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| 1 | Effects of spatial resolution of remotely sensed data on estimating urban impervious surfaces显示文摘Impervious surfaces are the result of urbanization that can be explicitly quantified,managed and controlled at each stage of land development.It is a very useful environmental indicator that can be used to measure the impacts of urbanization on surface runoff,water quality,air quality,biodiversity and microclimate.Therefore,accurate estimation of impervious surfaces is critical for urban environmental monitoring,land management,decision-making and urban planning.Many approaches have been developed to estimate surface imperviousness,using remotely sensed data with various spatial resolutions.However,few studies,have investigated the effects of spatial resolution on estimating surface imperviousness.We compare medium-resolution Landsat data with high-resolution SPOT images to quantify the imperviousness in Beijing,China.The results indicated that the overall 91% accuracy of estimates of imperviousness based on TM data was considerably higher than the 81% accuracy of the SPOT data.The higher resolution SPOT data did not always predict the imperviousness of the land better than the TM data.At the whole city level,the TM data better predicts the percentage cover of impervious surfaces.At the sub-city level,however,the ring belts from the central core to the urban-rural peripheral,the SPOT data may better predict the imperviousness.These results highlighted the need to combine multiple resolution data to quantify the percentage of imperviousness,as higher resolution data do not necessarily lead to more accurate estimates.The methodology and results in this study can be utilized to identify the most suitable remote sensing data to quickly and efficiently extract the pattern of the impervious land,which could provide the base for further study on many related urban environmental problems. | Weifeng Li Zhiyun Ouyang Weiqi Zhou Qiuwen Chen | 2011 | Journal of Environmental Sciences2011，23，8： | 8 |
| 2 | Flow field and dissolved oxygen distributions in the outer channel of the Orbal oxidation ditch by monitor and CFD simulation显示文摘In the Orbal oxidation ditch,denitrification is primarily accomplished in the outer channel.However,the detailed characteristics of the flow field and dissolved oxygen(DO)distribution in the outer channel are not well understood.Therefore,in this study,the flow velocity and DO concentration in the outer channel of an Orbal oxidation ditch system in a wastewater treatment plant in Beijing(China)were monitored under actual operation conditions.The flow field and DO concentration distributions were analyzed by computed fluid dynamic modeling.In situ monitoring and modeling both showed that the flow velocity was heterogeneous in the outer channel.As a result,the DO was also heterogeneously distributed in the outer channel,with concentration gradients occurring along the flow direction as well as in the cross-section.This heterogeneous DO distribution created many anoxic and aerobic zones,which may have facilitated simultaneous nitrification-denitrification in the channel.These findings may provide supporting information for rational optimization of the performance of the Orbal oxidation ditch. | Xuesong Guo Xin Zhou Qiuwen Chen Junxin Liu | 2013 | Journal of Environmental Sciences2013，25，4： | 5 |
| 3 | Comprehensive analysis of changes to catchment slope properties in the high-sediment region of the Loess Plateau, 1978-2010显示文摘To control soil erosion and restore the degraded environment in the Loess Plateau, a large number of measures related to soil and water conservation have been employed that have profoundly affected catchment properties. This study constructed three indicators to characterize changes to the catchment slope, proposed both a method for a regression analysis of adjacent images and a sequence model, and applied multisource remotely sensed images and GIS spatial clustering analysis technologies to extract thematic information and comprehensively analyze the catchment change characteristics. The results indicate that the catchment slope properties changed significantly. At