effect on UHIs.展开更多
Spatial autocorrelation methodologies, including Global Moran’s I and Local Indicators of Spatial Association statistic (LISA), were used to describe and map spatial clusters of 13 leading malignant neoplasms in Taiw...Spatial autocorrelation methodologies, including Global Moran’s I and Local Indicators of Spatial Association statistic (LISA), were used to describe and map spatial clusters of 13 leading malignant neoplasms in Taiwan. A logistic regression fit model was also used to identify similar characteristics over time. Two time periods (1995-1998 and 2005-2008) were compared in an attempt to formulate common spatio-temporal risks. Spatial cluster patterns were identified using local spatial autocorrelation analysis. We found a significant spatio-temporal variation between the leading malignant neoplasms and well-documented spatial risk factors. For instance, in Taiwan, cancer of the oral cavity in males was found to be clustered in locations in central Taiwan, with distinct differences between the two time periods. Stomach cancer morbidity clustered in aboriginal townships, where the prevalence of Helicobacter pylori is high and even quite marked differences between the two time periods were found. A method which combines LISA statistics and logistic regression is an effective tool for the detection of space-time patterns with discontinuous data. Spatio-temporal mapping comparison helps to clarify issues such as the spatial aspects of both two time periods for leading malignant neoplasms. This helps planners to assess spatio-temporal risk factors, and to ascertain what would be the most advantageous types of health care policies for the planning and implementation of health care services. These issues can greatly affect the performance and effectiveness of health care services and also provide a clear outline for helping us to better understand the results in depth.展开更多
Data are limitless. But those are usually not formed or created in our needs. Most of data providers deliver their data in Microsoft Excel spreadsheet, which is compatible with ArcGIS, the most widely used GIS (Geogr...Data are limitless. But those are usually not formed or created in our needs. Most of data providers deliver their data in Microsoft Excel spreadsheet, which is compatible with ArcGIS, the most widely used GIS (Geographic Information System) software in GIS sector. However, those table data contain much unnecessary information that do not need for a certain project. Using the raw data can increase processing times and reduce performance of geoprocessing tools. This study shows steps of how the raw data are being processed using ArcGIS ModelBuilder and Python script.展开更多
The aim of the present study was to assess spatial features of tuberculosis prevalence and their relationships with four main ethnic communities in Taiwan. Methods of spatial analysis were clustering pattern determina...The aim of the present study was to assess spatial features of tuberculosis prevalence and their relationships with four main ethnic communities in Taiwan. Methods of spatial analysis were clustering pattern determination (such as global version of Moran’s test and local version of Gi*(d) statistic), using logistic regression calculations to identify spatial distributions over a contiguous five years and identify significant similarities, discriminant analysis to classify variables, and geographically weighted regression (GWR) to determine the strength of relationships between tuberculosis prevalence and ethnic variables in spatial features. Tuberculosis demonstrated decreasing trends in prevalence in both genders during 2005 to 2009. All results of the global Moran’s tests indicated spatial heterogeneity and clusters in the plain and mountainous Aboriginal townships. The Gi*(d) statistic calculated z-score outcomes, categorized as clusters or non-clusters, at at 5% significance level. According to the stepwise Wilks’ lambda discriminant analysis, in the Aborigines and Hoklo communities townships with clusters of tuberculosis cases differentiated from townships without cluster cases, to a greater extent than in the other communities. In the GWR models, the explanatory variables demonstrated significant and positive signs of parameter estimates in clusters occurring in plain and mountainous aboriginal townships. The explanatory variables of both the Hoklo and Hakka communities demonstrated significant, but negative, signs of parameter estimates. The Mainlander community did not significantly associate with cluster patterns of tuberculosis in Taiwan. Results indicated that locations of high tuberculosis prevalence closely related to areas containing higher proportions of the Aboriginal community in Taiwan. This information is relevant for assessment of spatial risk factors, which, in turn, can facilitate the planning of the most advantageous types of health care policies, and implementation of effective health care services.展开更多
