Urbanization significantly increases the risk of urban flooding. Therefore, quantitative study of urban rainfall-runoff processes can provide a scientific basis for urban planning and management. In this paper, the bu...Urbanization significantly increases the risk of urban flooding. Therefore, quantitative study of urban rainfall-runoff processes can provide a scientific basis for urban planning and management. In this paper, the built-up region within the Fifth Ring Road of Beijing was selected as the study area. The details of land cover and urban function zones(UFZs) were identified using GIS and RS methods. On this basis, the SCS-CN model was adopted to analyze the rainfall-runoff risk characteristics of the study area. The results showed that:(1) UFZs within different levels of runoff risk varied under different rainfall conditions. The area ratio of the UFZs with high runoff risk increased from 18.90%(for rainfall return period of 1 a) to 54.74%(for period of 100 a). Specifically, urban commercial areas tended to have the highest runoff risk, while urban greening spaces had the lowest.(2) The spatial characteristics of the runoff risks showed an obvious circular distribution. Spatial cluster areas with high runoff risk were mainly concentrated in the center of the study area, while those with low runoff risk were mainly distributed between the fourth and fifth ring roads. The results indicated that the spatial clustering characteristic of urban runoff risk and runoff heterogeneity among different UFZs should be fully considered during urban rainwater management.展开更多
Crude oil transportation through pipelines presents danger to communities along its path. In the Niger Delta region of Nigeria for instance, pipeline vandalism occurs indiscriminately and regularly, such that every se...Crude oil transportation through pipelines presents danger to communities along its path. In the Niger Delta region of Nigeria for instance, pipeline vandalism occurs indiscriminately and regularly, such that every segment of a pipeline network becomes a potential target and possibly source of oil spill hazard. In terms of pipeline hazard and risk distribution, the oil plume’s ability to migrate freely in wetlands and encroachment on pipeline right of ways by people increases chances of wider contact and exposure opportunities to inhabitants and the environment. Despite several efforts to mitigate pipeline hazards in the oil and gas sector, none has been effective in Nigeria partly due to paucity of data in public domain and poor public participation. Therefore considering the environmental and human health challenges associated with oil spills, an alternative method was developed using multi-criteria decision analysis to model 1) pipeline hazard zones, 2) potential pipeline impact radius, and 3) high consequence areas with four attribute layers, i.e. land cover, population, river and pipeline to encourage public participation. The model identified land use areas, communities and rivers likely to be susceptible to pipeline hazards and areas requiring regular monitoring and possible intervention. Meanwhile the model sensitivity test indicated that the river layer was most sensitive, while transferability was limited to similar criteria variables. The model can stimulate public participation in pipeline hazard management while policy makers and regulators would find it relevant in oil spill impact mitigation.展开更多
目的联合空间位置-临床-影像特征探讨可切除肺腺癌淋巴结转移的危险因素,并构建淋巴结转移预测模型。方法回顾性纳入2016年6月—2020年6月于南京医科大学第一附属医院接受胸部CT,并经手术确诊为有或无淋巴结转移的浸润性肺腺癌患者。根...目的联合空间位置-临床-影像特征探讨可切除肺腺癌淋巴结转移的危险因素,并构建淋巴结转移预测模型。方法回顾性纳入2016年6月—2020年6月于南京医科大学第一附属医院接受胸部CT,并经手术确诊为有或无淋巴结转移的浸润性肺腺癌患者。根据有无淋巴结转移,将患者分为阳性组与阴性组。收集患者的临床及影像学资料,采用单因素和多因素logistic回归分析可切除肺腺癌淋巴结转移的独立危险因素,并建立淋巴结转移的空间位置-临床-影像特征联合预测模型,将其与不包含空间位置特征的传统淋巴结转移预测模型进行对比。结果共纳入611例患者,阳性组333例,其中男172例、女161例,平均年龄(58.9±9.7)岁;阴性组278例,其中男127例、女151例,平均年龄(60.1±11.4)岁。单因素及多因素logistic回归分析显示,病灶距离肺门的空间位置关系、结节类型、胸膜改变、血清癌胚抗原(carcinoembryonic antigen,CEA)水平是淋巴结转移的独立危险因素,以此为基础构建的空间位置-临床-影像特征联合预测模型敏感性为91.67%,特异性为74.05%,准确性为87.88%,曲线下面积(area under the curve,AUC)为0.885。不包含空间位置特征的传统淋巴结转移预测模型敏感性为76.40%,特异性为72.10%,准确性为53.86%,AUC为0.827。两种预测方法的AUC差异有统计学意义(P=0.026)。与传统预测模型相比,空间位置-临床-影像特征联合预测模型的预测效能有显著提升。结论在可切除肺腺癌患者中,空间位置、实性密度、胸膜改变为宽基底凹陷以及血清CEA水平升高者发生淋巴结转移的风险更高。展开更多