catchment scale, the average values of ARC, DVC and ART were 6.43%, 25.57% and 4.30%, respectively. There were six clustering types of catchment slope property changes. The maximum and minimum of the average similarities of the clustering types were 0.992 and 0.935. Each slope control measures had a distinct effect on catchment slope; the dominating factor of each clustering type was identified as: Type 1: D-VC, Type 2: D-VCLU, Type 3: D-LUVC, Type 4: D-TAVC, Type 5: D-TAC and Type 6: D-MFC. Type 5 and Type 1 covered the largest areas, respectively occupying 37.28% and 31.01%. Catchment slope property changes also had distinct types that depended on their geomorphological conditions. These findings provide a useful basis from which to further study catchment slope hydrological and soil erosion processes. | ZHOU Xu YANG Shengtian LIU Xiaoyan LIU Changming ZHAO Changsen ZHAO Haige ZHOU Qiuwen WANG Zhiwei | 2015 | Journal of Geographical Sciences2015，25，4： | 2 |
| 4 | Phylogenetic analysis of porcine epidemic diarrhea virus field strains prevailing recently in China显示文摘 | Yueyi Gao Qiuwen Kou Xinna Ge Lei Zhou Xin Guo Hanchun Yang | 2013 | Archives of Virology2013，，3： | 1 |
| 5 | Autophagy sustains the replication of porcine reproductive and respiratory virus in host cells显示文摘 | Qinghao Liu Yixian Qin Lei Zhou Qiuwen Kou Xin Guo Xinna Ge Hanchun Yang Hongbo Hu | 2012 | Virology2012，，2： | 1 |
| 6 | A soil erosion assessment of the upper Mekong River inYunnan Province, China 显示文摘 | Zhou Qiuwen Yang Shengtian Zhao Changsen | 2014 | Mountain Research andDevelopment2014，34，1： | 1 |
| 7 | Phylogenetic analysis of porcine epidemic diarrhea virus field strains prevailing recently in China显示文摘 | Yueyi Gao Qiuwen Kou Xinna Ge Lei Zhou Xin Guo Hanchun Yang | 2013 | Archives of Virology2013，，3： | 1 |
| 8 | Vegetation dynamics and its response to driving factors in typical karst regions,Guizhou Province,China显示文摘Analyzing the vegetation dynamics and its response to driving factors provides a vital reference for understanding regional ecological processes and ecosystem services.However,this issue has been poorly understood in karst areas.Taking Guizhou Province as a case study,based on the Normalized-Difference Vegetation Index of the Global Inventory Modeling and Mapping Studies and on meteorological data sets during 1982-2015,we evaluated vegetation dynamics and its response to climatic factors and human activities.We used several methods:the Mann-Kendall test,rescaled range analysis,partial correlation analysis,and residual analysis.The results are as follows:1)the mean annual Normalized-Difference Vegetation Index was 0.46 and exhibited a significant increasing trend with a variation rate of 0.01/10a during 1982-2015 in Guizhou Province.The vegetation cover showed was spatially heterogeneous:High vegetation cover was distributed mainly in the center and western margin of the study area,while the other parts of the study area mainly distributed with low vegetation cover,although the vegetation cover was higher in the nonkarst areas than in the karst areas;2)in general,the climate was getting warmer and drier in Guizhou Province during 1982-2015.Vegetation cover was positively correlated with temperature and negatively correlated with precipitation.Compared to precipitation,temperature was the dominant climatic factor impacting vegetation dynamics;3)'large-scale ecological restoration projects have obviously increased vegetation cover in Guizhou Province in recent years.The contribution of human activities to vegetation changes was 76%,while the contribution of climatic factors was 24%.In summary,compared to natural forces such as climatic factors and geographic parameters,human activities were the main factor driving the vegetation dynamics in Guizhou Province. | Xiaocha WEI Qiuwen ZHOU Ya LUO Mingyong CAI Xu ZHOU Weihong YAN Dawei PENG Ji ZHANG | 2021 | Frontiers of Earth Science2021，15，1： | 1 |
| 9 | Autophagy sustains the replication of porcine reproductive and respiratory virus in host cells显示文摘 | Qinghao Liu Yixian Qin Lei Zhou Qiuwen Kou Xin Guo Xinna Ge Hanchun Yang Hongbo Hu | 2012 | Virology2012，，2： | 1 |
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