Understanding the nonlinear relationship between hydrological response and key factors and the cause behind this relationship is vital for water resource management and earth system model.In this study,we undertook se...Understanding the nonlinear relationship between hydrological response and key factors and the cause behind this relationship is vital for water resource management and earth system model.In this study,we undertook several steps to explore the relationship.Initially,we partitioned runoff response change(RRC)into multiple components associated with climate and catchment properties,and examined the spatial patterns and smoothness indicated by the Moran's Index of RRC across the contiguous United States(CONUS).Subsequently,we employed a machine learning model to predict RRC using catchment attribute predictors encompassing climate,topography,hydrology,soil,land use/cover,and geology.Additionally,we identified the primary factors influencing RRC and quantified how these key factors control RRC by employing the accumulated local effect,which allows for the representation of not only dominant but also secondary effects.Finally,we explored the relationship between ecoregion patterns,climate gradients,and the distribution of RRC across CONUS.Our findings indicate that:(1)RRC demonstrating significant connections between catchments tends to be well predicted by catchment attributes in space;(2)climate,hydrology,and topography emerge as the top three key attributes nonlinearly influencing the RRC patterns,with their second-order effects determining the heterogeneous patterns of RRC;and(3)local Moran's I signifies a collaborative relationship between the patterns of RRC and their spatial smoothness,climate space,and ecoregions.展开更多
东北森林带作为国家主体生态区划"两屏三带"国家生态安全格局中的重要组成部分,在全球碳平衡中发挥着重要的碳汇作用。以东北森林带为研究区域,采用净生态系统生产力(NEP)评估其森林固碳服务,通过Anselin Local Moran's ...东北森林带作为国家主体生态区划"两屏三带"国家生态安全格局中的重要组成部分,在全球碳平衡中发挥着重要的碳汇作用。以东北森林带为研究区域,采用净生态系统生产力(NEP)评估其森林固碳服务,通过Anselin Local Moran's Ⅰ算法识别固碳服务的"热点"、"冷点"和"异常点",并分析探讨其空间格局与影响因素。结果表明:(1)东北森林带森林生态系统整体上是碳汇。2014年东北森林带森林固碳总量为36.41 Tg C/a,单位面积固碳量为89.57 g C m^(-2)a^(-1)。(2)固碳服务的热点区主要分布在大兴安岭北部和长白山中北部,冷点区主要分布在大兴安岭东部、小兴安岭和长白山南部,固碳服务的高值异常区域主要分布在森林边缘的农林交错带,低值异常区域主要分布在人为干扰严重的城市蔓延区。(3)东北森林带森林生态系统整体上受人为因素的影响小,其固碳服务与NDVI显著正相关。(4)城市扩张等人为干扰是固碳服务异常降低的根本原因,植被本身生长状况不佳和较高的温度是导致固碳服务的异常降低的重要影响因素。展开更多
This study examines the impact of spatial landscape configuration(e.g.,clustered,dispersed)on land-surface temperatures(LST)over Phoenix,Arizona,and Las Vegas,Nevada,USA.We classified detailed land-cover types via obj...This study examines the impact of spatial landscape configuration(e.g.,clustered,dispersed)on land-surface temperatures(LST)over Phoenix,Arizona,and Las Vegas,Nevada,USA.We classified detailed land-cover types via object-based image analysis(OBIA)using Geoeye-1 at 3-m resolution(Las Vegas)and QuickBird at 2.4-m resolution(Phoenix).Spatial autocorrelation(local Moran’s I)was then used to test for spatial dependence and to determine how clustered or dispersed points were arranged.Next,we used Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)data acquired over Phoenix(daytime on 10 June and nighttime on 17 October 2011)and Las Vegas(daytime on 6 July and nighttime on 27 August 2005)to examine day-and nighttime LST with regard to the spatial arrangement of anthropogenic and vegetation features.Local Moran’s I values of each land-cover type were spatially correlated to surface temperature.The spatial configuration of grass and trees shows strong negative correlations with LST,implying that clustered vegetation lowers surface temperatures more effectively.In contrast,clustered spatial arrangements of anthropogenic land-cover types,especially impervious surfaces and open soil,elevate LST.These findings suggest that city planners and managers should,where possible,incorporate clustered grass and trees to disperse unmanaged soil and paved surfaces,and fill open unmanaged soil with vegetation.Our findings are in line with national efforts to augment and strengthen green infrastructure,complete streets,parking management,and transit-oriented development practices,and reduce sprawling,unwalkable housing development.展开更多
基金Under the auspices of the National Social Science Foundation of China(No.16BJY039)
文摘The urban heat island(UHI) effect has significant effects on the quality of life and public health. Numerous studies have addressed the relationship between UHI and the increase in urban impervious surface area(ISA), but few of them have considered the impact of the spatial configuration of ISA on UHI. Land surface temperature(LST) may be affected not only by urban land cover, but also by neighboring land cover. The aim of this research was to investigate the effects of the abundance and spatial association of ISAs on LST. Taking Harbin City, China as an example, the impact of ISA spatial association on LST measurements was examined. The abundance of ISAs and the LST measurements were derived from Landsat Thematic Mapper(TM) imagery of 2000 and 2010, and the spatial association patterns of ISAs were calculated using the local Moran’s I index. The impacts of ISA abundance and spatial association on LST were examined using correlation analysis. The results suggested that LST has significant positive associations with both ISA abundance and the Moran’s I index of ISAs, indicating that both the abundance and spatial clustering of ISAs contribute to elevated values of LST. It was also found that LST is positively associated with clustering of high-ISA-percentage areas(i.e.,>50%) and negatively associated with clustering of low-ISA-percentage areas(i.e.,<25%). The results suggest that, in addition to the abundance of ISAs,their spatial association has a significant effect on UHIs.