Maramures Land is mostly characterized byagricultural and forestry land use due to its specificconfiguration of topography and its specific pedoclimaticconditions. Taking into consideration the trend of the lastcentur...Maramures Land is mostly characterized byagricultural and forestry land use due to its specificconfiguration of topography and its specific pedoclimaticconditions. Taking into consideration the trend of the lastcentury from the perspective of land management, adecrease in the surface of agricultural lands to theadvantage of built-up and grass lands, as well as anaccelerated decrease in the forest cover due to uncontrolledand irrational forest exploitation, has become obvious. Thefield analysis performed on the territory of Maramures Land has highlighted a high frequency of two geomor-phologic processes - landslides and soil erosion - whichhave a major negative impact on land use due to their rateof occurrence. The main aim of the present study is the GISmodeling of the two geomorphologic processes, determin-ing a state of vulnerability （the USLE model for soilerosion and a quantitative model based on the morpho-metric characteristics of the territory, derived from the HG.447/2003） and their integration in a complex model ofcumulated vulnerability identification. The modeling of therisk exposure was performed using a quantitative approachbased on models and equations of spatial analysis, whichwere developed with modeled raster data structures andprimary vector data, through a matrix highlighting thecorrespondence between vulnerability and land useclasses. The quantitative analysis of the risk was performedby taking into consideration the exposure classes asmodeled databases and the land price as a primaryalphanumeric database using spatial analysis techniquesfor each class by means of the attribute table. The spatialresults highlight the territories with a high risk to presentgeomorphologic processes that have a high degree ofoccurrence and represent a useful tool in the process ofspatial planning.展开更多
基金Major Program of National Natural Science Foundation of China,No.41590841Key Project for National Natural Science Foundation of China,No.41230633
文摘Urbanization significantly increases the risk of urban flooding. Therefore, quantitative study of urban rainfall-runoff processes can provide a scientific basis for urban planning and management. In this paper, the built-up region within the Fifth Ring Road of Beijing was selected as the study area. The details of land cover and urban function zones(UFZs) were identified using GIS and RS methods. On this basis, the SCS-CN model was adopted to analyze the rainfall-runoff risk characteristics of the study area. The results showed that:(1) UFZs within different levels of runoff risk varied under different rainfall conditions. The area ratio of the UFZs with high runoff risk increased from 18.90%(for rainfall return period of 1 a) to 54.74%(for period of 100 a). Specifically, urban commercial areas tended to have the highest runoff risk, while urban greening spaces had the lowest.(2) The spatial characteristics of the runoff risks showed an obvious circular distribution. Spatial cluster areas with high runoff risk were mainly concentrated in the center of the study area, while those with low runoff risk were mainly distributed between the fourth and fifth ring roads. The results indicated that the spatial clustering characteristic of urban runoff risk and runoff heterogeneity among different UFZs should be fully considered during urban rainwater management.
