利用甘南地区2006-2007年的外业实测样方草地干物质产量和MODIS植被指数数据,建立了草地地上部分干物质产量遥感反演模型,根据根冠比和干物质转碳率对2006-2008年甘南地区草地净初级生产力(NPP,netprimary productivity)进行了估算,绘...利用甘南地区2006-2007年的外业实测样方草地干物质产量和MODIS植被指数数据,建立了草地地上部分干物质产量遥感反演模型,根据根冠比和干物质转碳率对2006-2008年甘南地区草地净初级生产力(NPP,netprimary productivity)进行了估算,绘制了甘南草地NPP年累积量空间分布格局图和NPP月度变化动态图,对不同草地植被类型的NPP差异进行了评价。研究结果表明,2006-2008年甘南草地年NPP分别达637.04,599.98和566.59 g C/m2,其空间分布具有自西南向东北逐渐减少的趋势;年内不同草地类型的NPP均在7-8月达到最大累积量;NPP累积量最高的3种草地类型是沼泽、高寒灌丛草甸和高寒草甸,3年中最大月NPP的平均值分别达到1 137.28,553.76和527.66 g C/m2;2006-2008年甘南草地NPP持续下降,年草地NPP总量的减少速率为1.2Tg/a,尤其是沼泽湿地的NPP下降明显,年平均减少速率达到了125.92 g C/m2。展开更多
Based on the decomposing model of total factor productivity change(Malmquist Productivity Index),the paper analyses provincial productivity change during 1980～2003 years in China,and analyses convergence of provincia...Based on the decomposing model of total factor productivity change(Malmquist Productivity Index),the paper analyses provincial productivity change during 1980～2003 years in China,and analyses convergence of provincial technical efficiency.The conclusion shows that the total factor productivity of each province generally shows stronger growth situation in China.The growth of TFP mainly stems from the function of the technological progress.The technical efficiency exist very remarkable convergence during 1980～1995 years in provinces of China,but after 1995,technical efficiency convergence presented the downward trend.Therefore,it is necessary for the government to take certain policy and measure to promote this kind of convergence trend.展开更多
The north-south transect of tastern China (NSTEC) was a typical ecologcal region which was mostly driven by heat and varied with its vegetation along with latitude.In-depth knowing of the NSTEC will enhance our unders...The north-south transect of tastern China (NSTEC) was a typical ecologcal region which was mostly driven by heat and varied with its vegetation along with latitude.In-depth knowing of the NSTEC will enhance our understanding of global change along with global warming.In this paper,NOAA-AVHRR data was used to get the vegetation index across the NSTEC.Then a regression model was built to get the Net Primary Productivity (NPP) from it.Since the research area covered from 118°E to 128°E,40°N to 50°N,and from 108°E to 118°E,17.5°N to 40°N,to precisely acquire the NPP distribution pattern of the whole area,different vegetation indices were compared according to different land surface.Then three regression models were deduced for NPP.Finally,a NPP adjusting scheme was used to get a general NPP distribution map from the three regression results.The achievements well reflect the distribution character of NPP along the NSTEC and would support further analysis and simulation in land ecology system study and global change research.展开更多
文摘利用甘南地区2006-2007年的外业实测样方草地干物质产量和MODIS植被指数数据,建立了草地地上部分干物质产量遥感反演模型,根据根冠比和干物质转碳率对2006-2008年甘南地区草地净初级生产力(NPP,netprimary productivity)进行了估算,绘制了甘南草地NPP年累积量空间分布格局图和NPP月度变化动态图,对不同草地植被类型的NPP差异进行了评价。研究结果表明,2006-2008年甘南草地年NPP分别达637.04,599.98和566.59 g C/m2,其空间分布具有自西南向东北逐渐减少的趋势;年内不同草地类型的NPP均在7-8月达到最大累积量;NPP累积量最高的3种草地类型是沼泽、高寒灌丛草甸和高寒草甸,3年中最大月NPP的平均值分别达到1 137.28,553.76和527.66 g C/m2;2006-2008年甘南草地NPP持续下降,年草地NPP总量的减少速率为1.2Tg/a,尤其是沼泽湿地的NPP下降明显,年平均减少速率达到了125.92 g C/m2。
文摘Based on the decomposing model of total factor productivity change(Malmquist Productivity Index),the paper analyses provincial productivity change during 1980～2003 years in China,and analyses convergence of provincial technical efficiency.The conclusion shows that the total factor productivity of each province generally shows stronger growth situation in China.The growth of TFP mainly stems from the function of the technological progress.The technical efficiency exist very remarkable convergence during 1980～1995 years in provinces of China,but after 1995,technical efficiency convergence presented the downward trend.Therefore,it is necessary for the government to take certain policy and measure to promote this kind of convergence trend.
文摘The north-south transect of tastern China (NSTEC) was a typical ecologcal region which was mostly driven by heat and varied with its vegetation along with latitude.In-depth knowing of the NSTEC will enhance our understanding of global change along with global warming.In this paper,NOAA-AVHRR data was used to get the vegetation index across the NSTEC.Then a regression model was built to get the Net Primary Productivity (NPP) from it.Since the research area covered from 118°E to 128°E,40°N to 50°N,and from 108°E to 118°E,17.5°N to 40°N,to precisely acquire the NPP distribution pattern of the whole area,different vegetation indices were compared according to different land surface.Then three regression models were deduced for NPP.Finally,a NPP adjusting scheme was used to get a general NPP distribution map from the three regression results.The achievements well reflect the distribution character of NPP along the NSTEC and would support further analysis and simulation in land ecology system study and global change research.