文摘Spatial autocorrelation methodologies, including Global Moran’s I and Local Indicators of Spatial Association statistic (LISA), were used to describe and map spatial clusters of 13 leading malignant neoplasms in Taiwan. A logistic regression fit model was also used to identify similar characteristics over time. Two time periods (1995-1998 and 2005-2008) were compared in an attempt to formulate common spatio-temporal risks. Spatial cluster patterns were identified using local spatial autocorrelation analysis. We found a significant spatio-temporal variation between the leading malignant neoplasms and well-documented spatial risk factors. For instance, in Taiwan, cancer of the oral cavity in males was found to be clustered in locations in central Taiwan, with distinct differences between the two time periods. Stomach cancer morbidity clustered in aboriginal townships, where the prevalence of Helicobacter pylori is high and even quite marked differences between the two time periods were found. A method which combines LISA statistics and logistic regression is an effective tool for the detection of space-time patterns with discontinuous data. Spatio-temporal mapping comparison helps to clarify issues such as the spatial aspects of both two time periods for leading malignant neoplasms. This helps planners to assess spatio-temporal risk factors, and to ascertain what would be the most advantageous types of health care policies for the planning and implementation of health care services. These issues can greatly affect the performance and effectiveness of health care services and also provide a clear outline for helping us to better understand the results in depth.
文摘Data are limitless. But those are usually not formed or created in our needs. Most of data providers deliver their data in Microsoft Excel spreadsheet, which is compatible with ArcGIS, the most widely used GIS (Geographic Information System) software in GIS sector. However, those table data contain much unnecessary information that do not need for a certain project. Using the raw data can increase processing times and reduce performance of geoprocessing tools. This study shows steps of how the raw data are being processed using ArcGIS ModelBuilder and Python script.
文摘The aim of the present study was to assess spatial features of tuberculosis prevalence and their relationships with four main ethnic communities in Taiwan. Methods of spatial analysis were clustering pattern determination (such as global version of Moran’s test and local version of Gi*(d) statistic), using logistic regression calculations to identify spatial distributions over a contiguous five years and identify significant similarities, discriminant analysis to classify variables, and geographically weighted regression (GWR) to determine the strength of relationships between tuberculosis prevalence and ethnic variables in spatial features. Tuberculosis demonstrated decreasing trends in prevalence in both genders during 2005 to 2009. All results of the global Moran’s tests indicated spatial heterogeneity and clusters in the plain and mountainous Aboriginal townships. The Gi*(d) statistic calculated z-score outcomes, categorized as clusters or non-clusters, at at 5% significance level. According to the stepwise Wilks’ lambda discriminant analysis, in the Aborigines and Hoklo communities townships with clusters of tuberculosis cases differentiated from townships without cluster cases, to a greater extent than in the other communities. In the GWR models, the explanatory variables demonstrated significant and positive signs of parameter estimates in clusters occurring in plain and mountainous aboriginal townships. The explanatory variables of both the Hoklo and Hakka communities demonstrated significant, but negative, signs of parameter estimates. The Mainlander community did not significantly associate with cluster patterns of tuberculosis in Taiwan. Results indicated that locations of high tuberculosis prevalence closely related to areas containing higher proportions of the Aboriginal community in Taiwan. This information is relevant for assessment of spatial risk factors, which, in turn, can facilitate the planning of the most advantageous types of health care policies, and implementation of effective health care services.