文摘Crude oil transportation through pipelines presents danger to communities along its path. In the Niger Delta region of Nigeria for instance, pipeline vandalism occurs indiscriminately and regularly, such that every segment of a pipeline network becomes a potential target and possibly source of oil spill hazard. In terms of pipeline hazard and risk distribution, the oil plume’s ability to migrate freely in wetlands and encroachment on pipeline right of ways by people increases chances of wider contact and exposure opportunities to inhabitants and the environment. Despite several efforts to mitigate pipeline hazards in the oil and gas sector, none has been effective in Nigeria partly due to paucity of data in public domain and poor public participation. Therefore considering the environmental and human health challenges associated with oil spills, an alternative method was developed using multi-criteria decision analysis to model 1) pipeline hazard zones, 2) potential pipeline impact radius, and 3) high consequence areas with four attribute layers, i.e. land cover, population, river and pipeline to encourage public participation. The model identified land use areas, communities and rivers likely to be susceptible to pipeline hazards and areas requiring regular monitoring and possible intervention. Meanwhile the model sensitivity test indicated that the river layer was most sensitive, while transferability was limited to similar criteria variables. The model can stimulate public participation in pipeline hazard management while policy makers and regulators would find it relevant in oil spill impact mitigation.
文摘目的联合空间位置-临床-影像特征探讨可切除肺腺癌淋巴结转移的危险因素,并构建淋巴结转移预测模型。方法回顾性纳入2016年6月—2020年6月于南京医科大学第一附属医院接受胸部CT,并经手术确诊为有或无淋巴结转移的浸润性肺腺癌患者。根据有无淋巴结转移,将患者分为阳性组与阴性组。收集患者的临床及影像学资料,采用单因素和多因素logistic回归分析可切除肺腺癌淋巴结转移的独立危险因素,并建立淋巴结转移的空间位置-临床-影像特征联合预测模型,将其与不包含空间位置特征的传统淋巴结转移预测模型进行对比。结果共纳入611例患者,阳性组333例,其中男172例、女161例,平均年龄(58.9±9.7)岁;阴性组278例,其中男127例、女151例,平均年龄(60.1±11.4)岁。单因素及多因素logistic回归分析显示,病灶距离肺门的空间位置关系、结节类型、胸膜改变、血清癌胚抗原(carcinoembryonic antigen,CEA)水平是淋巴结转移的独立危险因素,以此为基础构建的空间位置-临床-影像特征联合预测模型敏感性为91.67%,特异性为74.05%,准确性为87.88%,曲线下面积(area under the curve,AUC)为0.885。不包含空间位置特征的传统淋巴结转移预测模型敏感性为76.40%,特异性为72.10%,准确性为53.86%,AUC为0.827。两种预测方法的AUC差异有统计学意义(P=0.026)。与传统预测模型相比,空间位置-临床-影像特征联合预测模型的预测效能有显著提升。结论在可切除肺腺癌患者中,空间位置、实性密度、胸膜改变为宽基底凹陷以及血清CEA水平升高者发生淋巴结转移的风险更高。
文摘Maramures Land is mostly characterized byagricultural and forestry land use due to its specificconfiguration of topography and its specific pedoclimaticconditions. Taking into consideration the trend of the lastcentury from the perspective of land management, adecrease in the surface of agricultural lands to theadvantage of built-up and grass lands, as well as anaccelerated decrease in the forest cover due to uncontrolledand irrational forest exploitation, has become obvious. Thefield analysis performed on the territory of Maramures Land has highlighted a high frequency of two geomor-phologic processes - landslides and soil erosion - whichhave a major negative impact on land use due to their rateof occurrence. The main aim of the present study is the GISmodeling of the two geomorphologic processes, determin-ing a state of vulnerability （the USLE model for soilerosion and a quantitative model based on the morpho-metric characteristics of the territory, derived from the HG.447/2003） and their integration in a complex model ofcumulated vulnerability identification. The modeling of therisk exposure was performed using a quantitative approachbased on models and equations of spatial analysis, whichwere developed with modeled raster data structures andprimary vector data, through a matrix highlighting thecorrespondence between vulnerability and land useclasses. The quantitative analysis of the risk was performedby taking into consideration the exposure classes asmodeled databases and the land price as a primaryalphanumeric database using spatial analysis techniquesfor each class by means of the attribute table. The spatialresults highlight the territories with a high risk to presentgeomorphologic processes that have a high degree ofoccurrence and represent a useful tool in the process ofspatial planning.
