The aim of this paper is to investigate the feasibility of using Landsat TM data to retrieve leaf area index (LAI). To get a LAI retrieval model based ground reflectance and vegetation index, detailed field data were ...The aim of this paper is to investigate the feasibility of using Landsat TM data to retrieve leaf area index (LAI). To get a LAI retrieval model based ground reflectance and vegetation index, detailed field data were collected in the study area of eastern China, dominated by bamboo, tea plant and greengage. Plant canopy reflectance of Landsat TM wavelength bands has been inversed using software of 6S. LAI is an important ecological parameter. In this paper, atmospheric corrected Landsat TM imagery was utilized to calculate different vegetation indices (VI), such as simple ratio vegetation index (SR), shortwave infrared modified simple ratio (MSR), and normalized difference vegetation index (NDVI). Data of 53 samples of LAI were measured by LAI-2000 (LI-COR) in the study area. LAI was modeled based on different reflectances of bands and different vegetation indices from Landsat TM and LAI samples data. There are certainly correlations between LAI and the reflectance of TM3, TM4, TM5 and TM7. The best model through analyzing the results is LAI = 1.2097*MSR + 0.4741 using the method of regression analysis. The result shows that the correlation coefficient R2 is 0.5157, and average accuracy is 85.75%. However, whether the model of this paper is suitable for application in subtropics needs to be verified in the future.展开更多
This paper provides an overview of the economic analysis,policy debate,and methodological issues on soybean production, import and export, and impacts of GMO regulation on soybean foreign trade of China. The paper ana...This paper provides an overview of the economic analysis,policy debate,and methodological issues on soybean production, import and export, and impacts of GMO regulation on soybean foreign trade of China. The paper analyzes China’s soybean production capability and discovers that the present yield of China’s soybean plant system cannot satisfy the domestic demand.The paperalso provides the method to solve such matters by using the result of a modified Cobb-Douglas model. In the third section of this paper, the impacts of GMO regulation on soybean trade and marketin China are analyzed.In this section,we provide a methodological issue to analyze the impacts of such regulation on trade.The paper then explains the implicated result induced by such regulations.展开更多
基金European Com mission Project, No.ICA 4-CT-2002-10004 N ational Natural Science Foundation of China, N o. 40371081 K now ledge Innovation ProjectofCA S,N o.K ZCX 3-SW -146
文摘The aim of this paper is to investigate the feasibility of using Landsat TM data to retrieve leaf area index (LAI). To get a LAI retrieval model based ground reflectance and vegetation index, detailed field data were collected in the study area of eastern China, dominated by bamboo, tea plant and greengage. Plant canopy reflectance of Landsat TM wavelength bands has been inversed using software of 6S. LAI is an important ecological parameter. In this paper, atmospheric corrected Landsat TM imagery was utilized to calculate different vegetation indices (VI), such as simple ratio vegetation index (SR), shortwave infrared modified simple ratio (MSR), and normalized difference vegetation index (NDVI). Data of 53 samples of LAI were measured by LAI-2000 (LI-COR) in the study area. LAI was modeled based on different reflectances of bands and different vegetation indices from Landsat TM and LAI samples data. There are certainly correlations between LAI and the reflectance of TM3, TM4, TM5 and TM7. The best model through analyzing the results is LAI = 1.2097*MSR + 0.4741 using the method of regression analysis. The result shows that the correlation coefficient R2 is 0.5157, and average accuracy is 85.75%. However, whether the model of this paper is suitable for application in subtropics needs to be verified in the future.
文摘This paper provides an overview of the economic analysis,policy debate,and methodological issues on soybean production, import and export, and impacts of GMO regulation on soybean foreign trade of China. The paper analyzes China’s soybean production capability and discovers that the present yield of China’s soybean plant system cannot satisfy the domestic demand.The paperalso provides the method to solve such matters by using the result of a modified Cobb-Douglas model. In the third section of this paper, the impacts of GMO regulation on soybean trade and marketin China are analyzed.In this section,we provide a methodological issue to analyze the impacts of such regulation on trade.The paper then explains the implicated result induced by such regulations.