基金National Natural Science Foundation of China,No.U2243203,No.51979069Natural Science Foundation of Jiangsu Province,China,No.BK20211202Research Council of Norway,No.FRINATEK Project 274310。
文摘Understanding the nonlinear relationship between hydrological response and key factors and the cause behind this relationship is vital for water resource management and earth system model.In this study,we undertook several steps to explore the relationship.Initially,we partitioned runoff response change(RRC)into multiple components associated with climate and catchment properties,and examined the spatial patterns and smoothness indicated by the Moran's Index of RRC across the contiguous United States(CONUS).Subsequently,we employed a machine learning model to predict RRC using catchment attribute predictors encompassing climate,topography,hydrology,soil,land use/cover,and geology.Additionally,we identified the primary factors influencing RRC and quantified how these key factors control RRC by employing the accumulated local effect,which allows for the representation of not only dominant but also secondary effects.Finally,we explored the relationship between ecoregion patterns,climate gradients,and the distribution of RRC across CONUS.Our findings indicate that:(1)RRC demonstrating significant connections between catchments tends to be well predicted by catchment attributes in space;(2)climate,hydrology,and topography emerge as the top three key attributes nonlinearly influencing the RRC patterns,with their second-order effects determining the heterogeneous patterns of RRC;and(3)local Moran's I signifies a collaborative relationship between the patterns of RRC and their spatial smoothness,climate space,and ecoregions.
文摘东北森林带作为国家主体生态区划"两屏三带"国家生态安全格局中的重要组成部分,在全球碳平衡中发挥着重要的碳汇作用。以东北森林带为研究区域,采用净生态系统生产力(NEP)评估其森林固碳服务,通过Anselin Local Moran's Ⅰ算法识别固碳服务的"热点"、"冷点"和"异常点",并分析探讨其空间格局与影响因素。结果表明:(1)东北森林带森林生态系统整体上是碳汇。2014年东北森林带森林固碳总量为36.41 Tg C/a,单位面积固碳量为89.57 g C m^(-2)a^(-1)。(2)固碳服务的热点区主要分布在大兴安岭北部和长白山中北部,冷点区主要分布在大兴安岭东部、小兴安岭和长白山南部,固碳服务的高值异常区域主要分布在森林边缘的农林交错带,低值异常区域主要分布在人为干扰严重的城市蔓延区。(3)东北森林带森林生态系统整体上受人为因素的影响小,其固碳服务与NDVI显著正相关。(4)城市扩张等人为干扰是固碳服务异常降低的根本原因,植被本身生长状况不佳和较高的温度是导致固碳服务的异常降低的重要影响因素。
基金This research study is supported by a NASA-funded project(NASA award number NNX12AM88G)titled"Understanding Impacts of Desert Urbanization on Climate and Surrounding Environments to Foster Sustainable Cities Using Remote Sensing and Numerical Modeling."This material is also based upon work supported by the National Science Foundation under grant number BCS-1026865,Central Arizona-Phoenix Long-Term Ecological Research(CAP LTER),and under NSF award number SES-0951366 and SES-0345945,Decision Center for a Desert City(DCDC).
文摘This study examines the impact of spatial landscape configuration(e.g.,clustered,dispersed)on land-surface temperatures(LST)over Phoenix,Arizona,and Las Vegas,Nevada,USA.We classified detailed land-cover types via object-based image analysis(OBIA)using Geoeye-1 at 3-m resolution(Las Vegas)and QuickBird at 2.4-m resolution(Phoenix).Spatial autocorrelation(local Moran’s I)was then used to test for spatial dependence and to determine how clustered or dispersed points were arranged.Next,we used Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER)data acquired over Phoenix(daytime on 10 June and nighttime on 17 October 2011)and Las Vegas(daytime on 6 July and nighttime on 27 August 2005)to examine day-and nighttime LST with regard to the spatial arrangement of anthropogenic and vegetation features.Local Moran’s I values of each land-cover type were spatially correlated to surface temperature.The spatial configuration of grass and trees shows strong negative correlations with LST,implying that clustered vegetation lowers surface temperatures more effectively.In contrast,clustered spatial arrangements of anthropogenic land-cover types,especially impervious surfaces and open soil,elevate LST.These findings suggest that city planners and managers should,where possible,incorporate clustered grass and trees to disperse unmanaged soil and paved surfaces,and fill open unmanaged soil with vegetation.Our findings are in line with national efforts to augment and strengthen green infrastructure,complete streets,parking management,and transit-oriented development practices,and reduce sprawling,unwalkable housing development.